xref: /openbmc/linux/tools/perf/util/symbol.c (revision 9cfc5c90)
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, moved = 0;
658 	struct rb_root *root = &dso->symbols[map->type];
659 	struct rb_node *next = rb_first(root);
660 
661 	if (!kmaps)
662 		return -1;
663 
664 	while (next) {
665 		char *module;
666 
667 		pos = rb_entry(next, struct symbol, rb_node);
668 		next = rb_next(&pos->rb_node);
669 
670 		module = strchr(pos->name, '\t');
671 		if (module)
672 			*module = '\0';
673 
674 		curr_map = map_groups__find(kmaps, map->type, pos->start);
675 
676 		if (!curr_map || (filter && filter(curr_map, pos))) {
677 			rb_erase_init(&pos->rb_node, root);
678 			symbol__delete(pos);
679 		} else {
680 			pos->start -= curr_map->start - curr_map->pgoff;
681 			if (pos->end)
682 				pos->end -= curr_map->start - curr_map->pgoff;
683 			if (curr_map->dso != map->dso) {
684 				rb_erase_init(&pos->rb_node, root);
685 				symbols__insert(
686 					&curr_map->dso->symbols[curr_map->type],
687 					pos);
688 				++moved;
689 			} else {
690 				++count;
691 			}
692 		}
693 	}
694 
695 	/* Symbols have been adjusted */
696 	dso->adjust_symbols = 1;
697 
698 	return count + moved;
699 }
700 
701 /*
702  * Split the symbols into maps, making sure there are no overlaps, i.e. the
703  * kernel range is broken in several maps, named [kernel].N, as we don't have
704  * the original ELF section names vmlinux have.
705  */
706 static int dso__split_kallsyms(struct dso *dso, struct map *map, u64 delta,
707 			       symbol_filter_t filter)
708 {
709 	struct map_groups *kmaps = map__kmaps(map);
710 	struct machine *machine;
711 	struct map *curr_map = map;
712 	struct symbol *pos;
713 	int count = 0, moved = 0;
714 	struct rb_root *root = &dso->symbols[map->type];
715 	struct rb_node *next = rb_first(root);
716 	int kernel_range = 0;
717 
718 	if (!kmaps)
719 		return -1;
720 
721 	machine = kmaps->machine;
722 
723 	while (next) {
724 		char *module;
725 
726 		pos = rb_entry(next, struct symbol, rb_node);
727 		next = rb_next(&pos->rb_node);
728 
729 		module = strchr(pos->name, '\t');
730 		if (module) {
731 			if (!symbol_conf.use_modules)
732 				goto discard_symbol;
733 
734 			*module++ = '\0';
735 
736 			if (strcmp(curr_map->dso->short_name, module)) {
737 				if (curr_map != map &&
738 				    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
739 				    machine__is_default_guest(machine)) {
740 					/*
741 					 * We assume all symbols of a module are
742 					 * continuous in * kallsyms, so curr_map
743 					 * points to a module and all its
744 					 * symbols are in its kmap. Mark it as
745 					 * loaded.
746 					 */
747 					dso__set_loaded(curr_map->dso,
748 							curr_map->type);
749 				}
750 
751 				curr_map = map_groups__find_by_name(kmaps,
752 							map->type, module);
753 				if (curr_map == NULL) {
754 					pr_debug("%s/proc/{kallsyms,modules} "
755 					         "inconsistency while looking "
756 						 "for \"%s\" module!\n",
757 						 machine->root_dir, module);
758 					curr_map = map;
759 					goto discard_symbol;
760 				}
761 
762 				if (curr_map->dso->loaded &&
763 				    !machine__is_default_guest(machine))
764 					goto discard_symbol;
765 			}
766 			/*
767 			 * So that we look just like we get from .ko files,
768 			 * i.e. not prelinked, relative to map->start.
769 			 */
770 			pos->start = curr_map->map_ip(curr_map, pos->start);
771 			pos->end   = curr_map->map_ip(curr_map, pos->end);
772 		} else if (curr_map != map) {
773 			char dso_name[PATH_MAX];
774 			struct dso *ndso;
775 
776 			if (delta) {
777 				/* Kernel was relocated at boot time */
778 				pos->start -= delta;
779 				pos->end -= delta;
780 			}
781 
782 			if (count == 0) {
783 				curr_map = map;
784 				goto filter_symbol;
785 			}
786 
787 			if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
788 				snprintf(dso_name, sizeof(dso_name),
789 					"[guest.kernel].%d",
790 					kernel_range++);
791 			else
792 				snprintf(dso_name, sizeof(dso_name),
793 					"[kernel].%d",
794 					kernel_range++);
795 
796 			ndso = dso__new(dso_name);
797 			if (ndso == NULL)
798 				return -1;
799 
800 			ndso->kernel = dso->kernel;
801 
802 			curr_map = map__new2(pos->start, ndso, map->type);
803 			if (curr_map == NULL) {
804 				dso__put(ndso);
805 				return -1;
806 			}
807 
808 			curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
809 			map_groups__insert(kmaps, curr_map);
810 			++kernel_range;
811 		} else if (delta) {
812 			/* Kernel was relocated at boot time */
813 			pos->start -= delta;
814 			pos->end -= delta;
815 		}
816 filter_symbol:
817 		if (filter && filter(curr_map, pos)) {
818 discard_symbol:		rb_erase(&pos->rb_node, root);
819 			symbol__delete(pos);
820 		} else {
821 			if (curr_map != map) {
822 				rb_erase(&pos->rb_node, root);
823 				symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
824 				++moved;
825 			} else
826 				++count;
