xref: /linux/tools/perf/util/symbol.c (revision e9fb13bfec7e017130ddc5c1b5466340470f4900)
1 #define _GNU_SOURCE
2 #include <ctype.h>
3 #include <dirent.h>
4 #include <errno.h>
5 #include <libgen.h>
6 #include <stdlib.h>
7 #include <stdio.h>
8 #include <string.h>
9 #include <sys/types.h>
10 #include <sys/stat.h>
11 #include <sys/param.h>
12 #include <fcntl.h>
13 #include <unistd.h>
14 #include <inttypes.h>
15 #include "build-id.h"
16 #include "debug.h"
17 #include "symbol.h"
18 #include "strlist.h"
19 
20 #include <libelf.h>
21 #include <gelf.h>
22 #include <elf.h>
23 #include <limits.h>
24 #include <sys/utsname.h>
25 
26 #ifndef KSYM_NAME_LEN
27 #define KSYM_NAME_LEN 128
28 #endif
29 
30 #ifndef NT_GNU_BUILD_ID
31 #define NT_GNU_BUILD_ID 3
32 #endif
33 
34 static bool dso__build_id_equal(const struct dso *self, u8 *build_id);
35 static int elf_read_build_id(Elf *elf, void *bf, size_t size);
36 static void dsos__add(struct list_head *head, struct dso *dso);
37 static struct map *map__new2(u64 start, struct dso *dso, enum map_type type);
38 static int dso__load_kernel_sym(struct dso *self, struct map *map,
39 				symbol_filter_t filter);
40 static int dso__load_guest_kernel_sym(struct dso *self, struct map *map,
41 			symbol_filter_t filter);
42 static int vmlinux_path__nr_entries;
43 static char **vmlinux_path;
44 
45 struct symbol_conf symbol_conf = {
46 	.exclude_other	  = true,
47 	.use_modules	  = true,
48 	.try_vmlinux_path = true,
49 	.symfs            = "",
50 };
51 
52 int dso__name_len(const struct dso *self)
53 {
54 	if (verbose)
55 		return self->long_name_len;
56 
57 	return self->short_name_len;
58 }
59 
60 bool dso__loaded(const struct dso *self, enum map_type type)
61 {
62 	return self->loaded & (1 << type);
63 }
64 
65 bool dso__sorted_by_name(const struct dso *self, enum map_type type)
66 {
67 	return self->sorted_by_name & (1 << type);
68 }
69 
70 static void dso__set_sorted_by_name(struct dso *self, enum map_type type)
71 {
72 	self->sorted_by_name |= (1 << type);
73 }
74 
75 bool symbol_type__is_a(char symbol_type, enum map_type map_type)
76 {
77 	switch (map_type) {
78 	case MAP__FUNCTION:
79 		return symbol_type == 'T' || symbol_type == 'W';
80 	case MAP__VARIABLE:
81 		return symbol_type == 'D' || symbol_type == 'd';
82 	default:
83 		return false;
84 	}
85 }
86 
87 static void symbols__fixup_end(struct rb_root *self)
88 {
89 	struct rb_node *nd, *prevnd = rb_first(self);
90 	struct symbol *curr, *prev;
91 
92 	if (prevnd == NULL)
93 		return;
94 
95 	curr = rb_entry(prevnd, struct symbol, rb_node);
96 
97 	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
98 		prev = curr;
99 		curr = rb_entry(nd, struct symbol, rb_node);
100 
101 		if (prev->end == prev->start && prev->end != curr->start)
102 			prev->end = curr->start - 1;
103 	}
104 
105 	/* Last entry */
106 	if (curr->end == curr->start)
107 		curr->end = roundup(curr->start, 4096);
108 }
109 
110 static void __map_groups__fixup_end(struct map_groups *self, enum map_type type)
111 {
112 	struct map *prev, *curr;
113 	struct rb_node *nd, *prevnd = rb_first(&self->maps[type]);
114 
115 	if (prevnd == NULL)
116 		return;
117 
118 	curr = rb_entry(prevnd, struct map, rb_node);
119 
120 	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
121 		prev = curr;
122 		curr = rb_entry(nd, struct map, rb_node);
123 		prev->end = curr->start - 1;
124 	}
125 
126 	/*
127 	 * We still haven't the actual symbols, so guess the
128 	 * last map final address.
129 	 */
130 	curr->end = ~0ULL;
131 }
132 
133 static void map_groups__fixup_end(struct map_groups *self)
134 {
135 	int i;
136 	for (i = 0; i < MAP__NR_TYPES; ++i)
137 		__map_groups__fixup_end(self, i);
138 }
139 
140 static struct symbol *symbol__new(u64 start, u64 len, u8 binding,
141 				  const char *name)
142 {
143 	size_t namelen = strlen(name) + 1;
144 	struct symbol *self = calloc(1, (symbol_conf.priv_size +
145 					 sizeof(*self) + namelen));
146 	if (self == NULL)
147 		return NULL;
148 
149 	if (symbol_conf.priv_size)
150 		self = ((void *)self) + symbol_conf.priv_size;
151 
152 	self->start   = start;
153 	self->end     = len ? start + len - 1 : start;
154 	self->binding = binding;
155 	self->namelen = namelen - 1;
156 
157 	pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n", __func__, name, start, self->end);
158 
159 	memcpy(self->name, name, namelen);
160 
161 	return self;
162 }
163 
164 void symbol__delete(struct symbol *self)
165 {
166 	free(((void *)self) - symbol_conf.priv_size);
167 }
168 
169 static size_t symbol__fprintf(struct symbol *self, FILE *fp)
170 {
171 	return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %c %s\n",
172 		       self->start, self->end,
173 		       self->binding == STB_GLOBAL ? 'g' :
174 		       self->binding == STB_LOCAL  ? 'l' : 'w',
175 		       self->name);
176 }
177 
178 void dso__set_long_name(struct dso *self, char *name)
179 {
180 	if (name == NULL)
181 		return;
182 	self->long_name = name;
183 	self->long_name_len = strlen(name);
184 }
185 
186 static void dso__set_short_name(struct dso *self, const char *name)
187 {
188 	if (name == NULL)
189 		return;
190 	self->short_name = name;
191 	self->short_name_len = strlen(name);
192 }
193 
194 static void dso__set_basename(struct dso *self)
195 {
196 	dso__set_short_name(self, basename(self->long_name));
197 }
198 
199 struct dso *dso__new(const char *name)
200 {
201 	struct dso *self = calloc(1, sizeof(*self) + strlen(name) + 1);
202 
203 	if (self != NULL) {
204 		int i;
205 		strcpy(self->name, name);
206 		dso__set_long_name(self, self->name);
207 		dso__set_short_name(self, self->name);
208 		for (i = 0; i < MAP__NR_TYPES; ++i)
209 			self->symbols[i] = self->symbol_names[i] = RB_ROOT;
210 		self->symtab_type = SYMTAB__NOT_FOUND;
211 		self->loaded = 0;
212 		self->sorted_by_name = 0;
213 		self->has_build_id = 0;
214 		self->kernel = DSO_TYPE_USER;
215 		INIT_LIST_HEAD(&self->node);
216 	}
217 
218 	return self;
219 }
220 
221 static void symbols__delete(struct rb_root *self)
222 {
223 	struct symbol *pos;
224 	struct rb_node *next = rb_first(self);
225 
226 	while (next) {
227 		pos = rb_entry(next, struct symbol, rb_node);
228 		next = rb_next(&pos->rb_node);
229 		rb_erase(&pos->rb_node, self);
230 		symbol__delete(pos);
231 	}
232 }
233 
234 void dso__delete(struct dso *self)
235 {
236 	int i;
237 	for (i = 0; i < MAP__NR_TYPES; ++i)
238 		symbols__delete(&self->symbols[i]);
239 	if (self->sname_alloc)
240 		free((char *)self->short_name);
241 	if (self->lname_alloc)
242 		free(self->long_name);
243 	free(self);
244 }
245 
246 void dso__set_build_id(struct dso *self, void *build_id)
247 {
248 	memcpy(self->build_id, build_id, sizeof(self->build_id));
249 	self->has_build_id = 1;
250 }
251 
252 static void symbols__insert(struct rb_root *self, struct symbol *sym)
253 {
254 	struct rb_node **p = &self->rb_node;
255 	struct rb_node *parent = NULL;
256 	const u64 ip = sym->start;
257 	struct symbol *s;
258 
259 	while (*p != NULL) {
260 		parent = *p;
261 		s = rb_entry(parent, struct symbol, rb_node);
262 		if (ip < s->start)
263 			p = &(*p)->rb_left;
264 		else
265 			p = &(*p)->rb_right;
266 	}
267 	rb_link_node(&sym->rb_node, parent, p);
268 	rb_insert_color(&sym->rb_node, self);
269 }
270 
271 static struct symbol *symbols__find(struct rb_root *self, u64 ip)
272 {
273 	struct rb_node *n;
274 
275 	if (self == NULL)
276 		return NULL;
277 
278 	n = self->rb_node;
279 
280 	while (n) {
281 		struct symbol *s = rb_entry(n, struct symbol, rb_node);
282 
283 		if (ip < s->start)
284 			n = n->rb_left;
285 		else if (ip > s->end)
286 			n = n->rb_right;
287 		else
288 			return s;
289 	}
290 
291 	return NULL;
292 }
293 
294 struct symbol_name_rb_node {
295 	struct rb_node	rb_node;
296 	struct symbol	sym;
297 };
298 
299 static void symbols__insert_by_name(struct rb_root *self, struct symbol *sym)
300 {
301 	struct rb_node **p = &self->rb_node;
302 	struct rb_node *parent = NULL;
303 	struct symbol_name_rb_node *symn, *s;
304 
305 	symn = container_of(sym, struct symbol_name_rb_node, sym);
306 
307 	while (*p != NULL) {
308 		parent = *p;
309 		s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
310 		if (strcmp(sym->name, s->sym.name) < 0)
