xref: /openbmc/linux/tools/perf/util/symbol.c (revision 2596e07a)
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 	.event_group		= true,
43 };
44 
45 static enum dso_binary_type binary_type_symtab[] = {
46 	DSO_BINARY_TYPE__KALLSYMS,
47 	DSO_BINARY_TYPE__GUEST_KALLSYMS,
48 	DSO_BINARY_TYPE__JAVA_JIT,
49 	DSO_BINARY_TYPE__DEBUGLINK,
50 	DSO_BINARY_TYPE__BUILD_ID_CACHE,
51 	DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
52 	DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
53 	DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
54 	DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
55 	DSO_BINARY_TYPE__GUEST_KMODULE,
56 	DSO_BINARY_TYPE__GUEST_KMODULE_COMP,
57 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
58 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP,
59 	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
60 	DSO_BINARY_TYPE__NOT_FOUND,
61 };
62 
63 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
64 
65 bool symbol_type__is_a(char symbol_type, enum map_type map_type)
66 {
67 	symbol_type = toupper(symbol_type);
68 
69 	switch (map_type) {
70 	case MAP__FUNCTION:
71 		return symbol_type == 'T' || symbol_type == 'W';
72 	case MAP__VARIABLE:
73 		return symbol_type == 'D';
74 	default:
75 		return false;
76 	}
77 }
78 
79 static int prefix_underscores_count(const char *str)
80 {
81 	const char *tail = str;
82 
83 	while (*tail == '_')
84 		tail++;
85 
86 	return tail - str;
87 }
88 
89 int __weak arch__choose_best_symbol(struct symbol *syma,
90 				    struct symbol *symb __maybe_unused)
91 {
92 	/* Avoid "SyS" kernel syscall aliases */
93 	if (strlen(syma->name) >= 3 && !strncmp(syma->name, "SyS", 3))
94 		return SYMBOL_B;
95 	if (strlen(syma->name) >= 10 && !strncmp(syma->name, "compat_SyS", 10))
96 		return SYMBOL_B;
97 
98 	return SYMBOL_A;
99 }
100 
101 static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
102 {
103 	s64 a;
104 	s64 b;
105 	size_t na, nb;
106 
107 	/* Prefer a symbol with non zero length */
108 	a = syma->end - syma->start;
109 	b = symb->end - symb->start;
110 	if ((b == 0) && (a > 0))
111 		return SYMBOL_A;
112 	else if ((a == 0) && (b > 0))
113 		return SYMBOL_B;
114 
115 	/* Prefer a non weak symbol over a weak one */
116 	a = syma->binding == STB_WEAK;
117 	b = symb->binding == STB_WEAK;
118 	if (b && !a)
119 		return SYMBOL_A;
120 	if (a && !b)
121 		return SYMBOL_B;
122 
123 	/* Prefer a global symbol over a non global one */
124 	a = syma->binding == STB_GLOBAL;
125 	b = symb->binding == STB_GLOBAL;
126 	if (a && !b)
127 		return SYMBOL_A;
128 	if (b && !a)
129 		return SYMBOL_B;
130 
131 	/* Prefer a symbol with less underscores */
132 	a = prefix_underscores_count(syma->name);
133 	b = prefix_underscores_count(symb->name);
134 	if (b > a)
135 		return SYMBOL_A;
136 	else if (a > b)
137 		return SYMBOL_B;
138 
139 	/* Choose the symbol with the longest name */
140 	na = strlen(syma->name);
141 	nb = strlen(symb->name);
142 	if (na > nb)
143 		return SYMBOL_A;
144 	else if (na < nb)
145 		return SYMBOL_B;
146 
147 	return arch__choose_best_symbol(syma, symb);
148 }
149 
150 void symbols__fixup_duplicate(struct rb_root *symbols)
151 {
152 	struct rb_node *nd;
153 	struct symbol *curr, *next;
154 
155 	nd = rb_first(symbols);
156 
157 	while (nd) {
158 		curr = rb_entry(nd, struct symbol, rb_node);
159 again:
160 		nd = rb_next(&curr->rb_node);
161 		next = rb_entry(nd, struct symbol, rb_node);
162 
163 		if (!nd)
164 			break;
165 
166 		if (curr->start != next->start)
167 			continue;
168 
169 		if (choose_best_symbol(curr, next) == SYMBOL_A) {
170 			rb_erase(&next->rb_node, symbols);
171 			symbol__delete(next);
172 			goto again;
173 		} else {
174 			nd = rb_next(&curr->rb_node);
175 			rb_erase(&curr->rb_node, symbols);
176 			symbol__delete(curr);
177 		}
178 	}
179 }
180 
181 void symbols__fixup_end(struct rb_root *symbols)
182 {
183 	struct rb_node *nd, *prevnd = rb_first(symbols);
184 	struct symbol *curr, *prev;
185 
186 	if (prevnd == NULL)
187 		return;
188 
189 	curr = rb_entry(prevnd, struct symbol, rb_node);
190 
191 	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
192 		prev = curr;
193 		curr = rb_entry(nd, struct symbol, rb_node);
194 
195 		if (prev->end == prev->start && prev->end != curr->start)
196 			prev->end = curr->start;
197 	}
198 
199 	/* Last entry */
200 	if (curr->end == curr->start)
201 		curr->end = roundup(curr->start, 4096);
202 }
203 
204 void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
205 {
206 	struct maps *maps = &mg->maps[type];
207 	struct map *next, *curr;
208 
209 	pthread_rwlock_wrlock(&maps->lock);
210 
211 	curr = maps__first(maps);
212 	if (curr == NULL)
213 		goto out_unlock;
214 
215 	for (next = map__next(curr); next; next = map__next(curr)) {
216 		curr->end = next->start;
217 		curr = next;
218 	}
219 
220 	/*
221 	 * We still haven't the actual symbols, so guess the
222 	 * last map final address.
