xref: /openbmc/linux/tools/perf/util/symbol.c (revision 2c684d89)
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 #include "intlist.h"
19 #include "header.h"
20 
21 #include <elf.h>
22 #include <limits.h>
23 #include <symbol/kallsyms.h>
24 #include <sys/utsname.h>
25 
26 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
27 				symbol_filter_t filter);
28 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
29 			symbol_filter_t filter);
30 int vmlinux_path__nr_entries;
31 char **vmlinux_path;
32 
33 struct symbol_conf symbol_conf = {
34 	.use_modules		= true,
35 	.try_vmlinux_path	= true,
36 	.annotate_src		= true,
37 	.demangle		= true,
38 	.demangle_kernel	= false,
39 	.cumulate_callchain	= true,
40 	.show_hist_headers	= true,
41 	.symfs			= "",
42 };
43 
44 static enum dso_binary_type binary_type_symtab[] = {
45 	DSO_BINARY_TYPE__KALLSYMS,
46 	DSO_BINARY_TYPE__GUEST_KALLSYMS,
47 	DSO_BINARY_TYPE__JAVA_JIT,
48 	DSO_BINARY_TYPE__DEBUGLINK,
49 	DSO_BINARY_TYPE__BUILD_ID_CACHE,
50 	DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
51 	DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
52 	DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
53 	DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
54 	DSO_BINARY_TYPE__GUEST_KMODULE,
55 	DSO_BINARY_TYPE__GUEST_KMODULE_COMP,
56 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
57 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP,
58 	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
59 	DSO_BINARY_TYPE__NOT_FOUND,
60 };
61 
62 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
63 
64 bool symbol_type__is_a(char symbol_type, enum map_type map_type)
65 {
66 	symbol_type = toupper(symbol_type);
67 
68 	switch (map_type) {
69 	case MAP__FUNCTION:
70 		return symbol_type == 'T' || symbol_type == 'W';
71 	case MAP__VARIABLE:
72 		return symbol_type == 'D';
73 	default:
74 		return false;
75 	}
76 }
77 
78 static int prefix_underscores_count(const char *str)
79 {
80 	const char *tail = str;
81 
82 	while (*tail == '_')
83 		tail++;
84 
85 	return tail - str;
86 }
87 
88 int __weak arch__choose_best_symbol(struct symbol *syma,
89 				    struct symbol *symb __maybe_unused)
90 {
91 	/* Avoid "SyS" kernel syscall aliases */
92 	if (strlen(syma->name) >= 3 && !strncmp(syma->name, "SyS", 3))
93 		return SYMBOL_B;
94 	if (strlen(syma->name) >= 10 && !strncmp(syma->name, "compat_SyS", 10))
95 		return SYMBOL_B;
96 
97 	return SYMBOL_A;
98 }
99 
100 static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
101 {
102 	s64 a;
103 	s64 b;
104 	size_t na, nb;
105 
106 	/* Prefer a symbol with non zero length */
107 	a = syma->end - syma->start;
108 	b = symb->end - symb->start;
109 	if ((b == 0) && (a > 0))
110 		return SYMBOL_A;
111 	else if ((a == 0) && (b > 0))
112 		return SYMBOL_B;
113 
114 	/* Prefer a non weak symbol over a weak one */
115 	a = syma->binding == STB_WEAK;
116 	b = symb->binding == STB_WEAK;
117 	if (b && !a)
118 		return SYMBOL_A;
119 	if (a && !b)
120 		return SYMBOL_B;
121 
122 	/* Prefer a global symbol over a non global one */
123 	a = syma->binding == STB_GLOBAL;
124 	b = symb->binding == STB_GLOBAL;
125 	if (a && !b)
126 		return SYMBOL_A;
127 	if (b && !a)
128 		return SYMBOL_B;
129 
130 	/* Prefer a symbol with less underscores */
131 	a = prefix_underscores_count(syma->name);
132 	b = prefix_underscores_count(symb->name);
133 	if (b > a)
134 		return SYMBOL_A;
135 	else if (a > b)
136 		return SYMBOL_B;
137 
138 	/* Choose the symbol with the longest name */
139 	na = strlen(syma->name);
140 	nb = strlen(symb->name);
141 	if (na > nb)
142 		return SYMBOL_A;
143 	else if (na < nb)
144 		return SYMBOL_B;
145 
146 	return arch__choose_best_symbol(syma, symb);
147 }
148 
149 void symbols__fixup_duplicate(struct rb_root *symbols)
150 {
151 	struct rb_node *nd;
152 	struct symbol *curr, *next;
153 
154 	nd = rb_first(symbols);
155 
156 	while (nd) {
157 		curr = rb_entry(nd, struct symbol, rb_node);
158 again:
159 		nd = rb_next(&curr->rb_node);
160 		next = rb_entry(nd, struct symbol, rb_node);
161 
162 		if (!nd)
163 			break;
164 
165 		if (curr->start != next->start)
166 			continue;
167 
168 		if (choose_best_symbol(curr, next) == SYMBOL_A) {
169 			rb_erase(&next->rb_node, symbols);
170 			symbol__delete(next);
171 			goto again;
172 		} else {
173 			nd = rb_next(&curr->rb_node);
174 			rb_erase(&curr->rb_node, symbols);
175 			symbol__delete(curr);
176 		}
177 	}
178 }
179 
180 void symbols__fixup_end(struct rb_root *symbols)
181 {
182 	struct rb_node *nd, *prevnd = rb_first(symbols);
183 	struct symbol *curr, *prev;
184 
185 	if (prevnd == NULL)
186 		return;
187 
188 	curr = rb_entry(prevnd, struct symbol, rb_node);
189 
190 	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
191 		prev = curr;
192 		curr = rb_entry(nd, struct symbol, rb_node);
193 
194 		if (prev->end == prev->start && prev->end != curr->start)
195 			prev->end = curr->start;
196 	}
197 
198 	/* Last entry */
199 	if (curr->end == curr->start)
200 		curr->end = roundup(curr->start, 4096);
201 }
202 
203 void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
204 {
205 	struct maps *maps = &mg->maps[type];
206 	struct map *next, *curr;
207 
208 	pthread_rwlock_wrlock(&maps->lock);
209 
210 	curr = maps__first(maps);
211 	if (curr == NULL)
212 		goto out_unlock;
213 
214 	for (next = map__next(curr); next; next = map__next(curr)) {
215 		curr->end = next->start;
216 		curr = next;
217 	}
218 
219 	/*
220 	 * We still haven't the actual symbols, so guess the
221 	 * last map final address.