311 			p = &(*p)->rb_left;
312 		else
313 			p = &(*p)->rb_right;
314 	}
315 	rb_link_node(&symn->rb_node, parent, p);
316 	rb_insert_color(&symn->rb_node, self);
317 }
318 
319 static void symbols__sort_by_name(struct rb_root *self, struct rb_root *source)
320 {
321 	struct rb_node *nd;
322 
323 	for (nd = rb_first(source); nd; nd = rb_next(nd)) {
324 		struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
325 		symbols__insert_by_name(self, pos);
326 	}
327 }
328 
329 static struct symbol *symbols__find_by_name(struct rb_root *self, const char *name)
330 {
331 	struct rb_node *n;
332 
333 	if (self == NULL)
334 		return NULL;
335 
336 	n = self->rb_node;
337 
338 	while (n) {
339 		struct symbol_name_rb_node *s;
340 		int cmp;
341 
342 		s = rb_entry(n, struct symbol_name_rb_node, rb_node);
343 		cmp = strcmp(name, s->sym.name);
344 
345 		if (cmp < 0)
346 			n = n->rb_left;
347 		else if (cmp > 0)
348 			n = n->rb_right;
349 		else
350 			return &s->sym;
351 	}
352 
353 	return NULL;
354 }
355 
356 struct symbol *dso__find_symbol(struct dso *self,
357 				enum map_type type, u64 addr)
358 {
359 	return symbols__find(&self->symbols[type], addr);
360 }
361 
362 struct symbol *dso__find_symbol_by_name(struct dso *self, enum map_type type,
363 					const char *name)
364 {
365 	return symbols__find_by_name(&self->symbol_names[type], name);
366 }
367 
368 void dso__sort_by_name(struct dso *self, enum map_type type)
369 {
370 	dso__set_sorted_by_name(self, type);
371 	return symbols__sort_by_name(&self->symbol_names[type],
372 				     &self->symbols[type]);
373 }
374 
375 int build_id__sprintf(const u8 *self, int len, char *bf)
376 {
377 	char *bid = bf;
378 	const u8 *raw = self;
379 	int i;
380 
381 	for (i = 0; i < len; ++i) {
382 		sprintf(bid, "%02x", *raw);
383 		++raw;
384 		bid += 2;
385 	}
386 
387 	return raw - self;
388 }
389 
390 size_t dso__fprintf_buildid(struct dso *self, FILE *fp)
391 {
392 	char sbuild_id[BUILD_ID_SIZE * 2 + 1];
393 
394 	build_id__sprintf(self->build_id, sizeof(self->build_id), sbuild_id);
395 	return fprintf(fp, "%s", sbuild_id);
396 }
397 
398 size_t dso__fprintf_symbols_by_name(struct dso *self, enum map_type type, FILE *fp)
399 {
400 	size_t ret = 0;
401 	struct rb_node *nd;
402 	struct symbol_name_rb_node *pos;
403 
404 	for (nd = rb_first(&self->symbol_names[type]); nd; nd = rb_next(nd)) {
405 		pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
406 		fprintf(fp, "%s\n", pos->sym.name);
407 	}
408 
409 	return ret;
410 }
411 
412 size_t dso__fprintf(struct dso *self, enum map_type type, FILE *fp)
413 {
414 	struct rb_node *nd;
415 	size_t ret = fprintf(fp, "dso: %s (", self->short_name);
416 
417 	if (self->short_name != self->long_name)
418 		ret += fprintf(fp, "%s, ", self->long_name);
419 	ret += fprintf(fp, "%s, %sloaded, ", map_type__name[type],
420 		       self->loaded ? "" : "NOT ");
421 	ret += dso__fprintf_buildid(self, fp);
422 	ret += fprintf(fp, ")\n");
423 	for (nd = rb_first(&self->symbols[type]); nd; nd = rb_next(nd)) {
424 		struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
425 		ret += symbol__fprintf(pos, fp);
426 	}
427 
428 	return ret;
429 }
430 
431 int kallsyms__parse(const char *filename, void *arg,
432 		    int (*process_symbol)(void *arg, const char *name,
433 					  char type, u64 start, u64 end))
434 {
435 	char *line = NULL;
436 	size_t n;
437 	int err = -1;
438 	u64 prev_start = 0;
439 	char prev_symbol_type = 0;
440 	char *prev_symbol_name;
441 	FILE *file = fopen(filename, "r");
442 
443 	if (file == NULL)
444 		goto out_failure;
445 
446 	prev_symbol_name = malloc(KSYM_NAME_LEN);
447 	if (prev_symbol_name == NULL)
448 		goto out_close;
449 
450 	err = 0;
451 
452 	while (!feof(file)) {
453 		u64 start;
454 		int line_len, len;
455 		char symbol_type;
456 		char *symbol_name;
457 
458 		line_len = getline(&line, &n, file);
459 		if (line_len < 0 || !line)
460 			break;
461 
462 		line[--line_len] = '\0'; /* \n */
463 
464 		len = hex2u64(line, &start);
465 
466 		len++;
467 		if (len + 2 >= line_len)
468 			continue;
469 
470 		symbol_type = toupper(line[len]);
471 		len += 2;
472 		symbol_name = line + len;
473 		len = line_len - len;
474 
475 		if (len >= KSYM_NAME_LEN) {
476 			err = -1;
477 			break;
478 		}
479 
480 		if (prev_symbol_type) {
481 			u64 end = start;
482 			if (end != prev_start)
483 				--end;
484 			err = process_symbol(arg, prev_symbol_name,
485 					     prev_symbol_type, prev_start, end);
486 			if (err)
487 				break;
488 		}
489 
490 		memcpy(prev_symbol_name, symbol_name, len + 1);
491 		prev_symbol_type = symbol_type;
492 		prev_start = start;
493 	}
494 
495 	free(prev_symbol_name);
496 	free(line);
497 out_close:
498 	fclose(file);
499 	return err;
500 
501 out_failure:
502 	return -1;
503 }
504 
505 struct process_kallsyms_args {
506 	struct map *map;
507 	struct dso *dso;
508 };
509 
510 static u8 kallsyms2elf_type(char type)
511 {
512 	if (type == 'W')
513 		return STB_WEAK;
514 
515 	return isupper(type) ? STB_GLOBAL : STB_LOCAL;
516 }
517 
518 static int map__process_kallsym_symbol(void *arg, const char *name,
519 				       char type, u64 start, u64 end)
520 {
521 	struct symbol *sym;
522 	struct process_kallsyms_args *a = arg;
523 	struct rb_root *root = &a->dso->symbols[a->map->type];
524 
525 	if (!symbol_type__is_a(type, a->map->type))
526 		return 0;
527 
528 	sym = symbol__new(start, end - start + 1,
529 			  kallsyms2elf_type(type), name);
530 	if (sym == NULL)
531 		return -ENOMEM;
532 	/*
533 	 * We will pass the symbols to the filter later, in
534 	 * map__split_kallsyms, when we have split the maps per module
535 	 */
536 	symbols__insert(root, sym);
537 
538 	return 0;
539 }
540 
541 /*
542  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
543  * so that we can in the next step set the symbol ->end address and then
544  * call kernel_maps__split_kallsyms.
545  */
546 static int dso__load_all_kallsyms(struct dso *self, const char *filename,
547 				  struct map *map)
548 {
549 	struct process_kallsyms_args args = { .map = map, .dso = self, };
550 	return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
551 }
552 
553 /*
554  * Split the symbols into maps, making sure there are no overlaps, i.e. the
555  * kernel range is broken in several maps, named [kernel].N, as we don't have
556  * the original ELF section names vmlinux have.
557  */
558 static int dso__split_kallsyms(struct dso *self, struct map *map,
559 			       symbol_filter_t filter)
560 {
561 	struct map_groups *kmaps = map__kmap(map)->kmaps;
562 	struct machine *machine = kmaps->machine;
563 	struct map *curr_map = map;
564 	struct symbol *pos;
565 	int count = 0, moved = 0;
566 	struct rb_root *root = &self->symbols[map->type];
567 	struct rb_node *next = rb_first(root);
568 	int kernel_range = 0;
569 
570 	while (next) {
571 		char *module;
572 
573 		pos = rb_entry(next, struct symbol, rb_node);
574 		next = rb_next(&pos->rb_node);
575 
576 		module = strchr(pos->name, '\t');
577 		if (module) {
578 			if (!symbol_conf.use_modules)
579 				goto discard_symbol;
580 
581 			*module++ = '\0';
582 
583 			if (strcmp(curr_map->dso->short_name, module)) {
584 				if (curr_map != map &&
585 				    self->kernel == DSO_TYPE_GUEST_KERNEL &&
586 				    machine__is_default_guest(machine)) {
587 					/*
588 					 * We assume all symbols of a module are
589 					 * continuous in * kallsyms, so curr_map
590 					 * points to a module and all its
591 					 * symbols are in its kmap. Mark it as
592 					 * loaded.
593 					 */
594 					dso__set_loaded(curr_map->dso,
595 							curr_map->type);
596 				}
597 
598 				curr_map = map_groups__find_by_name(kmaps,
599 							map->type, module);
600 				if (curr_map == NULL) {
601 					pr_debug("%s/proc/{kallsyms,modules} "
602 					         "inconsistency while looking "
603 						 "for \"%s\" module!\n",
604 						 machine->root_dir, module);
605 					curr_map = map;
606 					goto discard_symbol;
607 				}
608 
609 				if (curr_map->dso->loaded &&
610 				    !machine__is_default_guest(machine))
611 					goto discard_symbol;
612 			}
613 			/*
614 			 * So that we look just like we get from .ko files,
615 			 * i.e. not prelinked, relative to map->start.