223 	 */
224 	curr->end = ~0ULL;
225 
226 out_unlock:
227 	pthread_rwlock_unlock(&maps->lock);
228 }
229 
230 struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
231 {
232 	size_t namelen = strlen(name) + 1;
233 	struct symbol *sym = calloc(1, (symbol_conf.priv_size +
234 					sizeof(*sym) + namelen));
235 	if (sym == NULL)
236 		return NULL;
237 
238 	if (symbol_conf.priv_size)
239 		sym = ((void *)sym) + symbol_conf.priv_size;
240 
241 	sym->start   = start;
242 	sym->end     = len ? start + len : start;
243 	sym->binding = binding;
244 	sym->namelen = namelen - 1;
245 
246 	pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
247 		  __func__, name, start, sym->end);
248 	memcpy(sym->name, name, namelen);
249 
250 	return sym;
251 }
252 
253 void symbol__delete(struct symbol *sym)
254 {
255 	free(((void *)sym) - symbol_conf.priv_size);
256 }
257 
258 size_t symbol__fprintf(struct symbol *sym, FILE *fp)
259 {
260 	return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %c %s\n",
261 		       sym->start, sym->end,
262 		       sym->binding == STB_GLOBAL ? 'g' :
263 		       sym->binding == STB_LOCAL  ? 'l' : 'w',
264 		       sym->name);
265 }
266 
267 size_t symbol__fprintf_symname_offs(const struct symbol *sym,
268 				    const struct addr_location *al, FILE *fp)
269 {
270 	unsigned long offset;
271 	size_t length;
272 
273 	if (sym && sym->name) {
274 		length = fprintf(fp, "%s", sym->name);
275 		if (al) {
276 			if (al->addr < sym->end)
277 				offset = al->addr - sym->start;
278 			else
279 				offset = al->addr - al->map->start - sym->start;
280 			length += fprintf(fp, "+0x%lx", offset);
281 		}
282 		return length;
283 	} else
284 		return fprintf(fp, "[unknown]");
285 }
286 
287 size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
288 {
289 	return symbol__fprintf_symname_offs(sym, NULL, fp);
290 }
291 
292 void symbols__delete(struct rb_root *symbols)
293 {
294 	struct symbol *pos;
295 	struct rb_node *next = rb_first(symbols);
296 
297 	while (next) {
298 		pos = rb_entry(next, struct symbol, rb_node);
299 		next = rb_next(&pos->rb_node);
300 		rb_erase(&pos->rb_node, symbols);
301 		symbol__delete(pos);
302 	}
303 }
304 
305 void symbols__insert(struct rb_root *symbols, struct symbol *sym)
306 {
307 	struct rb_node **p = &symbols->rb_node;
308 	struct rb_node *parent = NULL;
309 	const u64 ip = sym->start;
310 	struct symbol *s;
311 
312 	while (*p != NULL) {
313 		parent = *p;
314 		s = rb_entry(parent, struct symbol, rb_node);
315 		if (ip < s->start)
316 			p = &(*p)->rb_left;
317 		else
318 			p = &(*p)->rb_right;
319 	}
320 	rb_link_node(&sym->rb_node, parent, p);
321 	rb_insert_color(&sym->rb_node, symbols);
322 }
323 
324 static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
325 {
326 	struct rb_node *n;
327 
328 	if (symbols == NULL)
329 		return NULL;
330 
331 	n = symbols->rb_node;
332 
333 	while (n) {
334 		struct symbol *s = rb_entry(n, struct symbol, rb_node);
335 
336 		if (ip < s->start)
337 			n = n->rb_left;
338 		else if (ip >= s->end)
339 			n = n->rb_right;
340 		else
341 			return s;
342 	}
343 
344 	return NULL;
345 }
346 
347 static struct symbol *symbols__first(struct rb_root *symbols)
348 {
349 	struct rb_node *n = rb_first(symbols);
350 
351 	if (n)
352 		return rb_entry(n, struct symbol, rb_node);
353 
354 	return NULL;
355 }
356 
357 static struct symbol *symbols__next(struct symbol *sym)
358 {
359 	struct rb_node *n = rb_next(&sym->rb_node);
360 
361 	if (n)
362 		return rb_entry(n, struct symbol, rb_node);
363 
364 	return NULL;
365 }
366 
367 struct symbol_name_rb_node {
368 	struct rb_node	rb_node;
369 	struct symbol	sym;
370 };
371 
372 static void symbols__insert_by_name(struct rb_root *symbols, struct symbol *sym)
373 {
374 	struct rb_node **p = &symbols->rb_node;
375 	struct rb_node *parent = NULL;
376 	struct symbol_name_rb_node *symn, *s;
377 
378 	symn = container_of(sym, struct symbol_name_rb_node, sym);
379 
380 	while (*p != NULL) {
381 		parent = *p;
382 		s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
383 		if (strcmp(sym->name, s->sym.name) < 0)
384 			p = &(*p)->rb_left;
385 		else
386 			p = &(*p)->rb_right;
387 	}
388 	rb_link_node(&symn->rb_node, parent, p);
389 	rb_insert_color(&symn->rb_node, symbols);
390 }
391 
392 static void symbols__sort_by_name(struct rb_root *symbols,
393 				  struct rb_root *source)
394 {
395 	struct rb_node *nd;
396 
397 	for (nd = rb_first(source); nd; nd = rb_next(nd)) {
398 		struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
399 		symbols__insert_by_name(symbols, pos);
400 	}
401 }
402 
403 static struct symbol *symbols__find_by_name(struct rb_root *symbols,
404 					    const char *name)
405 {
406 	struct rb_node *n;
407 	struct symbol_name_rb_node *s = NULL;
408 
409 	if (symbols == NULL)
410 		return NULL;
411 
412 	n = symbols->rb_node;
413 
414 	while (n) {
415 		int cmp;
416 
417 		s = rb_entry(n, struct symbol_name_rb_node, rb_node);
418 		cmp = arch__compare_symbol_names(name, s->sym.name);
419 
420 		if (cmp < 0)
421 			n = n->rb_left;
422 		else if (cmp > 0)
423 			n = n->rb_right;
424 		else
425 			break;
426 	}
427 
428 	if (n == NULL)
429 		return NULL;
430 
431 	/* return first symbol that has same name (if any) */
432 	for (n = rb_prev(n); n; n = rb_prev(n)) {
433 		struct symbol_name_rb_node *tmp;
434 
435 		tmp = rb_entry(n, struct symbol_name_rb_node, rb_node);
436 		if (arch__compare_symbol_names(tmp->sym.name, s->sym.name))
437 			break;
438 
439 		s = tmp;
440 	}
441 
442 	return &s->sym;
443 }
444 
445 void dso__reset_find_symbol_cache(struct dso *dso)
446 {
447 	enum map_type type;
448 
449 	for (type = MAP__FUNCTION; type <= MAP__VARIABLE; ++type) {
450 		dso->last_find_result[type].addr   = 0;
451 		dso->last_find_result[type].symbol = NULL;
452 	}
453 }
454 
455 struct symbol *dso__find_symbol(struct dso *dso,
456 				enum map_type type, u64 addr)
457 {
458 	if (dso->last_find_result[type].addr != addr) {
459 		dso->last_find_result[type].addr   = addr;
460 		dso->last_find_result[type].symbol = symbols__find(&dso->symbols[type], addr);
461 	}
462 
463 	return dso->last_find_result[type].symbol;
464 }
465 
466 struct symbol *dso__first_symbol(struct dso *dso, enum map_type type)
467 {
468 	return symbols__first(&dso->symbols[type]);
469 }
470 
471 struct symbol *dso__next_symbol(struct symbol *sym)
472 {
473 	return symbols__next(sym);
474 }
475 
476 struct symbol *symbol__next_by_name(struct symbol *sym)
477 {
478 	struct symbol_name_rb_node *s = container_of(sym, struct symbol_name_rb_node, sym);
479 	struct rb_node *n = rb_next(&s->rb_node);
480 
481 	return n ? &rb_entry(n, struct symbol_name_rb_node, rb_node)->sym : NULL;
482 }
483 
484  /*
485   * Teturns first symbol that matched with @name.
486   */
487 struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
488 					const char *name)
489 {
490 	return symbols__find_by_name(&dso->symbol_names[type], name);
491 }
492 
493 void dso__sort_by_name(struct dso *dso, enum map_type type)
494 {
495 	dso__set_sorted_by_name(dso, type);
496 	return symbols__sort_by_name(&dso->symbol_names[type],
497 				     &dso->symbols[type]);
498 }
499 
500 size_t dso__fprintf_symbols_by_name(struct dso *dso,
501 				    enum map_type type, FILE *fp)
502 {
503 	size_t ret = 0;
504 	struct rb_node *nd;
505 	struct symbol_name_rb_node *pos;
506 
507 	for (nd = rb_first(&dso->symbol_names[type]); nd; nd = rb_next(nd)) {
508 		pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
509 		fprintf(fp, "%s\n", pos->sym.name);
510 	}
511 
512 	return ret;
513 }
514 
515 int modules__parse(const char *filename, void *arg,
516 		   int (*process_module)(void *arg, const char *name,
517 					 u64 start))
518 {
519 	char *line = NULL;
520 	size_t n;
521 	FILE *file;
522 	int err = 0;
523 
524 	file = fopen(filename, "r");
525 	if (file == NULL)
526 		return -1;
527 
528 	while (1) {
529 		char name[PATH_MAX];
530 		u64 start;
531 		char *sep;
532 		ssize_t line_len;
533 
534 		line_len = getline(&line, &n, file);
535 		if (line_len < 0) {
536 			if (feof(file))
537 				break;
538 			err = -1;
539 			goto out;
540 		}
541 
542 		if (!line) {
543 			err = -1;
544 			goto out;
545 		}
546 
547 		line[--line_len] = '\0'; /* \n */
548 
549 		sep = strrchr(line, 'x');
550 		if (sep == NULL)
551 			continue;
552 
553 		hex2u64(sep + 1, &start);
554 
555 		sep = strchr(line, ' ');
556 		if (sep == NULL)
557 			continue;
558 
559 		*sep = '\0';
560 
561 		scnprintf(name, sizeof(name), "[%s]", line);
562 
563 		err = process_module(arg, name, start);
564 		if (err)
565 			break;
566 	}
567 out:
568 	free(line);
569 	fclose(file);
570 	return err;
571 }
572 
573 struct process_kallsyms_args {
574 	struct map *map;
575 	struct dso *dso;
576 };
577 
578 /*
579  * These are symbols in the kernel image, so make sure that
580  * sym is from a kernel DSO.
