xref: /openbmc/linux/tools/perf/util/symbol.c (revision 565d76cb)
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_map = map__new2(start, curr_dso,
1200 						     map->type);
1201 				if (curr_map == NULL) {
1202 					dso__delete(curr_dso);
1203 					goto out_elf_end;
1204 				}
1205 				curr_map->map_ip = identity__map_ip;
1206 				curr_map->unmap_ip = identity__map_ip;
1207 				curr_dso->symtab_type = self->symtab_type;
1208 				map_groups__insert(kmap->kmaps, curr_map);
1209 				dsos__add(&self->node, curr_dso);
1210 				dso__set_loaded(curr_dso, map->type);
1211 			} else
1212 				curr_dso = curr_map->dso;
1213 
1214 			goto new_symbol;
1215 		}
1216 
1217 		if (curr_dso->adjust_symbols) {
1218 			pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
1219 				  "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
1220 				  (u64)sym.st_value, (u64)shdr.sh_addr,
1221 				  (u64)shdr.sh_offset);
1222 			sym.st_value -= shdr.sh_addr - shdr.sh_offset;
1223 		}
1224 		/*
1225 		 * We need to figure out if the object was created from C++ sources
1226 		 * DWARF DW_compile_unit has this, but we don't always have access
1227 		 * to it...
1228 		 */
1229 		demangled = bfd_demangle(NULL, elf_name, DMGL_PARAMS | DMGL_ANSI);
1230 		if (demangled != NULL)
1231 			elf_name = demangled;
1232 new_symbol:
1233 		f = symbol__new(sym.st_value, sym.st_size,
1234 				GELF_ST_BIND(sym.st_info), elf_name);
1235 		free(demangled);
1236 		if (!f)
1237 			goto out_elf_end;
1238 
1239 		if (filter && filter(curr_map, f))
1240 			symbol__delete(f);
1241 		else {
1242 			symbols__insert(&curr_dso->symbols[curr_map->type], f);
1243 			nr++;
1244 		}
1245 	}
1246 
1247 	/*
1248 	 * For misannotated, zeroed, ASM function sizes.
1249 	 */
1250 	if (nr > 0) {
1251 		symbols__fixup_end(&self->symbols[map->type]);
1252 		if (kmap) {
1253 			/*
1254 			 * We need to fixup this here too because we create new
1255 			 * maps here, for things like vsyscall sections.
1256 			 */
1257 			__map_groups__fixup_end(kmap->kmaps, map->type);
1258 		}
1259 	}
1260 	err = nr;
1261 out_elf_end:
1262 	elf_end(elf);
1263 out_close:
1264 	return err;
1265 }
1266 
1267 static bool dso__build_id_equal(const struct dso *self, u8 *build_id)
1268 {
1269 	return memcmp(self->build_id, build_id, sizeof(self->build_id)) == 0;
1270 }
1271 
1272 bool __dsos__read_build_ids(struct list_head *head, bool with_hits)
1273 {
1274 	bool have_build_id = false;
1275 	struct dso *pos;
1276 
1277 	list_for_each_entry(pos, head, node) {
1278 		if (with_hits && !pos->hit)
1279 			continue;
1280 		if (pos->has_build_id) {
1281 			have_build_id = true;
1282 			continue;
1283 		}
1284 		if (filename__read_build_id(pos->long_name, pos->build_id,
1285 					    sizeof(pos->build_id)) > 0) {
1286 			have_build_id	  = true;
1287 			pos->has_build_id = true;
1288 		}
1289 	}
1290 
1291 	return have_build_id;
1292 }
1293 
1294 /*
1295  * Align offset to 4 bytes as needed for note name and descriptor data.
1296  */
1297 #define NOTE_ALIGN(n) (((n) + 3) & -4U)
1298 
1299 static int elf_read_build_id(Elf *elf, void *bf, size_t size)
1300 {
1301 	int err = -1;
1302 	GElf_Ehdr ehdr;
1303 	GElf_Shdr shdr;
1304 	Elf_Data *data;
1305 	Elf_Scn *sec;
1306 	Elf_Kind ek;
1307 	void *ptr;
1308 
1309 	if (size < BUILD_ID_SIZE)
1310 		goto out;
1311 
1312 	ek = elf_kind(elf);
1313 	if (ek != ELF_K_ELF)
1314 		goto out;
1315 
1316 	if (gelf_getehdr(elf, &ehdr) == NULL) {
1317 		pr_err("%s: cannot get elf header.\n", __func__);
1318 		goto out;
1319 	}
1320 
1321 	sec = elf_section_by_name(elf, &ehdr, &shdr,
1322 				  ".note.gnu.build-id", NULL);
1323 	if (sec == NULL) {
1324 		sec = elf_section_by_name(elf, &ehdr, &shdr,
1325 					  ".notes", NULL);
1326 		if (sec == NULL)
1327 			goto out;
1328 	}
1329 
1330 	data = elf_getdata(sec, NULL);
1331 	if (data == NULL)
1332 		goto out;
1333 
1334 	ptr = data->d_buf;
1335 	while (ptr < (data->d_buf + data->d_size)) {
1336 		GElf_Nhdr *nhdr = ptr;
1337 		int namesz = NOTE_ALIGN(nhdr->n_namesz),
1338 		    descsz = NOTE_ALIGN(nhdr->n_descsz);
1339 		const char *name;
1340 
1341 		ptr += sizeof(*nhdr);
1342 		name = ptr;
1343 		ptr += namesz;
1344 		if (nhdr->n_type == NT_GNU_BUILD_ID &&
1345 		    nhdr->n_namesz == sizeof("GNU")) {
1346 			if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
1347 				memcpy(bf, ptr, BUILD_ID_SIZE);
1348 				err = BUILD_ID_SIZE;
1349 				break;
1350 			}
1351 		}
1352 		ptr += descsz;
1353 	}
1354 
1355 out:
1356 	return err;
1357 }
1358 
1359 int filename__read_build_id(const char *filename, void *bf, size_t size)
1360 {
1361 	int fd, err = -1;
1362 	Elf *elf;
1363 
1364 	if (size < BUILD_ID_SIZE)
1365 		goto out;
1366 
1367 	fd = open(filename, O_RDONLY);
1368 	if (fd < 0)
1369 		goto out;
1370 
1371 	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1372 	if (elf == NULL) {
1373 		pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
1374 		goto out_close;
1375 	}
1376 