616 			 */
617 			pos->start = curr_map->map_ip(curr_map, pos->start);
618 			pos->end   = curr_map->map_ip(curr_map, pos->end);
619 		} else if (curr_map != map) {
620 			char dso_name[PATH_MAX];
621 			struct dso *dso;
622 
623 			if (count == 0) {
624 				curr_map = map;
625 				goto filter_symbol;
626 			}
627 
628 			if (self->kernel == DSO_TYPE_GUEST_KERNEL)
629 				snprintf(dso_name, sizeof(dso_name),
630 					"[guest.kernel].%d",
631 					kernel_range++);
632 			else
633 				snprintf(dso_name, sizeof(dso_name),
634 					"[kernel].%d",
635 					kernel_range++);
636 
637 			dso = dso__new(dso_name);
638 			if (dso == NULL)
639 				return -1;
640 
641 			dso->kernel = self->kernel;
642 
643 			curr_map = map__new2(pos->start, dso, map->type);
644 			if (curr_map == NULL) {
645 				dso__delete(dso);
646 				return -1;
647 			}
648 
649 			curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
650 			map_groups__insert(kmaps, curr_map);
651 			++kernel_range;
652 		}
653 filter_symbol:
654 		if (filter && filter(curr_map, pos)) {
655 discard_symbol:		rb_erase(&pos->rb_node, root);
656 			symbol__delete(pos);
657 		} else {
658 			if (curr_map != map) {
659 				rb_erase(&pos->rb_node, root);
660 				symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
661 				++moved;
662 			} else
663 				++count;
664 		}
665 	}
666 
667 	if (curr_map != map &&
668 	    self->kernel == DSO_TYPE_GUEST_KERNEL &&
669 	    machine__is_default_guest(kmaps->machine)) {
670 		dso__set_loaded(curr_map->dso, curr_map->type);
671 	}
672 
673 	return count + moved;
674 }
675 
676 int dso__load_kallsyms(struct dso *self, const char *filename,
677 		       struct map *map, symbol_filter_t filter)
678 {
679 	if (dso__load_all_kallsyms(self, filename, map) < 0)
680 		return -1;
681 
682 	if (self->kernel == DSO_TYPE_GUEST_KERNEL)
683 		self->symtab_type = SYMTAB__GUEST_KALLSYMS;
684 	else
685 		self->symtab_type = SYMTAB__KALLSYMS;
686 
687 	return dso__split_kallsyms(self, map, filter);
688 }
689 
690 static int dso__load_perf_map(struct dso *self, struct map *map,
691 			      symbol_filter_t filter)
692 {
693 	char *line = NULL;
694 	size_t n;
695 	FILE *file;
696 	int nr_syms = 0;
697 
698 	file = fopen(self->long_name, "r");
699 	if (file == NULL)
700 		goto out_failure;
701 
702 	while (!feof(file)) {
703 		u64 start, size;
704 		struct symbol *sym;
705 		int line_len, len;
706 
707 		line_len = getline(&line, &n, file);
708 		if (line_len < 0)
709 			break;
710 
711 		if (!line)
712 			goto out_failure;
713 
714 		line[--line_len] = '\0'; /* \n */
715 
716 		len = hex2u64(line, &start);
717 
718 		len++;
719 		if (len + 2 >= line_len)
720 			continue;
721 
722 		len += hex2u64(line + len, &size);
723 
724 		len++;
725 		if (len + 2 >= line_len)
726 			continue;
727 
728 		sym = symbol__new(start, size, STB_GLOBAL, line + len);
729 
730 		if (sym == NULL)
731 			goto out_delete_line;
732 
733 		if (filter && filter(map, sym))
734 			symbol__delete(sym);
735 		else {
736 			symbols__insert(&self->symbols[map->type], sym);
737 			nr_syms++;
738 		}
739 	}
740 
741 	free(line);
742 	fclose(file);
743 
744 	return nr_syms;
745 
746 out_delete_line:
747 	free(line);
748 out_failure:
749 	return -1;
750 }
751 
752 /**
753  * elf_symtab__for_each_symbol - iterate thru all the symbols
754  *
755  * @self: struct elf_symtab instance to iterate
756  * @idx: uint32_t idx
757  * @sym: GElf_Sym iterator
758  */
759 #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
760 	for (idx = 0, gelf_getsym(syms, idx, &sym);\
761 	     idx < nr_syms; \
762 	     idx++, gelf_getsym(syms, idx, &sym))
763 
764 static inline uint8_t elf_sym__type(const GElf_Sym *sym)
765 {
766 	return GELF_ST_TYPE(sym->st_info);
767 }
768 
769 static inline int elf_sym__is_function(const GElf_Sym *sym)
770 {
771 	return elf_sym__type(sym) == STT_FUNC &&
772 	       sym->st_name != 0 &&
773 	       sym->st_shndx != SHN_UNDEF;
774 }
775 
776 static inline bool elf_sym__is_object(const GElf_Sym *sym)
777 {
778 	return elf_sym__type(sym) == STT_OBJECT &&
779 		sym->st_name != 0 &&
780 		sym->st_shndx != SHN_UNDEF;
781 }
782 
783 static inline int elf_sym__is_label(const GElf_Sym *sym)
784 {
785 	return elf_sym__type(sym) == STT_NOTYPE &&
786 		sym->st_name != 0 &&
787 		sym->st_shndx != SHN_UNDEF &&
788 		sym->st_shndx != SHN_ABS;
789 }
790 
791 static inline const char *elf_sec__name(const GElf_Shdr *shdr,
792 					const Elf_Data *secstrs)
793 {
794 	return secstrs->d_buf + shdr->sh_name;
795 }
796 
797 static inline int elf_sec__is_text(const GElf_Shdr *shdr,
798 					const Elf_Data *secstrs)
799 {
800 	return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
801 }
802 
803 static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
804 				    const Elf_Data *secstrs)
805 {
806 	return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
807 }
808 
809 static inline const char *elf_sym__name(const GElf_Sym *sym,
810 					const Elf_Data *symstrs)
811 {
812 	return symstrs->d_buf + sym->st_name;
813 }
814 
815 static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
816 				    GElf_Shdr *shp, const char *name,
817 				    size_t *idx)
818 {
819 	Elf_Scn *sec = NULL;
820 	size_t cnt = 1;
821 
822 	while ((sec = elf_nextscn(elf, sec)) != NULL) {
823 		char *str;
824 
825 		gelf_getshdr(sec, shp);
826 		str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
827 		if (!strcmp(name, str)) {
828 			if (idx)
829 				*idx = cnt;
830 			break;
831 		}
832 		++cnt;
833 	}
834 
835 	return sec;
836 }
837 
838 #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
839 	for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
840 	     idx < nr_entries; \
841 	     ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
842 
843 #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
844 	for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
845 	     idx < nr_entries; \
846 	     ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
847 
848 /*
849  * We need to check if we have a .dynsym, so that we can handle the
850  * .plt, synthesizing its symbols, that aren't on the symtabs (be it
851  * .dynsym or .symtab).
852  * And always look at the original dso, not at debuginfo packages, that
853  * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
854  */
855 static int dso__synthesize_plt_symbols(struct  dso *self, struct map *map,
856 				       symbol_filter_t filter)
857 {
858 	uint32_t nr_rel_entries, idx;
859 	GElf_Sym sym;
860 	u64 plt_offset;
861 	GElf_Shdr shdr_plt;
862 	struct symbol *f;
863 	GElf_Shdr shdr_rel_plt, shdr_dynsym;
864 	Elf_Data *reldata, *syms, *symstrs;
865 	Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
866 	size_t dynsym_idx;
867 	GElf_Ehdr ehdr;
868 	char sympltname[1024];
869 	Elf *elf;
870 	int nr = 0, symidx, fd, err = 0;
871 	char name[PATH_MAX];
872 
873 	snprintf(name, sizeof(name), "%s%s",
874 		 symbol_conf.symfs, self->long_name);
875 	fd = open(name, O_RDONLY);
876 	if (fd < 0)
877 		goto out;
878 
879 	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
880 	if (elf == NULL)
881 		goto out_close;
882 
883 	if (gelf_getehdr(elf, &ehdr) == NULL)
884 		goto out_elf_end;
885 
886 	scn_dynsym = elf_section_by_name(elf, &ehdr, &shdr_dynsym,
887 					 ".dynsym", &dynsym_idx);
888 	if (scn_dynsym == NULL)
889 		goto out_elf_end;
890 
891 	scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
892 					  ".rela.plt", NULL);
893 	if (scn_plt_rel == NULL) {
894 		scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
895 						  ".rel.plt", NULL);
896 		if (scn_plt_rel == NULL)
897 			goto out_elf_end;
898 	}
899 
900 	err = -1;
901 
902 	if (shdr_rel_plt.sh_link != dynsym_idx)
903 		goto out_elf_end;
904 
905 	if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
906 		goto out_elf_end;
907 
908 	/*
909 	 * Fetch the relocation section to find the idxes to the GOT
910 	 * and the symbols in the .dynsym they refer to.
911 	 */
912 	reldata = elf_getdata(scn_plt_rel, NULL);
913 	if (reldata == NULL)
914 		goto out_elf_end;
915 
916 	syms = elf_getdata(scn_dynsym, NULL);
917 	if (syms == NULL)
918 		goto out_elf_end;
919 
920 	scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
921 	if (scn_symstrs == NULL)
922 		goto out_elf_end;
923 
924 	symstrs = elf_getdata(scn_symstrs, NULL);
925 	if (symstrs == NULL)
926 		goto out_elf_end;
927 
928 	nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
929 	plt_offset = shdr_plt.sh_offset;
930 
931 	if (shdr_rel_plt.sh_type == SHT_RELA) {
932 		GElf_Rela pos_mem, *pos;
933 
934 		elf_section__for_each_rela(reldata, pos, pos_mem, idx,
935 					   nr_rel_entries) {
936 			symidx = GELF_R_SYM(pos->r_info);
937 			plt_offset += shdr_plt.sh_entsize;
938 			gelf_getsym(syms, symidx, &sym);
939 			snprintf(sympltname, sizeof(sympltname),
940 				 "%s@plt", elf_sym__name(&sym, symstrs));
941 
942 			f = symbol__new(plt_offset, shdr_plt.sh_entsize,
943 					STB_GLOBAL, sympltname);
944 			if (!f)
945 				goto out_elf_end;
946 
947 			if (filter && filter(map, f))
948 				symbol__delete(f);
949 			else {
950 				symbols__insert(&self->symbols[map->type], f);
951 				++nr;
952 			}
953 		}
954 	} else if (shdr_rel_plt.sh_type == SHT_REL) {
955 		GElf_Rel pos_mem, *pos;
956 		elf_section__for_each_rel(reldata, pos, pos_mem, idx,
957 					  nr_rel_entries) {
958 			symidx = GELF_R_SYM(pos->r_info);
959 			plt_offset += shdr_plt.sh_entsize;
960 			gelf_getsym(syms, symidx, &sym);
961 			snprintf(sympltname, sizeof(sympltname),
962 				 "%s@plt", elf_sym__name(&sym, symstrs));
963 
964 			f = symbol__new(plt_offset, shdr_plt.sh_entsize,