581  */
582 bool symbol__is_idle(struct symbol *sym)
583 {
584 	const char * const idle_symbols[] = {
585 		"cpu_idle",
586 		"cpu_startup_entry",
587 		"intel_idle",
588 		"default_idle",
589 		"native_safe_halt",
590 		"enter_idle",
591 		"exit_idle",
592 		"mwait_idle",
593 		"mwait_idle_with_hints",
594 		"poll_idle",
595 		"ppc64_runlatch_off",
596 		"pseries_dedicated_idle_sleep",
597 		NULL
598 	};
599 
600 	int i;
601 
602 	if (!sym)
603 		return false;
604 
605 	for (i = 0; idle_symbols[i]; i++) {
606 		if (!strcmp(idle_symbols[i], sym->name))
607 			return true;
608 	}
609 
610 	return false;
611 }
612 
613 static int map__process_kallsym_symbol(void *arg, const char *name,
614 				       char type, u64 start)
615 {
616 	struct symbol *sym;
617 	struct process_kallsyms_args *a = arg;
618 	struct rb_root *root = &a->dso->symbols[a->map->type];
619 
620 	if (!symbol_type__is_a(type, a->map->type))
621 		return 0;
622 
623 	/*
624 	 * module symbols are not sorted so we add all
625 	 * symbols, setting length to 0, and rely on
626 	 * symbols__fixup_end() to fix it up.
627 	 */
628 	sym = symbol__new(start, 0, kallsyms2elf_binding(type), name);
629 	if (sym == NULL)
630 		return -ENOMEM;
631 	/*
632 	 * We will pass the symbols to the filter later, in
633 	 * map__split_kallsyms, when we have split the maps per module
634 	 */
635 	symbols__insert(root, sym);
636 
637 	return 0;
638 }
639 
640 /*
641  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
642  * so that we can in the next step set the symbol ->end address and then
643  * call kernel_maps__split_kallsyms.
644  */
645 static int dso__load_all_kallsyms(struct dso *dso, const char *filename,
646 				  struct map *map)
647 {
648 	struct process_kallsyms_args args = { .map = map, .dso = dso, };
649 	return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
650 }
651 
652 static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map,
653 					 symbol_filter_t filter)
654 {
655 	struct map_groups *kmaps = map__kmaps(map);
656 	struct map *curr_map;
657 	struct symbol *pos;
658 	int count = 0;
659 	struct rb_root old_root = dso->symbols[map->type];
660 	struct rb_root *root = &dso->symbols[map->type];
661 	struct rb_node *next = rb_first(root);
662 
663 	if (!kmaps)
664 		return -1;
665 
666 	*root = RB_ROOT;
667 
668 	while (next) {
669 		char *module;
670 
671 		pos = rb_entry(next, struct symbol, rb_node);
672 		next = rb_next(&pos->rb_node);
673 
674 		rb_erase_init(&pos->rb_node, &old_root);
675 
676 		module = strchr(pos->name, '\t');
677 		if (module)
678 			*module = '\0';
679 
680 		curr_map = map_groups__find(kmaps, map->type, pos->start);
681 
682 		if (!curr_map || (filter && filter(curr_map, pos))) {
683 			symbol__delete(pos);
684 			continue;
685 		}
686 
687 		pos->start -= curr_map->start - curr_map->pgoff;
688 		if (pos->end)
689 			pos->end -= curr_map->start - curr_map->pgoff;
690 		symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
691 		++count;
692 	}
693 
694 	/* Symbols have been adjusted */
695 	dso->adjust_symbols = 1;
696 
697 	return count;
698 }
699 
700 /*
701  * Split the symbols into maps, making sure there are no overlaps, i.e. the
702  * kernel range is broken in several maps, named [kernel].N, as we don't have
703  * the original ELF section names vmlinux have.
704  */
705 static int dso__split_kallsyms(struct dso *dso, struct map *map, u64 delta,
706 			       symbol_filter_t filter)
707 {
708 	struct map_groups *kmaps = map__kmaps(map);
709 	struct machine *machine;
710 	struct map *curr_map = map;
711 	struct symbol *pos;
712 	int count = 0, moved = 0;
713 	struct rb_root *root = &dso->symbols[map->type];
714 	struct rb_node *next = rb_first(root);
715 	int kernel_range = 0;
716 
717 	if (!kmaps)
718 		return -1;
719 
720 	machine = kmaps->machine;
721 
722 	while (next) {
723 		char *module;
724 
725 		pos = rb_entry(next, struct symbol, rb_node);
726 		next = rb_next(&pos->rb_node);
727 
728 		module = strchr(pos->name, '\t');
729 		if (module) {
730 			if (!symbol_conf.use_modules)
731 				goto discard_symbol;
732 
733 			*module++ = '\0';
734 
735 			if (strcmp(curr_map->dso->short_name, module)) {
736 				if (curr_map != map &&
737 				    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
738 				    machine__is_default_guest(machine)) {
739 					/*
740 					 * We assume all symbols of a module are
741 					 * continuous in * kallsyms, so curr_map
742 					 * points to a module and all its
743 					 * symbols are in its kmap. Mark it as
744 					 * loaded.
745 					 */
746 					dso__set_loaded(curr_map->dso,
747 							curr_map->type);
748 				}
749 
750 				curr_map = map_groups__find_by_name(kmaps,
751 							map->type, module);
752 				if (curr_map == NULL) {
753 					pr_debug("%s/proc/{kallsyms,modules} "
754 					         "inconsistency while looking "
755 						 "for \"%s\" module!\n",
756 						 machine->root_dir, module);
757 					curr_map = map;
758 					goto discard_symbol;
759 				}
760 
761 				if (curr_map->dso->loaded &&
762 				    !machine__is_default_guest(machine))
763 					goto discard_symbol;
764 			}
765 			/*
766 			 * So that we look just like we get from .ko files,
767 			 * i.e. not prelinked, relative to map->start.