1377 	err = elf_read_build_id(elf, bf, size);
1378 
1379 	elf_end(elf);
1380 out_close:
1381 	close(fd);
1382 out:
1383 	return err;
1384 }
1385 
1386 int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
1387 {
1388 	int fd, err = -1;
1389 
1390 	if (size < BUILD_ID_SIZE)
1391 		goto out;
1392 
1393 	fd = open(filename, O_RDONLY);
1394 	if (fd < 0)
1395 		goto out;
1396 
1397 	while (1) {
1398 		char bf[BUFSIZ];
1399 		GElf_Nhdr nhdr;
1400 		int namesz, descsz;
1401 
1402 		if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
1403 			break;
1404 
1405 		namesz = NOTE_ALIGN(nhdr.n_namesz);
1406 		descsz = NOTE_ALIGN(nhdr.n_descsz);
1407 		if (nhdr.n_type == NT_GNU_BUILD_ID &&
1408 		    nhdr.n_namesz == sizeof("GNU")) {
1409 			if (read(fd, bf, namesz) != namesz)
1410 				break;
1411 			if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
1412 				if (read(fd, build_id,
1413 				    BUILD_ID_SIZE) == BUILD_ID_SIZE) {
1414 					err = 0;
1415 					break;
1416 				}
1417 			} else if (read(fd, bf, descsz) != descsz)
1418 				break;
1419 		} else {
1420 			int n = namesz + descsz;
1421 			if (read(fd, bf, n) != n)
1422 				break;
1423 		}
1424 	}
1425 	close(fd);
1426 out:
1427 	return err;
1428 }
1429 
1430 char dso__symtab_origin(const struct dso *self)
1431 {
1432 	static const char origin[] = {
1433 		[SYMTAB__KALLSYMS]	      = 'k',
1434 		[SYMTAB__JAVA_JIT]	      = 'j',
1435 		[SYMTAB__BUILD_ID_CACHE]      = 'B',
1436 		[SYMTAB__FEDORA_DEBUGINFO]    = 'f',
1437 		[SYMTAB__UBUNTU_DEBUGINFO]    = 'u',
1438 		[SYMTAB__BUILDID_DEBUGINFO]   = 'b',
1439 		[SYMTAB__SYSTEM_PATH_DSO]     = 'd',
1440 		[SYMTAB__SYSTEM_PATH_KMODULE] = 'K',
1441 		[SYMTAB__GUEST_KALLSYMS]      =  'g',
1442 		[SYMTAB__GUEST_KMODULE]	      =  'G',
1443 	};
1444 
1445 	if (self == NULL || self->symtab_type == SYMTAB__NOT_FOUND)
1446 		return '!';
1447 	return origin[self->symtab_type];
1448 }
1449 
1450 int dso__load(struct dso *self, struct map *map, symbol_filter_t filter)
1451 {
1452 	int size = PATH_MAX;
1453 	char *name;
1454 	int ret = -1;
1455 	int fd;
1456 	struct machine *machine;
1457 	const char *root_dir;
1458 	int want_symtab;
1459 
1460 	dso__set_loaded(self, map->type);
1461 
1462 	if (self->kernel == DSO_TYPE_KERNEL)
1463 		return dso__load_kernel_sym(self, map, filter);
1464 	else if (self->kernel == DSO_TYPE_GUEST_KERNEL)
1465 		return dso__load_guest_kernel_sym(self, map, filter);
1466 
1467 	if (map->groups && map->groups->machine)
1468 		machine = map->groups->machine;
1469 	else
1470 		machine = NULL;
1471 
1472 	name = malloc(size);
1473 	if (!name)
1474 		return -1;
1475 
1476 	self->adjust_symbols = 0;
1477 
1478 	if (strncmp(self->name, "/tmp/perf-", 10) == 0) {
1479 		ret = dso__load_perf_map(self, map, filter);
1480 		self->symtab_type = ret > 0 ? SYMTAB__JAVA_JIT :
1481 					      SYMTAB__NOT_FOUND;
1482 		return ret;
1483 	}
1484 
1485 	/* Iterate over candidate debug images.
1486 	 * On the first pass, only load images if they have a full symtab.
1487 	 * Failing that, do a second pass where we accept .dynsym also
1488 	 */
1489 	for (self->symtab_type = SYMTAB__BUILD_ID_CACHE, want_symtab = 1;
1490 	     self->symtab_type != SYMTAB__NOT_FOUND;
1491 	     self->symtab_type++) {
1492 		switch (self->symtab_type) {
1493 		case SYMTAB__BUILD_ID_CACHE:
1494 			/* skip the locally configured cache if a symfs is given */
1495 			if (symbol_conf.symfs[0] ||
1496 			    (dso__build_id_filename(self, name, size) == NULL)) {
1497 				continue;
1498 			}
1499 			break;
1500 		case SYMTAB__FEDORA_DEBUGINFO:
1501 			snprintf(name, size, "%s/usr/lib/debug%s.debug",
1502 				 symbol_conf.symfs, self->long_name);
1503 			break;
1504 		case SYMTAB__UBUNTU_DEBUGINFO:
1505 			snprintf(name, size, "%s/usr/lib/debug%s",
1506 				 symbol_conf.symfs, self->long_name);
1507 			break;
1508 		case SYMTAB__BUILDID_DEBUGINFO: {
1509 			char build_id_hex[BUILD_ID_SIZE * 2 + 1];
1510 
1511 			if (!self->has_build_id)
1512 				continue;
1513 
1514 			build_id__sprintf(self->build_id,
1515 					  sizeof(self->build_id),
1516 					  build_id_hex);
1517 			snprintf(name, size,
1518 				 "%s/usr/lib/debug/.build-id/%.2s/%s.debug",
1519 				 symbol_conf.symfs, build_id_hex, build_id_hex + 2);
1520 			}
1521 			break;
1522 		case SYMTAB__SYSTEM_PATH_DSO:
1523 			snprintf(name, size, "%s%s",
1524 			     symbol_conf.symfs, self->long_name);
1525 			break;
1526 		case SYMTAB__GUEST_KMODULE:
1527 			if (map->groups && machine)
1528 				root_dir = machine->root_dir;
1529 			else
1530 				root_dir = "";
1531 			snprintf(name, size, "%s%s%s", symbol_conf.symfs,
1532 				 root_dir, self->long_name);
1533 			break;
1534 
1535 		case SYMTAB__SYSTEM_PATH_KMODULE:
1536 			snprintf(name, size, "%s%s", symbol_conf.symfs,
1537 				 self->long_name);
1538 			break;
1539 
1540 		default:
1541 			/*
1542 			 * If we wanted a full symtab but no image had one,
1543 			 * relax our requirements and repeat the search.