965 					STB_GLOBAL, sympltname);
966 			if (!f)
967 				goto out_elf_end;
968 
969 			if (filter && filter(map, f))
970 				symbol__delete(f);
971 			else {
972 				symbols__insert(&self->symbols[map->type], f);
973 				++nr;
974 			}
975 		}
976 	}
977 
978 	err = 0;
979 out_elf_end:
980 	elf_end(elf);
981 out_close:
982 	close(fd);
983 
984 	if (err == 0)
985 		return nr;
986 out:
987 	pr_debug("%s: problems reading %s PLT info.\n",
988 		 __func__, self->long_name);
989 	return 0;
990 }
991 
992 static bool elf_sym__is_a(GElf_Sym *self, enum map_type type)
993 {
994 	switch (type) {
995 	case MAP__FUNCTION:
996 		return elf_sym__is_function(self);
997 	case MAP__VARIABLE:
998 		return elf_sym__is_object(self);
999 	default:
1000 		return false;
1001 	}
1002 }
1003 
1004 static bool elf_sec__is_a(GElf_Shdr *self, Elf_Data *secstrs, enum map_type type)
1005 {
1006 	switch (type) {
1007 	case MAP__FUNCTION:
1008 		return elf_sec__is_text(self, secstrs);
1009 	case MAP__VARIABLE:
1010 		return elf_sec__is_data(self, secstrs);
1011 	default:
1012 		return false;
1013 	}
1014 }
1015 
1016 static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
1017 {
1018 	Elf_Scn *sec = NULL;
1019 	GElf_Shdr shdr;
1020 	size_t cnt = 1;
1021 
1022 	while ((sec = elf_nextscn(elf, sec)) != NULL) {
1023 		gelf_getshdr(sec, &shdr);
1024 
1025 		if ((addr >= shdr.sh_addr) &&
1026 		    (addr < (shdr.sh_addr + shdr.sh_size)))
1027 			return cnt;
1028 
1029 		++cnt;
1030 	}
1031 
1032 	return -1;
1033 }
1034 
1035 static int dso__load_sym(struct dso *self, struct map *map, const char *name,
1036 			 int fd, symbol_filter_t filter, int kmodule,
1037 			 int want_symtab)
1038 {
1039 	struct kmap *kmap = self->kernel ? map__kmap(map) : NULL;
1040 	struct map *curr_map = map;
1041 	struct dso *curr_dso = self;
1042 	Elf_Data *symstrs, *secstrs;
1043 	uint32_t nr_syms;
1044 	int err = -1;
1045 	uint32_t idx;
1046 	GElf_Ehdr ehdr;
1047 	GElf_Shdr shdr, opdshdr;
1048 	Elf_Data *syms, *opddata = NULL;
1049 	GElf_Sym sym;
1050 	Elf_Scn *sec, *sec_strndx, *opdsec;
1051 	Elf *elf;
1052 	int nr = 0;
1053 	size_t opdidx = 0;
1054 
1055 	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1056 	if (elf == NULL) {
1057 		pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
1058 		goto out_close;
1059 	}
1060 
1061 	if (gelf_getehdr(elf, &ehdr) == NULL) {
1062 		pr_debug("%s: cannot get elf header.\n", __func__);
1063 		goto out_elf_end;
1064 	}
1065 
1066 	/* Always reject images with a mismatched build-id: */
1067 	if (self->has_build_id) {
1068 		u8 build_id[BUILD_ID_SIZE];
1069 
1070 		if (elf_read_build_id(elf, build_id,
1071 				      BUILD_ID_SIZE) != BUILD_ID_SIZE)
1072 			goto out_elf_end;
1073 
1074 		if (!dso__build_id_equal(self, build_id))
1075 			goto out_elf_end;
1076 	}
1077 
1078 	sec = elf_section_by_name(elf, &ehdr, &shdr, ".symtab", NULL);
1079 	if (sec == NULL) {
1080 		if (want_symtab)
1081 			goto out_elf_end;
1082 
1083 		sec = elf_section_by_name(elf, &ehdr, &shdr, ".dynsym", NULL);
1084 		if (sec == NULL)
1085 			goto out_elf_end;
1086 	}
1087 
1088 	opdsec = elf_section_by_name(elf, &ehdr, &opdshdr, ".opd", &opdidx);
1089 	if (opdsec)
1090 		opddata = elf_rawdata(opdsec, NULL);
1091 
1092 	syms = elf_getdata(sec, NULL);
1093 	if (syms == NULL)
1094 		goto out_elf_end;
1095 
1096 	sec = elf_getscn(elf, shdr.sh_link);
1097 	if (sec == NULL)
1098 		goto out_elf_end;
1099 
1100 	symstrs = elf_getdata(sec, NULL);
1101 	if (symstrs == NULL)
1102 		goto out_elf_end;
1103 
1104 	sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
1105 	if (sec_strndx == NULL)
1106 		goto out_elf_end;
1107 
1108 	secstrs = elf_getdata(sec_strndx, NULL);
1109 	if (secstrs == NULL)
1110 		goto out_elf_end;
1111 
1112 	nr_syms = shdr.sh_size / shdr.sh_entsize;
1113 
1114 	memset(&sym, 0, sizeof(sym));
1115 	if (self->kernel == DSO_TYPE_USER) {
1116 		self->adjust_symbols = (ehdr.e_type == ET_EXEC ||
1117 				elf_section_by_name(elf, &ehdr, &shdr,
1118 						     ".gnu.prelink_undo",
1119 						     NULL) != NULL);
1120 	} else self->adjust_symbols = 0;
1121 
1122 	elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
1123 		struct symbol *f;
1124 		const char *elf_name = elf_sym__name(&sym, symstrs);
1125 		char *demangled = NULL;
1126 		int is_label = elf_sym__is_label(&sym);
1127 		const char *section_name;
1128 
1129 		if (kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
1130 		    strcmp(elf_name, kmap->ref_reloc_sym->name) == 0)
1131 			kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
1132 
1133 		if (!is_label && !elf_sym__is_a(&sym, map->type))
1134 			continue;
1135 
1136 		/* Reject ARM ELF "mapping symbols": these aren't unique and
1137 		 * don't identify functions, so will confuse the profile
1138 		 * output: */
1139 		if (ehdr.e_machine == EM_ARM) {
1140 			if (!strcmp(elf_name, "$a") ||
1141 			    !strcmp(elf_name, "$d") ||
1142 			    !strcmp(elf_name, "$t"))
1143 				continue;
1144 		}
1145 
1146 		if (opdsec && sym.st_shndx == opdidx) {
1147 			u32 offset = sym.st_value - opdshdr.sh_addr;
1148 			u64 *opd = opddata->d_buf + offset;
1149 			sym.st_value = *opd;
1150 			sym.st_shndx = elf_addr_to_index(elf, sym.st_value);
1151 		}
1152 
1153 		sec = elf_getscn(elf, sym.st_shndx);
1154 		if (!sec)
1155 			goto out_elf_end;
1156 
1157 		gelf_getshdr(sec, &shdr);
1158 
1159 		if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
1160 			continue;
1161 
1162 		section_name = elf_sec__name(&shdr, secstrs);
1163 
1164 		/* On ARM, symbols for thumb functions have 1 added to
1165 		 * the symbol address as a flag - remove it */
1166 		if ((ehdr.e_machine == EM_ARM) &&
1167 		    (map->type == MAP__FUNCTION) &&
1168 		    (sym.st_value & 1))
1169 			--sym.st_value;
1170 
1171 		if (self->kernel != DSO_TYPE_USER || kmodule) {
1172 			char dso_name[PATH_MAX];
1173 
1174 			if (strcmp(section_name,
1175 				   (curr_dso->short_name +
1176 				    self->short_name_len)) == 0)
1177 				goto new_symbol;
1178 
1179 			if (strcmp(section_name, ".text") == 0) {
1180 				curr_map = map;
1181 				curr_dso = self;
1182 				goto new_symbol;
1183 			}
1184 
1185 			snprintf(dso_name, sizeof(dso_name),
1186 				 "%s%s", self->short_name, section_name);
1187 
1188 			curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name);
1189 			if (curr_map == NULL) {
1190 				u64 start = sym.st_value;
1191 
1192 				if (kmodule)
1193 					start += map->start + shdr.sh_offset;
1194 
1195 				curr_dso = dso__new(dso_name);
1196 				if (curr_dso == NULL)
1197 					goto out_elf_end;
1198 				curr_dso->kernel = self->kernel;
1199 				curr_dso->long_name = self->long_name;
1200 				curr_dso->long_name_len = self->long_name_len;
1201 				curr_map = map__new2(start, curr_dso,
1202 						     map->type);
1203 				if (curr_map == NULL) {
1204 					dso__delete(curr_dso);
1205 					goto out_elf_end;
1206 				}
1207 				curr_map->map_ip = identity__map_ip;
1208 				curr_map->unmap_ip = identity__map_ip;
1209 				curr_dso->symtab_type = self->symtab_type;
1210 				map_groups__insert(kmap->kmaps, curr_map);
1211 				dsos__add(&self->node, curr_dso);
1212 				dso__set_loaded(curr_dso, map->type);
1213 			} else
1214 				curr_dso = curr_map->dso;
1215 
1216 			goto new_symbol;
1217 		}
1218 
1219 		if (curr_dso->adjust_symbols) {
1220 			pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
1221 				  "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
1222 				  (u64)sym.st_value, (u64)shdr.sh_addr,
1223 				  (u64)shdr.sh_offset);
1224 			sym.st_value -= shdr.sh_addr - shdr.sh_offset;
1225 		}
1226 		/*
1227 		 * We need to figure out if the object was created from C++ sources
1228 		 * DWARF DW_compile_unit has this, but we don't always have access
1229 		 * to it...
1230 		 */
1231 		demangled = bfd_demangle(NULL, elf_name, DMGL_PARAMS | DMGL_ANSI);
1232 		if (demangled != NULL)
1233 			elf_name = demangled;
1234 new_symbol:
1235 		f = symbol__new(sym.st_value, sym.st_size,
1236 				GELF_ST_BIND(sym.st_info), elf_name);
1237 		free(demangled);
1238 		if (!f)
1239 			goto out_elf_end;
1240 
1241 		if (filter && filter(curr_map, f))
1242 			symbol__delete(f);
1243 		else {
1244 			symbols__insert(&curr_dso->symbols[curr_map->type], f);
1245 			nr++;
1246 		}
1247 	}
1248 
1249 	/*
1250 	 * For misannotated, zeroed, ASM function sizes.
1251 	 */
1252 	if (nr > 0) {
1253 		symbols__fixup_end(&self->symbols[map->type]);
1254 		if (kmap) {
1255 			/*
1256 			 * We need to fixup this here too because we create new
1257 			 * maps here, for things like vsyscall sections.
1258 			 */
1259 			__map_groups__fixup_end(kmap->kmaps, map->type);
1260 		}
1261 	}
1262 	err = nr;
1263 out_elf_end:
1264 	elf_end(elf);
1265 out_close:
1266 	return err;
1267 }
1268 
1269 static bool dso__build_id_equal(const struct dso *self, u8 *build_id)
1270 {
1271 	return memcmp(self->build_id, build_id, sizeof(self->build_id)) == 0;
1272 }
1273 
1274 bool __dsos__read_build_ids(struct list_head *head, bool with_hits)
1275 {
1276 	bool have_build_id = false;
1277 	struct dso *pos;
1278 
1279 	list_for_each_entry(pos, head, node) {
1280 		if (with_hits && !pos->hit)
1281 			continue;
1282 		if (pos->has_build_id) {
1283 			have_build_id = true;
1284 			continue;
1285 		}
1286 		if (filename__read_build_id(pos->long_name, pos->build_id,
1287 					    sizeof(pos->build_id)) > 0) {
1288 			have_build_id	  = true;
1289 			pos->has_build_id = true;
1290 		}
1291 	}
1292 
1293 	return have_build_id;
1294 }
1295 
1296 /*
1297  * Align offset to 4 bytes as needed for note name and descriptor data.