768 			 */
769 			pos->start = curr_map->map_ip(curr_map, pos->start);
770 			pos->end   = curr_map->map_ip(curr_map, pos->end);
771 		} else if (curr_map != map) {
772 			char dso_name[PATH_MAX];
773 			struct dso *ndso;
774 
775 			if (delta) {
776 				/* Kernel was relocated at boot time */
777 				pos->start -= delta;
778 				pos->end -= delta;
779 			}
780 
781 			if (count == 0) {
782 				curr_map = map;
783 				goto filter_symbol;
784 			}
785 
786 			if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
787 				snprintf(dso_name, sizeof(dso_name),
788 					"[guest.kernel].%d",
789 					kernel_range++);
790 			else
791 				snprintf(dso_name, sizeof(dso_name),
792 					"[kernel].%d",
793 					kernel_range++);
794 
795 			ndso = dso__new(dso_name);
796 			if (ndso == NULL)
797 				return -1;
798 
799 			ndso->kernel = dso->kernel;
800 
801 			curr_map = map__new2(pos->start, ndso, map->type);
802 			if (curr_map == NULL) {
803 				dso__put(ndso);
804 				return -1;
805 			}
806 
807 			curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
808 			map_groups__insert(kmaps, curr_map);
809 			++kernel_range;
810 		} else if (delta) {
811 			/* Kernel was relocated at boot time */
812 			pos->start -= delta;
813 			pos->end -= delta;
814 		}
815 filter_symbol:
816 		if (filter && filter(curr_map, pos)) {
817 discard_symbol:		rb_erase(&pos->rb_node, root);
818 			symbol__delete(pos);
819 		} else {
820 			if (curr_map != map) {
821 				rb_erase(&pos->rb_node, root);
822 				symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
823 				++moved;
824 			} else
825 				++count;
826 		}
827 	}
828 
829 	if (curr_map != map &&
830 	    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
831 	    machine__is_default_guest(kmaps->machine)) {
832 		dso__set_loaded(curr_map->dso, curr_map->type);
833 	}
834 
835 	return count + moved;
836 }
837 
838 bool symbol__restricted_filename(const char *filename,
839 				 const char *restricted_filename)
840 {
841 	bool restricted = false;
842 
843 	if (symbol_conf.kptr_restrict) {
844 		char *r = realpath(filename, NULL);
845 
846 		if (r != NULL) {
847 			restricted = strcmp(r, restricted_filename) == 0;
848 			free(r);
849 			return restricted;
850 		}
851 	}
852 
853 	return restricted;
854 }
855 
856 struct module_info {
857 	struct rb_node rb_node;
858 	char *name;
859 	u64 start;
860 };
861 
862 static void add_module(struct module_info *mi, struct rb_root *modules)
863 {
864 	struct rb_node **p = &modules->rb_node;
865 	struct rb_node *parent = NULL;
866 	struct module_info *m;
867 
868 	while (*p != NULL) {
869 		parent = *p;
870 		m = rb_entry(parent, struct module_info, rb_node);
871 		if (strcmp(mi->name, m->name) < 0)
872 			p = &(*p)->rb_left;
873 		else
874 			p = &(*p)->rb_right;
875 	}
876 	rb_link_node(&mi->rb_node, parent, p);
877 	rb_insert_color(&mi->rb_node, modules);
878 }
879 
880 static void delete_modules(struct rb_root *modules)
881 {
882 	struct module_info *mi;
883 	struct rb_node *next = rb_first(modules);
884 
885 	while (next) {
886 		mi = rb_entry(next, struct module_info, rb_node);
887 		next = rb_next(&mi->rb_node);
888 		rb_erase(&mi->rb_node, modules);
889 		zfree(&mi->name);
890 		free(mi);
891 	}
892 }
893 
894 static struct module_info *find_module(const char *name,
895 				       struct rb_root *modules)
896 {
897 	struct rb_node *n = modules->rb_node;
898 
899 	while (n) {
900 		struct module_info *m;
901 		int cmp;
902 
903 		m = rb_entry(n, struct module_info, rb_node);
904 		cmp = strcmp(name, m->name);
905 		if (cmp < 0)
906 			n = n->rb_left;
907 		else if (cmp > 0)
908 			n = n->rb_right;
909 		else
910 			return m;
911 	}
912 
913 	return NULL;
914 }
915 
916 static int __read_proc_modules(void *arg, const char *name, u64 start)
917 {
918 	struct rb_root *modules = arg;
919 	struct module_info *mi;
920 
921 	mi = zalloc(sizeof(struct module_info));
922 	if (!mi)
923 		return -ENOMEM;
924 
925 	mi->name = strdup(name);
926 	mi->start = start;
927 
928 	if (!mi->name) {
929 		free(mi);
930 		return -ENOMEM;
931 	}
932 
933 	add_module(mi, modules);
934 
935 	return 0;
936 }
937 
938 static int read_proc_modules(const char *filename, struct rb_root *modules)
939 {
940 	if (symbol__restricted_filename(filename, "/proc/modules"))
941 		return -1;
942 
943 	if (modules__parse(filename, modules, __read_proc_modules)) {
944 		delete_modules(modules);
945 		return -1;
946 	}
947 
948 	return 0;
949 }
950 
951 int compare_proc_modules(const char *from, const char *to)
952 {
953 	struct rb_root from_modules = RB_ROOT;
954 	struct rb_root to_modules = RB_ROOT;
955 	struct rb_node *from_node, *to_node;
956 	struct module_info *from_m, *to_m;
957 	int ret = -1;
958 
959 	if (read_proc_modules(from, &from_modules))
960 		return -1;
961 
962 	if (read_proc_modules(to, &to_modules))
963 		goto out_delete_from;
964 
965 	from_node = rb_first(&from_modules);
966 	to_node = rb_first(&to_modules);
967 	while (from_node) {
968 		if (!to_node)
969 			break;
970 
971 		from_m = rb_entry(from_node, struct module_info, rb_node);
972 		to_m = rb_entry(to_node, struct module_info, rb_node);
973 
974 		if (from_m->start != to_m->start ||
975 		    strcmp(from_m->name, to_m->name))
976 			break;
977 
978 		from_node = rb_next(from_node);
979 		to_node = rb_next(to_node);
980 	}
981 
982 	if (!from_node && !to_node)
983 		ret = 0;
984 
985 	delete_modules(&to_modules);
986 out_delete_from:
987 	delete_modules(&from_modules);
988 
989 	return ret;
990 }
991 
992 static int do_validate_kcore_modules(const char *filename, struct map *map,
993 				  struct map_groups *kmaps)
994 {
995 	struct rb_root modules = RB_ROOT;
996 	struct map *old_map;
997 	int err;
998 
999 	err = read_proc_modules(filename, &modules);
1000 	if (err)
1001 		return err;
1002 
1003 	old_map = map_groups__first(kmaps, map->type);
1004 	while (old_map) {
1005 		struct map *next = map_groups__next(old_map);
1006 		struct module_info *mi;
1007 
1008 		if (old_map == map || old_map->start == map->start) {
1009 			/* The kernel map */
1010 			old_map = next;
1011 			continue;
1012 		}
1013 
1014 		/* Module must be in memory at the same address */
1015 		mi = find_module(old_map->dso->short_name, &modules);
1016 		if (!mi || mi->start != old_map->start) {
1017 			err = -EINVAL;
1018 			goto out;
1019 		}
1020 
1021 		old_map = next;
1022 	}
1023 out:
1024 	delete_modules(&modules);
1025 	return err;
1026 }
1027 
1028 /*
1029  * If kallsyms is referenced by name then we look for filename in the same
1030  * directory.
