symbol.c 39.9 KB
Newer Older
1 2 3 4 5 6 7 8 9 10
#include <dirent.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <fcntl.h>
#include <unistd.h>
11
#include <inttypes.h>
12
#include "build-id.h"
13
#include "util.h"
14
#include "debug.h"
15
#include "machine.h"
16
#include "symbol.h"
17
#include "strlist.h"
18 19

#include <elf.h>
20
#include <limits.h>
21
#include <sys/utsname.h>
P
Peter Zijlstra 已提交
22

23
#ifndef KSYM_NAME_LEN
24
#define KSYM_NAME_LEN 256
25 26
#endif

27
static int dso__load_kernel_sym(struct dso *dso, struct map *map,
28
				symbol_filter_t filter);
29
static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
30
			symbol_filter_t filter);
31 32
int vmlinux_path__nr_entries;
char **vmlinux_path;
33

34
struct symbol_conf symbol_conf = {
35 36
	.use_modules	  = true,
	.try_vmlinux_path = true,
37
	.annotate_src	  = true,
38
	.demangle	  = true,
39
	.symfs            = "",
40 41
};

42 43 44 45 46 47 48 49 50 51 52 53
static enum dso_binary_type binary_type_symtab[] = {
	DSO_BINARY_TYPE__KALLSYMS,
	DSO_BINARY_TYPE__GUEST_KALLSYMS,
	DSO_BINARY_TYPE__JAVA_JIT,
	DSO_BINARY_TYPE__DEBUGLINK,
	DSO_BINARY_TYPE__BUILD_ID_CACHE,
	DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
	DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
	DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
	DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
	DSO_BINARY_TYPE__GUEST_KMODULE,
	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
54
	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
55 56 57
	DSO_BINARY_TYPE__NOT_FOUND,
};

58
#define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
59

60
bool symbol_type__is_a(char symbol_type, enum map_type map_type)
61
{
62 63
	symbol_type = toupper(symbol_type);

64 65 66
	switch (map_type) {
	case MAP__FUNCTION:
		return symbol_type == 'T' || symbol_type == 'W';
67
	case MAP__VARIABLE:
68
		return symbol_type == 'D';
69 70 71 72 73
	default:
		return false;
	}
}

74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90
static int prefix_underscores_count(const char *str)
{
	const char *tail = str;

	while (*tail == '_')
		tail++;

	return tail - str;
}

#define SYMBOL_A 0
#define SYMBOL_B 1

static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
{
	s64 a;
	s64 b;
91
	size_t na, nb;
92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124

	/* Prefer a symbol with non zero length */
	a = syma->end - syma->start;
	b = symb->end - symb->start;
	if ((b == 0) && (a > 0))
		return SYMBOL_A;
	else if ((a == 0) && (b > 0))
		return SYMBOL_B;

	/* Prefer a non weak symbol over a weak one */
	a = syma->binding == STB_WEAK;
	b = symb->binding == STB_WEAK;
	if (b && !a)
		return SYMBOL_A;
	if (a && !b)
		return SYMBOL_B;

	/* Prefer a global symbol over a non global one */
	a = syma->binding == STB_GLOBAL;
	b = symb->binding == STB_GLOBAL;
	if (a && !b)
		return SYMBOL_A;
	if (b && !a)
		return SYMBOL_B;

	/* Prefer a symbol with less underscores */
	a = prefix_underscores_count(syma->name);
	b = prefix_underscores_count(symb->name);
	if (b > a)
		return SYMBOL_A;
	else if (a > b)
		return SYMBOL_B;

125 126 127 128
	/* Choose the symbol with the longest name */
	na = strlen(syma->name);
	nb = strlen(symb->name);
	if (na > nb)
129
		return SYMBOL_A;
130
	else if (na < nb)
131
		return SYMBOL_B;
132 133 134 135 136 137 138 139

	/* Avoid "SyS" kernel syscall aliases */
	if (na >= 3 && !strncmp(syma->name, "SyS", 3))
		return SYMBOL_B;
	if (na >= 10 && !strncmp(syma->name, "compat_SyS", 10))
		return SYMBOL_B;

	return SYMBOL_A;
140 141
}

142
void symbols__fixup_duplicate(struct rb_root *symbols)
143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162
{
	struct rb_node *nd;
	struct symbol *curr, *next;

	nd = rb_first(symbols);

	while (nd) {
		curr = rb_entry(nd, struct symbol, rb_node);
again:
		nd = rb_next(&curr->rb_node);
		next = rb_entry(nd, struct symbol, rb_node);

		if (!nd)
			break;

		if (curr->start != next->start)
			continue;

		if (choose_best_symbol(curr, next) == SYMBOL_A) {
			rb_erase(&next->rb_node, symbols);
163
			symbol__delete(next);
164 165 166 167
			goto again;
		} else {
			nd = rb_next(&curr->rb_node);
			rb_erase(&curr->rb_node, symbols);
168
			symbol__delete(curr);
169 170 171 172
		}
	}
}