1544 			 */
1545 			if (want_symtab) {
1546 				want_symtab = 0;
1547 				self->symtab_type = SYMTAB__BUILD_ID_CACHE;
1548 			} else
1549 				continue;
1550 		}
1551 
1552 		/* Name is now the name of the next image to try */
1553 		fd = open(name, O_RDONLY);
1554 		if (fd < 0)
1555 			continue;
1556 
1557 		ret = dso__load_sym(self, map, name, fd, filter, 0,
1558 				    want_symtab);
1559 		close(fd);
1560 
1561 		/*
1562 		 * Some people seem to have debuginfo files _WITHOUT_ debug
1563 		 * info!?!?
1564 		 */
1565 		if (!ret)
1566 			continue;
1567 
1568 		if (ret > 0) {
1569 			int nr_plt = dso__synthesize_plt_symbols(self, map, filter);
1570 			if (nr_plt > 0)
1571 				ret += nr_plt;
1572 			break;
1573 		}
1574 	}
1575 
1576 	free(name);
1577 	if (ret < 0 && strstr(self->name, " (deleted)") != NULL)
1578 		return 0;
1579 	return ret;
1580 }
1581 
1582 struct map *map_groups__find_by_name(struct map_groups *self,
1583 				     enum map_type type, const char *name)
1584 {
1585 	struct rb_node *nd;
1586 
1587 	for (nd = rb_first(&self->maps[type]); nd; nd = rb_next(nd)) {
1588 		struct map *map = rb_entry(nd, struct map, rb_node);
1589 
1590 		if (map->dso && strcmp(map->dso->short_name, name) == 0)
1591 			return map;
1592 	}
1593 
1594 	return NULL;
1595 }
1596 
1597 static int dso__kernel_module_get_build_id(struct dso *self,
1598 				const char *root_dir)
1599 {
1600 	char filename[PATH_MAX];
1601 	/*
1602 	 * kernel module short names are of the form "[module]" and
1603 	 * we need just "module" here.
1604 	 */
1605 	const char *name = self->short_name + 1;
1606 
1607 	snprintf(filename, sizeof(filename),
1608 		 "%s/sys/module/%.*s/notes/.note.gnu.build-id",
1609 		 root_dir, (int)strlen(name) - 1, name);
1610 
1611 	if (sysfs__read_build_id(filename, self->build_id,
1612 				 sizeof(self->build_id)) == 0)
1613 		self->has_build_id = true;
1614 
1615 	return 0;
1616 }
1617 
1618 static int map_groups__set_modules_path_dir(struct map_groups *self,
1619 				const char *dir_name)
1620 {
1621 	struct dirent *dent;
1622 	DIR *dir = opendir(dir_name);
1623 	int ret = 0;
1624 
1625 	if (!dir) {
1626 		pr_debug("%s: cannot open %s dir\n", __func__, dir_name);
1627 		return -1;
1628 	}
1629 
1630 	while ((dent = readdir(dir)) != NULL) {
1631 		char path[PATH_MAX];
1632 		struct stat st;
1633 
1634 		/*sshfs might return bad dent->d_type, so we have to stat*/
1635 		sprintf(path, "%s/%s", dir_name, dent->d_name);
1636 		if (stat(path, &st))
1637 			continue;
1638 
1639 		if (S_ISDIR(st.st_mode)) {
1640 			if (!strcmp(dent->d_name, ".") ||
1641 			    !strcmp(dent->d_name, ".."))
1642 				continue;
1643 
1644 			snprintf(path, sizeof(path), "%s/%s",
1645 				 dir_name, dent->d_name);
1646 			ret = map_groups__set_modules_path_dir(self, path);
1647 			if (ret < 0)
1648 				goto out;
1649 		} else {
1650 			char *dot = strrchr(dent->d_name, '.'),
1651 			     dso_name[PATH_MAX];
1652 			struct map *map;
1653 			char *long_name;
1654 
1655 			if (dot == NULL || strcmp(dot, ".ko"))
1656 				continue;
1657 			snprintf(dso_name, sizeof(dso_name), "[%.*s]",
1658 				 (int)(dot - dent->d_name), dent->d_name);
1659 
1660 			strxfrchar(dso_name, '-', '_');
1661 			map = map_groups__find_by_name(self, MAP__FUNCTION, dso_name);
1662 			if (map == NULL)
1663 				continue;
1664 
1665 			snprintf(path, sizeof(path), "%s/%s",
1666 				 dir_name, dent->d_name);
1667 
1668 			long_name = strdup(path);
1669 			if (long_name == NULL) {
1670 				ret = -1;
1671 				goto out;
1672 			}
1673 			dso__set_long_name(map->dso, long_name);
1674 			map->dso->lname_alloc = 1;
1675 			dso__kernel_module_get_build_id(map->dso, "");
1676 		}
1677 	}
1678 
1679 out:
1680 	closedir(dir);
1681 	return ret;
1682 }
1683 
1684 static char *get_kernel_version(const char *root_dir)
1685 {
1686 	char version[PATH_MAX];
1687 	FILE *file;
1688 	char *name, *tmp;
1689 	const char *prefix = "Linux version ";
1690 
1691 	sprintf(version, "%s/proc/version", root_dir);
1692 	file = fopen(version, "r");
1693 	if (!file)
1694 		return NULL;
1695 
1696 	version[0] = '\0';
1697 	tmp = fgets(version, sizeof(version), file);
1698 	fclose(file);
1699 
1700 	name = strstr(version, prefix);
1701 	if (!name)
1702 		return NULL;
1703 	name += strlen(prefix);
1704 	tmp = strchr(name, ' ');
1705 	if (tmp)
1706 		*tmp = '\0';
1707 
1708 	return strdup(name);
1709 }
1710 
1711 static int machine__set_modules_path(struct machine *self)
1712 {
1713 	char *version;
1714 	char modules_path[PATH_MAX];
1715 
1716 	version = get_kernel_version(self->root_dir);
1717 	if (!version)
1718 		return -1;
1719 
1720 	snprintf(modules_path, sizeof(modules_path), "%s/lib/modules/%s/kernel",
1721 		 self->root_dir, version);
1722 	free(version);
1723 
1724 	return map_groups__set_modules_path_dir(&self->kmaps, modules_path);
1725 }
1726 
1727 /*
1728  * Constructor variant for modules (where we know from /proc/modules where
1729  * they are loaded) and for vmlinux, where only after we load all the
1730  * symbols we'll know where it starts and ends.