1298  */
1299 #define NOTE_ALIGN(n) (((n) + 3) & -4U)
1300 
1301 static int elf_read_build_id(Elf *elf, void *bf, size_t size)
1302 {
1303 	int err = -1;
1304 	GElf_Ehdr ehdr;
1305 	GElf_Shdr shdr;
1306 	Elf_Data *data;
1307 	Elf_Scn *sec;
1308 	Elf_Kind ek;
1309 	void *ptr;
1310 
1311 	if (size < BUILD_ID_SIZE)
1312 		goto out;
1313 
1314 	ek = elf_kind(elf);
1315 	if (ek != ELF_K_ELF)
1316 		goto out;
1317 
1318 	if (gelf_getehdr(elf, &ehdr) == NULL) {
1319 		pr_err("%s: cannot get elf header.\n", __func__);
1320 		goto out;
1321 	}
1322 
1323 	sec = elf_section_by_name(elf, &ehdr, &shdr,
1324 				  ".note.gnu.build-id", NULL);
1325 	if (sec == NULL) {
1326 		sec = elf_section_by_name(elf, &ehdr, &shdr,
1327 					  ".notes", NULL);
1328 		if (sec == NULL)
1329 			goto out;
1330 	}
1331 
1332 	data = elf_getdata(sec, NULL);
1333 	if (data == NULL)
1334 		goto out;
1335 
1336 	ptr = data->d_buf;
1337 	while (ptr < (data->d_buf + data->d_size)) {
1338 		GElf_Nhdr *nhdr = ptr;
1339 		int namesz = NOTE_ALIGN(nhdr->n_namesz),
1340 		    descsz = NOTE_ALIGN(nhdr->n_descsz);
1341 		const char *name;
1342 
1343 		ptr += sizeof(*nhdr);
1344 		name = ptr;
1345 		ptr += namesz;
1346 		if (nhdr->n_type == NT_GNU_BUILD_ID &&
1347 		    nhdr->n_namesz == sizeof("GNU")) {
1348 			if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
1349 				memcpy(bf, ptr, BUILD_ID_SIZE);
1350 				err = BUILD_ID_SIZE;
1351 				break;
1352 			}
1353 		}
1354 		ptr += descsz;
1355 	}
1356 
1357 out:
1358 	return err;
1359 }
1360 
1361 int filename__read_build_id(const char *filename, void *bf, size_t size)
1362 {
1363 	int fd, err = -1;
1364 	Elf *elf;
1365 
1366 	if (size < BUILD_ID_SIZE)
1367 		goto out;
1368 
1369 	fd = open(filename, O_RDONLY);
1370 	if (fd < 0)
1371 		goto out;
1372 
1373 	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1374 	if (elf == NULL) {
1375 		pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
1376 		goto out_close;
1377 	}
1378 
1379 	err = elf_read_build_id(elf, bf, size);
1380 
1381 	elf_end(elf);
1382 out_close:
1383 	close(fd);
1384 out:
1385 	return err;
1386 }
1387 
1388 int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
1389 {
1390 	int fd, err = -1;
1391 
1392 	if (size < BUILD_ID_SIZE)
1393 		goto out;
1394 
1395 	fd = open(filename, O_RDONLY);
1396 	if (fd < 0)
1397 		goto out;
1398 
1399 	while (1) {
1400 		char bf[BUFSIZ];
1401 		GElf_Nhdr nhdr;
1402 		int namesz, descsz;
1403 
1404 		if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
1405 			break;
1406 
1407 		namesz = NOTE_ALIGN(nhdr.n_namesz);
1408 		descsz = NOTE_ALIGN(nhdr.n_descsz);
1409 		if (nhdr.n_type == NT_GNU_BUILD_ID &&
1410 		    nhdr.n_namesz == sizeof("GNU")) {
1411 			if (read(fd, bf, namesz) != namesz)
1412 				break;
1413 			if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
1414 				if (read(fd, build_id,
1415 				    BUILD_ID_SIZE) == BUILD_ID_SIZE) {
1416 					err = 0;
1417 					break;
1418 				}
1419 			} else if (read(fd, bf, descsz) != descsz)
1420 				break;
1421 		} else {
1422 			int n = namesz + descsz;
1423 			if (read(fd, bf, n) != n)
1424 				break;
1425 		}
1426 	}
1427 	close(fd);
1428 out:
1429 	return err;
1430 }
1431 
1432 char dso__symtab_origin(const struct dso *self)
1433 {
1434 	static const char origin[] = {
1435 		[SYMTAB__KALLSYMS]	      = 'k',
1436 		[SYMTAB__JAVA_JIT]	      = 'j',
1437 		[SYMTAB__BUILD_ID_CACHE]      = 'B',
1438 		[SYMTAB__FEDORA_DEBUGINFO]    = 'f',
1439 		[SYMTAB__UBUNTU_DEBUGINFO]    = 'u',
1440 		[SYMTAB__BUILDID_DEBUGINFO]   = 'b',
1441 		[SYMTAB__SYSTEM_PATH_DSO]     = 'd',
1442 		[SYMTAB__SYSTEM_PATH_KMODULE] = 'K',
1443 		[SYMTAB__GUEST_KALLSYMS]      =  'g',
1444 		[SYMTAB__GUEST_KMODULE]	      =  'G',
1445 	};
1446 
1447 	if (self == NULL || self->symtab_type == SYMTAB__NOT_FOUND)
1448 		return '!';
1449 	return origin[self->symtab_type];
1450 }
1451 
1452 int dso__load(struct dso *self, struct map *map, symbol_filter_t filter)
1453 {
1454 	int size = PATH_MAX;
1455 	char *name;
1456 	int ret = -1;
1457 	int fd;
1458 	struct machine *machine;
1459 	const char *root_dir;
1460 	int want_symtab;
1461 
1462 	dso__set_loaded(self, map->type);
1463 
1464 	if (self->kernel == DSO_TYPE_KERNEL)
1465 		return dso__load_kernel_sym(self, map, filter);
1466 	else if (self->kernel == DSO_TYPE_GUEST_KERNEL)
1467 		return dso__load_guest_kernel_sym(self, map, filter);
1468 
1469 	if (map->groups && map->groups->machine)
1470 		machine = map->groups->machine;
1471 	else
1472 		machine = NULL;
1473 
1474 	name = malloc(size);
1475 	if (!name)
1476 		return -1;
1477 
1478 	self->adjust_symbols = 0;
1479 
1480 	if (strncmp(self->name, "/tmp/perf-", 10) == 0) {
1481 		ret = dso__load_perf_map(self, map, filter);
1482 		self->symtab_type = ret > 0 ? SYMTAB__JAVA_JIT :
1483 					      SYMTAB__NOT_FOUND;
1484 		return ret;
1485 	}
1486 
1487 	/* Iterate over candidate debug images.
1488 	 * On the first pass, only load images if they have a full symtab.
1489 	 * Failing that, do a second pass where we accept .dynsym also
1490 	 */
1491 	want_symtab = 1;
1492 restart:
1493 	for (self->symtab_type = SYMTAB__BUILD_ID_CACHE;
1494 	     self->symtab_type != SYMTAB__NOT_FOUND;
1495 	     self->symtab_type++) {
1496 		switch (self->symtab_type) {
1497 		case SYMTAB__BUILD_ID_CACHE:
1498 			/* skip the locally configured cache if a symfs is given */
1499 			if (symbol_conf.symfs[0] ||
1500 			    (dso__build_id_filename(self, name, size) == NULL)) {
1501 				continue;
1502 			}
1503 			break;
1504 		case SYMTAB__FEDORA_DEBUGINFO:
1505 			snprintf(name, size, "%s/usr/lib/debug%s.debug",
1506 				 symbol_conf.symfs, self->long_name);
1507 			break;
1508 		case SYMTAB__UBUNTU_DEBUGINFO:
1509 			snprintf(name, size, "%s/usr/lib/debug%s",
1510 				 symbol_conf.symfs, self->long_name);
1511 			break;
1512 		case SYMTAB__BUILDID_DEBUGINFO: {
1513 			char build_id_hex[BUILD_ID_SIZE * 2 + 1];
1514 
1515 			if (!self->has_build_id)
1516 				continue;
1517 
1518 			build_id__sprintf(self->build_id,
1519 					  sizeof(self->build_id),
1520 					  build_id_hex);
1521 			snprintf(name, size,
1522 				 "%s/usr/lib/debug/.build-id/%.2s/%s.debug",
1523 				 symbol_conf.symfs, build_id_hex, build_id_hex + 2);
1524 			}
1525 			break;
1526 		case SYMTAB__SYSTEM_PATH_DSO:
1527 			snprintf(name, size, "%s%s",
1528 			     symbol_conf.symfs, self->long_name);
1529 			break;
1530 		case SYMTAB__GUEST_KMODULE:
1531 			if (map->groups && machine)
1532 				root_dir = machine->root_dir;
1533 			else
1534 				root_dir = "";
1535 			snprintf(name, size, "%s%s%s", symbol_conf.symfs,
1536 				 root_dir, self->long_name);
1537 			break;
1538 
1539 		case SYMTAB__SYSTEM_PATH_KMODULE:
1540 			snprintf(name, size, "%s%s", symbol_conf.symfs,
1541 				 self->long_name);
1542 			break;
1543 		default:;
1544 		}
1545 
1546 		/* Name is now the name of the next image to try */
1547 		fd = open(name, O_RDONLY);
1548 		if (fd < 0)
1549 			continue;
1550 
1551 		ret = dso__load_sym(self, map, name, fd, filter, 0,
1552 				    want_symtab);
1553 		close(fd);
1554 
1555 		/*
1556 		 * Some people seem to have debuginfo files _WITHOUT_ debug
1557 		 * info!?!?
1558 		 */
1559 		if (!ret)
1560 			continue;
1561 
1562 		if (ret > 0) {
1563 			int nr_plt = dso__synthesize_plt_symbols(self, map, filter);
1564 			if (nr_plt > 0)
1565 				ret += nr_plt;
1566 			break;
1567 		}
1568 	}
1569 
1570 	/*
1571 	 * If we wanted a full symtab but no image had one,
1572 	 * relax our requirements and repeat the search.
1573 	 */
1574 	if (ret <= 0 && want_symtab) {
1575 		want_symtab = 0;
1576 		goto restart;
1577 	}
1578 
1579 	free(name);
1580 	if (ret < 0 && strstr(self->name, " (deleted)") != NULL)
1581 		return 0;
1582 	return ret;
1583 }
1584 
1585 struct map *map_groups__find_by_name(struct map_groups *self,
1586 				     enum map_type type, const char *name)
1587 {
1588 	struct rb_node *nd;
1589 
1590 	for (nd = rb_first(&self->maps[type]); nd; nd = rb_next(nd)) {
1591 		struct map *map = rb_entry(nd, struct map, rb_node);
1592 
1593 		if (map->dso && strcmp(map->dso->short_name, name) == 0)
1594 			return map;
1595 	}
1596 
1597 	return NULL;
1598 }
1599 
1600 static int dso__kernel_module_get_build_id(struct dso *self,
1601 				const char *root_dir)
1602 {
1603 	char filename[PATH_MAX];
1604 	/*
1605 	 * kernel module short names are of the form "[module]" and
1606 	 * we need just "module" here.
1607 	 */
1608 	const char *name = self->short_name + 1;
1609 
1610 	snprintf(filename, sizeof(filename),
1611 		 "%s/sys/module/%.*s/notes/.note.gnu.build-id",
1612 		 root_dir, (int)strlen(name) - 1, name);
1613 
1614 	if (sysfs__read_build_id(filename, self->build_id,
1615 				 sizeof(self->build_id)) == 0)
1616 		self->has_build_id = true;
1617 
1618 	return 0;
1619 }
1620 
1621 static int map_groups__set_modules_path_dir(struct map_groups *self,
1622 				const char *dir_name)
1623 {
1624 	struct dirent *dent;
1625 	DIR *dir = opendir(dir_name);
1626 	int ret = 0;
1627 
1628 	if (!dir) {
1629 		pr_debug("%s: cannot open %s dir\n", __func__, dir_name);
1630 		return -1;
1631 	}
1632 
1633 	while ((dent = readdir(dir)) != NULL) {
1634 		char path[PATH_MAX];
1635 		struct stat st;
1636 
1637 		/*sshfs might return bad dent->d_type, so we have to stat*/
1638 		sprintf(path, "%s/%s", dir_name, dent->d_name);
1639 		if (stat(path, &st))
1640 			continue;
1641 
1642 		if (S_ISDIR(st.st_mode)) {
1643 			if (!strcmp(dent->d_name, ".") ||
1644 			    !strcmp(dent->d_name, ".."))