173
void symbols__fixup_end(struct rb_root *symbols)
174
{
175
	struct rb_node *nd, *prevnd = rb_first(symbols);
176
	struct symbol *curr, *prev;
177 178 179 180

	if (prevnd == NULL)
		return;

181 182
	curr = rb_entry(prevnd, struct symbol, rb_node);

183
	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
184 185
		prev = curr;
		curr = rb_entry(nd, struct symbol, rb_node);
186

187
		if (prev->end == prev->start && prev->end != curr->start)
188 189
			prev->end = curr->start - 1;
	}
190 191 192 193

	/* Last entry */
	if (curr->end == curr->start)
		curr->end = roundup(curr->start, 4096);
194 195
}

196
void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
197 198
{
	struct map *prev, *curr;
199
	struct rb_node *nd, *prevnd = rb_first(&mg->maps[type]);
200 201 202 203 204 205 206 207 208 209

	if (prevnd == NULL)
		return;

	curr = rb_entry(prevnd, struct map, rb_node);

	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
		prev = curr;
		curr = rb_entry(nd, struct map, rb_node);
		prev->end = curr->start - 1;
210
	}
211 212 213 214 215

	/*
	 * We still haven't the actual symbols, so guess the
	 * last map final address.
	 */
216
	curr->end = ~0ULL;
217 218
}

219
struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
220
{
221
	size_t namelen = strlen(name) + 1;
222 223 224
	struct symbol *sym = calloc(1, (symbol_conf.priv_size +
					sizeof(*sym) + namelen));
	if (sym == NULL)
225 226
		return NULL;

227
	if (symbol_conf.priv_size)
228
		sym = ((void *)sym) + symbol_conf.priv_size;
229

230 231 232 233
	sym->start   = start;
	sym->end     = len ? start + len - 1 : start;
	sym->binding = binding;
	sym->namelen = namelen - 1;
234

235 236 237
	pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
		  __func__, name, start, sym->end);
	memcpy(sym->name, name, namelen);
238

239
	return sym;
240 241
}

242
void symbol__delete(struct symbol *sym)
243
{
244
	free(((void *)sym) - symbol_conf.priv_size);
245 246
}

247
size_t symbol__fprintf(struct symbol *sym, FILE *fp)
248
{
249
	return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %c %s\n",
250 251 252 253
		       sym->start, sym->end,
		       sym->binding == STB_GLOBAL ? 'g' :
		       sym->binding == STB_LOCAL  ? 'l' : 'w',
		       sym->name);
254 255
}

256 257
size_t symbol__fprintf_symname_offs(const struct symbol *sym,
				    const struct addr_location *al, FILE *fp)
258
{
259 260 261 262 263 264
	unsigned long offset;
	size_t length;

	if (sym && sym->name) {
		length = fprintf(fp, "%s", sym->name);
		if (al) {
265 266 267 268
			if (al->addr < sym->end)
				offset = al->addr - sym->start;
			else
				offset = al->addr - al->map->start - sym->start;
269 270 271 272 273 274
			length += fprintf(fp, "+0x%lx", offset);
		}
		return length;
	} else
		return fprintf(fp, "[unknown]");
}
275

276 277 278
size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
{
	return symbol__fprintf_symname_offs(sym, NULL, fp);
279 280
}

281
void symbols__delete(struct rb_root *symbols)
282 283
{
	struct symbol *pos;
284
	struct rb_node *next = rb_first(symbols);
285 286 287 288

	while (next) {
		pos = rb_entry(next, struct symbol, rb_node);
		next = rb_next(&pos->rb_node);
289
		rb_erase(&pos->rb_node, symbols);
290
		symbol__delete(pos);
291 292 293
	}
}

294
void symbols__insert(struct rb_root *symbols, struct symbol *sym)
295
{
296
	struct rb_node **p = &symbols->rb_node;
297
	struct rb_node *parent = NULL;
298
	const u64 ip = sym->start;
299 300 301 302 303 304 305 306 307 308 309
	struct symbol *s;

	while (*p != NULL) {
		parent = *p;
		s = rb_entry(parent, struct symbol, rb_node);
		if (ip < s->start)
			p = &(*p)->rb_left;
		else
			p = &(*p)->rb_right;
	}
	rb_link_node(&sym->rb_node, parent, p);
310
	rb_insert_color(&sym->rb_node, symbols);
311 312
}

313
static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
314 315 316
{
	struct rb_node *n;

317
	if (symbols == NULL)
318 319
		return NULL;