222 	 */
223 	curr->end = ~0ULL;
224 
225 out_unlock:
226 	pthread_rwlock_unlock(&maps->lock);
227 }
228 
229 struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
230 {
231 	size_t namelen = strlen(name) + 1;
232 	struct symbol *sym = calloc(1, (symbol_conf.priv_size +
233 					sizeof(*sym) + namelen));
234 	if (sym == NULL)
235 		return NULL;
236 
237 	if (symbol_conf.priv_size)
238 		sym = ((void *)sym) + symbol_conf.priv_size;
239 
240 	sym->start   = start;
241 	sym->end     = len ? start + len : start;
242 	sym->binding = binding;
243 	sym->namelen = namelen - 1;
244 
245 	pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
246 		  __func__, name, start, sym->end);
247 	memcpy(sym->name, name, namelen);
248 
249 	return sym;
250 }
251 
252 void symbol__delete(struct symbol *sym)
253 {
254 	free(((void *)sym) - symbol_conf.priv_size);
255 }
256 
257 size_t symbol__fprintf(struct symbol *sym, FILE *fp)
258 {
259 	return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %c %s\n",
260 		       sym->start, sym->end,
261 		       sym->binding == STB_GLOBAL ? 'g' :
262 		       sym->binding == STB_LOCAL  ? 'l' : 'w',
263 		       sym->name);
264 }
265 
266 size_t symbol__fprintf_symname_offs(const struct symbol *sym,
267 				    const struct addr_location *al, FILE *fp)
268 {
269 	unsigned long offset;
270 	size_t length;
271 
272 	if (sym && sym->name) {
273 		length = fprintf(fp, "%s", sym->name);
274 		if (al) {
275 			if (al->addr < sym->end)
276 				offset = al->addr - sym->start;
277 			else
278 				offset = al->addr - al->map->start - sym->start;
279 			length += fprintf(fp, "+0x%lx", offset);
280 		}
281 		return length;
282 	} else
283 		return fprintf(fp, "[unknown]");
284 }
285 
286 size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
287 {
288 	return symbol__fprintf_symname_offs(sym, NULL, fp);
289 }
290 
291 void symbols__delete(struct rb_root *symbols)
292 {
293 	struct symbol *pos;
294 	struct rb_node *next = rb_first(symbols);
295 
296 	while (next) {
297 		pos = rb_entry(next, struct symbol, rb_node);
298 		next = rb_next(&pos->rb_node);
299 		rb_erase(&pos->rb_node, symbols);
300 		symbol__delete(pos);
301 	}
302 }
303 
304 void symbols__insert(struct rb_root *symbols, struct symbol *sym)
305 {
306 	struct rb_node **p = &symbols->rb_node;
307 	struct rb_node *parent = NULL;
308 	const u64 ip = sym->start;
309 	struct symbol *s;
310 
311 	while (*p != NULL) {
312 		parent = *p;
313 		s = rb_entry(parent, struct symbol, rb_node);
314 		if (ip < s->start)
315 			p = &(*p)->rb_left;
316 		else
317 			p = &(*p)->rb_right;
318 	}
319 	rb_link_node(&sym->rb_node, parent, p);
320 	rb_insert_color(&sym->rb_node, symbols);
321 }
322 
323 static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
324 {
325 	struct rb_node *n;
326 
327 	if (symbols == NULL)
328 		return NULL;
329 
330 	n = symbols->rb_node;
331 
332 	while (n) {
333 		struct symbol *s = rb_entry(n, struct symbol, rb_node);
334 
335 		if (ip < s->start)
336 			n = n->rb_left;
337 		else if (ip >= s->end)
338 			n = n->rb_right;
339 		else
340 			return s;
341 	}
342 
343 	return NULL;
344 }
345 
346 static struct symbol *symbols__first(struct rb_root *symbols)
347 {
348 	struct rb_node *n = rb_first(symbols);
349 
350 	if (n)
351 		return rb_entry(n, struct symbol, rb_node);
352 
353 	return NULL;
354 }
355 
356 static struct symbol *symbols__next(struct symbol *sym)
357 {
358 	struct rb_node *n = rb_next(&sym->rb_node);
359 
360 	if (n)
361 		return rb_entry(n, struct symbol, rb_node);
362 
363 	return NULL;
364 }
365 
366 struct symbol_name_rb_node {
367 	struct rb_node	rb_node;
368 	struct symbol	sym;
369 };
370 
371 static void symbols__insert_by_name(struct rb_root *symbols, struct symbol *sym)
372 {
373 	struct rb_node **p = &symbols->rb_node;
374 	struct rb_node *parent = NULL;
375 	struct symbol_name_rb_node *symn, *s;
376 
377 	symn = container_of(sym, struct symbol_name_rb_node, sym);
378 
379 	while (*p != NULL) {
380 		parent = *p;
381 		s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
382 		if (strcmp(sym->name, s->sym.name) < 0)
383 			p = &(*p)->rb_left;
384 		else
385 			p = &(*p)->rb_right;
386 	}
387 	rb_link_node(&symn->rb_node, parent, p);
388 	rb_insert_color(&symn->rb_node, symbols);
389 }
390 
391 static void symbols__sort_by_name(struct rb_root *symbols,
392 				  struct rb_root *source)
393 {
394 	struct rb_node *nd;
395 
396 	for (nd = rb_first(source); nd; nd = rb_next(nd)) {
397 		struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
398 		symbols__insert_by_name(symbols, pos);
399 	}
400 }
401 
402 static struct symbol *symbols__find_by_name(struct rb_root *symbols,
403 					    const char *name)
404 {
405 	struct rb_node *n;
406 	struct symbol_name_rb_node *s = NULL;
407 
408 	if (symbols == NULL)
409 		return NULL;
410 
411 	n = symbols->rb_node;
412 
413 	while (n) {
414 		int cmp;
415 
416 		s = rb_entry(n, struct symbol_name_rb_node, rb_node);
417 		cmp = arch__compare_symbol_names(name, s->sym.name);
418 
419 		if (cmp < 0)
420 			n = n->rb_left;
421 		else if (cmp > 0)
422 			n = n->rb_right;
423 		else
424 			break;
425 	}
426 
427 	if (n == NULL)
428 		return NULL;
429 
430 	/* return first symbol that has same name (if any) */
431 	for (n = rb_prev(n); n; n = rb_prev(n)) {
432 		struct symbol_name_rb_node *tmp;
433 
434 		tmp = rb_entry(n, struct symbol_name_rb_node, rb_node);
435 		if (arch__compare_symbol_names(tmp->sym.name, s->sym.name))
436 			break;
437 
438 		s = tmp;
439 	}
440 
441 	return &s->sym;
442 }
443 
444 void dso__reset_find_symbol_cache(struct dso *dso)
445 {
446 	enum map_type type;
447 
448 	for (type = MAP__FUNCTION; type <= MAP__VARIABLE; ++type) {
449 		dso->last_find_result[type].addr   = 0;
450 		dso->last_find_result[type].symbol = NULL;
451 	}
452 }
453 
454 struct symbol *dso__find_symbol(struct dso *dso,
455 				enum map_type type, u64 addr)
456 {
457 	if (dso->last_find_result[type].addr != addr) {
458 		dso->last_find_result[type].addr   = addr;
459 		dso->last_find_result[type].symbol = symbols__find(&dso->symbols[type], addr);
460 	}
461 
462 	return dso->last_find_result[type].symbol;
463 }
464 
465 struct symbol *dso__first_symbol(struct dso *dso, enum map_type type)
466 {
467 	return symbols__first(&dso->symbols[type]);
468 }
469 
470 struct symbol *dso__next_symbol(struct symbol *sym)
471 {
472 	return symbols__next(sym);
473 }
474 
475 struct symbol *symbol__next_by_name(struct symbol *sym)
476 {
477 	struct symbol_name_rb_node *s = container_of(sym, struct symbol_name_rb_node, sym);
478 	struct rb_node *n = rb_next(&s->rb_node);
479 
480 	return n ? &rb_entry(n, struct symbol_name_rb_node, rb_node)->sym : NULL;
481 }
482 
483  /*
484   * Teturns first symbol that matched with @name.