827 		}
828 	}
829 
830 	if (curr_map != map &&
831 	    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
832 	    machine__is_default_guest(kmaps->machine)) {
833 		dso__set_loaded(curr_map->dso, curr_map->type);
834 	}
835 
836 	return count + moved;
837 }
838 
839 bool symbol__restricted_filename(const char *filename,
840 				 const char *restricted_filename)
841 {
842 	bool restricted = false;
843 
844 	if (symbol_conf.kptr_restrict) {
845 		char *r = realpath(filename, NULL);
846 
847 		if (r != NULL) {
848 			restricted = strcmp(r, restricted_filename) == 0;
849 			free(r);
850 			return restricted;
851 		}
852 	}
853 
854 	return restricted;
855 }
856 
857 struct module_info {
858 	struct rb_node rb_node;
859 	char *name;
860 	u64 start;
861 };
862 
863 static void add_module(struct module_info *mi, struct rb_root *modules)
864 {
865 	struct rb_node **p = &modules->rb_node;
866 	struct rb_node *parent = NULL;
867 	struct module_info *m;
868 
869 	while (*p != NULL) {
870 		parent = *p;
871 		m = rb_entry(parent, struct module_info, rb_node);
872 		if (strcmp(mi->name, m->name) < 0)
873 			p = &(*p)->rb_left;
874 		else
875 			p = &(*p)->rb_right;
876 	}
877 	rb_link_node(&mi->rb_node, parent, p);
878 	rb_insert_color(&mi->rb_node, modules);
879 }
880 
881 static void delete_modules(struct rb_root *modules)
882 {
883 	struct module_info *mi;
884 	struct rb_node *next = rb_first(modules);
885 
886 	while (next) {
887 		mi = rb_entry(next, struct module_info, rb_node);
888 		next = rb_next(&mi->rb_node);
889 		rb_erase(&mi->rb_node, modules);
890 		zfree(&mi->name);
891 		free(mi);
892 	}
893 }
894 
895 static struct module_info *find_module(const char *name,
896 				       struct rb_root *modules)
897 {
898 	struct rb_node *n = modules->rb_node;
899 
900 	while (n) {
901 		struct module_info *m;
902 		int cmp;
903 
904 		m = rb_entry(n, struct module_info, rb_node);
905 		cmp = strcmp(name, m->name);
906 		if (cmp < 0)
907 			n = n->rb_left;
908 		else if (cmp > 0)
909 			n = n->rb_right;
910 		else
911 			return m;
912 	}
913 
914 	return NULL;
915 }
916 
917 static int __read_proc_modules(void *arg, const char *name, u64 start)
918 {
919 	struct rb_root *modules = arg;
920 	struct module_info *mi;
921 
922 	mi = zalloc(sizeof(struct module_info));
923 	if (!mi)
924 		return -ENOMEM;
925 
926 	mi->name = strdup(name);
927 	mi->start = start;
928 
929 	if (!mi->name) {
930 		free(mi);
931 		return -ENOMEM;
932 	}
933 
934 	add_module(mi, modules);
935 
936 	return 0;
937 }
938 
939 static int read_proc_modules(const char *filename, struct rb_root *modules)
940 {
941 	if (symbol__restricted_filename(filename, "/proc/modules"))
942 		return -1;
943 
944 	if (modules__parse(filename, modules, __read_proc_modules)) {
945 		delete_modules(modules);
946 		return -1;
947 	}
948 
949 	return 0;
950 }
951 
952 int compare_proc_modules(const char *from, const char *to)
953 {
954 	struct rb_root from_modules = RB_ROOT;
955 	struct rb_root to_modules = RB_ROOT;
956 	struct rb_node *from_node, *to_node;
957 	struct module_info *from_m, *to_m;
958 	int ret = -1;
959 
960 	if (read_proc_modules(from, &from_modules))
961 		return -1;
962 
963 	if (read_proc_modules(to, &to_modules))
964 		goto out_delete_from;
965 
966 	from_node = rb_first(&from_modules);
967 	to_node = rb_first(&to_modules);
968 	while (from_node) {
969 		if (!to_node)
970 			break;
971 
972 		from_m = rb_entry(from_node, struct module_info, rb_node);
973 		to_m = rb_entry(to_node, struct module_info, rb_node);
974 
975 		if (from_m->start != to_m->start ||
976 		    strcmp(from_m->name, to_m->name))
977 			break;
978 
979 		from_node = rb_next(from_node);
980 		to_node = rb_next(to_node);
981 	}
982 
983 	if (!from_node && !to_node)
984 		ret = 0;
985 
986 	delete_modules(&to_modules);
987 out_delete_from:
988 	delete_modules(&from_modules);
989 
990 	return ret;
991 }
992 
993 static int do_validate_kcore_modules(const char *filename, struct map *map,
994 				  struct map_groups *kmaps)
995 {
996 	struct rb_root modules = RB_ROOT;
997 	struct map *old_map;
998 	int err;
999 
1000 	err = read_proc_modules(filename, &modules);
1001 	if (err)
1002 		return err;
1003 
1004 	old_map = map_groups__first(kmaps, map->type);
1005 	while (old_map) {
1006 		struct map *next = map_groups__next(old_map);
1007 		struct module_info *mi;
1008 
1009 		if (old_map == map || old_map->start == map->start) {
1010 			/* The kernel map */
1011 			old_map = next;
1012 			continue;
1013 		}
1014 
1015 		/* Module must be in memory at the same address */
1016 		mi = find_module(old_map->dso->short_name, &modules);
1017 		if (!mi || mi->start != old_map->start) {
1018 			err = -EINVAL;
1019 			goto out;
1020 		}
1021 
1022 		old_map = next;
1023 	}
1024 out:
1025 	delete_modules(&modules);
1026 	return err;
1027 }
1028 
1029 /*
1030  * If kallsyms is referenced by name then we look for filename in the same
1031  * directory.