320
	n = symbols->rb_node;
321 322 323 324 325 326 327 328 329 330 331 332 333 334 335

	while (n) {
		struct symbol *s = rb_entry(n, struct symbol, rb_node);

		if (ip < s->start)
			n = n->rb_left;
		else if (ip > s->end)
			n = n->rb_right;
		else
			return s;
	}

	return NULL;
}

336 337 338 339 340 341 342 343 344 345
static struct symbol *symbols__first(struct rb_root *symbols)
{
	struct rb_node *n = rb_first(symbols);

	if (n)
		return rb_entry(n, struct symbol, rb_node);

	return NULL;
}

346 347 348 349 350
struct symbol_name_rb_node {
	struct rb_node	rb_node;
	struct symbol	sym;
};

351
static void symbols__insert_by_name(struct rb_root *symbols, struct symbol *sym)
352
{
353
	struct rb_node **p = &symbols->rb_node;
354
	struct rb_node *parent = NULL;
355 356 357
	struct symbol_name_rb_node *symn, *s;

	symn = container_of(sym, struct symbol_name_rb_node, sym);
358 359 360 361 362 363 364 365 366 367

	while (*p != NULL) {
		parent = *p;
		s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
		if (strcmp(sym->name, s->sym.name) < 0)
			p = &(*p)->rb_left;
		else
			p = &(*p)->rb_right;
	}
	rb_link_node(&symn->rb_node, parent, p);
368
	rb_insert_color(&symn->rb_node, symbols);
369 370
}

371 372
static void symbols__sort_by_name(struct rb_root *symbols,
				  struct rb_root *source)
373 374 375 376 377
{
	struct rb_node *nd;

	for (nd = rb_first(source); nd; nd = rb_next(nd)) {
		struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
378
		symbols__insert_by_name(symbols, pos);
379 380 381
	}
}

382 383
static struct symbol *symbols__find_by_name(struct rb_root *symbols,
					    const char *name)
384 385 386
{
	struct rb_node *n;

387
	if (symbols == NULL)
388 389
		return NULL;

390
	n = symbols->rb_node;
391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409

	while (n) {
		struct symbol_name_rb_node *s;
		int cmp;

		s = rb_entry(n, struct symbol_name_rb_node, rb_node);
		cmp = strcmp(name, s->sym.name);

		if (cmp < 0)
			n = n->rb_left;
		else if (cmp > 0)
			n = n->rb_right;
		else
			return &s->sym;
	}

	return NULL;
}

410
struct symbol *dso__find_symbol(struct dso *dso,
411
				enum map_type type, u64 addr)
412
{
413
	return symbols__find(&dso->symbols[type], addr);
414 415
}

416 417 418 419 420
struct symbol *dso__first_symbol(struct dso *dso, enum map_type type)
{
	return symbols__first(&dso->symbols[type]);
}

421
struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
422 423
					const char *name)
{
424
	return symbols__find_by_name(&dso->symbol_names[type], name);
425 426
}

427
void dso__sort_by_name(struct dso *dso, enum map_type type)
428
{
429 430 431
	dso__set_sorted_by_name(dso, type);
	return symbols__sort_by_name(&dso->symbol_names[type],
				     &dso->symbols[type]);
432 433
}

434 435
size_t dso__fprintf_symbols_by_name(struct dso *dso,
				    enum map_type type, FILE *fp)
436 437 438 439 440
{
	size_t ret = 0;
	struct rb_node *nd;
	struct symbol_name_rb_node *pos;

441
	for (nd = rb_first(&dso->symbol_names[type]); nd; nd = rb_next(nd)) {
442 443 444 445 446 447 448
		pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
		fprintf(fp, "%s\n", pos->sym.name);
	}

	return ret;
}

449 450
int kallsyms__parse(const char *filename, void *arg,
		    int (*process_symbol)(void *arg, const char *name,
451
					  char type, u64 start))
452 453 454
{
	char *line = NULL;
	size_t n;
455
	int err = -1;
456
	FILE *file = fopen(filename, "r");
457 458 459 460

	if (file == NULL)
		goto out_failure;

461 462
	err = 0;

463
	while (!feof(file)) {
464
		u64 start;
465 466
		int line_len, len;
		char symbol_type;
467
		char *symbol_name;
468 469

		line_len = getline(&line, &n, file);
470
		if (line_len < 0 || !line)
471 472 473 474
			break;

		line[--line_len] = '\0'; /* \n */

475
		len = hex2u64(line, &start);
476 477 478 479 480

		len++;
		if (len + 2 >= line_len)
			continue;

481
		symbol_type = line[len];
482 483 484
		len += 2;
		symbol_name = line + len;
		len = line_len - len;
485