485   */
486 struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
487 					const char *name)
488 {
489 	return symbols__find_by_name(&dso->symbol_names[type], name);
490 }
491 
492 void dso__sort_by_name(struct dso *dso, enum map_type type)
493 {
494 	dso__set_sorted_by_name(dso, type);
495 	return symbols__sort_by_name(&dso->symbol_names[type],
496 				     &dso->symbols[type]);
497 }
498 
499 size_t dso__fprintf_symbols_by_name(struct dso *dso,
500 				    enum map_type type, FILE *fp)
501 {
502 	size_t ret = 0;
503 	struct rb_node *nd;
504 	struct symbol_name_rb_node *pos;
505 
506 	for (nd = rb_first(&dso->symbol_names[type]); nd; nd = rb_next(nd)) {
507 		pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
508 		fprintf(fp, "%s\n", pos->sym.name);
509 	}
510 
511 	return ret;
512 }
513 
514 int modules__parse(const char *filename, void *arg,
515 		   int (*process_module)(void *arg, const char *name,
516 					 u64 start))
517 {
518 	char *line = NULL;
519 	size_t n;
520 	FILE *file;
521 	int err = 0;
522 
523 	file = fopen(filename, "r");
524 	if (file == NULL)
525 		return -1;
526 
527 	while (1) {
528 		char name[PATH_MAX];
529 		u64 start;
530 		char *sep;
531 		ssize_t line_len;
532 
533 		line_len = getline(&line, &n, file);
534 		if (line_len < 0) {
535 			if (feof(file))
536 				break;
537 			err = -1;
538 			goto out;
539 		}
540 
541 		if (!line) {
542 			err = -1;
543 			goto out;
544 		}
545 
546 		line[--line_len] = '\0'; /* \n */
547 
548 		sep = strrchr(line, 'x');
549 		if (sep == NULL)
550 			continue;
551 
552 		hex2u64(sep + 1, &start);
553 
554 		sep = strchr(line, ' ');
555 		if (sep == NULL)
556 			continue;
557 
558 		*sep = '\0';
559 
560 		scnprintf(name, sizeof(name), "[%s]", line);
561 
562 		err = process_module(arg, name, start);
563 		if (err)
564 			break;
565 	}
566 out:
567 	free(line);
568 	fclose(file);
569 	return err;
570 }
571 
572 struct process_kallsyms_args {
573 	struct map *map;
574 	struct dso *dso;
575 };
576 
577 /*
578  * These are symbols in the kernel image, so make sure that
579  * sym is from a kernel DSO.
580  */
581 bool symbol__is_idle(struct symbol *sym)
582 {
583 	const char * const idle_symbols[] = {
584 		"cpu_idle",
585 		"cpu_startup_entry",
586 		"intel_idle",
587 		"default_idle",
588 		"native_safe_halt",
589 		"enter_idle",
590 		"exit_idle",
591 		"mwait_idle",
592 		"mwait_idle_with_hints",
593 		"poll_idle",
594 		"ppc64_runlatch_off",
595 		"pseries_dedicated_idle_sleep",
596 		NULL
597 	};
598 
599 	int i;
600 
601 	if (!sym)
602 		return false;
603 
604 	for (i = 0; idle_symbols[i]; i++) {
605 		if (!strcmp(idle_symbols[i], sym->name))
606 			return true;
607 	}
608 
609 	return false;
610 }
611 
612 static int map__process_kallsym_symbol(void *arg, const char *name,
613 				       char type, u64 start)
614 {
615 	struct symbol *sym;
616 	struct process_kallsyms_args *a = arg;
617 	struct rb_root *root = &a->dso->symbols[a->map->type];
618 
619 	if (!symbol_type__is_a(type, a->map->type))
620 		return 0;
621 
622 	/*
623 	 * module symbols are not sorted so we add all
624 	 * symbols, setting length to 0, and rely on
625 	 * symbols__fixup_end() to fix it up.
626 	 */
627 	sym = symbol__new(start, 0, kallsyms2elf_binding(type), name);
628 	if (sym == NULL)
629 		return -ENOMEM;
630 	/*
631 	 * We will pass the symbols to the filter later, in
632 	 * map__split_kallsyms, when we have split the maps per module
633 	 */
634 	symbols__insert(root, sym);
635 
636 	return 0;
637 }
638 
639 /*
640  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
641  * so that we can in the next step set the symbol ->end address and then
642  * call kernel_maps__split_kallsyms.
643  */
644 static int dso__load_all_kallsyms(struct dso *dso, const char *filename,
645 				  struct map *map)
646 {
647 	struct process_kallsyms_args args = { .map = map, .dso = dso, };
648 	return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
649 }
650 
651 static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map,
652 					 symbol_filter_t filter)
653 {
654 	struct map_groups *kmaps = map__kmaps(map);
655 	struct map *curr_map;
656 	struct symbol *pos;
657 	int count = 0;
658 	struct rb_root old_root = dso->symbols[map->type];
659 	struct rb_root *root = &dso->symbols[map->type];
660 	struct rb_node *next = rb_first(root);
661 
662 	if (!kmaps)
663 		return -1;
664 
665 	*root = RB_ROOT;
666 
667 	while (next) {
668 		char *module;
669 
670 		pos = rb_entry(next, struct symbol, rb_node);
671 		next = rb_next(&pos->rb_node);
672 
673 		rb_erase_init(&pos->rb_node, &old_root);
674 
675 		module = strchr(pos->name, '\t');
676 		if (module)
677 			*module = '\0';
678 
679 		curr_map = map_groups__find(kmaps, map->type, pos->start);
680 
681 		if (!curr_map || (filter && filter(curr_map, pos))) {
682 			symbol__delete(pos);
683 			continue;
684 		}
685 
686 		pos->start -= curr_map->start - curr_map->pgoff;
687 		if (pos->end)
688 			pos->end -= curr_map->start - curr_map->pgoff;
689 		symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
690 		++count;
691 	}
692 
693 	/* Symbols have been adjusted */
694 	dso->adjust_symbols = 1;
695 
696 	return count;
697 }
698 
699 /*
700  * Split the symbols into maps, making sure there are no overlaps, i.e. the
701  * kernel range is broken in several maps, named [kernel].N, as we don't have
702  * the original ELF section names vmlinux have.
703  */
704 static int dso__split_kallsyms(struct dso *dso, struct map *map, u64 delta,
705 			       symbol_filter_t filter)
706 {
707 	struct map_groups *kmaps = map__kmaps(map);
708 	struct machine *machine;
709 	struct map *curr_map = map;
710 	struct symbol *pos;
711 	int count = 0, moved = 0;
712 	struct rb_root *root = &dso->symbols[map->type];
713 	struct rb_node *next = rb_first(root);
714 	int kernel_range = 0;
715 
716 	if (!kmaps)
717 		return -1;
718 
719 	machine = kmaps->machine;
720 
721 	while (next) {
722 		char *module;
723 
724 		pos = rb_entry(next, struct symbol, rb_node);
725 		next = rb_next(&pos->rb_node);
726 
727 		module = strchr(pos->name, '\t');
728 		if (module) {
729 			if (!symbol_conf.use_modules)
730 				goto discard_symbol;
731 
732 			*module++ = '\0';
733 
734 			if (strcmp(curr_map->dso->short_name, module)) {
735 				if (curr_map != map &&
736 				    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
737 				    machine__is_default_guest(machine)) {
738 					/*
739 					 * We assume all symbols of a module are
740 					 * continuous in * kallsyms, so curr_map
741 					 * points to a module and all its
742 					 * symbols are in its kmap. Mark it as
743 					 * loaded.
744 					 */
745 					dso__set_loaded(curr_map->dso,
746 							curr_map->type);
747 				}
748 
749 				curr_map = map_groups__find_by_name(kmaps,
750 							map->type, module);
751 				if (curr_map == NULL) {
752 					pr_debug("%s/proc/{kallsyms,modules} "
753 					         "inconsistency while looking "
754 						 "for \"%s\" module!\n",
755 						 machine->root_dir, module);
756 					curr_map = map;
757 					goto discard_symbol;
758 				}
759 
760 				if (curr_map->dso->loaded &&
761 				    !machine__is_default_guest(machine))
762 					goto discard_symbol;
763 			}
764 			/*
765 			 * So that we look just like we get from .ko files,
766 			 * i.e. not prelinked, relative to map->start.