1032  */
1033 static bool filename_from_kallsyms_filename(char *filename,
1034 					    const char *base_name,
1035 					    const char *kallsyms_filename)
1036 {
1037 	char *name;
1038 
1039 	strcpy(filename, kallsyms_filename);
1040 	name = strrchr(filename, '/');
1041 	if (!name)
1042 		return false;
1043 
1044 	name += 1;
1045 
1046 	if (!strcmp(name, "kallsyms")) {
1047 		strcpy(name, base_name);
1048 		return true;
1049 	}
1050 
1051 	return false;
1052 }
1053 
1054 static int validate_kcore_modules(const char *kallsyms_filename,
1055 				  struct map *map)
1056 {
1057 	struct map_groups *kmaps = map__kmaps(map);
1058 	char modules_filename[PATH_MAX];
1059 
1060 	if (!kmaps)
1061 		return -EINVAL;
1062 
1063 	if (!filename_from_kallsyms_filename(modules_filename, "modules",
1064 					     kallsyms_filename))
1065 		return -EINVAL;
1066 
1067 	if (do_validate_kcore_modules(modules_filename, map, kmaps))
1068 		return -EINVAL;
1069 
1070 	return 0;
1071 }
1072 
1073 static int validate_kcore_addresses(const char *kallsyms_filename,
1074 				    struct map *map)
1075 {
1076 	struct kmap *kmap = map__kmap(map);
1077 
1078 	if (!kmap)
1079 		return -EINVAL;
1080 
1081 	if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
1082 		u64 start;
1083 
1084 		start = kallsyms__get_function_start(kallsyms_filename,
1085 						     kmap->ref_reloc_sym->name);
1086 		if (start != kmap->ref_reloc_sym->addr)
1087 			return -EINVAL;
1088 	}
1089 
1090 	return validate_kcore_modules(kallsyms_filename, map);
1091 }
1092 
1093 struct kcore_mapfn_data {
1094 	struct dso *dso;
1095 	enum map_type type;
1096 	struct list_head maps;
1097 };
1098 
1099 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1100 {
1101 	struct kcore_mapfn_data *md = data;
1102 	struct map *map;
1103 
1104 	map = map__new2(start, md->dso, md->type);
1105 	if (map == NULL)
1106 		return -ENOMEM;
1107 
1108 	map->end = map->start + len;
1109 	map->pgoff = pgoff;
1110 
1111 	list_add(&map->node, &md->maps);
1112 
1113 	return 0;
1114 }
1115 
1116 static int dso__load_kcore(struct dso *dso, struct map *map,
1117 			   const char *kallsyms_filename)
1118 {
1119 	struct map_groups *kmaps = map__kmaps(map);
1120 	struct machine *machine;
1121 	struct kcore_mapfn_data md;
1122 	struct map *old_map, *new_map, *replacement_map = NULL;
1123 	bool is_64_bit;
1124 	int err, fd;
1125 	char kcore_filename[PATH_MAX];
1126 	struct symbol *sym;
1127 
1128 	if (!kmaps)
1129 		return -EINVAL;
1130 
1131 	machine = kmaps->machine;
1132 
1133 	/* This function requires that the map is the kernel map */
1134 	if (map != machine->vmlinux_maps[map->type])
1135 		return -EINVAL;
1136 
1137 	if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1138 					     kallsyms_filename))
1139 		return -EINVAL;
1140 
1141 	/* Modules and kernel must be present at their original addresses */
1142 	if (validate_kcore_addresses(kallsyms_filename, map))
1143 		return -EINVAL;
1144 
1145 	md.dso = dso;
1146 	md.type = map->type;
1147 	INIT_LIST_HEAD(&md.maps);
1148 
1149 	fd = open(kcore_filename, O_RDONLY);
1150 	if (fd < 0) {
1151 		pr_debug("Failed to open %s. Note /proc/kcore requires CAP_SYS_RAWIO capability to access.\n",
1152 			 kcore_filename);
1153 		return -EINVAL;
1154 	}
1155 
1156 	/* Read new maps into temporary lists */
1157 	err = file__read_maps(fd, md.type == MAP__FUNCTION, kcore_mapfn, &md,
1158 			      &is_64_bit);
1159 	if (err)
1160 		goto out_err;
1161 	dso->is_64_bit = is_64_bit;
1162 
1163 	if (list_empty(&md.maps)) {
1164 		err = -EINVAL;
1165 		goto out_err;
1166 	}
1167 
1168 	/* Remove old maps */
1169 	old_map = map_groups__first(kmaps, map->type);
1170 	while (old_map) {
1171 		struct map *next = map_groups__next(old_map);
1172 
1173 		if (old_map != map)
1174 			map_groups__remove(kmaps, old_map);
1175 		old_map = next;
1176 	}
1177 
1178 	/* Find the kernel map using the first symbol */
1179 	sym = dso__first_symbol(dso, map->type);
1180 	list_for_each_entry(new_map, &md.maps, node) {
1181 		if (sym && sym->start >= new_map->start &&
1182 		    sym->start < new_map->end) {
1183 			replacement_map = new_map;
1184 			break;
1185 		}
1186 	}
1187 
1188 	if (!replacement_map)
1189 		replacement_map = list_entry(md.maps.next, struct map, node);
1190 
1191 	/* Add new maps */
1192 	while (!list_empty(&md.maps)) {
1193 		new_map = list_entry(md.maps.next, struct map, node);
1194 		list_del_init(&new_map->node);
1195 		if (new_map == replacement_map) {
1196 			map->start	= new_map->start;
1197 			map->end	= new_map->end;
1198 			map->pgoff	= new_map->pgoff;
1199 			map->map_ip	= new_map->map_ip;
1200 			map->unmap_ip	= new_map->unmap_ip;
1201 			/* Ensure maps are correctly ordered */
1202 			map__get(map);
1203 			map_groups__remove(kmaps, map);
1204 			map_groups__insert(kmaps, map);
1205 			map__put(map);
1206 		} else {
1207 			map_groups__insert(kmaps, new_map);
1208 		}
1209 
1210 		map__put(new_map);
1211 	}
1212 
1213 	/*
1214 	 * Set the data type and long name so that kcore can be read via
1215 	 * dso__data_read_addr().