1731  */
1732 static struct map *map__new2(u64 start, struct dso *dso, enum map_type type)
1733 {
1734 	struct map *self = calloc(1, (sizeof(*self) +
1735 				      (dso->kernel ? sizeof(struct kmap) : 0)));
1736 	if (self != NULL) {
1737 		/*
1738 		 * ->end will be filled after we load all the symbols
1739 		 */
1740 		map__init(self, type, start, 0, 0, dso);
1741 	}
1742 
1743 	return self;
1744 }
1745 
1746 struct map *machine__new_module(struct machine *self, u64 start,
1747 				const char *filename)
1748 {
1749 	struct map *map;
1750 	struct dso *dso = __dsos__findnew(&self->kernel_dsos, filename);
1751 
1752 	if (dso == NULL)
1753 		return NULL;
1754 
1755 	map = map__new2(start, dso, MAP__FUNCTION);
1756 	if (map == NULL)
1757 		return NULL;
1758 
1759 	if (machine__is_host(self))
1760 		dso->symtab_type = SYMTAB__SYSTEM_PATH_KMODULE;
1761 	else
1762 		dso->symtab_type = SYMTAB__GUEST_KMODULE;
1763 	map_groups__insert(&self->kmaps, map);
1764 	return map;
1765 }
1766 
1767 static int machine__create_modules(struct machine *self)
1768 {
1769 	char *line = NULL;
1770 	size_t n;
1771 	FILE *file;
1772 	struct map *map;
1773 	const char *modules;
1774 	char path[PATH_MAX];
1775 
1776 	if (machine__is_default_guest(self))
1777 		modules = symbol_conf.default_guest_modules;
1778 	else {
1779 		sprintf(path, "%s/proc/modules", self->root_dir);
1780 		modules = path;
1781 	}
1782 
1783 	file = fopen(modules, "r");
1784 	if (file == NULL)
1785 		return -1;
1786 
1787 	while (!feof(file)) {
1788 		char name[PATH_MAX];
1789 		u64 start;
1790 		char *sep;
1791 		int line_len;
1792 
1793 		line_len = getline(&line, &n, file);
1794 		if (line_len < 0)
1795 			break;
1796 
1797 		if (!line)
1798 			goto out_failure;
1799 
1800 		line[--line_len] = '\0'; /* \n */
1801 
1802 		sep = strrchr(line, 'x');
1803 		if (sep == NULL)
1804 			continue;
1805 
1806 		hex2u64(sep + 1, &start);
1807 
1808 		sep = strchr(line, ' ');
1809 		if (sep == NULL)
1810 			continue;
1811 
1812 		*sep = '\0';
1813 
1814 		snprintf(name, sizeof(name), "[%s]", line);
1815 		map = machine__new_module(self, start, name);
1816 		if (map == NULL)
1817 			goto out_delete_line;
1818 		dso__kernel_module_get_build_id(map->dso, self->root_dir);
1819 	}
1820 
1821 	free(line);
1822 	fclose(file);
1823 
1824 	return machine__set_modules_path(self);
1825 
1826 out_delete_line:
1827 	free(line);
1828 out_failure:
1829 	return -1;
1830 }
1831 
1832 int dso__load_vmlinux(struct dso *self, struct map *map,
1833 		      const char *vmlinux, symbol_filter_t filter)
1834 {
1835 	int err = -1, fd;
1836 	char symfs_vmlinux[PATH_MAX];
1837 
1838 	snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s",
1839 		 symbol_conf.symfs, vmlinux);
1840 	fd = open(symfs_vmlinux, O_RDONLY);
1841 	if (fd < 0)
1842 		return -1;
1843 
1844 	dso__set_loaded(self, map->type);
1845 	err = dso__load_sym(self, map, symfs_vmlinux, fd, filter, 0, 0);
1846 	close(fd);
1847 
1848 	if (err > 0)
1849 		pr_debug("Using %s for symbols\n", symfs_vmlinux);
1850 
1851 	return err;
1852 }
1853 
1854 int dso__load_vmlinux_path(struct dso *self, struct map *map,
1855 			   symbol_filter_t filter)
1856 {
1857 	int i, err = 0;
1858 	char *filename;
1859 
1860 	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
1861 		 vmlinux_path__nr_entries + 1);
1862 
1863 	filename = dso__build_id_filename(self, NULL, 0);
1864 	if (filename != NULL) {
1865 		err = dso__load_vmlinux(self, map, filename, filter);
1866 		if (err > 0) {
1867 			dso__set_long_name(self, filename);
1868 			goto out;
1869 		}
1870 		free(filename);
1871 	}
1872 
1873 	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
1874 		err = dso__load_vmlinux(self, map, vmlinux_path[i], filter);
1875 		if (err > 0) {
1876 			dso__set_long_name(self, strdup(vmlinux_path[i]));
1877 			break;
1878 		}
1879 	}
1880 out:
1881 	return err;
1882 }
1883 
1884 static int dso__load_kernel_sym(struct dso *self, struct map *map,
1885 				symbol_filter_t filter)
1886 {
1887 	int err;
1888 	const char *kallsyms_filename = NULL;
1889 	char *kallsyms_allocated_filename = NULL;
1890 	/*
1891 	 * Step 1: if the user specified a kallsyms or vmlinux filename, use
1892 	 * it and only it, reporting errors to the user if it cannot be used.
1893 	 *
1894 	 * For instance, try to analyse an ARM perf.data file _without_ a
1895 	 * build-id, or if the user specifies the wrong path to the right
1896 	 * vmlinux file, obviously we can't fallback to another vmlinux (a
1897 	 * x86_86 one, on the machine where analysis is being performed, say),
1898 	 * or worse, /proc/kallsyms.