1031  */
1032 static bool filename_from_kallsyms_filename(char *filename,
1033 					    const char *base_name,
1034 					    const char *kallsyms_filename)
1035 {
1036 	char *name;
1037 
1038 	strcpy(filename, kallsyms_filename);
1039 	name = strrchr(filename, '/');
1040 	if (!name)
1041 		return false;
1042 
1043 	name += 1;
1044 
1045 	if (!strcmp(name, "kallsyms")) {
1046 		strcpy(name, base_name);
1047 		return true;
1048 	}
1049 
1050 	return false;
1051 }
1052 
1053 static int validate_kcore_modules(const char *kallsyms_filename,
1054 				  struct map *map)
1055 {
1056 	struct map_groups *kmaps = map__kmaps(map);
1057 	char modules_filename[PATH_MAX];
1058 
1059 	if (!kmaps)
1060 		return -EINVAL;
1061 
1062 	if (!filename_from_kallsyms_filename(modules_filename, "modules",
1063 					     kallsyms_filename))
1064 		return -EINVAL;
1065 
1066 	if (do_validate_kcore_modules(modules_filename, map, kmaps))
1067 		return -EINVAL;
1068 
1069 	return 0;
1070 }
1071 
1072 static int validate_kcore_addresses(const char *kallsyms_filename,
1073 				    struct map *map)
1074 {
1075 	struct kmap *kmap = map__kmap(map);
1076 
1077 	if (!kmap)
1078 		return -EINVAL;
1079 
1080 	if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
1081 		u64 start;
1082 
1083 		start = kallsyms__get_function_start(kallsyms_filename,
1084 						     kmap->ref_reloc_sym->name);
1085 		if (start != kmap->ref_reloc_sym->addr)
1086 			return -EINVAL;
1087 	}
1088 
1089 	return validate_kcore_modules(kallsyms_filename, map);
1090 }
1091 
1092 struct kcore_mapfn_data {
1093 	struct dso *dso;
1094 	enum map_type type;
1095 	struct list_head maps;
1096 };
1097 
1098 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1099 {
1100 	struct kcore_mapfn_data *md = data;
1101 	struct map *map;
1102 
1103 	map = map__new2(start, md->dso, md->type);
1104 	if (map == NULL)
1105 		return -ENOMEM;
1106 
1107 	map->end = map->start + len;
1108 	map->pgoff = pgoff;
1109 
1110 	list_add(&map->node, &md->maps);
1111 
1112 	return 0;
1113 }
1114 
1115 static int dso__load_kcore(struct dso *dso, struct map *map,
1116 			   const char *kallsyms_filename)
1117 {
1118 	struct map_groups *kmaps = map__kmaps(map);
1119 	struct machine *machine;
1120 	struct kcore_mapfn_data md;
1121 	struct map *old_map, *new_map, *replacement_map = NULL;
1122 	bool is_64_bit;
1123 	int err, fd;
1124 	char kcore_filename[PATH_MAX];
1125 	struct symbol *sym;
1126 
1127 	if (!kmaps)
1128 		return -EINVAL;
1129 
1130 	machine = kmaps->machine;
1131 
1132 	/* This function requires that the map is the kernel map */
1133 	if (map != machine->vmlinux_maps[map->type])
1134 		return -EINVAL;
1135 
1136 	if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1137 					     kallsyms_filename))
1138 		return -EINVAL;
1139 
1140 	/* Modules and kernel must be present at their original addresses */
1141 	if (validate_kcore_addresses(kallsyms_filename, map))
1142 		return -EINVAL;
1143 
1144 	md.dso = dso;
1145 	md.type = map->type;
1146 	INIT_LIST_HEAD(&md.maps);
1147 
1148 	fd = open(kcore_filename, O_RDONLY);
1149 	if (fd < 0) {
1150 		pr_debug("Failed to open %s. Note /proc/kcore requires CAP_SYS_RAWIO capability to access.\n",
1151 			 kcore_filename);
1152 		return -EINVAL;
1153 	}
1154 
1155 	/* Read new maps into temporary lists */
1156 	err = file__read_maps(fd, md.type == MAP__FUNCTION, kcore_mapfn, &md,
1157 			      &is_64_bit);
1158 	if (err)
1159 		goto out_err;
1160 	dso->is_64_bit = is_64_bit;
1161 
1162 	if (list_empty(&md.maps)) {
1163 		err = -EINVAL;
1164 		goto out_err;
1165 	}
1166 
1167 	/* Remove old maps */
1168 	old_map = map_groups__first(kmaps, map->type);
1169 	while (old_map) {
1170 		struct map *next = map_groups__next(old_map);
1171 
1172 		if (old_map != map)
1173 			map_groups__remove(kmaps, old_map);
1174 		old_map = next;
1175 	}
1176 
1177 	/* Find the kernel map using the first symbol */
1178 	sym = dso__first_symbol(dso, map->type);
1179 	list_for_each_entry(new_map, &md.maps, node) {
1180 		if (sym && sym->start >= new_map->start &&
1181 		    sym->start < new_map->end) {
1182 			replacement_map = new_map;
1183 			break;
1184 		}
1185 	}
1186 
1187 	if (!replacement_map)
1188 		replacement_map = list_entry(md.maps.next, struct map, node);
1189 
1190 	/* Add new maps */
1191 	while (!list_empty(&md.maps)) {
1192 		new_map = list_entry(md.maps.next, struct map, node);
1193 		list_del_init(&new_map->node);
1194 		if (new_map == replacement_map) {
1195 			map->start	= new_map->start;
1196 			map->end	= new_map->end;
1197 			map->pgoff	= new_map->pgoff;
1198 			map->map_ip	= new_map->map_ip;
1199 			map->unmap_ip	= new_map->unmap_ip;
1200 			/* Ensure maps are correctly ordered */
1201 			map__get(map);
1202 			map_groups__remove(kmaps, map);
1203 			map_groups__insert(kmaps, map);
1204 			map__put(map);
1205 		} else {
1206 			map_groups__insert(kmaps, new_map);
1207 		}
1208 
1209 		map__put(new_map);
1210 	}
1211 
1212 	/*
1213 	 * Set the data type and long name so that kcore can be read via
1214 	 * dso__data_read_addr().
1215 	 */
1216 	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1217 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
1218 	else
1219 		dso->binary_type = DSO_BINARY_TYPE__KCORE;
1220 	dso__set_long_name(dso, strdup(kcore_filename), true);
1221 
1222 	close(fd);
1223 
1224 	if (map->type == MAP__FUNCTION)
1225 		pr_debug("Using %s for kernel object code\n", kcore_filename);
1226 	else
1227 		pr_debug("Using %s for kernel data\n", kcore_filename);
1228 
1229 	return 0;
1230 
1231 out_err:
1232 	while (!list_empty(&md.maps)) {
1233 		map = list_entry(md.maps.next, struct map, node);
1234 		list_del_init(&map->node);
1235 		map__put(map);
1236 	}
1237 	close(fd);
1238 	return -EINVAL;
1239 }
1240 
1241 /*
1242  * If the kernel is relocated at boot time, kallsyms won't match.  Compute the
1243  * delta based on the relocation reference symbol.
1244  */
1245 static int kallsyms__delta(struct map *map, const char *filename, u64 *delta)
1246 {
1247 	struct kmap *kmap = map__kmap(map);
1248 	u64 addr;
1249 
1250 	if (!kmap)
1251 		return -1;
1252 
1253 	if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1254 		return 0;
1255 
1256 	addr = kallsyms__get_function_start(filename,
1257 					    kmap->ref_reloc_sym->name);
1258 	if (!addr)
1259 		return -1;
1260 
1261 	*delta = addr - kmap->ref_reloc_sym->addr;
1262 	return 0;
1263 }
1264 
1265 int dso__load_kallsyms(struct dso *dso, const char *filename,
1266 		       struct map *map, symbol_filter_t filter)
1267 {
1268 	u64 delta = 0;
1269 
1270 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1271 		return -1;
1272 
1273 	if (dso__load_all_kallsyms(dso, filename, map) < 0)
1274 		return -1;
1275 
1276 	if (kallsyms__delta(map, filename, &delta))
1277 		return -1;
1278 
1279 	symbols__fixup_duplicate(&dso->symbols[map->type]);
1280 	symbols__fixup_end(&dso->symbols[map->type]);
1281 
1282 	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1283 		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1284 	else
1285 		dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1286 
1287 	if (!dso__load_kcore(dso, map, filename))
1288 		return dso__split_kallsyms_for_kcore(dso, map, filter);
1289 	else
1290 		return dso__split_kallsyms(dso, map, delta, filter);
1291 }
1292 
1293 static int dso__load_perf_map(struct dso *dso, struct map *map,
1294 			      symbol_filter_t filter)
1295 {
1296 	char *line = NULL;
1297 	size_t n;
1298 	FILE *file;
1299 	int nr_syms = 0;
1300 
1301 	file = fopen(dso->long_name, "r");
1302 	if (file == NULL)
1303 		goto out_failure;
1304 
1305 	while (!feof(file)) {
1306 		u64 start, size;
1307 		struct symbol *sym;
1308 		int line_len, len;
1309 
1310 		line_len = getline(&line, &n, file);
1311 		if (line_len < 0)
1312 			break;
1313 
1314 		if (!line)
1315 			goto out_failure;
1316 
1317 		line[--line_len] = '\0'; /* \n */
1318 
1319 		len = hex2u64(line, &start);
1320 
1321 		len++;
1322 		if (len + 2 >= line_len)
1323 			continue;
1324 
1325 		len += hex2u64(line + len, &size);
1326 
1327 		len++;
1328 		if (len + 2 >= line_len)
1329 			continue;
1330 
1331 		sym = symbol__new(start, size, STB_GLOBAL, line + len);
1332 
1333 		if (sym == NULL)
1334 			goto out_delete_line;
1335 
1336 		if (filter && filter(map, sym))
1337 			symbol__delete(sym);
1338 		else {
1339 			symbols__insert(&dso->symbols[map->type], sym);
1340 			nr_syms++;
1341 		}
1342 	}
1343 
1344 	free(line);
1345 	fclose(file);
1346 
1347 	return nr_syms;
1348 
1349 out_delete_line:
1350 	free(line);
1351 out_failure:
1352 	return -1;
1353 }
1354 
1355 static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
1356 					   enum dso_binary_type type)
1357 {
1358 	switch (type) {
1359 	case DSO_BINARY_TYPE__JAVA_JIT:
1360 	case DSO_BINARY_TYPE__DEBUGLINK:
1361 	case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
1362 	case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
1363 	case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
1364 	case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
1365 	case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
1366 		return !kmod && dso->kernel == DSO_TYPE_USER;
1367 
1368 	case DSO_BINARY_TYPE__KALLSYMS:
1369 	case DSO_BINARY_TYPE__VMLINUX:
1370 	case DSO_BINARY_TYPE__KCORE:
1371 		return dso->kernel == DSO_TYPE_KERNEL;
1372 
1373 	case DSO_BINARY_TYPE__GUEST_KALLSYMS:
1374 	case DSO_BINARY_TYPE__GUEST_VMLINUX:
1375 	case DSO_BINARY_TYPE__GUEST_KCORE:
1376 		return dso->kernel == DSO_TYPE_GUEST_KERNEL;
1377 
1378 	case DSO_BINARY_TYPE__GUEST_KMODULE:
1379 	case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
1380 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
1381 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
1382 		/*
1383 		 * kernel modules know their symtab type - it's set when
1384 		 * creating a module dso in machine__findnew_module_map().