767 			 */
768 			pos->start = curr_map->map_ip(curr_map, pos->start);
769 			pos->end   = curr_map->map_ip(curr_map, pos->end);
770 		} else if (curr_map != map) {
771 			char dso_name[PATH_MAX];
772 			struct dso *ndso;
773 
774 			if (delta) {
775 				/* Kernel was relocated at boot time */
776 				pos->start -= delta;
777 				pos->end -= delta;
778 			}
779 
780 			if (count == 0) {
781 				curr_map = map;
782 				goto filter_symbol;
783 			}
784 
785 			if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
786 				snprintf(dso_name, sizeof(dso_name),
787 					"[guest.kernel].%d",
788 					kernel_range++);
789 			else
790 				snprintf(dso_name, sizeof(dso_name),
791 					"[kernel].%d",
792 					kernel_range++);
793 
794 			ndso = dso__new(dso_name);
795 			if (ndso == NULL)
796 				return -1;
797 
798 			ndso->kernel = dso->kernel;
799 
800 			curr_map = map__new2(pos->start, ndso, map->type);
801 			if (curr_map == NULL) {
802 				dso__put(ndso);
803 				return -1;
804 			}
805 
806 			curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
807 			map_groups__insert(kmaps, curr_map);
808 			++kernel_range;
809 		} else if (delta) {
810 			/* Kernel was relocated at boot time */
811 			pos->start -= delta;
812 			pos->end -= delta;
813 		}
814 filter_symbol:
815 		if (filter && filter(curr_map, pos)) {
816 discard_symbol:		rb_erase(&pos->rb_node, root);
817 			symbol__delete(pos);
818 		} else {
819 			if (curr_map != map) {
820 				rb_erase(&pos->rb_node, root);
821 				symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
822 				++moved;
823 			} else
824 				++count;
825 		}
826 	}
827 
828 	if (curr_map != map &&
829 	    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
830 	    machine__is_default_guest(kmaps->machine)) {
831 		dso__set_loaded(curr_map->dso, curr_map->type);
832 	}
833 
834 	return count + moved;
835 }
836 
837 bool symbol__restricted_filename(const char *filename,
838 				 const char *restricted_filename)
839 {
840 	bool restricted = false;
841 
842 	if (symbol_conf.kptr_restrict) {
843 		char *r = realpath(filename, NULL);
844 
845 		if (r != NULL) {
846 			restricted = strcmp(r, restricted_filename) == 0;
847 			free(r);
848 			return restricted;
849 		}
850 	}
851 
852 	return restricted;
853 }
854 
855 struct module_info {
856 	struct rb_node rb_node;
857 	char *name;
858 	u64 start;
859 };
860 
861 static void add_module(struct module_info *mi, struct rb_root *modules)
862 {
863 	struct rb_node **p = &modules->rb_node;
864 	struct rb_node *parent = NULL;
865 	struct module_info *m;
866 
867 	while (*p != NULL) {
868 		parent = *p;
869 		m = rb_entry(parent, struct module_info, rb_node);
870 		if (strcmp(mi->name, m->name) < 0)
871 			p = &(*p)->rb_left;
872 		else
873 			p = &(*p)->rb_right;
874 	}
875 	rb_link_node(&mi->rb_node, parent, p);
876 	rb_insert_color(&mi->rb_node, modules);
877 }
878 
879 static void delete_modules(struct rb_root *modules)
880 {
881 	struct module_info *mi;
882 	struct rb_node *next = rb_first(modules);
883 
884 	while (next) {
885 		mi = rb_entry(next, struct module_info, rb_node);
886 		next = rb_next(&mi->rb_node);
887 		rb_erase(&mi->rb_node, modules);
888 		zfree(&mi->name);
889 		free(mi);
890 	}
891 }
892 
893 static struct module_info *find_module(const char *name,
894 				       struct rb_root *modules)
895 {
896 	struct rb_node *n = modules->rb_node;
897 
898 	while (n) {
899 		struct module_info *m;
900 		int cmp;
901 
902 		m = rb_entry(n, struct module_info, rb_node);
903 		cmp = strcmp(name, m->name);
904 		if (cmp < 0)
905 			n = n->rb_left;
906 		else if (cmp > 0)
907 			n = n->rb_right;
908 		else
909 			return m;
910 	}
911 
912 	return NULL;
913 }
914 
915 static int __read_proc_modules(void *arg, const char *name, u64 start)
916 {
917 	struct rb_root *modules = arg;
918 	struct module_info *mi;
919 
920 	mi = zalloc(sizeof(struct module_info));
921 	if (!mi)
922 		return -ENOMEM;
923 
924 	mi->name = strdup(name);
925 	mi->start = start;
926 
927 	if (!mi->name) {
928 		free(mi);
929 		return -ENOMEM;
930 	}
931 
932 	add_module(mi, modules);
933 
934 	return 0;
935 }
936 
937 static int read_proc_modules(const char *filename, struct rb_root *modules)
938 {
939 	if (symbol__restricted_filename(filename, "/proc/modules"))
940 		return -1;
941 
942 	if (modules__parse(filename, modules, __read_proc_modules)) {
943 		delete_modules(modules);
944 		return -1;
945 	}
946 
947 	return 0;
948 }
949 
950 int compare_proc_modules(const char *from, const char *to)
951 {
952 	struct rb_root from_modules = RB_ROOT;
953 	struct rb_root to_modules = RB_ROOT;
954 	struct rb_node *from_node, *to_node;
955 	struct module_info *from_m, *to_m;
956 	int ret = -1;
957 
958 	if (read_proc_modules(from, &from_modules))
959 		return -1;
960 
961 	if (read_proc_modules(to, &to_modules))
962 		goto out_delete_from;
963 
964 	from_node = rb_first(&from_modules);
965 	to_node = rb_first(&to_modules);
966 	while (from_node) {
967 		if (!to_node)
968 			break;
969 
970 		from_m = rb_entry(from_node, struct module_info, rb_node);
971 		to_m = rb_entry(to_node, struct module_info, rb_node);
972 
973 		if (from_m->start != to_m->start ||
974 		    strcmp(from_m->name, to_m->name))
975 			break;
976 
977 		from_node = rb_next(from_node);
978 		to_node = rb_next(to_node);
979 	}
980 
981 	if (!from_node && !to_node)
982 		ret = 0;
983 
984 	delete_modules(&to_modules);
985 out_delete_from:
986 	delete_modules(&from_modules);
987 
988 	return ret;
989 }
990 
991 static int do_validate_kcore_modules(const char *filename, struct map *map,
992 				  struct map_groups *kmaps)
993 {
994 	struct rb_root modules = RB_ROOT;
995 	struct map *old_map;
996 	int err;
997 
998 	err = read_proc_modules(filename, &modules);
999 	if (err)
1000 		return err;
1001 
1002 	old_map = map_groups__first(kmaps, map->type);
1003 	while (old_map) {
1004 		struct map *next = map_groups__next(old_map);
1005 		struct module_info *mi;
1006 
1007 		if (old_map == map || old_map->start == map->start) {
1008 			/* The kernel map */
1009 			old_map = next;
1010 			continue;
1011 		}
1012 
1013 		/* Module must be in memory at the same address */
1014 		mi = find_module(old_map->dso->short_name, &modules);
1015 		if (!mi || mi->start != old_map->start) {
1016 			err = -EINVAL;
1017 			goto out;
1018 		}
1019 
1020 		old_map = next;
1021 	}
1022 out:
1023 	delete_modules(&modules);
1024 	return err;
1025 }
1026 
1027 /*
1028  * If kallsyms is referenced by name then we look for filename in the same
1029  * directory.