486 487
		if (len >= KSYM_NAME_LEN) {
			err = -1;
488
			break;
489 490
		}

491
		err = process_symbol(arg, symbol_name,
492
				     symbol_type, start);
493 494
		if (err)
			break;
495 496 497 498
	}

	free(line);
	fclose(file);
499
	return err;
500 501 502 503 504

out_failure:
	return -1;
}

505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562
int modules__parse(const char *filename, void *arg,
		   int (*process_module)(void *arg, const char *name,
					 u64 start))
{
	char *line = NULL;
	size_t n;
	FILE *file;
	int err = 0;

	file = fopen(filename, "r");
	if (file == NULL)
		return -1;

	while (1) {
		char name[PATH_MAX];
		u64 start;
		char *sep;
		ssize_t line_len;

		line_len = getline(&line, &n, file);
		if (line_len < 0) {
			if (feof(file))
				break;
			err = -1;
			goto out;
		}

		if (!line) {
			err = -1;
			goto out;
		}

		line[--line_len] = '\0'; /* \n */

		sep = strrchr(line, 'x');
		if (sep == NULL)
			continue;

		hex2u64(sep + 1, &start);

		sep = strchr(line, ' ');
		if (sep == NULL)
			continue;

		*sep = '\0';

		scnprintf(name, sizeof(name), "[%s]", line);

		err = process_module(arg, name, start);
		if (err)
			break;
	}
out:
	free(line);
	fclose(file);
	return err;
}

563 564 565 566 567
struct process_kallsyms_args {
	struct map *map;
	struct dso *dso;
};

568 569 570 571 572 573 574 575
static u8 kallsyms2elf_type(char type)
{
	if (type == 'W')
		return STB_WEAK;

	return isupper(type) ? STB_GLOBAL : STB_LOCAL;
}

576
static int map__process_kallsym_symbol(void *arg, const char *name,
577
				       char type, u64 start)
578 579 580 581 582 583 584 585
{
	struct symbol *sym;
	struct process_kallsyms_args *a = arg;
	struct rb_root *root = &a->dso->symbols[a->map->type];

	if (!symbol_type__is_a(type, a->map->type))
		return 0;

586 587 588 589 590 591
	/*
	 * module symbols are not sorted so we add all
	 * symbols, setting length to 0, and rely on
	 * symbols__fixup_end() to fix it up.
	 */
	sym = symbol__new(start, 0, kallsyms2elf_type(type), name);
592 593 594 595 596 597 598
	if (sym == NULL)
		return -ENOMEM;
	/*
	 * We will pass the symbols to the filter later, in
	 * map__split_kallsyms, when we have split the maps per module
	 */
	symbols__insert(root, sym);
599

600 601 602 603 604 605 606 607
	return 0;
}

/*
 * Loads the function entries in /proc/kallsyms into kernel_map->dso,
 * so that we can in the next step set the symbol ->end address and then
 * call kernel_maps__split_kallsyms.
 */
608
static int dso__load_all_kallsyms(struct dso *dso, const char *filename,
609
				  struct map *map)
610
{
611
	struct process_kallsyms_args args = { .map = map, .dso = dso, };
612
	return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
613 614
}

615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661
static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map,
					 symbol_filter_t filter)
{
	struct map_groups *kmaps = map__kmap(map)->kmaps;
	struct map *curr_map;
	struct symbol *pos;
	int count = 0, moved = 0;
	struct rb_root *root = &dso->symbols[map->type];
	struct rb_node *next = rb_first(root);

	while (next) {
		char *module;

		pos = rb_entry(next, struct symbol, rb_node);
		next = rb_next(&pos->rb_node);

		module = strchr(pos->name, '\t');
		if (module)
			*module = '\0';

		curr_map = map_groups__find(kmaps, map->type, pos->start);

		if (!curr_map || (filter && filter(curr_map, pos))) {
			rb_erase(&pos->rb_node, root);
			symbol__delete(pos);
		} else {
			pos->start -= curr_map->start - curr_map->pgoff;
			if (pos->end)
				pos->end -= curr_map->start - curr_map->pgoff;
			if (curr_map != map) {
				rb_erase(&pos->rb_node, root);
				symbols__insert(
					&curr_map->dso->symbols[curr_map->type],
					pos);
				++moved;
			} else {
				++count;
			}
		}
	}