1216 	 */
1217 	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1218 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
1219 	else
1220 		dso->binary_type = DSO_BINARY_TYPE__KCORE;
1221 	dso__set_long_name(dso, strdup(kcore_filename), true);
1222 
1223 	close(fd);
1224 
1225 	if (map->type == MAP__FUNCTION)
1226 		pr_debug("Using %s for kernel object code\n", kcore_filename);
1227 	else
1228 		pr_debug("Using %s for kernel data\n", kcore_filename);
1229 
1230 	return 0;
1231 
1232 out_err:
1233 	while (!list_empty(&md.maps)) {
1234 		map = list_entry(md.maps.next, struct map, node);
1235 		list_del_init(&map->node);
1236 		map__put(map);
1237 	}
1238 	close(fd);
1239 	return -EINVAL;
1240 }
1241 
1242 /*
1243  * If the kernel is relocated at boot time, kallsyms won't match.  Compute the
1244  * delta based on the relocation reference symbol.
1245  */
1246 static int kallsyms__delta(struct map *map, const char *filename, u64 *delta)
1247 {
1248 	struct kmap *kmap = map__kmap(map);
1249 	u64 addr;
1250 
1251 	if (!kmap)
1252 		return -1;
1253 
1254 	if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1255 		return 0;
1256 
1257 	addr = kallsyms__get_function_start(filename,
1258 					    kmap->ref_reloc_sym->name);
1259 	if (!addr)
1260 		return -1;
1261 
1262 	*delta = addr - kmap->ref_reloc_sym->addr;
1263 	return 0;
1264 }
1265 
1266 int dso__load_kallsyms(struct dso *dso, const char *filename,
1267 		       struct map *map, symbol_filter_t filter)
1268 {
1269 	u64 delta = 0;
1270 
1271 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1272 		return -1;
1273 
1274 	if (dso__load_all_kallsyms(dso, filename, map) < 0)
1275 		return -1;
1276 
1277 	if (kallsyms__delta(map, filename, &delta))
1278 		return -1;
1279 
1280 	symbols__fixup_duplicate(&dso->symbols[map->type]);
1281 	symbols__fixup_end(&dso->symbols[map->type]);
1282 
1283 	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1284 		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1285 	else
1286 		dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1287 
1288 	if (!dso__load_kcore(dso, map, filename))
1289 		return dso__split_kallsyms_for_kcore(dso, map, filter);
1290 	else
1291 		return dso__split_kallsyms(dso, map, delta, filter);
1292 }
1293 
1294 static int dso__load_perf_map(struct dso *dso, struct map *map,
1295 			      symbol_filter_t filter)
1296 {
1297 	char *line = NULL;
1298 	size_t n;
1299 	FILE *file;
1300 	int nr_syms = 0;
1301 
1302 	file = fopen(dso->long_name, "r");
1303 	if (file == NULL)
1304 		goto out_failure;
1305 
1306 	while (!feof(file)) {
1307 		u64 start, size;
1308 		struct symbol *sym;
1309 		int line_len, len;
1310 
1311 		line_len = getline(&line, &n, file);
1312 		if (line_len < 0)
1313 			break;
1314 
1315 		if (!line)
1316 			goto out_failure;
1317 
1318 		line[--line_len] = '\0'; /* \n */
1319 
1320 		len = hex2u64(line, &start);
1321 
1322 		len++;
1323 		if (len + 2 >= line_len)
1324 			continue;
1325 
1326 		len += hex2u64(line + len, &size);
1327 
1328 		len++;
1329 		if (len + 2 >= line_len)
1330 			continue;
1331 
1332 		sym = symbol__new(start, size, STB_GLOBAL, line + len);
1333 
1334 		if (sym == NULL)
1335 			goto out_delete_line;
1336 
1337 		if (filter && filter(map, sym))
1338 			symbol__delete(sym);
1339 		else {
1340 			symbols__insert(&dso->symbols[map->type], sym);
1341 			nr_syms++;
1342 		}
1343 	}
1344 
1345 	free(line);
1346 	fclose(file);
1347 
1348 	return nr_syms;
1349 
1350 out_delete_line:
1351 	free(line);
1352 out_failure:
1353 	return -1;
1354 }
1355 
1356 static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
1357 					   enum dso_binary_type type)
1358 {
1359 	switch (type) {
1360 	case DSO_BINARY_TYPE__JAVA_JIT:
1361 	case DSO_BINARY_TYPE__DEBUGLINK:
1362 	case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
1363 	case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
1364 	case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
1365 	case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
1366 	case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
1367 		return !kmod && dso->kernel == DSO_TYPE_USER;
1368 
1369 	case DSO_BINARY_TYPE__KALLSYMS:
1370 	case DSO_BINARY_TYPE__VMLINUX:
1371 	case DSO_BINARY_TYPE__KCORE:
1372 		return dso->kernel == DSO_TYPE_KERNEL;
1373 
1374 	case DSO_BINARY_TYPE__GUEST_KALLSYMS:
1375 	case DSO_BINARY_TYPE__GUEST_VMLINUX:
1376 	case DSO_BINARY_TYPE__GUEST_KCORE:
1377 		return dso->kernel == DSO_TYPE_GUEST_KERNEL;
1378 
1379 	case DSO_BINARY_TYPE__GUEST_KMODULE:
1380 	case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
1381 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
1382 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
1383 		/*
1384 		 * kernel modules know their symtab type - it's set when
1385 		 * creating a module dso in machine__findnew_module_map().