1385 		 */
1386 		return kmod && dso->symtab_type == type;
1387 
1388 	case DSO_BINARY_TYPE__BUILD_ID_CACHE:
1389 		return true;
1390 
1391 	case DSO_BINARY_TYPE__NOT_FOUND:
1392 	default:
1393 		return false;
1394 	}
1395 }
1396 
1397 int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
1398 {
1399 	char *name;
1400 	int ret = -1;
1401 	u_int i;
1402 	struct machine *machine;
1403 	char *root_dir = (char *) "";
1404 	int ss_pos = 0;
1405 	struct symsrc ss_[2];
1406 	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1407 	bool kmod;
1408 	unsigned char build_id[BUILD_ID_SIZE];
1409 
1410 	pthread_mutex_lock(&dso->lock);
1411 
1412 	/* check again under the dso->lock */
1413 	if (dso__loaded(dso, map->type)) {
1414 		ret = 1;
1415 		goto out;
1416 	}
1417 
1418 	if (dso->kernel) {
1419 		if (dso->kernel == DSO_TYPE_KERNEL)
1420 			ret = dso__load_kernel_sym(dso, map, filter);
1421 		else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1422 			ret = dso__load_guest_kernel_sym(dso, map, filter);
1423 
1424 		goto out;
1425 	}
1426 
1427 	if (map->groups && map->groups->machine)
1428 		machine = map->groups->machine;
1429 	else
1430 		machine = NULL;
1431 
1432 	dso->adjust_symbols = 0;
1433 
1434 	if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
1435 		struct stat st;
1436 
1437 		if (lstat(dso->name, &st) < 0)
1438 			goto out;
1439 
1440 		if (!symbol_conf.force && st.st_uid && (st.st_uid != geteuid())) {
1441 			pr_warning("File %s not owned by current user or root, "
1442 				   "ignoring it (use -f to override).\n", dso->name);
1443 			goto out;
1444 		}
1445 
1446 		ret = dso__load_perf_map(dso, map, filter);
1447 		dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1448 					     DSO_BINARY_TYPE__NOT_FOUND;
1449 		goto out;
1450 	}
1451 
1452 	if (machine)
1453 		root_dir = machine->root_dir;
1454 
1455 	name = malloc(PATH_MAX);
1456 	if (!name)
1457 		goto out;
1458 
1459 	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1460 		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
1461 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
1462 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
1463 
1464 
1465 	/*
1466 	 * Read the build id if possible. This is required for
1467 	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
1468 	 */
1469 	if (filename__read_build_id(dso->long_name, build_id, BUILD_ID_SIZE) > 0)
1470 		dso__set_build_id(dso, build_id);
1471 
1472 	/*
1473 	 * Iterate over candidate debug images.
1474 	 * Keep track of "interesting" ones (those which have a symtab, dynsym,
1475 	 * and/or opd section) for processing.
1476 	 */
1477 	for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1478 		struct symsrc *ss = &ss_[ss_pos];
1479 		bool next_slot = false;
1480 
1481 		enum dso_binary_type symtab_type = binary_type_symtab[i];
1482 
1483 		if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
1484 			continue;
1485 
1486 		if (dso__read_binary_type_filename(dso, symtab_type,
1487 						   root_dir, name, PATH_MAX))
1488 			continue;
1489 
1490 		/* Name is now the name of the next image to try */
1491 		if (symsrc__init(ss, dso, name, symtab_type) < 0)
1492 			continue;
1493 
1494 		if (!syms_ss && symsrc__has_symtab(ss)) {
1495 			syms_ss = ss;
1496 			next_slot = true;
1497 			if (!dso->symsrc_filename)
1498 				dso->symsrc_filename = strdup(name);
1499 		}
1500 
1501 		if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1502 			runtime_ss = ss;
1503 			next_slot = true;
1504 		}
1505 
1506 		if (next_slot) {
1507 			ss_pos++;
1508 
1509 			if (syms_ss && runtime_ss)
1510 				break;
1511 		} else {
1512 			symsrc__destroy(ss);
1513 		}
1514 
1515 	}
1516 
1517 	if (!runtime_ss && !syms_ss)
1518 		goto out_free;
1519 
1520 	if (runtime_ss && !syms_ss) {
1521 		syms_ss = runtime_ss;
1522 	}
1523 
1524 	/* We'll have to hope for the best */
1525 	if (!runtime_ss && syms_ss)
1526 		runtime_ss = syms_ss;
1527 
1528 	if (syms_ss)
1529 		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, kmod);
1530 	else
1531 		ret = -1;
1532 
1533 	if (ret > 0) {
1534 		int nr_plt;
1535 
1536 		nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss, map, filter);
1537 		if (nr_plt > 0)
1538 			ret += nr_plt;
1539 	}
1540 
1541 	for (; ss_pos > 0; ss_pos--)
1542 		symsrc__destroy(&ss_[ss_pos - 1]);
1543 out_free:
1544 	free(name);
1545 	if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1546 		ret = 0;
1547 out:
1548 	dso__set_loaded(dso, map->type);
1549 	pthread_mutex_unlock(&dso->lock);
1550 
1551 	return ret;
1552 }
1553 
1554 struct map *map_groups__find_by_name(struct map_groups *mg,
1555 				     enum map_type type, const char *name)
1556 {
1557 	struct maps *maps = &mg->maps[type];
1558 	struct map *map;
1559 
1560 	pthread_rwlock_rdlock(&maps->lock);
1561 
1562 	for (map = maps__first(maps); map; map = map__next(map)) {
1563 		if (map->dso && strcmp(map->dso->short_name, name) == 0)
1564 			goto out_unlock;
1565 	}
1566 
1567 	map = NULL;
1568 
1569 out_unlock:
1570 	pthread_rwlock_unlock(&maps->lock);
1571 	return map;
1572 }
1573 
1574 int dso__load_vmlinux(struct dso *dso, struct map *map,
1575 		      const char *vmlinux, bool vmlinux_allocated,
1576 		      symbol_filter_t filter)
1577 {
1578 	int err = -1;
1579 	struct symsrc ss;
1580 	char symfs_vmlinux[PATH_MAX];
1581 	enum dso_binary_type symtab_type;
1582 
1583 	if (vmlinux[0] == '/')
1584 		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
1585 	else
1586 		symbol__join_symfs(symfs_vmlinux, vmlinux);
1587 
1588 	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1589 		symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1590 	else
1591 		symtab_type = DSO_BINARY_TYPE__VMLINUX;
1592 
1593 	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
1594 		return -1;
1595 
1596 	err = dso__load_sym(dso, map, &ss, &ss, filter, 0);
1597 	symsrc__destroy(&ss);
1598 
1599 	if (err > 0) {
1600 		if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1601 			dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1602 		else
1603 			dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
1604 		dso__set_long_name(dso, vmlinux, vmlinux_allocated);
1605 		dso__set_loaded(dso, map->type);
1606 		pr_debug("Using %s for symbols\n", symfs_vmlinux);
1607 	}
1608 
1609 	return err;
1610 }
1611 