1645 				continue;
1646 
1647 			snprintf(path, sizeof(path), "%s/%s",
1648 				 dir_name, dent->d_name);
1649 			ret = map_groups__set_modules_path_dir(self, path);
1650 			if (ret < 0)
1651 				goto out;
1652 		} else {
1653 			char *dot = strrchr(dent->d_name, '.'),
1654 			     dso_name[PATH_MAX];
1655 			struct map *map;
1656 			char *long_name;
1657 
1658 			if (dot == NULL || strcmp(dot, ".ko"))
1659 				continue;
1660 			snprintf(dso_name, sizeof(dso_name), "[%.*s]",
1661 				 (int)(dot - dent->d_name), dent->d_name);
1662 
1663 			strxfrchar(dso_name, '-', '_');
1664 			map = map_groups__find_by_name(self, MAP__FUNCTION, dso_name);
1665 			if (map == NULL)
1666 				continue;
1667 
1668 			snprintf(path, sizeof(path), "%s/%s",
1669 				 dir_name, dent->d_name);
1670 
1671 			long_name = strdup(path);
1672 			if (long_name == NULL) {
1673 				ret = -1;
1674 				goto out;
1675 			}
1676 			dso__set_long_name(map->dso, long_name);
1677 			map->dso->lname_alloc = 1;
1678 			dso__kernel_module_get_build_id(map->dso, "");
1679 		}
1680 	}
1681 
1682 out:
1683 	closedir(dir);
1684 	return ret;
1685 }
1686 
1687 static char *get_kernel_version(const char *root_dir)
1688 {
1689 	char version[PATH_MAX];
1690 	FILE *file;
1691 	char *name, *tmp;
1692 	const char *prefix = "Linux version ";
1693 
1694 	sprintf(version, "%s/proc/version", root_dir);
1695 	file = fopen(version, "r");
1696 	if (!file)
1697 		return NULL;
1698 
1699 	version[0] = '\0';
1700 	tmp = fgets(version, sizeof(version), file);
1701 	fclose(file);
1702 
1703 	name = strstr(version, prefix);
1704 	if (!name)
1705 		return NULL;
1706 	name += strlen(prefix);
1707 	tmp = strchr(name, ' ');
1708 	if (tmp)
1709 		*tmp = '\0';
1710 
1711 	return strdup(name);
1712 }
1713 
1714 static int machine__set_modules_path(struct machine *self)
1715 {
1716 	char *version;
1717 	char modules_path[PATH_MAX];
1718 
1719 	version = get_kernel_version(self->root_dir);
1720 	if (!version)
1721 		return -1;
1722 
1723 	snprintf(modules_path, sizeof(modules_path), "%s/lib/modules/%s/kernel",
1724 		 self->root_dir, version);
1725 	free(version);
1726 
1727 	return map_groups__set_modules_path_dir(&self->kmaps, modules_path);
1728 }
1729 
1730 /*
1731  * Constructor variant for modules (where we know from /proc/modules where
1732  * they are loaded) and for vmlinux, where only after we load all the
1733  * symbols we'll know where it starts and ends.
1734  */
1735 static struct map *map__new2(u64 start, struct dso *dso, enum map_type type)
1736 {
1737 	struct map *self = calloc(1, (sizeof(*self) +
1738 				      (dso->kernel ? sizeof(struct kmap) : 0)));
1739 	if (self != NULL) {
1740 		/*
1741 		 * ->end will be filled after we load all the symbols
1742 		 */
1743 		map__init(self, type, start, 0, 0, dso);
1744 	}
1745 
1746 	return self;
1747 }
1748 
1749 struct map *machine__new_module(struct machine *self, u64 start,
1750 				const char *filename)
1751 {
1752 	struct map *map;
1753 	struct dso *dso = __dsos__findnew(&self->kernel_dsos, filename);
1754 
1755 	if (dso == NULL)
1756 		return NULL;
1757 
1758 	map = map__new2(start, dso, MAP__FUNCTION);
1759 	if (map == NULL)
1760 		return NULL;
1761 
1762 	if (machine__is_host(self))
1763 		dso->symtab_type = SYMTAB__SYSTEM_PATH_KMODULE;
1764 	else
1765 		dso->symtab_type = SYMTAB__GUEST_KMODULE;
1766 	map_groups__insert(&self->kmaps, map);
1767 	return map;
1768 }
1769 
1770 static int machine__create_modules(struct machine *self)
1771 {
1772 	char *line = NULL;
1773 	size_t n;
1774 	FILE *file;
1775 	struct map *map;
1776 	const char *modules;
1777 	char path[PATH_MAX];
1778 
1779 	if (machine__is_default_guest(self))
1780 		modules = symbol_conf.default_guest_modules;
1781 	else {
1782 		sprintf(path, "%s/proc/modules", self->root_dir);
1783 		modules = path;
1784 	}
1785 
1786 	file = fopen(modules, "r");
1787 	if (file == NULL)
1788 		return -1;
1789 
1790 	while (!feof(file)) {
1791 		char name[PATH_MAX];
1792 		u64 start;
1793 		char *sep;
1794 		int line_len;
1795 
1796 		line_len = getline(&line, &n, file);
1797 		if (line_len < 0)
1798 			break;
1799 
1800 		if (!line)
1801 			goto out_failure;
1802 
1803 		line[--line_len] = '\0'; /* \n */
1804 
1805 		sep = strrchr(line, 'x');
1806 		if (sep == NULL)
1807 			continue;
1808 
1809 		hex2u64(sep + 1, &start);
1810 
1811 		sep = strchr(line, ' ');
1812 		if (sep == NULL)
1813 			continue;
1814 
1815 		*sep = '\0';
1816 
1817 		snprintf(name, sizeof(name), "[%s]", line);
1818 		map = machine__new_module(self, start, name);
1819 		if (map == NULL)
1820 			goto out_delete_line;
1821 		dso__kernel_module_get_build_id(map->dso, self->root_dir);
1822 	}
1823 
1824 	free(line);
1825 	fclose(file);
1826 
1827 	return machine__set_modules_path(self);
1828 
1829 out_delete_line:
1830 	free(line);
1831 out_failure:
1832 	return -1;
1833 }
1834 
1835 int dso__load_vmlinux(struct dso *self, struct map *map,
1836 		      const char *vmlinux, symbol_filter_t filter)
1837 {
1838 	int err = -1, fd;
1839 	char symfs_vmlinux[PATH_MAX];
1840 
1841 	snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s",
1842 		 symbol_conf.symfs, vmlinux);
1843 	fd = open(symfs_vmlinux, O_RDONLY);
1844 	if (fd < 0)
1845 		return -1;
1846 
1847 	dso__set_long_name(self, (char *)vmlinux);
1848 	dso__set_loaded(self, map->type);
1849 	err = dso__load_sym(self, map, symfs_vmlinux, fd, filter, 0, 0);
1850 	close(fd);
1851 
1852 	if (err > 0)
1853 		pr_debug("Using %s for symbols\n", symfs_vmlinux);
1854 
1855 	return err;
1856 }
1857 
1858 int dso__load_vmlinux_path(struct dso *self, struct map *map,
1859 			   symbol_filter_t filter)
1860 {
1861 	int i, err = 0;
1862 	char *filename;
1863 
1864 	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
1865 		 vmlinux_path__nr_entries + 1);
1866 
1867 	filename = dso__build_id_filename(self, NULL, 0);
1868 	if (filename != NULL) {
1869 		err = dso__load_vmlinux(self, map, filename, filter);
1870 		if (err > 0) {
1871 			dso__set_long_name(self, filename);
1872 			goto out;
1873 		}
1874 		free(filename);
1875 	}
1876 
1877 	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
1878 		err = dso__load_vmlinux(self, map, vmlinux_path[i], filter);
1879 		if (err > 0) {
1880 			dso__set_long_name(self, strdup(vmlinux_path[i]));
1881 			break;
1882 		}
1883 	}
1884 out:
1885 	return err;
1886 }
1887 
1888 static int dso__load_kernel_sym(struct dso *self, struct map *map,
1889 				symbol_filter_t filter)
1890 {
1891 	int err;
1892 	const char *kallsyms_filename = NULL;
1893 	char *kallsyms_allocated_filename = NULL;
1894 	/*
1895 	 * Step 1: if the user specified a kallsyms or vmlinux filename, use
1896 	 * it and only it, reporting errors to the user if it cannot be used.
1897 	 *
1898 	 * For instance, try to analyse an ARM perf.data file _without_ a
1899 	 * build-id, or if the user specifies the wrong path to the right
1900 	 * vmlinux file, obviously we can't fallback to another vmlinux (a
1901 	 * x86_86 one, on the machine where analysis is being performed, say),
1902 	 * or worse, /proc/kallsyms.
1903 	 *
1904 	 * If the specified file _has_ a build-id and there is a build-id
1905 	 * section in the perf.data file, we will still do the expected
1906 	 * validation in dso__load_vmlinux and will bail out if they don't
1907 	 * match.
1908 	 */
1909 	if (symbol_conf.kallsyms_name != NULL) {
1910 		kallsyms_filename = symbol_conf.kallsyms_name;
1911 		goto do_kallsyms;
1912 	}
1913 
1914 	if (symbol_conf.vmlinux_name != NULL) {
1915 		err = dso__load_vmlinux(self, map,
1916 					symbol_conf.vmlinux_name, filter);
1917 		if (err > 0) {
1918 			dso__set_long_name(self,
1919 					   strdup(symbol_conf.vmlinux_name));
1920 			goto out_fixup;
1921 		}
1922 		return err;
1923 	}
1924 
1925 	if (vmlinux_path != NULL) {
1926 		err = dso__load_vmlinux_path(self, map, filter);
1927 		if (err > 0)
1928 			goto out_fixup;
1929 	}
1930 
1931 	/* do not try local files if a symfs was given */
1932 	if (symbol_conf.symfs[0] != 0)
1933 		return -1;
1934 
1935 	/*
1936 	 * Say the kernel DSO was created when processing the build-id header table,
1937 	 * we have a build-id, so check if it is the same as the running kernel,
1938 	 * using it if it is.
1939 	 */
1940 	if (self->has_build_id) {
1941 		u8 kallsyms_build_id[BUILD_ID_SIZE];
1942 		char sbuild_id[BUILD_ID_SIZE * 2 + 1];
1943 
1944 		if (sysfs__read_build_id("/sys/kernel/notes", kallsyms_build_id,
1945 					 sizeof(kallsyms_build_id)) == 0) {
1946 			if (dso__build_id_equal(self, kallsyms_build_id)) {
1947 				kallsyms_filename = "/proc/kallsyms";
1948 				goto do_kallsyms;
1949 			}
1950 		}
1951 		/*
1952 		 * Now look if we have it on the build-id cache in
1953 		 * $HOME/.debug/[kernel.kallsyms].
1954 		 */
1955 		build_id__sprintf(self->build_id, sizeof(self->build_id),
1956 				  sbuild_id);
1957 
1958 		if (asprintf(&kallsyms_allocated_filename,
1959 			     "%s/.debug/[kernel.kallsyms]/%s",
1960 			     getenv("HOME"), sbuild_id) == -1) {
1961 			pr_err("Not enough memory for kallsyms file lookup\n");
1962 			return -1;
1963 		}
1964 
1965 		kallsyms_filename = kallsyms_allocated_filename;
1966 
1967 		if (access(kallsyms_filename, F_OK)) {
1968 			pr_err("No kallsyms or vmlinux with build-id %s "
1969 			       "was found\n", sbuild_id);
1970 			free(kallsyms_allocated_filename);
1971 			return -1;
1972 		}
1973 	} else {
1974 		/*
1975 		 * Last resort, if we don't have a build-id and couldn't find
1976 		 * any vmlinux file, try the running kernel kallsyms table.