1386 		 */
1387 		return kmod && dso->symtab_type == type;
1388 
1389 	case DSO_BINARY_TYPE__BUILD_ID_CACHE:
1390 		return true;
1391 
1392 	case DSO_BINARY_TYPE__NOT_FOUND:
1393 	default:
1394 		return false;
1395 	}
1396 }
1397 
1398 int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
1399 {
1400 	char *name;
1401 	int ret = -1;
1402 	u_int i;
1403 	struct machine *machine;
1404 	char *root_dir = (char *) "";
1405 	int ss_pos = 0;
1406 	struct symsrc ss_[2];
1407 	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1408 	bool kmod;
1409 	unsigned char build_id[BUILD_ID_SIZE];
1410 
1411 	pthread_mutex_lock(&dso->lock);
1412 
1413 	/* check again under the dso->lock */
1414 	if (dso__loaded(dso, map->type)) {
1415 		ret = 1;
1416 		goto out;
1417 	}
1418 
1419 	if (dso->kernel) {
1420 		if (dso->kernel == DSO_TYPE_KERNEL)
1421 			ret = dso__load_kernel_sym(dso, map, filter);
1422 		else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1423 			ret = dso__load_guest_kernel_sym(dso, map, filter);
1424 
1425 		goto out;
1426 	}
1427 
1428 	if (map->groups && map->groups->machine)
1429 		machine = map->groups->machine;
1430 	else
1431 		machine = NULL;
1432 
1433 	dso->adjust_symbols = 0;
1434 
1435 	if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
1436 		struct stat st;
1437 
1438 		if (lstat(dso->name, &st) < 0)
1439 			goto out;
1440 
1441 		if (st.st_uid && (st.st_uid != geteuid())) {
1442 			pr_warning("File %s not owned by current user or root, "
1443 				"ignoring it.\n", dso->name);
1444 			goto out;
1445 		}
1446 
1447 		ret = dso__load_perf_map(dso, map, filter);
1448 		dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1449 					     DSO_BINARY_TYPE__NOT_FOUND;
1450 		goto out;
1451 	}
1452 
1453 	if (machine)
1454 		root_dir = machine->root_dir;
1455 
1456 	name = malloc(PATH_MAX);
1457 	if (!name)
1458 		goto out;
1459 
1460 	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1461 		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
1462 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
1463 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
1464 
1465 
1466 	/*
1467 	 * Read the build id if possible. This is required for
1468 	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
1469 	 */
1470 	if (filename__read_build_id(dso->name, build_id, BUILD_ID_SIZE) > 0)
1471 		dso__set_build_id(dso, build_id);
1472 
1473 	/*
1474 	 * Iterate over candidate debug images.
1475 	 * Keep track of "interesting" ones (those which have a symtab, dynsym,
1476 	 * and/or opd section) for processing.
1477 	 */
1478 	for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1479 		struct symsrc *ss = &ss_[ss_pos];
1480 		bool next_slot = false;
1481 
1482 		enum dso_binary_type symtab_type = binary_type_symtab[i];
1483 
1484 		if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
1485 			continue;
1486 
1487 		if (dso__read_binary_type_filename(dso, symtab_type,
1488 						   root_dir, name, PATH_MAX))
1489 			continue;
1490 
1491 		/* Name is now the name of the next image to try */
1492 		if (symsrc__init(ss, dso, name, symtab_type) < 0)
1493 			continue;
1494 
1495 		if (!syms_ss && symsrc__has_symtab(ss)) {
1496 			syms_ss = ss;
1497 			next_slot = true;
1498 			if (!dso->symsrc_filename)
1499 				dso->symsrc_filename = strdup(name);
1500 		}
1501 
1502 		if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1503 			runtime_ss = ss;
1504 			next_slot = true;
1505 		}
1506 
1507 		if (next_slot) {
1508 			ss_pos++;
1509 
1510 			if (syms_ss && runtime_ss)
1511 				break;
1512 		} else {
1513 			symsrc__destroy(ss);
1514 		}
1515 
1516 	}
1517 
1518 	if (!runtime_ss && !syms_ss)
1519 		goto out_free;
1520 
1521 	if (runtime_ss && !syms_ss) {
1522 		syms_ss = runtime_ss;
1523 	}
1524 
1525 	/* We'll have to hope for the best */
1526 	if (!runtime_ss && syms_ss)
1527 		runtime_ss = syms_ss;
1528 
1529 	if (syms_ss)
1530 		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, kmod);
1531 	else
1532 		ret = -1;
1533 
1534 	if (ret > 0) {
1535 		int nr_plt;
1536 
1537 		nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss, map, filter);
1538 		if (nr_plt > 0)
1539 			ret += nr_plt;
1540 	}
1541 
1542 	for (; ss_pos > 0; ss_pos--)
1543 		symsrc__destroy(&ss_[ss_pos - 1]);
1544 out_free:
1545 	free(name);
1546 	if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1547 		ret = 0;
1548 out:
1549 	dso__set_loaded(dso, map->type);