1899 	 *
1900 	 * If the specified file _has_ a build-id and there is a build-id
1901 	 * section in the perf.data file, we will still do the expected
1902 	 * validation in dso__load_vmlinux and will bail out if they don't
1903 	 * match.
1904 	 */
1905 	if (symbol_conf.kallsyms_name != NULL) {
1906 		kallsyms_filename = symbol_conf.kallsyms_name;
1907 		goto do_kallsyms;
1908 	}
1909 
1910 	if (symbol_conf.vmlinux_name != NULL) {
1911 		err = dso__load_vmlinux(self, map,
1912 					symbol_conf.vmlinux_name, filter);
1913 		if (err > 0) {
1914 			dso__set_long_name(self,
1915 					   strdup(symbol_conf.vmlinux_name));
1916 			goto out_fixup;
1917 		}
1918 		return err;
1919 	}
1920 
1921 	if (vmlinux_path != NULL) {
1922 		err = dso__load_vmlinux_path(self, map, filter);
1923 		if (err > 0)
1924 			goto out_fixup;
1925 	}
1926 
1927 	/* do not try local files if a symfs was given */
1928 	if (symbol_conf.symfs[0] != 0)
1929 		return -1;
1930 
1931 	/*
1932 	 * Say the kernel DSO was created when processing the build-id header table,
1933 	 * we have a build-id, so check if it is the same as the running kernel,
1934 	 * using it if it is.
1935 	 */
1936 	if (self->has_build_id) {
1937 		u8 kallsyms_build_id[BUILD_ID_SIZE];
1938 		char sbuild_id[BUILD_ID_SIZE * 2 + 1];
1939 
1940 		if (sysfs__read_build_id("/sys/kernel/notes", kallsyms_build_id,
1941 					 sizeof(kallsyms_build_id)) == 0) {
1942 			if (dso__build_id_equal(self, kallsyms_build_id)) {
1943 				kallsyms_filename = "/proc/kallsyms";
1944 				goto do_kallsyms;
1945 			}
1946 		}
1947 		/*
1948 		 * Now look if we have it on the build-id cache in
1949 		 * $HOME/.debug/[kernel.kallsyms].
1950 		 */
1951 		build_id__sprintf(self->build_id, sizeof(self->build_id),
1952 				  sbuild_id);
1953 
1954 		if (asprintf(&kallsyms_allocated_filename,
1955 			     "%s/.debug/[kernel.kallsyms]/%s",
1956 			     getenv("HOME"), sbuild_id) == -1) {
1957 			pr_err("Not enough memory for kallsyms file lookup\n");
1958 			return -1;
1959 		}
1960 
1961 		kallsyms_filename = kallsyms_allocated_filename;
1962 
1963 		if (access(kallsyms_filename, F_OK)) {
1964 			pr_err("No kallsyms or vmlinux with build-id %s "
1965 			       "was found\n", sbuild_id);
1966 			free(kallsyms_allocated_filename);
1967 			return -1;
1968 		}
1969 	} else {
1970 		/*
1971 		 * Last resort, if we don't have a build-id and couldn't find
1972 		 * any vmlinux file, try the running kernel kallsyms table.
1973 		 */
1974 		kallsyms_filename = "/proc/kallsyms";
1975 	}
1976 
1977 do_kallsyms:
1978 	err = dso__load_kallsyms(self, kallsyms_filename, map, filter);
1979 	if (err > 0)
1980 		pr_debug("Using %s for symbols\n", kallsyms_filename);
1981 	free(kallsyms_allocated_filename);
1982 
1983 	if (err > 0) {
1984 out_fixup:
1985 		if (kallsyms_filename != NULL)
1986 			dso__set_long_name(self, strdup("[kernel.kallsyms]"));
1987 		map__fixup_start(map);
1988 		map__fixup_end(map);
1989 	}
1990 
1991 	return err;
1992 }
1993 
1994 static int dso__load_guest_kernel_sym(struct dso *self, struct map *map,
1995 				symbol_filter_t filter)
1996 {
1997 	int err;
1998 	const char *kallsyms_filename = NULL;
1999 	struct machine *machine;
2000 	char path[PATH_MAX];
2001 
2002 	if (!map->groups) {
2003 		pr_debug("Guest kernel map hasn't the point to groups\n");
2004 		return -1;
2005 	}
2006 	machine = map->groups->machine;
2007 
2008 	if (machine__is_default_guest(machine)) {
2009 		/*
2010 		 * if the user specified a vmlinux filename, use it and only
2011 		 * it, reporting errors to the user if it cannot be used.