1612 int dso__load_vmlinux_path(struct dso *dso, struct map *map,
1613 			   symbol_filter_t filter)
1614 {
1615 	int i, err = 0;
1616 	char *filename = NULL;
1617 
1618 	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
1619 		 vmlinux_path__nr_entries + 1);
1620 
1621 	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
1622 		err = dso__load_vmlinux(dso, map, vmlinux_path[i], false, filter);
1623 		if (err > 0)
1624 			goto out;
1625 	}
1626 
1627 	if (!symbol_conf.ignore_vmlinux_buildid)
1628 		filename = dso__build_id_filename(dso, NULL, 0);
1629 	if (filename != NULL) {
1630 		err = dso__load_vmlinux(dso, map, filename, true, filter);
1631 		if (err > 0)
1632 			goto out;
1633 		free(filename);
1634 	}
1635 out:
1636 	return err;
1637 }
1638 
1639 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
1640 {
1641 	char kallsyms_filename[PATH_MAX];
1642 	struct dirent *dent;
1643 	int ret = -1;
1644 	DIR *d;
1645 
1646 	d = opendir(dir);
1647 	if (!d)
1648 		return -1;
1649 
1650 	while (1) {
1651 		dent = readdir(d);
1652 		if (!dent)
1653 			break;
1654 		if (dent->d_type != DT_DIR)
1655 			continue;
1656 		scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
1657 			  "%s/%s/kallsyms", dir, dent->d_name);
1658 		if (!validate_kcore_addresses(kallsyms_filename, map)) {
1659 			strlcpy(dir, kallsyms_filename, dir_sz);
1660 			ret = 0;
1661 			break;
1662 		}
1663 	}
1664 
1665 	closedir(d);
1666 
1667 	return ret;
1668 }
1669 
1670 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
1671 {
1672 	u8 host_build_id[BUILD_ID_SIZE];
1673 	char sbuild_id[BUILD_ID_SIZE * 2 + 1];
1674 	bool is_host = false;
1675 	char path[PATH_MAX];
1676 
1677 	if (!dso->has_build_id) {
1678 		/*
1679 		 * Last resort, if we don't have a build-id and couldn't find
1680 		 * any vmlinux file, try the running kernel kallsyms table.
1681 		 */
1682 		goto proc_kallsyms;
1683 	}
1684 
1685 	if (sysfs__read_build_id("/sys/kernel/notes", host_build_id,
1686 				 sizeof(host_build_id)) == 0)
1687 		is_host = dso__build_id_equal(dso, host_build_id);
1688 
1689 	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
1690 
1691 	scnprintf(path, sizeof(path), "%s/[kernel.kcore]/%s", buildid_dir,
1692 		  sbuild_id);
1693 
1694 	/* Use /proc/kallsyms if possible */
1695 	if (is_host) {
1696 		DIR *d;
1697 		int fd;
1698 
1699 		/* If no cached kcore go with /proc/kallsyms */
1700 		d = opendir(path);
1701 		if (!d)
1702 			goto proc_kallsyms;
1703 		closedir(d);
1704 
1705 		/*
1706 		 * Do not check the build-id cache, until we know we cannot use
1707 		 * /proc/kcore.
1708 		 */
1709 		fd = open("/proc/kcore", O_RDONLY);
1710 		if (fd != -1) {
1711 			close(fd);
1712 			/* If module maps match go with /proc/kallsyms */
1713 			if (!validate_kcore_addresses("/proc/kallsyms", map))
1714 				goto proc_kallsyms;
1715 		}
1716 
1717 		/* Find kallsyms in build-id cache with kcore */
1718 		if (!find_matching_kcore(map, path, sizeof(path)))
1719 			return strdup(path);
1720 
1721 		goto proc_kallsyms;
1722 	}
1723 
1724 	/* Find kallsyms in build-id cache with kcore */
1725 	if (!find_matching_kcore(map, path, sizeof(path)))
1726 		return strdup(path);
1727 
1728 	scnprintf(path, sizeof(path), "%s/[kernel.kallsyms]/%s",
1729 		  buildid_dir, sbuild_id);
1730 
1731 	if (access(path, F_OK)) {
1732 		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
1733 		       sbuild_id);
1734 		return NULL;
1735 	}
1736 
1737 	return strdup(path);
1738 
1739 proc_kallsyms:
1740 	return strdup("/proc/kallsyms");
1741 }
1742 
1743 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
1744 				symbol_filter_t filter)
1745 {
1746 	int err;
1747 	const char *kallsyms_filename = NULL;
1748 	char *kallsyms_allocated_filename = NULL;
1749 	/*
1750 	 * Step 1: if the user specified a kallsyms or vmlinux filename, use
1751 	 * it and only it, reporting errors to the user if it cannot be used.
1752 	 *
1753 	 * For instance, try to analyse an ARM perf.data file _without_ a
1754 	 * build-id, or if the user specifies the wrong path to the right
1755 	 * vmlinux file, obviously we can't fallback to another vmlinux (a
1756 	 * x86_86 one, on the machine where analysis is being performed, say),
1757 	 * or worse, /proc/kallsyms.
1758 	 *
1759 	 * If the specified file _has_ a build-id and there is a build-id
1760 	 * section in the perf.data file, we will still do the expected
1761 	 * validation in dso__load_vmlinux and will bail out if they don't
1762 	 * match.
1763 	 */
1764 	if (symbol_conf.kallsyms_name != NULL) {
1765 		kallsyms_filename = symbol_conf.kallsyms_name;
1766 		goto do_kallsyms;
1767 	}
1768 
1769 	if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
1770 		return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name,
1771 					 false, filter);
1772 	}
1773 
1774 	if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
1775 		err = dso__load_vmlinux_path(dso, map, filter);
1776 		if (err > 0)
1777 			return err;
1778 	}
1779 
1780 	/* do not try local files if a symfs was given */
1781 	if (symbol_conf.symfs[0] != 0)
1782 		return -1;
1783 
1784 	kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
1785 	if (!kallsyms_allocated_filename)
1786 		return -1;
1787 
1788 	kallsyms_filename = kallsyms_allocated_filename;
1789 
1790 do_kallsyms:
1791 	err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1792 	if (err > 0)
1793 		pr_debug("Using %s for symbols\n", kallsyms_filename);
1794 	free(kallsyms_allocated_filename);
1795 
1796 	if (err > 0 && !dso__is_kcore(dso)) {
1797 		dso->binary_type = DSO_BINARY_TYPE__KALLSYMS;
1798 		dso__set_long_name(dso, "[kernel.kallsyms]", false);
1799 		map__fixup_start(map);
1800 		map__fixup_end(map);
1801 	}
1802 
1803 	return err;
1804 }
1805 
1806 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
1807 				      symbol_filter_t filter)
1808 {
1809 	int err;
1810 	const char *kallsyms_filename = NULL;
1811 	struct machine *machine;
1812 	char path[PATH_MAX];
1813 
1814 	if (!map->groups) {
1815 		pr_debug("Guest kernel map hasn't the point to groups\n");
1816 		return -1;
1817 	}
1818 	machine = map->groups->machine;
1819 
1820 	if (machine__is_default_guest(machine)) {
1821 		/*
1822 		 * if the user specified a vmlinux filename, use it and only
1823 		 * it, reporting errors to the user if it cannot be used.