1550 	pthread_mutex_unlock(&dso->lock);
1551 
1552 	return ret;
1553 }
1554 
1555 struct map *map_groups__find_by_name(struct map_groups *mg,
1556 				     enum map_type type, const char *name)
1557 {
1558 	struct maps *maps = &mg->maps[type];
1559 	struct map *map;
1560 
1561 	pthread_rwlock_rdlock(&maps->lock);
1562 
1563 	for (map = maps__first(maps); map; map = map__next(map)) {
1564 		if (map->dso && strcmp(map->dso->short_name, name) == 0)
1565 			goto out_unlock;
1566 	}
1567 
1568 	map = NULL;
1569 
1570 out_unlock:
1571 	pthread_rwlock_unlock(&maps->lock);
1572 	return map;
1573 }
1574 
1575 int dso__load_vmlinux(struct dso *dso, struct map *map,
1576 		      const char *vmlinux, bool vmlinux_allocated,
1577 		      symbol_filter_t filter)
1578 {
1579 	int err = -1;
1580 	struct symsrc ss;
1581 	char symfs_vmlinux[PATH_MAX];
1582 	enum dso_binary_type symtab_type;
1583 
1584 	if (vmlinux[0] == '/')
1585 		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
1586 	else
1587 		symbol__join_symfs(symfs_vmlinux, vmlinux);
1588 
1589 	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1590 		symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1591 	else
1592 		symtab_type = DSO_BINARY_TYPE__VMLINUX;
1593 
1594 	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
1595 		return -1;
1596 
1597 	err = dso__load_sym(dso, map, &ss, &ss, filter, 0);
1598 	symsrc__destroy(&ss);
1599 
1600 	if (err > 0) {
1601 		if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1602 			dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1603 		else
1604 			dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
1605 		dso__set_long_name(dso, vmlinux, vmlinux_allocated);
1606 		dso__set_loaded(dso, map->type);
1607 		pr_debug("Using %s for symbols\n", symfs_vmlinux);
1608 	}
1609 
1610 	return err;
1611 }
1612 
1613 int dso__load_vmlinux_path(struct dso *dso, struct map *map,
1614 			   symbol_filter_t filter)
1615 {
1616 	int i, err = 0;
1617 	char *filename = NULL;
1618 
1619 	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
1620 		 vmlinux_path__nr_entries + 1);
1621 
1622 	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
1623 		err = dso__load_vmlinux(dso, map, vmlinux_path[i], false, filter);
1624 		if (err > 0)
1625 			goto out;
1626 	}
1627 
1628 	if (!symbol_conf.ignore_vmlinux_buildid)
1629 		filename = dso__build_id_filename(dso, NULL, 0);
1630 	if (filename != NULL) {
1631 		err = dso__load_vmlinux(dso, map, filename, true, filter);
1632 		if (err > 0)
1633 			goto out;
1634 		free(filename);
1635 	}
1636 out:
1637 	return err;
1638 }
1639 
1640 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
1641 {
1642 	char kallsyms_filename[PATH_MAX];
1643 	struct dirent *dent;
1644 	int ret = -1;
1645 	DIR *d;
1646 
1647 	d = opendir(dir);
1648 	if (!d)
1649 		return -1;
1650 
1651 	while (1) {
1652 		dent = readdir(d);
1653 		if (!dent)
1654 			break;
1655 		if (dent->d_type != DT_DIR)
1656 			continue;
1657 		scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
1658 			  "%s/%s/kallsyms", dir, dent->d_name);
1659 		if (!validate_kcore_addresses(kallsyms_filename, map)) {
1660 			strlcpy(dir, kallsyms_filename, dir_sz);
1661 			ret = 0;
1662 			break;
1663 		}
1664 	}
1665 
1666 	closedir(d);
1667 
1668 	return ret;
1669 }
1670 
1671 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
1672 {
1673 	u8 host_build_id[BUILD_ID_SIZE];
1674 	char sbuild_id[BUILD_ID_SIZE * 2 + 1];
1675 	bool is_host = false;
1676 	char path[PATH_MAX];
1677 
1678 	if (!dso->has_build_id) {
1679 		/*
1680 		 * Last resort, if we don't have a build-id and couldn't find
1681 		 * any vmlinux file, try the running kernel kallsyms table.
1682 		 */
1683 		goto proc_kallsyms;
1684 	}
1685 
1686 	if (sysfs__read_build_id("/sys/kernel/notes", host_build_id,
1687 				 sizeof(host_build_id)) == 0)
1688 		is_host = dso__build_id_equal(dso, host_build_id);
1689 
1690 	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
1691 
1692 	scnprintf(path, sizeof(path), "%s/[kernel.kcore]/%s", buildid_dir,
1693 		  sbuild_id);
1694 
1695 	/* Use /proc/kallsyms if possible */
1696 	if (is_host) {
1697 		DIR *d;
1698 		int fd;
1699 
1700 		/* If no cached kcore go with /proc/kallsyms */
1701 		d = opendir(path);
1702 		if (!d)
1703 			goto proc_kallsyms;
1704 		closedir(d);
1705 
1706 		/*
1707 		 * Do not check the build-id cache, until we know we cannot use
1708 		 * /proc/kcore.