2012 		 * Or use file guest_kallsyms inputted by user on commandline
2013 		 */
2014 		if (symbol_conf.default_guest_vmlinux_name != NULL) {
2015 			err = dso__load_vmlinux(self, map,
2016 				symbol_conf.default_guest_vmlinux_name, filter);
2017 			goto out_try_fixup;
2018 		}
2019 
2020 		kallsyms_filename = symbol_conf.default_guest_kallsyms;
2021 		if (!kallsyms_filename)
2022 			return -1;
2023 	} else {
2024 		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
2025 		kallsyms_filename = path;
2026 	}
2027 
2028 	err = dso__load_kallsyms(self, kallsyms_filename, map, filter);
2029 	if (err > 0)
2030 		pr_debug("Using %s for symbols\n", kallsyms_filename);
2031 
2032 out_try_fixup:
2033 	if (err > 0) {
2034 		if (kallsyms_filename != NULL) {
2035 			machine__mmap_name(machine, path, sizeof(path));
2036 			dso__set_long_name(self, strdup(path));
2037 		}
2038 		map__fixup_start(map);
2039 		map__fixup_end(map);
2040 	}
2041 
2042 	return err;
2043 }
2044 
2045 static void dsos__add(struct list_head *head, struct dso *dso)
2046 {
2047 	list_add_tail(&dso->node, head);
2048 }
2049 
2050 static struct dso *dsos__find(struct list_head *head, const char *name)
2051 {
2052 	struct dso *pos;
2053 
2054 	list_for_each_entry(pos, head, node)
2055 		if (strcmp(pos->long_name, name) == 0)
2056 			return pos;
2057 	return NULL;
2058 }
2059 
2060 struct dso *__dsos__findnew(struct list_head *head, const char *name)
2061 {
2062 	struct dso *dso = dsos__find(head, name);
2063 
2064 	if (!dso) {
2065 		dso = dso__new(name);
2066 		if (dso != NULL) {
2067 			dsos__add(head, dso);
2068 			dso__set_basename(dso);
2069 		}
2070 	}
2071 
2072 	return dso;
2073 }
2074 
2075 size_t __dsos__fprintf(struct list_head *head, FILE *fp)
2076 {
2077 	struct dso *pos;
2078 	size_t ret = 0;
2079 
2080 	list_for_each_entry(pos, head, node) {
2081 		int i;
2082 		for (i = 0; i < MAP__NR_TYPES; ++i)
2083 			ret += dso__fprintf(pos, i, fp);
2084 	}
2085 
2086 	return ret;
2087 }
2088 
2089 size_t machines__fprintf_dsos(struct rb_root *self, FILE *fp)
2090 {
2091 	struct rb_node *nd;
2092 	size_t ret = 0;
2093 
2094 	for (nd = rb_first(self); nd; nd = rb_next(nd)) {
2095 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
2096 		ret += __dsos__fprintf(&pos->kernel_dsos, fp);
2097 		ret += __dsos__fprintf(&pos->user_dsos, fp);
2098 	}
2099 
2100 	return ret;
2101 }
2102 
2103 static size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp,
2104 				      bool with_hits)
2105 {
2106 	struct dso *pos;
2107 	size_t ret = 0;
2108 
2109 	list_for_each_entry(pos, head, node) {
2110 		if (with_hits && !pos->hit)
2111 			continue;
2112 		ret += dso__fprintf_buildid(pos, fp);
2113 		ret += fprintf(fp, " %s\n", pos->long_name);
2114 	}
2115 	return ret;
2116 }
2117 
2118 size_t machine__fprintf_dsos_buildid(struct machine *self, FILE *fp, bool with_hits)
2119 {
2120 	return __dsos__fprintf_buildid(&self->kernel_dsos, fp, with_hits) +
2121 	       __dsos__fprintf_buildid(&self->user_dsos, fp, with_hits);
2122 }
2123 
2124 size_t machines__fprintf_dsos_buildid(struct rb_root *self, FILE *fp, bool with_hits)
2125 {
2126 	struct rb_node *nd;
2127 	size_t ret = 0;
2128 
2129 	for (nd = rb_first(self); nd; nd = rb_next(nd)) {
2130 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
2131 		ret += machine__fprintf_dsos_buildid(pos, fp, with_hits);
2132 	}
2133 	return ret;
2134 }
2135 
2136 struct dso *dso__new_kernel(const char *name)
2137 {
2138 	struct dso *self = dso__new(name ?: "[kernel.kallsyms]");
2139 
2140 	if (self != NULL) {
2141 		dso__set_short_name(self, "[kernel]");
2142 		self->kernel = DSO_TYPE_KERNEL;
2143 	}
2144 
2145 	return self;
2146 }
2147 
2148 static struct dso *dso__new_guest_kernel(struct machine *machine,
2149 					const char *name)
2150 {
2151 	char bf[PATH_MAX];
2152 	struct dso *self = dso__new(name ?: machine__mmap_name(machine, bf, sizeof(bf)));
2153 
2154 	if (self != NULL) {
2155 		dso__set_short_name(self, "[guest.kernel]");
2156 		self->kernel = DSO_TYPE_GUEST_KERNEL;
2157 	}
2158 
2159 	return self;
2160 }
2161 
2162 void dso__read_running_kernel_build_id(struct dso *self, struct machine *machine)
2163 {
2164 	char path[PATH_MAX];
2165 
2166 	if (machine__is_default_guest(machine))
2167 		return;
2168 	sprintf(path, "%s/sys/kernel/notes", machine->root_dir);
2169 	if (sysfs__read_build_id(path, self->build_id,
2170 				 sizeof(self->build_id)) == 0)
2171 		self->has_build_id = true;
2172 }
2173 
2174 static struct dso *machine__create_kernel(struct machine *self)
2175 {
2176 	const char *vmlinux_name = NULL;
2177 	struct dso *kernel;
2178 
2179 	if (machine__is_host(self)) {
2180 		vmlinux_name = symbol_conf.vmlinux_name;
2181 		kernel = dso__new_kernel(vmlinux_name);
2182 	} else {
2183 		if (machine__is_default_guest(self))
2184 			vmlinux_name = symbol_conf.default_guest_vmlinux_name;
2185 		kernel = dso__new_guest_kernel(self, vmlinux_name);
2186 	}
2187 
2188 	if (kernel != NULL) {
2189 		dso__read_running_kernel_build_id(kernel, self);
2190 		dsos__add(&self->kernel_dsos, kernel);
2191 	}
2192 	return kernel;
2193 }
2194 
2195 struct process_args {
2196 	u64 start;
2197 };
2198 
2199 static int symbol__in_kernel(void *arg, const char *name,
2200 			     char type __used, u64 start, u64 end __used)
2201 {
2202 	struct process_args *args = arg;
2203 
2204 	if (strchr(name, '['))
2205 		return 0;
2206 
2207 	args->start = start;
2208 	return 1;
2209 }
2210 
2211 /* Figure out the start address of kernel map from /proc/kallsyms */
2212 static u64 machine__get_kernel_start_addr(struct machine *machine)
2213 {
2214 	const char *filename;
2215 	char path[PATH_MAX];
2216 	struct process_args args;
2217 
2218 	if (machine__is_host(machine)) {
2219 		filename = "/proc/kallsyms";
2220 	} else {
2221 		if (machine__is_default_guest(machine))
2222 			filename = (char *)symbol_conf.default_guest_kallsyms;
2223 		else {
2224 			sprintf(path, "%s/proc/kallsyms", machine->root_dir);
2225 			filename = path;
2226 		}
2227 	}
2228 
2229 	if (kallsyms__parse(filename, &args, symbol__in_kernel) <= 0)
2230 		return 0;
2231 
2232 	return args.start;
2233 }
2234 
2235 int __machine__create_kernel_maps(struct machine *self, struct dso *kernel)
2236 {
2237 	enum map_type type;
2238 	u64 start = machine__get_kernel_start_addr(self);
2239 
2240 	for (type = 0; type < MAP__NR_TYPES; ++type) {
2241 		struct kmap *kmap;
2242 
2243 		self->vmlinux_maps[type] = map__new2(start, kernel, type);
2244 		if (self->vmlinux_maps[type] == NULL)
2245 			return -1;
2246 
2247 		self->vmlinux_maps[type]->map_ip =
2248 			self->vmlinux_maps[type]->unmap_ip = identity__map_ip;
2249 
2250 		kmap = map__kmap(self->vmlinux_maps[type]);
2251 		kmap->kmaps = &self->kmaps;
2252 		map_groups__insert(&self->kmaps, self->vmlinux_maps[type]);
2253 	}
2254 
2255 	return 0;
2256 }
2257 
2258 void machine__destroy_kernel_maps(struct machine *self)
2259 {
2260 	enum map_type type;
2261 
2262 	for (type = 0; type < MAP__NR_TYPES; ++type) {
2263 		struct kmap *kmap;
2264 
2265 		if (self->vmlinux_maps[type] == NULL)
2266 			continue;
2267 
2268 		kmap = map__kmap(self->vmlinux_maps[type]);
2269 		map_groups__remove(&self->kmaps, self->vmlinux_maps[type]);
2270 		if (kmap->ref_reloc_sym) {
2271 			/*
2272 			 * ref_reloc_sym is shared among all maps, so free just
2273 			 * on one of them.