	/* Symbols have been adjusted */
	dso->adjust_symbols = 1;

	return count + moved;
}

662 663 664 665 666
/*
 * Split the symbols into maps, making sure there are no overlaps, i.e. the
 * kernel range is broken in several maps, named [kernel].N, as we don't have
 * the original ELF section names vmlinux have.
 */
667
static int dso__split_kallsyms(struct dso *dso, struct map *map,
668
			       symbol_filter_t filter)
669
{
670
	struct map_groups *kmaps = map__kmap(map)->kmaps;
671
	struct machine *machine = kmaps->machine;
672
	struct map *curr_map = map;
673
	struct symbol *pos;
674
	int count = 0, moved = 0;	
675
	struct rb_root *root = &dso->symbols[map->type];
676
	struct rb_node *next = rb_first(root);
677 678 679 680 681 682 683 684 685 686
	int kernel_range = 0;

	while (next) {
		char *module;

		pos = rb_entry(next, struct symbol, rb_node);
		next = rb_next(&pos->rb_node);

		module = strchr(pos->name, '\t');
		if (module) {
687
			if (!symbol_conf.use_modules)
688 689
				goto discard_symbol;

690 691
			*module++ = '\0';

692
			if (strcmp(curr_map->dso->short_name, module)) {
693
				if (curr_map != map &&
694
				    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
695
				    machine__is_default_guest(machine)) {
696 697 698 699 700 701 702 703 704 705 706 707 708
					/*
					 * We assume all symbols of a module are
					 * continuous in * kallsyms, so curr_map
					 * points to a module and all its
					 * symbols are in its kmap. Mark it as
					 * loaded.
					 */
					dso__set_loaded(curr_map->dso,
							curr_map->type);
				}

				curr_map = map_groups__find_by_name(kmaps,
							map->type, module);
709
				if (curr_map == NULL) {
710
					pr_debug("%s/proc/{kallsyms,modules} "
711
					         "inconsistency while looking "
712
						 "for \"%s\" module!\n",
713
						 machine->root_dir, module);
714 715
					curr_map = map;
					goto discard_symbol;
716
				}
717

718
				if (curr_map->dso->loaded &&
719
				    !machine__is_default_guest(machine))
720
					goto discard_symbol;
721
			}
722 723 724 725
			/*
			 * So that we look just like we get from .ko files,
			 * i.e. not prelinked, relative to map->start.
			 */
726 727 728
			pos->start = curr_map->map_ip(curr_map, pos->start);
			pos->end   = curr_map->map_ip(curr_map, pos->end);
		} else if (curr_map != map) {
729
			char dso_name[PATH_MAX];
730
			struct dso *ndso;
731

732 733 734 735 736
			if (count == 0) {
				curr_map = map;
				goto filter_symbol;
			}

737
			if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
738 739 740 741 742 743 744
				snprintf(dso_name, sizeof(dso_name),
					"[guest.kernel].%d",
					kernel_range++);
			else
				snprintf(dso_name, sizeof(dso_name),
					"[kernel].%d",
					kernel_range++);
745

746 747
			ndso = dso__new(dso_name);
			if (ndso == NULL)
748 749
				return -1;

750
			ndso->kernel = dso->kernel;
751

752
			curr_map = map__new2(pos->start, ndso, map->type);
753
			if (curr_map == NULL) {
754
				dso__delete(ndso);
755 756
				return -1;
			}
757

758
			curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
759
			map_groups__insert(kmaps, curr_map);
760 761
			++kernel_range;
		}
762
filter_symbol:
763
		if (filter && filter(curr_map, pos)) {
764
discard_symbol:		rb_erase(&pos->rb_node, root);
765
			symbol__delete(pos);
766
		} else {
767 768 769
			if (curr_map != map) {
				rb_erase(&pos->rb_node, root);
				symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
770 771 772
				++moved;
			} else
				++count;
773
		}
774 775
	}

776
	if (curr_map != map &&
777
	    dso->kernel == DSO_TYPE_GUEST_KERNEL &&
778
	    machine__is_default_guest(kmaps->machine)) {
779 780 781
		dso__set_loaded(curr_map->dso, curr_map->type);
	}

782
	return count + moved;
783
}
784

785 786
bool symbol__restricted_filename(const char *filename,
				 const char *restricted_filename)
787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802
{
	bool restricted = false;

	if (symbol_conf.kptr_restrict) {
		char *r = realpath(filename, NULL);

		if (r != NULL) {
			restricted = strcmp(r, restricted_filename) == 0;
			free(r);
			return restricted;
		}
	}

	return restricted;
}

803 804 805 806
struct module_info {
	struct rb_node rb_node;
	char *name;
	u64 start;
807 808
};

809
static void add_module(struct module_info *mi, struct rb_root *modules)
810
{
811 812 813
	struct rb_node **p = &modules->rb_node;
	struct rb_node *parent = NULL;
	struct module_info *m;
814