1709 		 */
1710 		fd = open("/proc/kcore", O_RDONLY);
1711 		if (fd != -1) {
1712 			close(fd);
1713 			/* If module maps match go with /proc/kallsyms */
1714 			if (!validate_kcore_addresses("/proc/kallsyms", map))
1715 				goto proc_kallsyms;
1716 		}
1717 
1718 		/* Find kallsyms in build-id cache with kcore */
1719 		if (!find_matching_kcore(map, path, sizeof(path)))
1720 			return strdup(path);
1721 
1722 		goto proc_kallsyms;
1723 	}
1724 
1725 	/* Find kallsyms in build-id cache with kcore */
1726 	if (!find_matching_kcore(map, path, sizeof(path)))
1727 		return strdup(path);
1728 
1729 	scnprintf(path, sizeof(path), "%s/[kernel.kallsyms]/%s",
1730 		  buildid_dir, sbuild_id);
1731 
1732 	if (access(path, F_OK)) {
1733 		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
1734 		       sbuild_id);
1735 		return NULL;
1736 	}
1737 
1738 	return strdup(path);
1739 
1740 proc_kallsyms:
1741 	return strdup("/proc/kallsyms");
1742 }
1743 
1744 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
1745 				symbol_filter_t filter)
1746 {
1747 	int err;
1748 	const char *kallsyms_filename = NULL;
1749 	char *kallsyms_allocated_filename = NULL;
1750 	/*
1751 	 * Step 1: if the user specified a kallsyms or vmlinux filename, use
1752 	 * it and only it, reporting errors to the user if it cannot be used.
1753 	 *
1754 	 * For instance, try to analyse an ARM perf.data file _without_ a
1755 	 * build-id, or if the user specifies the wrong path to the right
1756 	 * vmlinux file, obviously we can't fallback to another vmlinux (a
1757 	 * x86_86 one, on the machine where analysis is being performed, say),
1758 	 * or worse, /proc/kallsyms.
1759 	 *
1760 	 * If the specified file _has_ a build-id and there is a build-id
1761 	 * section in the perf.data file, we will still do the expected
1762 	 * validation in dso__load_vmlinux and will bail out if they don't
1763 	 * match.
1764 	 */
1765 	if (symbol_conf.kallsyms_name != NULL) {
1766 		kallsyms_filename = symbol_conf.kallsyms_name;
1767 		goto do_kallsyms;
1768 	}
1769 
1770 	if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
1771 		return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name,
1772 					 false, filter);
1773 	}
1774 
1775 	if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
1776 		err = dso__load_vmlinux_path(dso, map, filter);
1777 		if (err > 0)
1778 			return err;
1779 	}
1780 
1781 	/* do not try local files if a symfs was given */
1782 	if (symbol_conf.symfs[0] != 0)
1783 		return -1;
1784 
1785 	kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
1786 	if (!kallsyms_allocated_filename)
1787 		return -1;
1788 
1789 	kallsyms_filename = kallsyms_allocated_filename;
1790 
1791 do_kallsyms:
1792 	err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1793 	if (err > 0)
1794 		pr_debug("Using %s for symbols\n", kallsyms_filename);
1795 	free(kallsyms_allocated_filename);
1796 
1797 	if (err > 0 && !dso__is_kcore(dso)) {
1798 		dso->binary_type = DSO_BINARY_TYPE__KALLSYMS;
1799 		dso__set_long_name(dso, "[kernel.kallsyms]", false);
1800 		map__fixup_start(map);
1801 		map__fixup_end(map);
1802 	}
1803 
1804 	return err;
1805 }
1806 
1807 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
1808 				      symbol_filter_t filter)
1809 {
1810 	int err;
1811 	const char *kallsyms_filename = NULL;
1812 	struct machine *machine;
1813 	char path[PATH_MAX];
1814 
1815 	if (!map->groups) {
1816 		pr_debug("Guest kernel map hasn't the point to groups\n");
1817 		return -1;
1818 	}
1819 	machine = map->groups->machine;
1820 
1821 	if (machine__is_default_guest(machine)) {
1822 		/*
1823 		 * if the user specified a vmlinux filename, use it and only
1824 		 * it, reporting errors to the user if it cannot be used.
1825 		 * Or use file guest_kallsyms inputted by user on commandline
1826 		 */
1827 		if (symbol_conf.default_guest_vmlinux_name != NULL) {
1828 			err = dso__load_vmlinux(dso, map,
1829 						symbol_conf.default_guest_vmlinux_name,
1830 						false, filter);
1831 			return err;
1832 		}
1833 
1834 		kallsyms_filename = symbol_conf.default_guest_kallsyms;
1835 		if (!kallsyms_filename)
1836 			return -1;
1837 	} else {
1838 		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
1839 		kallsyms_filename = path;
1840 	}
1841 
1842 	err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1843 	if (err > 0)
1844 		pr_debug("Using %s for symbols\n", kallsyms_filename);
1845 	if (err > 0 && !dso__is_kcore(dso)) {
1846 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1847 		machine__mmap_name(machine, path, sizeof(path));
1848 		dso__set_long_name(dso, strdup(path), true);
1849 		map__fixup_start(map);
1850 		map__fixup_end(map);
1851 	}
1852 
1853 	return err;
1854 }
1855 
1856 static void vmlinux_path__exit(void)
1857 {
1858 	while (--vmlinux_path__nr_entries >= 0)
1859 		zfree(&vmlinux_path[vmlinux_path__nr_entries]);
1860 	vmlinux_path__nr_entries = 0;
1861 
1862 	zfree(&vmlinux_path);
1863 }
1864 
1865 static int vmlinux_path__init(struct perf_env *env)
1866 {
1867 	struct utsname uts;
1868 	char bf[PATH_MAX];
1869 	char *kernel_version;
1870 
1871 	vmlinux_path = malloc(sizeof(char *) * 6);
1872 	if (vmlinux_path == NULL)
1873 		return -1;
1874 
1875 	vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux");
1876 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1877 		goto out_fail;