1030  */
1031 static bool filename_from_kallsyms_filename(char *filename,
1032 					    const char *base_name,
1033 					    const char *kallsyms_filename)
1034 {
1035 	char *name;
1036 
1037 	strcpy(filename, kallsyms_filename);
1038 	name = strrchr(filename, '/');
1039 	if (!name)
1040 		return false;
1041 
1042 	name += 1;
1043 
1044 	if (!strcmp(name, "kallsyms")) {
1045 		strcpy(name, base_name);
1046 		return true;
1047 	}
1048 
1049 	return false;
1050 }
1051 
1052 static int validate_kcore_modules(const char *kallsyms_filename,
1053 				  struct map *map)
1054 {
1055 	struct map_groups *kmaps = map__kmaps(map);
1056 	char modules_filename[PATH_MAX];
1057 
1058 	if (!kmaps)
1059 		return -EINVAL;
1060 
1061 	if (!filename_from_kallsyms_filename(modules_filename, "modules",
1062 					     kallsyms_filename))
1063 		return -EINVAL;
1064 
1065 	if (do_validate_kcore_modules(modules_filename, map, kmaps))
1066 		return -EINVAL;
1067 
1068 	return 0;
1069 }
1070 
1071 static int validate_kcore_addresses(const char *kallsyms_filename,
1072 				    struct map *map)
1073 {
1074 	struct kmap *kmap = map__kmap(map);
1075 
1076 	if (!kmap)
1077 		return -EINVAL;
1078 
1079 	if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
1080 		u64 start;
1081 
1082 		start = kallsyms__get_function_start(kallsyms_filename,
1083 						     kmap->ref_reloc_sym->name);
1084 		if (start != kmap->ref_reloc_sym->addr)
1085 			return -EINVAL;
1086 	}
1087 
1088 	return validate_kcore_modules(kallsyms_filename, map);
1089 }
1090 
1091 struct kcore_mapfn_data {
1092 	struct dso *dso;
1093 	enum map_type type;
1094 	struct list_head maps;
1095 };
1096 
1097 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1098 {
1099 	struct kcore_mapfn_data *md = data;
1100 	struct map *map;
1101 
1102 	map = map__new2(start, md->dso, md->type);
1103 	if (map == NULL)
1104 		return -ENOMEM;
1105 
1106 	map->end = map->start + len;
1107 	map->pgoff = pgoff;
1108 
1109 	list_add(&map->node, &md->maps);
1110 
1111 	return 0;
1112 }
1113 
1114 static int dso__load_kcore(struct dso *dso, struct map *map,
1115 			   const char *kallsyms_filename)
1116 {
1117 	struct map_groups *kmaps = map__kmaps(map);
1118 	struct machine *machine;
1119 	struct kcore_mapfn_data md;
1120 	struct map *old_map, *new_map, *replacement_map = NULL;
1121 	bool is_64_bit;
1122 	int err, fd;
1123 	char kcore_filename[PATH_MAX];
1124 	struct symbol *sym;
1125 
1126 	if (!kmaps)
1127 		return -EINVAL;
1128 
1129 	machine = kmaps->machine;
1130 
1131 	/* This function requires that the map is the kernel map */
1132 	if (map != machine->vmlinux_maps[map->type])
1133 		return -EINVAL;
1134 
1135 	if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1136 					     kallsyms_filename))
1137 		return -EINVAL;
1138 
1139 	/* Modules and kernel must be present at their original addresses */
1140 	if (validate_kcore_addresses(kallsyms_filename, map))
1141 		return -EINVAL;
1142 
1143 	md.dso = dso;
1144 	md.type = map->type;
1145 	INIT_LIST_HEAD(&md.maps);
1146 
1147 	fd = open(kcore_filename, O_RDONLY);
1148 	if (fd < 0) {
1149 		pr_debug("Failed to open %s. Note /proc/kcore requires CAP_SYS_RAWIO capability to access.\n",
1150 			 kcore_filename);
1151 		return -EINVAL;
1152 	}
1153 
1154 	/* Read new maps into temporary lists */
1155 	err = file__read_maps(fd, md.type == MAP__FUNCTION, kcore_mapfn, &md,
1156 			      &is_64_bit);
1157 	if (err)
1158 		goto out_err;
1159 	dso->is_64_bit = is_64_bit;
1160 
1161 	if (list_empty(&md.maps)) {
1162 		err = -EINVAL;
1163 		goto out_err;
1164 	}
1165 
1166 	/* Remove old maps */
1167 	old_map = map_groups__first(kmaps, map->type);
1168 	while (old_map) {
1169 		struct map *next = map_groups__next(old_map);
1170 
1171 		if (old_map != map)
1172 			map_groups__remove(kmaps, old_map);
1173 		old_map = next;
1174 	}
1175 
1176 	/* Find the kernel map using the first symbol */
1177 	sym = dso__first_symbol(dso, map->type);
1178 	list_for_each_entry(new_map, &md.maps, node) {
1179 		if (sym && sym->start >= new_map->start &&
1180 		    sym->start < new_map->end) {
1181 			replacement_map = new_map;
1182 			break;
1183 		}
1184 	}
1185 
1186 	if (!replacement_map)
1187 		replacement_map = list_entry(md.maps.next, struct map, node);
1188 
1189 	/* Add new maps */
1190 	while (!list_empty(&md.maps)) {
1191 		new_map = list_entry(md.maps.next, struct map, node);
1192 		list_del_init(&new_map->node);
1193 		if (new_map == replacement_map) {
1194 			map->start	= new_map->start;
1195 			map->end	= new_map->end;
1196 			map->pgoff	= new_map->pgoff;
1197 			map->map_ip	= new_map->map_ip;
1198 			map->unmap_ip	= new_map->unmap_ip;
1199 			/* Ensure maps are correctly ordered */
1200 			map__get(map);
1201 			map_groups__remove(kmaps, map);
1202 			map_groups__insert(kmaps, map);
1203 			map__put(map);
1204 		} else {
1205 			map_groups__insert(kmaps, new_map);
1206 		}
1207 
1208 		map__put(new_map);
1209 	}
1210 
1211 	/*
1212 	 * Set the data type and long name so that kcore can be read via
1213 	 * dso__data_read_addr().
1214 	 */
1215 	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1216 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
1217 	else
1218 		dso->binary_type = DSO_BINARY_TYPE__KCORE;
1219 	dso__set_long_name(dso, strdup(kcore_filename), true);
1220 
1221 	close(fd);
1222 
1223 	if (map->type == MAP__FUNCTION)
1224 		pr_debug("Using %s for kernel object code\n", kcore_filename);
1225 	else
1226 		pr_debug("Using %s for kernel data\n", kcore_filename);
1227 
1228 	return 0;
1229 
1230 out_err:
1231 	while (!list_empty(&md.maps)) {
1232 		map = list_entry(md.maps.next, struct map, node);
1233 		list_del_init(&map->node);
1234 		map__put(map);
1235 	}
1236 	close(fd);
1237 	return -EINVAL;
1238 }
1239 
1240 /*
1241  * If the kernel is relocated at boot time, kallsyms won't match.  Compute the
1242  * delta based on the relocation reference symbol.