815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869
	while (*p != NULL) {
		parent = *p;
		m = rb_entry(parent, struct module_info, rb_node);
		if (strcmp(mi->name, m->name) < 0)
			p = &(*p)->rb_left;
		else
			p = &(*p)->rb_right;
	}
	rb_link_node(&mi->rb_node, parent, p);
	rb_insert_color(&mi->rb_node, modules);
}

static void delete_modules(struct rb_root *modules)
{
	struct module_info *mi;
	struct rb_node *next = rb_first(modules);

	while (next) {
		mi = rb_entry(next, struct module_info, rb_node);
		next = rb_next(&mi->rb_node);
		rb_erase(&mi->rb_node, modules);
		free(mi->name);
		free(mi);
	}
}

static struct module_info *find_module(const char *name,
				       struct rb_root *modules)
{
	struct rb_node *n = modules->rb_node;

	while (n) {
		struct module_info *m;
		int cmp;

		m = rb_entry(n, struct module_info, rb_node);
		cmp = strcmp(name, m->name);
		if (cmp < 0)
			n = n->rb_left;
		else if (cmp > 0)
			n = n->rb_right;
		else
			return m;
	}

	return NULL;
}

static int __read_proc_modules(void *arg, const char *name, u64 start)
{
	struct rb_root *modules = arg;
	struct module_info *mi;

	mi = zalloc(sizeof(struct module_info));
	if (!mi)
870 871
		return -ENOMEM;

872 873
	mi->name = strdup(name);
	mi->start = start;
874

875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893
	if (!mi->name) {
		free(mi);
		return -ENOMEM;
	}

	add_module(mi, modules);

	return 0;
}

static int read_proc_modules(const char *filename, struct rb_root *modules)
{
	if (symbol__restricted_filename(filename, "/proc/modules"))
		return -1;

	if (modules__parse(filename, modules, __read_proc_modules)) {
		delete_modules(modules);
		return -1;
	}
894 895 896 897

	return 0;
}

898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938
int compare_proc_modules(const char *from, const char *to)
{
	struct rb_root from_modules = RB_ROOT;
	struct rb_root to_modules = RB_ROOT;
	struct rb_node *from_node, *to_node;
	struct module_info *from_m, *to_m;
	int ret = -1;

	if (read_proc_modules(from, &from_modules))
		return -1;

	if (read_proc_modules(to, &to_modules))
		goto out_delete_from;

	from_node = rb_first(&from_modules);
	to_node = rb_first(&to_modules);
	while (from_node) {
		if (!to_node)
			break;

		from_m = rb_entry(from_node, struct module_info, rb_node);
		to_m = rb_entry(to_node, struct module_info, rb_node);

		if (from_m->start != to_m->start ||
		    strcmp(from_m->name, to_m->name))
			break;

		from_node = rb_next(from_node);
		to_node = rb_next(to_node);
	}

	if (!from_node && !to_node)
		ret = 0;

	delete_modules(&to_modules);
out_delete_from:
	delete_modules(&from_modules);

	return ret;
}

939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974
static int do_validate_kcore_modules(const char *filename, struct map *map,
				  struct map_groups *kmaps)
{
	struct rb_root modules = RB_ROOT;
	struct map *old_map;
	int err;

	err = read_proc_modules(filename, &modules);
	if (err)
		return err;

	old_map = map_groups__first(kmaps, map->type);
	while (old_map) {
		struct map *next = map_groups__next(old_map);
		struct module_info *mi;

		if (old_map == map || old_map->start == map->start) {
			/* The kernel map */
			old_map = next;
			continue;
		}

		/* Module must be in memory at the same address */
		mi = find_module(old_map->dso->short_name, &modules);
		if (!mi || mi->start != old_map->start) {
			err = -EINVAL;
			goto out;
		}

		old_map = next;
	}
out:
	delete_modules(&modules);
	return err;
}

975
/*
976
 * If kallsyms is referenced by name then we look for filename in the same
977 978
 * directory.
 */
979 980 981
static bool filename_from_kallsyms_filename(char *filename,
					    const char *base_name,
					    const char *kallsyms_filename)
982 983 984
{
	char *name;

985 986
	strcpy(filename, kallsyms_filename);
	name = strrchr(filename, '/');
987 988 989
	if (!name)
		return false;

990 991 992 993
	name += 1;

	if (!strcmp(name, "kallsyms")) {
		strcpy(name, base_name);
994 995 996 997 998 999
		return true;
	}

	return false;
}

1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038
static int validate_kcore_modules(const char *kallsyms_filename,
				  struct map *map)
{
	struct map_groups *kmaps = map__kmap(map)->kmaps;
	char modules_filename[PATH_MAX];

	if (!filename_from_kallsyms_filename(modules_filename, "modules",
					     kallsyms_filename))
		return -EINVAL;

	if (do_validate_kcore_modules(modules_filename, map, kmaps))
		return -EINVAL;

	return 0;
}

struct kcore_mapfn_data {
	struct dso *dso;
	enum map_type type;
	struct list_head maps;
};