1878 	++vmlinux_path__nr_entries;
1879 	vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux");
1880 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1881 		goto out_fail;
1882 	++vmlinux_path__nr_entries;
1883 
1884 	/* only try kernel version if no symfs was given */
1885 	if (symbol_conf.symfs[0] != 0)
1886 		return 0;
1887 
1888 	if (env) {
1889 		kernel_version = env->os_release;
1890 	} else {
1891 		if (uname(&uts) < 0)
1892 			goto out_fail;
1893 
1894 		kernel_version = uts.release;
1895 	}
1896 
1897 	snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", kernel_version);
1898 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1899 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1900 		goto out_fail;
1901 	++vmlinux_path__nr_entries;
1902 	snprintf(bf, sizeof(bf), "/usr/lib/debug/boot/vmlinux-%s",
1903 		 kernel_version);
1904 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1905 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1906 		goto out_fail;
1907         ++vmlinux_path__nr_entries;
1908 	snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", kernel_version);
1909 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1910 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1911 		goto out_fail;
1912 	++vmlinux_path__nr_entries;
1913 	snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
1914 		 kernel_version);
1915 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1916 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1917 		goto out_fail;
1918 	++vmlinux_path__nr_entries;
1919 
1920 	return 0;
1921 
1922 out_fail:
1923 	vmlinux_path__exit();
1924 	return -1;
1925 }
1926 
1927 int setup_list(struct strlist **list, const char *list_str,
1928 		      const char *list_name)
1929 {
1930 	if (list_str == NULL)
1931 		return 0;
1932 
1933 	*list = strlist__new(list_str, NULL);
1934 	if (!*list) {
1935 		pr_err("problems parsing %s list\n", list_name);
1936 		return -1;
1937 	}
1938 
1939 	symbol_conf.has_filter = true;
1940 	return 0;
1941 }
1942 
1943 int setup_intlist(struct intlist **list, const char *list_str,
1944 		  const char *list_name)
1945 {
1946 	if (list_str == NULL)
1947 		return 0;
1948 
1949 	*list = intlist__new(list_str);
1950 	if (!*list) {
1951 		pr_err("problems parsing %s list\n", list_name);
1952 		return -1;
1953 	}
1954 	return 0;
1955 }
1956 
1957 static bool symbol__read_kptr_restrict(void)
1958 {
1959 	bool value = false;
1960 
1961 	if (geteuid() != 0) {
1962 		FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
1963 		if (fp != NULL) {
1964 			char line[8];
1965 
1966 			if (fgets(line, sizeof(line), fp) != NULL)
1967 				value = atoi(line) != 0;
1968 
1969 			fclose(fp);
1970 		}
1971 	}
1972 
1973 	return value;
1974 }
1975 
1976 int symbol__init(struct perf_env *env)
1977 {
1978 	const char *symfs;
1979 
1980 	if (symbol_conf.initialized)
1981 		return 0;
1982 
1983 	symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
1984 
1985 	symbol__elf_init();
1986 
1987 	if (symbol_conf.sort_by_name)
1988 		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
1989 					  sizeof(struct symbol));
1990 
1991 	if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
1992 		return -1;
1993 
1994 	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
1995 		pr_err("'.' is the only non valid --field-separator argument\n");
1996 		return -1;
1997 	}
1998 
1999 	if (setup_list(&symbol_conf.dso_list,
2000 		       symbol_conf.dso_list_str, "dso") < 0)
2001 		return -1;
2002 
2003 	if (setup_list(&symbol_conf.comm_list,
2004 		       symbol_conf.comm_list_str, "comm") < 0)
2005 		goto out_free_dso_list;
2006 
2007 	if (setup_intlist(&symbol_conf.pid_list,
2008 		       symbol_conf.pid_list_str, "pid") < 0)
2009 		goto out_free_comm_list;
2010 
2011 	if (setup_intlist(&symbol_conf.tid_list,
2012 		       symbol_conf.tid_list_str, "tid") < 0)
2013 		goto out_free_pid_list;
2014 
2015 	if (setup_list(&symbol_conf.sym_list,
2016 		       symbol_conf.sym_list_str, "symbol") < 0)
2017 		goto out_free_tid_list;
2018 
2019 	/*
2020 	 * A path to symbols of "/" is identical to ""
2021 	 * reset here for simplicity.
2022 	 */
2023 	symfs = realpath(symbol_conf.symfs, NULL);
2024 	if (symfs == NULL)
2025 		symfs = symbol_conf.symfs;
2026 	if (strcmp(symfs, "/") == 0)
2027 		symbol_conf.symfs = "";
2028 	if (symfs != symbol_conf.symfs)
2029 		free((void *)symfs);
2030 
2031 	symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
2032 
2033 	symbol_conf.initialized = true;
2034 	return 0;
2035 
2036 out_free_tid_list:
2037 	intlist__delete(symbol_conf.tid_list);
2038 out_free_pid_list:
2039 	intlist__delete(symbol_conf.pid_list);
2040 out_free_comm_list:
2041 	strlist__delete(symbol_conf.comm_list);
2042 out_free_dso_list:
2043 	strlist__delete(symbol_conf.dso_list);
2044 	return -1;
2045 }
2046 
2047 void symbol__exit(void)
2048 {
2049 	if (!symbol_conf.initialized)
2050 		return;
2051 	strlist__delete(symbol_conf.sym_list);
2052 	strlist__delete(symbol_conf.dso_list);
2053 	strlist__delete(symbol_conf.comm_list);
2054 	intlist__delete(symbol_conf.tid_list);
2055 	intlist__delete(symbol_conf.pid_list);
2056 	vmlinux_path__exit();
2057 	symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2058 	symbol_conf.initialized = false;
2059 }
2060