2274 			 */
2275 			if (type == MAP__FUNCTION) {
2276 				free((char *)kmap->ref_reloc_sym->name);
2277 				kmap->ref_reloc_sym->name = NULL;
2278 				free(kmap->ref_reloc_sym);
2279 			}
2280 			kmap->ref_reloc_sym = NULL;
2281 		}
2282 
2283 		map__delete(self->vmlinux_maps[type]);
2284 		self->vmlinux_maps[type] = NULL;
2285 	}
2286 }
2287 
2288 int machine__create_kernel_maps(struct machine *self)
2289 {
2290 	struct dso *kernel = machine__create_kernel(self);
2291 
2292 	if (kernel == NULL ||
2293 	    __machine__create_kernel_maps(self, kernel) < 0)
2294 		return -1;
2295 
2296 	if (symbol_conf.use_modules && machine__create_modules(self) < 0)
2297 		pr_debug("Problems creating module maps, continuing anyway...\n");
2298 	/*
2299 	 * Now that we have all the maps created, just set the ->end of them:
2300 	 */
2301 	map_groups__fixup_end(&self->kmaps);
2302 	return 0;
2303 }
2304 
2305 static void vmlinux_path__exit(void)
2306 {
2307 	while (--vmlinux_path__nr_entries >= 0) {
2308 		free(vmlinux_path[vmlinux_path__nr_entries]);
2309 		vmlinux_path[vmlinux_path__nr_entries] = NULL;
2310 	}
2311 
2312 	free(vmlinux_path);
2313 	vmlinux_path = NULL;
2314 }
2315 
2316 static int vmlinux_path__init(void)
2317 {
2318 	struct utsname uts;
2319 	char bf[PATH_MAX];
2320 
2321 	vmlinux_path = malloc(sizeof(char *) * 5);
2322 	if (vmlinux_path == NULL)
2323 		return -1;
2324 
2325 	vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux");
2326 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2327 		goto out_fail;
2328 	++vmlinux_path__nr_entries;
2329 	vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux");
2330 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2331 		goto out_fail;
2332 	++vmlinux_path__nr_entries;
2333 
2334 	/* only try running kernel version if no symfs was given */
2335 	if (symbol_conf.symfs[0] != 0)
2336 		return 0;
2337 
2338 	if (uname(&uts) < 0)
2339 		return -1;
2340 
2341 	snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release);
2342 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
2343 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2344 		goto out_fail;
2345 	++vmlinux_path__nr_entries;
2346 	snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", uts.release);
2347 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
2348 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2349 		goto out_fail;
2350 	++vmlinux_path__nr_entries;
2351 	snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
2352 		 uts.release);
2353 	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
2354 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2355 		goto out_fail;
2356 	++vmlinux_path__nr_entries;
2357 
2358 	return 0;
2359 
2360 out_fail:
2361 	vmlinux_path__exit();
2362 	return -1;
2363 }
2364 
2365 size_t machine__fprintf_vmlinux_path(struct machine *self, FILE *fp)
2366 {
2367 	int i;
2368 	size_t printed = 0;
2369 	struct dso *kdso = self->vmlinux_maps[MAP__FUNCTION]->dso;
2370 
2371 	if (kdso->has_build_id) {
2372 		char filename[PATH_MAX];
2373 		if (dso__build_id_filename(kdso, filename, sizeof(filename)))
2374 			printed += fprintf(fp, "[0] %s\n", filename);
2375 	}
2376 
2377 	for (i = 0; i < vmlinux_path__nr_entries; ++i)
2378 		printed += fprintf(fp, "[%d] %s\n",
2379 				   i + kdso->has_build_id, vmlinux_path[i]);
2380 
2381 	return printed;
2382 }
2383 
2384 static int setup_list(struct strlist **list, const char *list_str,
2385 		      const char *list_name)
2386 {
2387 	if (list_str == NULL)
2388 		return 0;
2389 
2390 	*list = strlist__new(true, list_str);
2391 	if (!*list) {
2392 		pr_err("problems parsing %s list\n", list_name);
2393 		return -1;
2394 	}
2395 	return 0;
2396 }
2397 
2398 int symbol__init(void)
2399 {
2400 	const char *symfs;
2401 
2402 	if (symbol_conf.initialized)
2403 		return 0;
2404 
2405 	elf_version(EV_CURRENT);
2406 	if (symbol_conf.sort_by_name)
2407 		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
2408 					  sizeof(struct symbol));
2409 
2410 	if (symbol_conf.try_vmlinux_path && vmlinux_path__init() < 0)
2411 		return -1;
2412 
2413 	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
2414 		pr_err("'.' is the only non valid --field-separator argument\n");
2415 		return -1;
2416 	}
2417 
2418 	if (setup_list(&symbol_conf.dso_list,
2419 		       symbol_conf.dso_list_str, "dso") < 0)
2420 		return -1;
2421 
2422 	if (setup_list(&symbol_conf.comm_list,
2423 		       symbol_conf.comm_list_str, "comm") < 0)
2424 		goto out_free_dso_list;
2425 
2426 	if (setup_list(&symbol_conf.sym_list,
2427 		       symbol_conf.sym_list_str, "symbol") < 0)
2428 		goto out_free_comm_list;
2429 
2430 	/*
2431 	 * A path to symbols of "/" is identical to ""
2432 	 * reset here for simplicity.