1243  */
1244 static int kallsyms__delta(struct map *map, const char *filename, u64 *delta)
1245 {
1246 	struct kmap *kmap = map__kmap(map);
1247 	u64 addr;
1248 
1249 	if (!kmap)
1250 		return -1;
1251 
1252 	if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1253 		return 0;
1254 
1255 	addr = kallsyms__get_function_start(filename,
1256 					    kmap->ref_reloc_sym->name);
1257 	if (!addr)
1258 		return -1;
1259 
1260 	*delta = addr - kmap->ref_reloc_sym->addr;
1261 	return 0;
1262 }
1263 
1264 int dso__load_kallsyms(struct dso *dso, const char *filename,
1265 		       struct map *map, symbol_filter_t filter)
1266 {
1267 	u64 delta = 0;
1268 
1269 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1270 		return -1;
1271 
1272 	if (dso__load_all_kallsyms(dso, filename, map) < 0)
1273 		return -1;
1274 
1275 	if (kallsyms__delta(map, filename, &delta))
1276 		return -1;
1277 
1278 	symbols__fixup_duplicate(&dso->symbols[map->type]);
1279 	symbols__fixup_end(&dso->symbols[map->type]);
1280 
1281 	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1282 		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1283 	else
1284 		dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1285 
1286 	if (!dso__load_kcore(dso, map, filename))
1287 		return dso__split_kallsyms_for_kcore(dso, map, filter);
1288 	else
1289 		return dso__split_kallsyms(dso, map, delta, filter);
1290 }
1291 
1292 static int dso__load_perf_map(struct dso *dso, struct map *map,
1293 			      symbol_filter_t filter)
1294 {
1295 	char *line = NULL;
1296 	size_t n;
1297 	FILE *file;
1298 	int nr_syms = 0;
1299 
1300 	file = fopen(dso->long_name, "r");
1301 	if (file == NULL)
1302 		goto out_failure;
1303 
1304 	while (!feof(file)) {
1305 		u64 start, size;
1306 		struct symbol *sym;
1307 		int line_len, len;
1308 
1309 		line_len = getline(&line, &n, file);
1310 		if (line_len < 0)
1311 			break;
1312 
1313 		if (!line)
1314 			goto out_failure;
1315 
1316 		line[--line_len] = '\0'; /* \n */
1317 
1318 		len = hex2u64(line, &start);
1319 
1320 		len++;
1321 		if (len + 2 >= line_len)
1322 			continue;
1323 
1324 		len += hex2u64(line + len, &size);
1325 
1326 		len++;
1327 		if (len + 2 >= line_len)
1328 			continue;
1329 
1330 		sym = symbol__new(start, size, STB_GLOBAL, line + len);
1331 
1332 		if (sym == NULL)
1333 			goto out_delete_line;
1334 
1335 		if (filter && filter(map, sym))
1336 			symbol__delete(sym);
1337 		else {
1338 			symbols__insert(&dso->symbols[map->type], sym);
1339 			nr_syms++;
1340 		}
1341 	}
1342 
1343 	free(line);
1344 	fclose(file);
1345 
1346 	return nr_syms;
1347 
1348 out_delete_line:
1349 	free(line);
1350 out_failure:
1351 	return -1;
1352 }
1353 
1354 static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
1355 					   enum dso_binary_type type)
1356 {
1357 	switch (type) {
1358 	case DSO_BINARY_TYPE__JAVA_JIT:
1359 	case DSO_BINARY_TYPE__DEBUGLINK:
1360 	case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
1361 	case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
1362 	case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
1363 	case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
1364 	case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
1365 		return !kmod && dso->kernel == DSO_TYPE_USER;
1366 
1367 	case DSO_BINARY_TYPE__KALLSYMS:
1368 	case DSO_BINARY_TYPE__VMLINUX:
1369 	case DSO_BINARY_TYPE__KCORE:
1370 		return dso->kernel == DSO_TYPE_KERNEL;
1371 
1372 	case DSO_BINARY_TYPE__GUEST_KALLSYMS:
1373 	case DSO_BINARY_TYPE__GUEST_VMLINUX:
1374 	case DSO_BINARY_TYPE__GUEST_KCORE:
1375 		return dso->kernel == DSO_TYPE_GUEST_KERNEL;
1376 
1377 	case DSO_BINARY_TYPE__GUEST_KMODULE:
1378 	case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
1379 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
1380 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
1381 		/*
1382 		 * kernel modules know their symtab type - it's set when
1383 		 * creating a module dso in machine__findnew_module_map().
1384 		 */
1385 		return kmod && dso->symtab_type == type;
1386 
1387 	case DSO_BINARY_TYPE__BUILD_ID_CACHE:
1388 		return true;
1389 
1390 	case DSO_BINARY_TYPE__NOT_FOUND:
1391 	default:
1392 		return false;
1393 	}
1394 }
1395 
1396 int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
1397 {
1398 	char *name;
1399 	int ret = -1;
1400 	u_int i;
1401 	struct machine *machine;
1402 	char *root_dir = (char *) "";
1403 	int ss_pos = 0;
1404 	struct symsrc ss_[2];
1405 	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1406 	bool kmod;
1407 	unsigned char build_id[BUILD_ID_SIZE];
1408 
1409 	pthread_mutex_lock(&dso->lock);
1410 
1411 	/* check again under the dso->lock */
1412 	if (dso__loaded(dso, map->type)) {
1413 		ret = 1;
1414 		goto out;
1415 	}
1416 
1417 	if (dso->kernel) {
1418 		if (dso->kernel == DSO_TYPE_KERNEL)
1419 			ret = dso__load_kernel_sym(dso, map, filter);
1420 		else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1421 			ret = dso__load_guest_kernel_sym(dso, map, filter);
1422 
1423 		goto out;
1424 	}
1425 
1426 	if (map->groups && map->groups->machine)
1427 		machine = map->groups->machine;
1428 	else
1429 		machine = NULL;
1430 
1431 	dso->adjust_symbols = 0;
1432 
1433 	if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
1434 		struct stat st;
1435 
1436 		if (lstat(dso->name, &st) < 0)
1437 			goto out;
1438 
1439 		if (!symbol_conf.force && st.st_uid && (st.st_uid != geteuid())) {
1440 			pr_warning("File %s not owned by current user or root, "
1441 				   "ignoring it (use -f to override).\n", dso->name);
1442 			goto out;
1443 		}
1444 
1445 		ret = dso__load_perf_map(dso, map, filter);
1446 		dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1447 					     DSO_BINARY_TYPE__NOT_FOUND;
1448 		goto out;
1449 	}
1450 
1451 	if (machine)
1452 		root_dir = machine->root_dir;
1453 
1454 	name = malloc(PATH_MAX);
1455 	if (!name)
1456 		goto out;
1457 
1458 	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1459 		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
1460 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
1461 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
1462 
1463 
1464 	/*
1465 	 * Read the build id if possible. This is required for
1466 	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
1467 	 */
1468 	if (filename__read_build_id(dso->name, build_id, BUILD_ID_SIZE) > 0)
1469 		dso__set_build_id(dso, build_id);
1470 
1471 	/*
1472 	 * Iterate over candidate debug images.
1473 	 * Keep track of "interesting" ones (those which have a symtab, dynsym,
1474 	 * and/or opd section) for processing.