static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
{
	struct kcore_mapfn_data *md = data;
	struct map *map;

	map = map__new2(start, md->dso, md->type);
	if (map == NULL)
		return -ENOMEM;

	map->end = map->start + len;
	map->pgoff = pgoff;

	list_add(&map->node, &md->maps);

	return 0;
}

1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054
static int dso__load_kcore(struct dso *dso, struct map *map,
			   const char *kallsyms_filename)
{
	struct map_groups *kmaps = map__kmap(map)->kmaps;
	struct machine *machine = kmaps->machine;
	struct kcore_mapfn_data md;
	struct map *old_map, *new_map, *replacement_map = NULL;
	bool is_64_bit;
	int err, fd;
	char kcore_filename[PATH_MAX];
	struct symbol *sym;

	/* This function requires that the map is the kernel map */
	if (map != machine->vmlinux_maps[map->type])
		return -EINVAL;

1055 1056 1057 1058 1059 1060
	if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
					     kallsyms_filename))
		return -EINVAL;

	/* All modules must be present at their original addresses */
	if (validate_kcore_modules(kallsyms_filename, map))
1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152
		return -EINVAL;

	md.dso = dso;
	md.type = map->type;
	INIT_LIST_HEAD(&md.maps);

	fd = open(kcore_filename, O_RDONLY);
	if (fd < 0)
		return -EINVAL;

	/* Read new maps into temporary lists */
	err = file__read_maps(fd, md.type == MAP__FUNCTION, kcore_mapfn, &md,
			      &is_64_bit);
	if (err)
		goto out_err;

	if (list_empty(&md.maps)) {
		err = -EINVAL;
		goto out_err;
	}

	/* Remove old maps */
	old_map = map_groups__first(kmaps, map->type);
	while (old_map) {
		struct map *next = map_groups__next(old_map);

		if (old_map != map)
			map_groups__remove(kmaps, old_map);
		old_map = next;
	}

	/* Find the kernel map using the first symbol */
	sym = dso__first_symbol(dso, map->type);
	list_for_each_entry(new_map, &md.maps, node) {
		if (sym && sym->start >= new_map->start &&
		    sym->start < new_map->end) {
			replacement_map = new_map;
			break;
		}
	}

	if (!replacement_map)
		replacement_map = list_entry(md.maps.next, struct map, node);

	/* Add new maps */
	while (!list_empty(&md.maps)) {
		new_map = list_entry(md.maps.next, struct map, node);
		list_del(&new_map->node);
		if (new_map == replacement_map) {
			map->start	= new_map->start;
			map->end	= new_map->end;
			map->pgoff	= new_map->pgoff;
			map->map_ip	= new_map->map_ip;
			map->unmap_ip	= new_map->unmap_ip;
			map__delete(new_map);
			/* Ensure maps are correctly ordered */
			map_groups__remove(kmaps, map);
			map_groups__insert(kmaps, map);
		} else {
			map_groups__insert(kmaps, new_map);
		}
	}

	/*
	 * Set the data type and long name so that kcore can be read via
	 * dso__data_read_addr().
	 */
	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
		dso->data_type = DSO_BINARY_TYPE__GUEST_KCORE;
	else
		dso->data_type = DSO_BINARY_TYPE__KCORE;
	dso__set_long_name(dso, strdup(kcore_filename));

	close(fd);

	if (map->type == MAP__FUNCTION)
		pr_debug("Using %s for kernel object code\n", kcore_filename);
	else
		pr_debug("Using %s for kernel data\n", kcore_filename);

	return 0;

out_err:
	while (!list_empty(&md.maps)) {
		map = list_entry(md.maps.next, struct map, node);
		list_del(&map->node);
		map__delete(map);
	}
	close(fd);
	return -EINVAL;
}

1153
int dso__load_kallsyms(struct dso *dso, const char *filename,
1154
		       struct map *map, symbol_filter_t filter)
1155
{
1156 1157 1158
	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
		return -1;

1159
	if (dso__load_all_kallsyms(dso, filename, map) < 0)
1160 1161
		return -1;

1162
	symbols__fixup_duplicate(&dso->symbols[map->type]);
1163 1164
	symbols__fixup_end(&dso->symbols[map->type]);

1165
	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1166
		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1167
	else
1168
		dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1169

1170 1171 1172 1173
	if (!dso__load_kcore(dso, map, filename))
		return dso__split_kallsyms_for_kcore(dso, map, filter);
	else
		return dso__split_kallsyms(dso, map, filter);
1174 1175
}

1176
static int dso__load_perf_map(struct dso *dso, struct map *map,
1177
			      symbol_filter_t filter)
1178 1179 1180 1181 1182 1183
{
	char *line = NULL;
	size_t n;
	FILE *file;
	int nr_syms = 0;