1977 		 */
1978 		kallsyms_filename = "/proc/kallsyms";
1979 	}
1980 
1981 do_kallsyms:
1982 	err = dso__load_kallsyms(self, kallsyms_filename, map, filter);
1983 	if (err > 0)
1984 		pr_debug("Using %s for symbols\n", kallsyms_filename);
1985 	free(kallsyms_allocated_filename);
1986 
1987 	if (err > 0) {
1988 out_fixup:
1989 		if (kallsyms_filename != NULL)
1990 			dso__set_long_name(self, strdup("[kernel.kallsyms]"));
1991 		map__fixup_start(map);
1992 		map__fixup_end(map);
1993 	}
1994 
1995 	return err;
1996 }
1997 
1998 static int dso__load_guest_kernel_sym(struct dso *self, struct map *map,
1999 				symbol_filter_t filter)
2000 {
2001 	int err;
2002 	const char *kallsyms_filename = NULL;
2003 	struct machine *machine;
2004 	char path[PATH_MAX];
2005 
2006 	if (!map->groups) {
2007 		pr_debug("Guest kernel map hasn't the point to groups\n");
2008 		return -1;
2009 	}
2010 	machine = map->groups->machine;
2011 
2012 	if (machine__is_default_guest(machine)) {
2013 		/*
2014 		 * if the user specified a vmlinux filename, use it and only
2015 		 * it, reporting errors to the user if it cannot be used.
2016 		 * Or use file guest_kallsyms inputted by user on commandline
2017 		 */
2018 		if (symbol_conf.default_guest_vmlinux_name != NULL) {
2019 			err = dso__load_vmlinux(self, map,
2020 				symbol_conf.default_guest_vmlinux_name, filter);
2021 			goto out_try_fixup;
2022 		}
2023 
2024 		kallsyms_filename = symbol_conf.default_guest_kallsyms;
2025 		if (!kallsyms_filename)
2026 			return -1;
2027 	} else {
2028 		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
2029 		kallsyms_filename = path;
2030 	}
2031 
2032 	err = dso__load_kallsyms(self, kallsyms_filename, map, filter);
2033 	if (err > 0)
2034 		pr_debug("Using %s for symbols\n", kallsyms_filename);
2035 
2036 out_try_fixup:
2037 	if (err > 0) {
2038 		if (kallsyms_filename != NULL) {
2039 			machine__mmap_name(machine, path, sizeof(path));
2040 			dso__set_long_name(self, strdup(path));
2041 		}
2042 		map__fixup_start(map);
2043 		map__fixup_end(map);
2044 	}
2045 
2046 	return err;
2047 }
2048 
2049 static void dsos__add(struct list_head *head, struct dso *dso)
2050 {
2051 	list_add_tail(&dso->node, head);
2052 }
2053 
2054 static struct dso *dsos__find(struct list_head *head, const char *name)
2055 {
2056 	struct dso *pos;
2057 
2058 	list_for_each_entry(pos, head, node)
2059 		if (strcmp(pos->long_name, name) == 0)
2060 			return pos;
2061 	return NULL;
2062 }
2063 
2064 struct dso *__dsos__findnew(struct list_head *head, const char *name)
2065 {
2066 	struct dso *dso = dsos__find(head, name);
2067 
2068 	if (!dso) {
2069 		dso = dso__new(name);
2070 		if (dso != NULL) {
2071 			dsos__add(head, dso);
2072 			dso__set_basename(dso);
2073 		}
2074 	}
2075 
2076 	return dso;
2077 }
2078 
2079 size_t __dsos__fprintf(struct list_head *head, FILE *fp)
2080 {
2081 	struct dso *pos;
2082 	size_t ret = 0;
2083 
2084 	list_for_each_entry(pos, head, node) {
2085 		int i;
2086 		for (i = 0; i < MAP__NR_TYPES; ++i)
2087 			ret += dso__fprintf(pos, i, fp);
2088 	}
2089 
2090 	return ret;
2091 }
2092 
2093 size_t machines__fprintf_dsos(struct rb_root *self, FILE *fp)
2094 {
2095 	struct rb_node *nd;
2096 	size_t ret = 0;
2097 
2098 	for (nd = rb_first(self); nd; nd = rb_next(nd)) {
2099 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
2100 		ret += __dsos__fprintf(&pos->kernel_dsos, fp);
2101 		ret += __dsos__fprintf(&pos->user_dsos, fp);
2102 	}
2103 
2104 	return ret;
2105 }
2106 
2107 static size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp,
2108 				      bool with_hits)
2109 {
2110 	struct dso *pos;
2111 	size_t ret = 0;
2112 
2113 	list_for_each_entry(pos, head, node) {
2114 		if (with_hits && !pos->hit)
2115 			continue;
2116 		ret += dso__fprintf_buildid(pos, fp);
2117 		ret += fprintf(fp, " %s\n", pos->long_name);
2118 	}
2119 	return ret;
2120 }
2121 
2122 size_t machine__fprintf_dsos_buildid(struct machine *self, FILE *fp, bool with_hits)
2123 {
2124 	return __dsos__fprintf_buildid(&self->kernel_dsos, fp, with_hits) +
2125 	       __dsos__fprintf_buildid(&self->user_dsos, fp, with_hits);
2126 }
2127 
2128 size_t machines__fprintf_dsos_buildid(struct rb_root *self, FILE *fp, bool with_hits)
2129 {
2130 	struct rb_node *nd;
2131 	size_t ret = 0;
2132 
2133 	for (nd = rb_first(self); nd; nd = rb_next(nd)) {
2134 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
2135 		ret += machine__fprintf_dsos_buildid(pos, fp, with_hits);
2136 	}
2137 	return ret;
2138 }
2139 
2140 struct dso *dso__new_kernel(const char *name)
2141 {
2142 	struct dso *self = dso__new(name ?: "[kernel.kallsyms]");
2143 
2144 	if (self != NULL) {
2145 		dso__set_short_name(self, "[kernel]");
2146 		self->kernel = DSO_TYPE_KERNEL;
2147 	}
2148 
2149 	return self;
2150 }
2151 
2152 static struct dso *dso__new_guest_kernel(struct machine *machine,
2153 					const char *name)
2154 {
2155 	char bf[PATH_MAX];
2156 	struct dso *self = dso__new(name ?: machine__mmap_name(machine, bf, sizeof(bf)));
2157 
2158 	if (self != NULL) {
2159 		dso__set_short_name(self, "[guest.kernel]");
2160 		self->kernel = DSO_TYPE_GUEST_KERNEL;
2161 	}
2162 
2163 	return self;
2164 }
2165 
2166 void dso__read_running_kernel_build_id(struct dso *self, struct machine *machine)
2167 {
2168 	char path[PATH_MAX];
2169 
2170 	if (machine__is_default_guest(machine))
2171 		return;
2172 	sprintf(path, "%s/sys/kernel/notes", machine->root_dir);
2173 	if (sysfs__read_build_id(path, self->build_id,
2174 				 sizeof(self->build_id)) == 0)
2175 		self->has_build_id = true;
2176 }
2177 
2178 static struct dso *machine__create_kernel(struct machine *self)
2179 {
2180 	const char *vmlinux_name = NULL;
2181 	struct dso *kernel;
2182 
2183 	if (machine__is_host(self)) {
2184 		vmlinux_name = symbol_conf.vmlinux_name;
2185 		kernel = dso__new_kernel(vmlinux_name);
2186 	} else {
2187 		if (machine__is_default_guest(self))
2188 			vmlinux_name = symbol_conf.default_guest_vmlinux_name;
2189 		kernel = dso__new_guest_kernel(self, vmlinux_name);
2190 	}
2191 
2192 	if (kernel != NULL) {
2193 		dso__read_running_kernel_build_id(kernel, self);
2194 		dsos__add(&self->kernel_dsos, kernel);
2195 	}
2196 	return kernel;
2197 }
2198 
2199 struct process_args {
2200 	u64 start;
2201 };
2202 
2203 static int symbol__in_kernel(void *arg, const char *name,
2204 			     char type __used, u64 start, u64 end __used)
2205 {
2206 	struct process_args *args = arg;
2207 
2208 	if (strchr(name, '['))
2209 		return 0;
2210 
2211 	args->start = start;
2212 	return 1;
2213 }
2214 
2215 /* Figure out the start address of kernel map from /proc/kallsyms */
2216 static u64 machine__get_kernel_start_addr(struct machine *machine)
2217 {
2218 	const char *filename;
2219 	char path[PATH_MAX];
2220 	struct process_args args;
2221 
2222 	if (machine__is_host(machine)) {
2223 		filename = "/proc/kallsyms";
2224 	} else {
2225 		if (machine__is_default_guest(machine))
2226 			filename = (char *)symbol_conf.default_guest_kallsyms;
2227 		else {
2228 			sprintf(path, "%s/proc/kallsyms", machine->root_dir);
2229 			filename = path;
2230 		}
2231 	}
2232 
2233 	if (kallsyms__parse(filename, &args, symbol__in_kernel) <= 0)
2234 		return 0;
2235 
2236 	return args.start;
2237 }
2238 
2239 int __machine__create_kernel_maps(struct machine *self, struct dso *kernel)
2240 {
2241 	enum map_type type;
2242 	u64 start = machine__get_kernel_start_addr(self);
2243 
2244 	for (type = 0; type < MAP__NR_TYPES; ++type) {
2245 		struct kmap *kmap;
2246 
2247 		self->vmlinux_maps[type] = map__new2(start, kernel, type);
2248 		if (self->vmlinux_maps[type] == NULL)
2249 			return -1;
2250 
2251 		self->vmlinux_maps[type]->map_ip =
2252 			self->vmlinux_maps[type]->unmap_ip = identity__map_ip;
2253 
2254 		kmap = map__kmap(self->vmlinux_maps[type]);
2255 		kmap->kmaps = &self->kmaps;
2256 		map_groups__insert(&self->kmaps, self->vmlinux_maps[type]);
2257 	}
2258 
2259 	return 0;
2260 }
2261 
2262 void machine__destroy_kernel_maps(struct machine *self)
2263 {
2264 	enum map_type type;
2265 
2266 	for (type = 0; type < MAP__NR_TYPES; ++type) {
2267 		struct kmap *kmap;
2268 
2269 		if (self->vmlinux_maps[type] == NULL)
2270 			continue;
2271 
2272 		kmap = map__kmap(self->vmlinux_maps[type]);
2273 		map_groups__remove(&self->kmaps, self->vmlinux_maps[type]);
2274 		if (kmap->ref_reloc_sym) {
2275 			/*
2276 			 * ref_reloc_sym is shared among all maps, so free just
2277 			 * on one of them.