1475 	 */
1476 	for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1477 		struct symsrc *ss = &ss_[ss_pos];
1478 		bool next_slot = false;
1479 
1480 		enum dso_binary_type symtab_type = binary_type_symtab[i];
1481 
1482 		if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
1483 			continue;
1484 
1485 		if (dso__read_binary_type_filename(dso, symtab_type,
1486 						   root_dir, name, PATH_MAX))
1487 			continue;
1488 
1489 		/* Name is now the name of the next image to try */
1490 		if (symsrc__init(ss, dso, name, symtab_type) < 0)
1491 			continue;
1492 
1493 		if (!syms_ss && symsrc__has_symtab(ss)) {
1494 			syms_ss = ss;
1495 			next_slot = true;
1496 			if (!dso->symsrc_filename)
1497 				dso->symsrc_filename = strdup(name);
1498 		}
1499 
1500 		if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1501 			runtime_ss = ss;
1502 			next_slot = true;
1503 		}
1504 
1505 		if (next_slot) {
1506 			ss_pos++;
1507 
1508 			if (syms_ss && runtime_ss)
1509 				break;
1510 		} else {
1511 			symsrc__destroy(ss);
1512 		}
1513 
1514 	}
1515 
1516 	if (!runtime_ss && !syms_ss)
1517 		goto out_free;
1518 
1519 	if (runtime_ss && !syms_ss) {
1520 		syms_ss = runtime_ss;
1521 	}
1522 
1523 	/* We'll have to hope for the best */
1524 	if (!runtime_ss && syms_ss)
1525 		runtime_ss = syms_ss;
1526 
1527 	if (syms_ss)
1528 		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, kmod);
1529 	else
1530 		ret = -1;
1531 
1532 	if (ret > 0) {
1533 		int nr_plt;
1534 
1535 		nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss, map, filter);
1536 		if (nr_plt > 0)
1537 			ret += nr_plt;
1538 	}
1539 
1540 	for (; ss_pos > 0; ss_pos--)
1541 		symsrc__destroy(&ss_[ss_pos - 1]);
1542 out_free:
1543 	free(name);
1544 	if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1545 		ret = 0;
1546 out:
1547 	dso__set_loaded(dso, map->type);
1548 	pthread_mutex_unlock(&dso->lock);
1549 
1550 	return ret;
1551 }
1552 
1553 struct map *map_groups__find_by_name(struct map_groups *mg,
1554 				     enum map_type type, const char *name)
1555 {
1556 	struct maps *maps = &mg->maps[type];
1557 	struct map *map;
1558 
1559 	pthread_rwlock_rdlock(&maps->lock);
1560 
1561 	for (map = maps__first(maps); map; map = map__next(map)) {
1562 		if (map->dso && strcmp(map->dso->short_name, name) == 0)
1563 			goto out_unlock;
1564 	}
1565 
1566 	map = NULL;
1567 
1568 out_unlock:
1569 	pthread_rwlock_unlock(&maps->lock);
1570 	return map;
1571 }
1572 
1573 int dso__load_vmlinux(struct dso *dso, struct map *map,
1574 		      const char *vmlinux, bool vmlinux_allocated,
1575 		      symbol_filter_t filter)
1576 {
1577 	int err = -1;
1578 	struct symsrc ss;
1579 	char symfs_vmlinux[PATH_MAX];
1580 	enum dso_binary_type symtab_type;
1581 
1582 	if (vmlinux[0] == '/')
1583 		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
1584 	else
1585 		symbol__join_symfs(symfs_vmlinux, vmlinux);
1586 
1587 	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1588 		symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1589 	else
1590 		symtab_type = DSO_BINARY_TYPE__VMLINUX;
1591 
1592 	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
1593 		return -1;
1594 
1595 	err = dso__load_sym(dso, map, &ss, &ss, filter, 0);
1596 	symsrc__destroy(&ss);
1597 
1598 	if (err > 0) {
1599 		if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1600 			dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1601 		else
1602 			dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
1603 		dso__set_long_name(dso, vmlinux, vmlinux_allocated);
1604 		dso__set_loaded(dso, map->type);
1605 		pr_debug("Using %s for symbols\n", symfs_vmlinux);
1606 	}
1607 
1608 	return err;
1609 }
1610 
1611 int dso__load_vmlinux_path(struct dso *dso, struct map *map,
1612 			   symbol_filter_t filter)
1613 {
1614 	int i, err = 0;
1615 	char *filename = NULL;
1616 
1617 	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
1618 		 vmlinux_path__nr_entries + 1);
1619 
1620 	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
1621 		err = dso__load_vmlinux(dso, map, vmlinux_path[i], false, filter);
1622 		if (err > 0)
1623 			goto out;
1624 	}
1625 
1626 	if (!symbol_conf.ignore_vmlinux_buildid)
1627 		filename = dso__build_id_filename(dso, NULL, 0);
1628 	if (filename != NULL) {
1629 		err = dso__load_vmlinux(dso, map, filename, true, filter);
1630 		if (err > 0)
1631 			goto out;
1632 		free(filename);
1633 	}
1634 out:
1635 	return err;
1636 }
1637 
1638 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
1639 {
1640 	char kallsyms_filename[PATH_MAX];
1641 	struct dirent *dent;
1642 	int ret = -1;
1643 	DIR *d;
1644 
1645 	d = opendir(dir);
1646 	if (!d)
1647 		return -1;
1648 
1649 	while (1) {
1650 		dent = readdir(d);
1651 		if (!dent)
1652 			break;
1653 		if (dent->d_type != DT_DIR)
1654 			continue;
1655 		scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
1656 			  "%s/%s/kallsyms", dir, dent->d_name);
1657 		if (!validate_kcore_addresses(kallsyms_filename, map)) {
1658 			strlcpy(dir, kallsyms_filename, dir_sz);
1659 			ret = 0;
1660 			break;
1661 		}
1662 	}
1663 
1664 	closedir(d);
1665 
1666 	return ret;
1667 }
1668 
1669 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
1670 {
1671 	u8 host_build_id[BUILD_ID_SIZE];
1672 	char sbuild_id[BUILD_ID_SIZE * 2 + 1];
1673 	bool is_host = false;
1674 	char path[PATH_MAX];
1675 
1676 	if (!dso->has_build_id) {
1677 		/*
1678 		 * Last resort, if we don't have a build-id and couldn't find
1679 		 * any vmlinux file, try the running kernel kallsyms table.
1680 		 */
1681 		goto proc_kallsyms;
1682 	}
1683 
1684 	if (sysfs__read_build_id("/sys/kernel/notes", host_build_id,
1685 				 sizeof(host_build_id)) == 0)
1686 		is_host = dso__build_id_equal(dso, host_build_id);
1687 
1688 	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
1689 
1690 	scnprintf(path, sizeof(path), "%s/[kernel.kcore]/%s", buildid_dir,
1691 		  sbuild_id);
1692 
1693 	/* Use /proc/kallsyms if possible */
1694 	if (is_host) {
1695 		DIR *d;
1696 		int fd;
1697 
1698 		/* If no cached kcore go with /proc/kallsyms */
1699 		d = opendir(path);
1700 		if (!d)
1701 			goto proc_kallsyms;
1702 		closedir(d);
1703 
1704 		/*
1705 		 * Do not check the build-id cache, until we know we cannot use
1706 		 * /proc/kcore.
1707 		 */
1708 		fd = open("/proc/kcore", O_RDONLY);
1709 		if (fd != -1) {
1710 			close(fd);
1711 			/* If module maps match go with /proc/kallsyms */
1712 			if (!validate_kcore_addresses("/proc/kallsyms", map))
1713 				goto proc_kallsyms;
1714 		}
1715 
1716 		/* Find kallsyms in build-id cache with kcore */
1717 		if (!find_matching_kcore(map, path, sizeof(path)))
1718 			return strdup(path);
1719 
1720 		goto proc_kallsyms;
1721 	}
1722 
1723 	/* Find kallsyms in build-id cache with kcore */
1724 	if (!find_matching_kcore(map, path, sizeof(path)))
1725 		return strdup(path);
1726 
1727 	scnprintf(path, sizeof(path), "%s/[kernel.kallsyms]/%s",
1728 		  buildid_dir, sbuild_id);
1729 
1730 	if (access(path, F_OK)) {
1731 		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
1732 		       sbuild_id);
1733 		return NULL;
1734 	}
1735 
1736 	return strdup(path);
1737 
1738 proc_kallsyms:
1739 	return strdup("/proc/kallsyms");
1740 }
1741 
1742 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
1743 				symbol_filter_t filter)
1744 {
1745 	int err;
1746 	const char *kallsyms_filename = NULL;
1747 	char *kallsyms_allocated_filename = NULL;
1748 	/*
1749 	 * Step 1: if the user specified a kallsyms or vmlinux filename, use
1750 	 * it and only it, reporting errors to the user if it cannot be used.
1751 	 *
1752 	 * For instance, try to analyse an ARM perf.data file _without_ a
1753 	 * build-id, or if the user specifies the wrong path to the right
1754 	 * vmlinux file, obviously we can't fallback to another vmlinux (a
1755 	 * x86_86 one, on the machine where analysis is being performed, say),
1756 	 * or worse, /proc/kallsyms.
1757 	 *
1758 	 * If the specified file _has_ a build-id and there is a build-id
1759 	 * section in the perf.data file, we will still do the expected
1760 	 * validation in dso__load_vmlinux and will bail out if they don't
1761 	 * match.
1762 	 */
1763 	if (symbol_conf.kallsyms_name != NULL) {
1764 		kallsyms_filename = symbol_conf.kallsyms_name;
1765 		goto do_kallsyms;
1766 	}
1767 
1768 	if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
1769 		return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name,
1770 					 false, filter);
1771 	}
1772 
1773 	if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
1774 		err = dso__load_vmlinux_path(dso, map, filter);
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, filter);
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, "[kernel.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 				      symbol_filter_t filter)
1807 {
1808 	int err;
1809 	const char *kallsyms_filename = NULL;
1810 	struct machine *machine;
1811 	char path[PATH_MAX];
1812 
1813 	if (!map->groups) {
1814 		pr_debug("Guest kernel map hasn't the point to groups\n");
1815 		return -1;
1816 	}
1817 	machine = map->groups->machine;
1818 
1819 	if (machine__is_default_guest(machine)) {
1820 		/*
1821 		 * if the user specified a vmlinux filename, use it and only
1822 		 * it, reporting errors to the user if it cannot be used.