2433 	 */
2434 	symfs = realpath(symbol_conf.symfs, NULL);
2435 	if (symfs == NULL)
2436 		symfs = symbol_conf.symfs;
2437 	if (strcmp(symfs, "/") == 0)
2438 		symbol_conf.symfs = "";
2439 	if (symfs != symbol_conf.symfs)
2440 		free((void *)symfs);
2441 
2442 	symbol_conf.initialized = true;
2443 	return 0;
2444 
2445 out_free_dso_list:
2446 	strlist__delete(symbol_conf.dso_list);
2447 out_free_comm_list:
2448 	strlist__delete(symbol_conf.comm_list);
2449 	return -1;
2450 }
2451 
2452 void symbol__exit(void)
2453 {
2454 	if (!symbol_conf.initialized)
2455 		return;
2456 	strlist__delete(symbol_conf.sym_list);
2457 	strlist__delete(symbol_conf.dso_list);
2458 	strlist__delete(symbol_conf.comm_list);
2459 	vmlinux_path__exit();
2460 	symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2461 	symbol_conf.initialized = false;
2462 }
2463 
2464 int machines__create_kernel_maps(struct rb_root *self, pid_t pid)
2465 {
2466 	struct machine *machine = machines__findnew(self, pid);
2467 
2468 	if (machine == NULL)
2469 		return -1;
2470 
2471 	return machine__create_kernel_maps(machine);
2472 }
2473 
2474 static int hex(char ch)
2475 {
2476 	if ((ch >= '0') && (ch <= '9'))
2477 		return ch - '0';
2478 	if ((ch >= 'a') && (ch <= 'f'))
2479 		return ch - 'a' + 10;
2480 	if ((ch >= 'A') && (ch <= 'F'))
2481 		return ch - 'A' + 10;
2482 	return -1;
2483 }
2484 
2485 /*
2486  * While we find nice hex chars, build a long_val.
2487  * Return number of chars processed.
2488  */
2489 int hex2u64(const char *ptr, u64 *long_val)
2490 {
2491 	const char *p = ptr;
2492 	*long_val = 0;
2493 
2494 	while (*p) {
2495 		const int hex_val = hex(*p);
2496 
2497 		if (hex_val < 0)
2498 			break;
2499 
2500 		*long_val = (*long_val << 4) | hex_val;
2501 		p++;
2502 	}
2503 
2504 	return p - ptr;
2505 }
2506 
2507 char *strxfrchar(char *s, char from, char to)
2508 {
2509 	char *p = s;
2510 
2511 	while ((p = strchr(p, from)) != NULL)
2512 		*p++ = to;
2513 
2514 	return s;
2515 }
2516 
2517 int machines__create_guest_kernel_maps(struct rb_root *self)
2518 {
2519 	int ret = 0;
2520 	struct dirent **namelist = NULL;
2521 	int i, items = 0;
2522 	char path[PATH_MAX];
2523 	pid_t pid;
2524 
2525 	if (symbol_conf.default_guest_vmlinux_name ||
2526 	    symbol_conf.default_guest_modules ||
2527 	    symbol_conf.default_guest_kallsyms) {
2528 		machines__create_kernel_maps(self, DEFAULT_GUEST_KERNEL_ID);
2529 	}
2530 
2531 	if (symbol_conf.guestmount) {
2532 		items = scandir(symbol_conf.guestmount, &namelist, NULL, NULL);
2533 		if (items <= 0)
2534 			return -ENOENT;
2535 		for (i = 0; i < items; i++) {
2536 			if (!isdigit(namelist[i]->d_name[0])) {
2537 				/* Filter out . and .. */
2538 				continue;
2539 			}
2540 			pid = atoi(namelist[i]->d_name);
2541 			sprintf(path, "%s/%s/proc/kallsyms",
2542 				symbol_conf.guestmount,
2543 				namelist[i]->d_name);
2544 			ret = access(path, R_OK);
2545 			if (ret) {
2546 				pr_debug("Can't access file %s\n", path);
2547 				goto failure;
2548 			}
2549 			machines__create_kernel_maps(self, pid);
2550 		}
2551 failure:
2552 		free(namelist);
2553 	}
2554 
2555 	return ret;
2556 }
2557 
2558 void machines__destroy_guest_kernel_maps(struct rb_root *self)
2559 {
2560 	struct rb_node *next = rb_first(self);
2561 
2562 	while (next) {
2563 		struct machine *pos = rb_entry(next, struct machine, rb_node);
2564 
2565 		next = rb_next(&pos->rb_node);
2566 		rb_erase(&pos->rb_node, self);
2567 		machine__delete(pos);
2568 	}
2569 }
2570 
2571 int machine__load_kallsyms(struct machine *self, const char *filename,
2572 			   enum map_type type, symbol_filter_t filter)
2573 {
2574 	struct map *map = self->vmlinux_maps[type];
2575 	int ret = dso__load_kallsyms(map->dso, filename, map, filter);
2576 
2577 	if (ret > 0) {
2578 		dso__set_loaded(map->dso, type);
2579 		/*
2580 		 * Since /proc/kallsyms will have multiple sessions for the
2581 		 * kernel, with modules between them, fixup the end of all
2582 		 * sections.
2583 		 */
2584 		__map_groups__fixup_end(&self->kmaps, type);
2585 	}
2586 
2587 	return ret;
2588 }
2589 
2590 int machine__load_vmlinux_path(struct machine *self, enum map_type type,
2591 			       symbol_filter_t filter)
2592 {
2593 	struct map *map = self->vmlinux_maps[type];
2594 	int ret = dso__load_vmlinux_path(map->dso, map, filter);
2595 
2596 	if (ret > 0) {
2597 		dso__set_loaded(map->dso, type);
2598 		map__reloc_vmlinux(map);
2599 	}
2600 
2601 	return ret;
2602 }
2603