2278 			 */
2279 			if (type == MAP__FUNCTION) {
2280 				free((char *)kmap->ref_reloc_sym->name);
2281 				kmap->ref_reloc_sym->name = NULL;
2282 				free(kmap->ref_reloc_sym);
2283 			}
2284 			kmap->ref_reloc_sym = NULL;
2285 		}
2286 
2287 		map__delete(self->vmlinux_maps[type]);
2288 		self->vmlinux_maps[type] = NULL;
2289 	}
2290 }
2291 
2292 int machine__create_kernel_maps(struct machine *self)
2293 {
2294 	struct dso *kernel = machine__create_kernel(self);
2295 
2296 	if (kernel == NULL ||
2297 	    __machine__create_kernel_maps(self, kernel) < 0)
2298 		return -1;
2299 
2300 	if (symbol_conf.use_modules && machine__create_modules(self) < 0)
2301 		pr_debug("Problems creating module maps, continuing anyway...\n");
2302 	/*
2303 	 * Now that we have all the maps created, just set the ->end of them:
2304 	 */
2305 	map_groups__fixup_end(&self->kmaps);
2306 	return 0;
2307 }
2308 
2309 static void vmlinux_path__exit(void)
2310 {
2311 	while (--vmlinux_path__nr_entries >= 0) {
2312 		free(vmlinux_path[vmlinux_path__nr_entries]);
2313 		vmlinux_path[vmlinux_path__nr_entries] = NULL;
2314 	}
2315 
2316 	free(vmlinux_path);
2317 	vmlinux_path = NULL;
2318 }
2319 
2320 static int vmlinux_path__init(void)
2321 {
2322 	struct utsname uts;
2323 	char bf[PATH_MAX];
2324 
2325 	vmlinux_path = malloc(sizeof(char *) * 5);
2326 	if (vmlinux_path == NULL)
2327 		return -1;
2328 
2329 	vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux");
2330 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2331 		goto out_fail;
2332 	++vmlinux_path__nr_entries;
2333 	vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux");
2334 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2335 		goto out_fail;
2336 	++vmlinux_path__nr_entries;
2337 
2338 	/* only try running kernel version if no symfs was given */
2339 	if (symbol_conf.symfs[0] != 0)
2340 		return 0;
2341 
2342 	if (uname(&uts) < 0)
2343 		return -1;
2344 
2345 	snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release);
2346 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
2347 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2348 		goto out_fail;
2349 	++vmlinux_path__nr_entries;
2350 	snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", uts.release);
2351 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
2352 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2353 		goto out_fail;
2354 	++vmlinux_path__nr_entries;
2355 	snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
2356 		 uts.release);
2357 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
2358 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2359 		goto out_fail;
2360 	++vmlinux_path__nr_entries;
2361 
2362 	return 0;
2363 
2364 out_fail:
2365 	vmlinux_path__exit();
2366 	return -1;
2367 }
2368 
2369 size_t machine__fprintf_vmlinux_path(struct machine *self, FILE *fp)
2370 {
2371 	int i;
2372 	size_t printed = 0;
2373 	struct dso *kdso = self->vmlinux_maps[MAP__FUNCTION]->dso;
2374 
2375 	if (kdso->has_build_id) {
2376 		char filename[PATH_MAX];
2377 		if (dso__build_id_filename(kdso, filename, sizeof(filename)))
2378 			printed += fprintf(fp, "[0] %s\n", filename);
2379 	}
2380 
2381 	for (i = 0; i < vmlinux_path__nr_entries; ++i)
2382 		printed += fprintf(fp, "[%d] %s\n",
2383 				   i + kdso->has_build_id, vmlinux_path[i]);
2384 
2385 	return printed;
2386 }
2387 
2388 static int setup_list(struct strlist **list, const char *list_str,
2389 		      const char *list_name)
2390 {
2391 	if (list_str == NULL)
2392 		return 0;
2393 
2394 	*list = strlist__new(true, list_str);
2395 	if (!*list) {
2396 		pr_err("problems parsing %s list\n", list_name);
2397 		return -1;
2398 	}
2399 	return 0;
2400 }
2401 
2402 int symbol__init(void)
2403 {
2404 	const char *symfs;
2405 
2406 	if (symbol_conf.initialized)
2407 		return 0;
2408 
2409 	symbol_conf.priv_size = ALIGN(symbol_conf.priv_size, sizeof(u64));
2410 
2411 	elf_version(EV_CURRENT);
2412 	if (symbol_conf.sort_by_name)
2413 		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
2414 					  sizeof(struct symbol));
2415 
2416 	if (symbol_conf.try_vmlinux_path && vmlinux_path__init() < 0)
2417 		return -1;
2418 
2419 	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
2420 		pr_err("'.' is the only non valid --field-separator argument\n");
2421 		return -1;
2422 	}
2423 
2424 	if (setup_list(&symbol_conf.dso_list,
2425 		       symbol_conf.dso_list_str, "dso") < 0)
2426 		return -1;
2427 
2428 	if (setup_list(&symbol_conf.comm_list,
2429 		       symbol_conf.comm_list_str, "comm") < 0)
2430 		goto out_free_dso_list;
2431 
2432 	if (setup_list(&symbol_conf.sym_list,
2433 		       symbol_conf.sym_list_str, "symbol") < 0)
2434 		goto out_free_comm_list;
2435 
2436 	/*
2437 	 * A path to symbols of "/" is identical to ""
2438 	 * reset here for simplicity.
2439 	 */
2440 	symfs = realpath(symbol_conf.symfs, NULL);
2441 	if (symfs == NULL)
2442 		symfs = symbol_conf.symfs;
2443 	if (strcmp(symfs, "/") == 0)
2444 		symbol_conf.symfs = "";
2445 	if (symfs != symbol_conf.symfs)
2446 		free((void *)symfs);
2447 
2448 	symbol_conf.initialized = true;
2449 	return 0;
2450 
2451 out_free_dso_list:
2452 	strlist__delete(symbol_conf.dso_list);
2453 out_free_comm_list:
2454 	strlist__delete(symbol_conf.comm_list);
2455 	return -1;
2456 }
2457 
2458 void symbol__exit(void)
2459 {
2460 	if (!symbol_conf.initialized)
2461 		return;
2462 	strlist__delete(symbol_conf.sym_list);
2463 	strlist__delete(symbol_conf.dso_list);
2464 	strlist__delete(symbol_conf.comm_list);
2465 	vmlinux_path__exit();
2466 	symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2467 	symbol_conf.initialized = false;
2468 }
2469 
2470 int machines__create_kernel_maps(struct rb_root *self, pid_t pid)
2471 {
2472 	struct machine *machine = machines__findnew(self, pid);
2473 
2474 	if (machine == NULL)
2475 		return -1;
2476 
2477 	return machine__create_kernel_maps(machine);
2478 }
2479 
2480 static int hex(char ch)
2481 {
2482 	if ((ch >= '0') && (ch <= '9'))
2483 		return ch - '0';
2484 	if ((ch >= 'a') && (ch <= 'f'))
2485 		return ch - 'a' + 10;
2486 	if ((ch >= 'A') && (ch <= 'F'))
2487 		return ch - 'A' + 10;
2488 	return -1;
2489 }
2490 
2491 /*
2492  * While we find nice hex chars, build a long_val.
2493  * Return number of chars processed.
2494  */
2495 int hex2u64(const char *ptr, u64 *long_val)
2496 {
2497 	const char *p = ptr;
2498 	*long_val = 0;
2499 
2500 	while (*p) {
2501 		const int hex_val = hex(*p);
2502 
2503 		if (hex_val < 0)
2504 			break;
2505 
2506 		*long_val = (*long_val << 4) | hex_val;
2507 		p++;
2508 	}
2509 
2510 	return p - ptr;
2511 }
2512 
2513 char *strxfrchar(char *s, char from, char to)
2514 {
2515 	char *p = s;
2516 
2517 	while ((p = strchr(p, from)) != NULL)
2518 		*p++ = to;
2519 
2520 	return s;
2521 }
2522 
2523 int machines__create_guest_kernel_maps(struct rb_root *self)
2524 {
2525 	int ret = 0;
2526 	struct dirent **namelist = NULL;
2527 	int i, items = 0;
2528 	char path[PATH_MAX];
2529 	pid_t pid;
2530 
2531 	if (symbol_conf.default_guest_vmlinux_name ||
2532 	    symbol_conf.default_guest_modules ||
2533 	    symbol_conf.default_guest_kallsyms) {
2534 		machines__create_kernel_maps(self, DEFAULT_GUEST_KERNEL_ID);
2535 	}
2536 
2537 	if (symbol_conf.guestmount) {
2538 		items = scandir(symbol_conf.guestmount, &namelist, NULL, NULL);
2539 		if (items <= 0)
2540 			return -ENOENT;
2541 		for (i = 0; i < items; i++) {
2542 			if (!isdigit(namelist[i]->d_name[0])) {
2543 				/* Filter out . and .. */
2544 				continue;
2545 			}
2546 			pid = atoi(namelist[i]->d_name);
2547 			sprintf(path, "%s/%s/proc/kallsyms",
2548 				symbol_conf.guestmount,
2549 				namelist[i]->d_name);
2550 			ret = access(path, R_OK);
2551 			if (ret) {
2552 				pr_debug("Can't access file %s\n", path);
2553 				goto failure;
2554 			}
2555 			machines__create_kernel_maps(self, pid);
2556 		}
2557 failure:
2558 		free(namelist);
2559 	}
2560 
2561 	return ret;
2562 }
2563 
2564 void machines__destroy_guest_kernel_maps(struct rb_root *self)
2565 {
2566 	struct rb_node *next = rb_first(self);
2567 
2568 	while (next) {
2569 		struct machine *pos = rb_entry(next, struct machine, rb_node);
2570 
2571 		next = rb_next(&pos->rb_node);
2572 		rb_erase(&pos->rb_node, self);
2573 		machine__delete(pos);
2574 	}
2575 }
2576 
2577 int machine__load_kallsyms(struct machine *self, const char *filename,
2578 			   enum map_type type, symbol_filter_t filter)
2579 {
2580 	struct map *map = self->vmlinux_maps[type];
2581 	int ret = dso__load_kallsyms(map->dso, filename, map, filter);
2582 
2583 	if (ret > 0) {
2584 		dso__set_loaded(map->dso, type);
2585 		/*
2586 		 * Since /proc/kallsyms will have multiple sessions for the
2587 		 * kernel, with modules between them, fixup the end of all
2588 		 * sections.
2589 		 */
2590 		__map_groups__fixup_end(&self->kmaps, type);
2591 	}
2592 
2593 	return ret;
2594 }
2595 
2596 int machine__load_vmlinux_path(struct machine *self, enum map_type type,
2597 			       symbol_filter_t filter)
2598 {
2599 	struct map *map = self->vmlinux_maps[type];
2600 	int ret = dso__load_vmlinux_path(map->dso, map, filter);
2601 
2602 	if (ret > 0) {
2603 		dso__set_loaded(map->dso, type);
2604 		map__reloc_vmlinux(map);
2605 	}
2606 
2607 	return ret;
2608 }
2609