1823 		 * Or use file guest_kallsyms inputted by user on commandline
1824 		 */
1825 		if (symbol_conf.default_guest_vmlinux_name != NULL) {
1826 			err = dso__load_vmlinux(dso, map,
1827 						symbol_conf.default_guest_vmlinux_name,
1828 						false, filter);
1829 			return err;
1830 		}
1831 
1832 		kallsyms_filename = symbol_conf.default_guest_kallsyms;
1833 		if (!kallsyms_filename)
1834 			return -1;
1835 	} else {
1836 		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
1837 		kallsyms_filename = path;
1838 	}
1839 
1840 	err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1841 	if (err > 0)
1842 		pr_debug("Using %s for symbols\n", kallsyms_filename);
1843 	if (err > 0 && !dso__is_kcore(dso)) {
1844 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1845 		machine__mmap_name(machine, path, sizeof(path));
1846 		dso__set_long_name(dso, strdup(path), true);
1847 		map__fixup_start(map);
1848 		map__fixup_end(map);
1849 	}
1850 
1851 	return err;
1852 }
1853 
1854 static void vmlinux_path__exit(void)
1855 {
1856 	while (--vmlinux_path__nr_entries >= 0)
1857 		zfree(&vmlinux_path[vmlinux_path__nr_entries]);
1858 	vmlinux_path__nr_entries = 0;
1859 
1860 	zfree(&vmlinux_path);
1861 }
1862 
1863 static int vmlinux_path__init(struct perf_env *env)
1864 {
1865 	struct utsname uts;
1866 	char bf[PATH_MAX];
1867 	char *kernel_version;
1868 
1869 	vmlinux_path = malloc(sizeof(char *) * 6);
1870 	if (vmlinux_path == NULL)
1871 		return -1;
1872 
1873 	vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux");
1874 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1875 		goto out_fail;
1876 	++vmlinux_path__nr_entries;
1877 	vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux");
1878 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1879 		goto out_fail;
1880 	++vmlinux_path__nr_entries;
1881 
1882 	/* only try kernel version if no symfs was given */
1883 	if (symbol_conf.symfs[0] != 0)
1884 		return 0;
1885 
1886 	if (env) {
1887 		kernel_version = env->os_release;
1888 	} else {
1889 		if (uname(&uts) < 0)
1890 			goto out_fail;
1891 
1892 		kernel_version = uts.release;
1893 	}
1894 
1895 	snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", kernel_version);
1896 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1897 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1898 		goto out_fail;
1899 	++vmlinux_path__nr_entries;
1900 	snprintf(bf, sizeof(bf), "/usr/lib/debug/boot/vmlinux-%s",
1901 		 kernel_version);
1902 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1903 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1904 		goto out_fail;
1905         ++vmlinux_path__nr_entries;
1906 	snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", kernel_version);
1907 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1908 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1909 		goto out_fail;
1910 	++vmlinux_path__nr_entries;
1911 	snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
1912 		 kernel_version);
1913 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1914 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1915 		goto out_fail;
1916 	++vmlinux_path__nr_entries;
1917 
1918 	return 0;
1919 
1920 out_fail:
1921 	vmlinux_path__exit();
1922 	return -1;
1923 }
1924 
1925 int setup_list(struct strlist **list, const char *list_str,
1926 		      const char *list_name)
1927 {
1928 	if (list_str == NULL)
1929 		return 0;
1930 
1931 	*list = strlist__new(list_str, NULL);
1932 	if (!*list) {
1933 		pr_err("problems parsing %s list\n", list_name);
1934 		return -1;
1935 	}
1936 
1937 	symbol_conf.has_filter = true;
1938 	return 0;
1939 }
1940 
1941 int setup_intlist(struct intlist **list, const char *list_str,
1942 		  const char *list_name)
1943 {
1944 	if (list_str == NULL)
1945 		return 0;
1946 
1947 	*list = intlist__new(list_str);
1948 	if (!*list) {
1949 		pr_err("problems parsing %s list\n", list_name);
1950 		return -1;
1951 	}
1952 	return 0;
1953 }
1954 
1955 static bool symbol__read_kptr_restrict(void)
1956 {
1957 	bool value = false;
1958 
1959 	if (geteuid() != 0) {
1960 		FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
1961 		if (fp != NULL) {
1962 			char line[8];
1963 
1964 			if (fgets(line, sizeof(line), fp) != NULL)
1965 				value = atoi(line) != 0;
1966 
1967 			fclose(fp);
1968 		}
1969 	}
1970 
1971 	return value;
1972 }
1973 
1974 int symbol__init(struct perf_env *env)
1975 {
1976 	const char *symfs;
1977 
1978 	if (symbol_conf.initialized)
1979 		return 0;
1980 
1981 	symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
1982 
1983 	symbol__elf_init();
1984 
1985 	if (symbol_conf.sort_by_name)
1986 		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
1987 					  sizeof(struct symbol));
1988 
1989 	if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
1990 		return -1;
1991 
1992 	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
1993 		pr_err("'.' is the only non valid --field-separator argument\n");
1994 		return -1;
1995 	}
1996 
1997 	if (setup_list(&symbol_conf.dso_list,
1998 		       symbol_conf.dso_list_str, "dso") < 0)
1999 		return -1;
2000 
2001 	if (setup_list(&symbol_conf.comm_list,
2002 		       symbol_conf.comm_list_str, "comm") < 0)
2003 		goto out_free_dso_list;
2004 
2005 	if (setup_intlist(&symbol_conf.pid_list,
2006 		       symbol_conf.pid_list_str, "pid") < 0)
2007 		goto out_free_comm_list;
2008 
2009 	if (setup_intlist(&symbol_conf.tid_list,
2010 		       symbol_conf.tid_list_str, "tid") < 0)
2011 		goto out_free_pid_list;
2012 
2013 	if (setup_list(&symbol_conf.sym_list,
2014 		       symbol_conf.sym_list_str, "symbol") < 0)
2015 		goto out_free_tid_list;
2016 
2017 	/*
2018 	 * A path to symbols of "/" is identical to ""
2019 	 * reset here for simplicity.
2020 	 */
2021 	symfs = realpath(symbol_conf.symfs, NULL);
2022 	if (symfs == NULL)
2023 		symfs = symbol_conf.symfs;
2024 	if (strcmp(symfs, "/") == 0)
2025 		symbol_conf.symfs = "";
2026 	if (symfs != symbol_conf.symfs)
2027 		free((void *)symfs);
2028 
2029 	symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
2030 
2031 	symbol_conf.initialized = true;
2032 	return 0;
2033 
2034 out_free_tid_list:
2035 	intlist__delete(symbol_conf.tid_list);
2036 out_free_pid_list:
2037 	intlist__delete(symbol_conf.pid_list);
2038 out_free_comm_list:
2039 	strlist__delete(symbol_conf.comm_list);
2040 out_free_dso_list:
2041 	strlist__delete(symbol_conf.dso_list);
2042 	return -1;
2043 }
2044 
2045 void symbol__exit(void)
2046 {
2047 	if (!symbol_conf.initialized)
2048 		return;
2049 	strlist__delete(symbol_conf.sym_list);
2050 	strlist__delete(symbol_conf.dso_list);
2051 	strlist__delete(symbol_conf.comm_list);
2052 	intlist__delete(symbol_conf.tid_list);
2053 	intlist__delete(symbol_conf.pid_list);
2054 	vmlinux_path__exit();
2055 	symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2056 	symbol_conf.initialized = false;
2057 }
2058