1824 		 * Or use file guest_kallsyms inputted by user on commandline
1825 		 */
1826 		if (symbol_conf.default_guest_vmlinux_name != NULL) {
1827 			err = dso__load_vmlinux(dso, map,
1828 						symbol_conf.default_guest_vmlinux_name,
1829 						false, filter);
1830 			return err;
1831 		}
1832 
1833 		kallsyms_filename = symbol_conf.default_guest_kallsyms;
1834 		if (!kallsyms_filename)
1835 			return -1;
1836 	} else {
1837 		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
1838 		kallsyms_filename = path;
1839 	}
1840 
1841 	err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1842 	if (err > 0)
1843 		pr_debug("Using %s for symbols\n", kallsyms_filename);
1844 	if (err > 0 && !dso__is_kcore(dso)) {
1845 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1846 		machine__mmap_name(machine, path, sizeof(path));
1847 		dso__set_long_name(dso, strdup(path), true);
1848 		map__fixup_start(map);
1849 		map__fixup_end(map);
1850 	}
1851 
1852 	return err;
1853 }
1854 
1855 static void vmlinux_path__exit(void)
1856 {
1857 	while (--vmlinux_path__nr_entries >= 0)
1858 		zfree(&vmlinux_path[vmlinux_path__nr_entries]);
1859 	vmlinux_path__nr_entries = 0;
1860 
1861 	zfree(&vmlinux_path);
1862 }
1863 
1864 static const char * const vmlinux_paths[] = {
1865 	"vmlinux",
1866 	"/boot/vmlinux"
1867 };
1868 
1869 static const char * const vmlinux_paths_upd[] = {
1870 	"/boot/vmlinux-%s",
1871 	"/usr/lib/debug/boot/vmlinux-%s",
1872 	"/lib/modules/%s/build/vmlinux",
1873 	"/usr/lib/debug/lib/modules/%s/vmlinux",
1874 	"/usr/lib/debug/boot/vmlinux-%s.debug"
1875 };
1876 
1877 static int vmlinux_path__add(const char *new_entry)
1878 {
1879 	vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
1880 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1881 		return -1;
1882 	++vmlinux_path__nr_entries;
1883 
1884 	return 0;
1885 }
1886 
1887 static int vmlinux_path__init(struct perf_env *env)
1888 {
1889 	struct utsname uts;
1890 	char bf[PATH_MAX];
1891 	char *kernel_version;
1892 	unsigned int i;
1893 
1894 	vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
1895 			      ARRAY_SIZE(vmlinux_paths_upd)));
1896 	if (vmlinux_path == NULL)
1897 		return -1;
1898 
1899 	for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
1900 		if (vmlinux_path__add(vmlinux_paths[i]) < 0)
1901 			goto out_fail;
1902 
1903 	/* only try kernel version if no symfs was given */
1904 	if (symbol_conf.symfs[0] != 0)
1905 		return 0;
1906 
1907 	if (env) {
1908 		kernel_version = env->os_release;
1909 	} else {
1910 		if (uname(&uts) < 0)
1911 			goto out_fail;
1912 
1913 		kernel_version = uts.release;
1914 	}
1915 
1916 	for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
1917 		snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
1918 		if (vmlinux_path__add(bf) < 0)
1919 			goto out_fail;
1920 	}
1921 
1922 	return 0;
1923 
1924 out_fail:
1925 	vmlinux_path__exit();
1926 	return -1;
1927 }
1928 
1929 int setup_list(struct strlist **list, const char *list_str,
1930 		      const char *list_name)
1931 {
1932 	if (list_str == NULL)
1933 		return 0;
1934 
1935 	*list = strlist__new(list_str, NULL);
1936 	if (!*list) {
1937 		pr_err("problems parsing %s list\n", list_name);
1938 		return -1;
1939 	}
1940 
1941 	symbol_conf.has_filter = true;
1942 	return 0;
1943 }
1944 
1945 int setup_intlist(struct intlist **list, const char *list_str,
1946 		  const char *list_name)
1947 {
1948 	if (list_str == NULL)
1949 		return 0;
1950 
1951 	*list = intlist__new(list_str);
1952 	if (!*list) {
1953 		pr_err("problems parsing %s list\n", list_name);
1954 		return -1;
1955 	}
1956 	return 0;
1957 }
1958 
1959 static bool symbol__read_kptr_restrict(void)
1960 {
1961 	bool value = false;
1962 
1963 	if (geteuid() != 0) {
1964 		FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
1965 		if (fp != NULL) {
1966 			char line[8];
1967 
1968 			if (fgets(line, sizeof(line), fp) != NULL)
1969 				value = atoi(line) != 0;
1970 
1971 			fclose(fp);
1972 		}
1973 	}
1974 
1975 	return value;
1976 }
1977 
1978 int symbol__init(struct perf_env *env)
1979 {
1980 	const char *symfs;
1981 
1982 	if (symbol_conf.initialized)
1983 		return 0;
1984 
1985 	symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
1986 
1987 	symbol__elf_init();
1988 
1989 	if (symbol_conf.sort_by_name)
1990 		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
1991 					  sizeof(struct symbol));
1992 
1993 	if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
1994 		return -1;
1995 
1996 	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
1997 		pr_err("'.' is the only non valid --field-separator argument\n");
1998 		return -1;
1999 	}
2000 
2001 	if (setup_list(&symbol_conf.dso_list,
2002 		       symbol_conf.dso_list_str, "dso") < 0)
2003 		return -1;
2004 
2005 	if (setup_list(&symbol_conf.comm_list,
2006 		       symbol_conf.comm_list_str, "comm") < 0)
2007 		goto out_free_dso_list;
2008 
2009 	if (setup_intlist(&symbol_conf.pid_list,
2010 		       symbol_conf.pid_list_str, "pid") < 0)
2011 		goto out_free_comm_list;
2012 
2013 	if (setup_intlist(&symbol_conf.tid_list,
2014 		       symbol_conf.tid_list_str, "tid") < 0)
2015 		goto out_free_pid_list;
2016 
2017 	if (setup_list(&symbol_conf.sym_list,
2018 		       symbol_conf.sym_list_str, "symbol") < 0)
2019 		goto out_free_tid_list;
2020 
2021 	/*
2022 	 * A path to symbols of "/" is identical to ""
2023 	 * reset here for simplicity.
2024 	 */
2025 	symfs = realpath(symbol_conf.symfs, NULL);
2026 	if (symfs == NULL)
2027 		symfs = symbol_conf.symfs;
2028 	if (strcmp(symfs, "/") == 0)
2029 		symbol_conf.symfs = "";
2030 	if (symfs != symbol_conf.symfs)
2031 		free((void *)symfs);
2032 
2033 	symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
2034 
2035 	symbol_conf.initialized = true;
2036 	return 0;
2037 
2038 out_free_tid_list:
2039 	intlist__delete(symbol_conf.tid_list);
2040 out_free_pid_list:
2041 	intlist__delete(symbol_conf.pid_list);
2042 out_free_comm_list:
2043 	strlist__delete(symbol_conf.comm_list);
2044 out_free_dso_list:
2045 	strlist__delete(symbol_conf.dso_list);
2046 	return -1;
2047 }
2048 
2049 void symbol__exit(void)
2050 {
2051 	if (!symbol_conf.initialized)
2052 		return;
2053 	strlist__delete(symbol_conf.sym_list);
2054 	strlist__delete(symbol_conf.dso_list);
2055 	strlist__delete(symbol_conf.comm_list);
2056 	intlist__delete(symbol_conf.tid_list);
2057 	intlist__delete(symbol_conf.pid_list);
2058 	vmlinux_path__exit();
2059 	symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2060 	symbol_conf.initialized = false;
2061 }
2062