1184
	file = fopen(dso->long_name, "r");
1185 1186 1187 1188
	if (file == NULL)
		goto out_failure;

	while (!feof(file)) {
1189
		u64 start, size;
1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213
		struct symbol *sym;
		int line_len, len;

		line_len = getline(&line, &n, file);
		if (line_len < 0)
			break;

		if (!line)
			goto out_failure;

		line[--line_len] = '\0'; /* \n */

		len = hex2u64(line, &start);

		len++;
		if (len + 2 >= line_len)
			continue;

		len += hex2u64(line + len, &size);

		len++;
		if (len + 2 >= line_len)
			continue;

1214
		sym = symbol__new(start, size, STB_GLOBAL, line + len);
1215 1216 1217 1218

		if (sym == NULL)
			goto out_delete_line;

1219
		if (filter && filter(map, sym))
1220
			symbol__delete(sym);
1221
		else {
1222
			symbols__insert(&dso->symbols[map->type], sym);
1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237
			nr_syms++;
		}
	}

	free(line);
	fclose(file);

	return nr_syms;

out_delete_line:
	free(line);
out_failure:
	return -1;
}

1238
int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
1239
{
1240
	char *name;
1241
	int ret = -1;
1242
	u_int i;
1243
	struct machine *machine;
1244
	char *root_dir = (char *) "";
1245 1246 1247
	int ss_pos = 0;
	struct symsrc ss_[2];
	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1248

1249
	dso__set_loaded(dso, map->type);
1250

1251 1252 1253 1254
	if (dso->kernel == DSO_TYPE_KERNEL)
		return dso__load_kernel_sym(dso, map, filter);
	else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
		return dso__load_guest_kernel_sym(dso, map, filter);
1255

1256 1257
	if (map->groups && map->groups->machine)
		machine = map->groups->machine;
1258
	else
1259
		machine = NULL;
1260

1261
	dso->adjust_symbols = 0;
1262

1263
	if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
1264 1265
		struct stat st;

1266
		if (lstat(dso->name, &st) < 0)
1267 1268 1269 1270 1271 1272 1273 1274
			return -1;

		if (st.st_uid && (st.st_uid != geteuid())) {
			pr_warning("File %s not owned by current user or root, "
				"ignoring it.\n", dso->name);
			return -1;
		}

1275
		ret = dso__load_perf_map(dso, map, filter);
1276 1277
		dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
					     DSO_BINARY_TYPE__NOT_FOUND;
1278 1279 1280
		return ret;
	}

1281 1282 1283
	if (machine)
		root_dir = machine->root_dir;

1284 1285 1286 1287
	name = malloc(PATH_MAX);
	if (!name)
		return -1;

1288
	/* Iterate over candidate debug images.
1289 1290
	 * Keep track of "interesting" ones (those which have a symtab, dynsym,
	 * and/or opd section) for processing.
1291
	 */
1292
	for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1293 1294
		struct symsrc *ss = &ss_[ss_pos];
		bool next_slot = false;
1295

1296
		enum dso_binary_type symtab_type = binary_type_symtab[i];
1297

1298
		if (dso__binary_type_file(dso, symtab_type,
1299 1300
					  root_dir, name, PATH_MAX))
			continue;
1301 1302

		/* Name is now the name of the next image to try */
1303
		if (symsrc__init(ss, dso, name, symtab_type) < 0)
1304
			continue;
1305

1306 1307 1308
		if (!syms_ss && symsrc__has_symtab(ss)) {
			syms_ss = ss;
			next_slot = true;
1309 1310
		}

1311 1312 1313
		if (!runtime_ss && symsrc__possibly_runtime(ss)) {
			runtime_ss = ss;
			next_slot = true;
1314
		}
1315

1316 1317
		if (next_slot) {
			ss_pos++;
1318

1319 1320
			if (syms_ss && runtime_ss)
				break;
1321
		}
1322

1323
	}
1324

1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335
	if (!runtime_ss && !syms_ss)
		goto out_free;

	if (runtime_ss && !syms_ss) {
		syms_ss = runtime_ss;
	}

	/* We'll have to hope for the best */
	if (!runtime_ss && syms_ss)
		runtime_ss = syms_ss;

1336 1337 1338 1339 1340 1341 1342
	if (syms_ss) {
		int km;

		km = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
		     dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE;
		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, km);
	} else {
1343
		ret = -1;
1344
	}
1345

1346
	if (ret > 0) {
1347 1348 1349 1350 1351
		int nr_plt;

		nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss, map, filter);
		if (nr_plt > 0)
			ret += nr_plt;
1352 1353
	}

1354 1355 1356
	for (; ss_pos > 0; ss_pos--)
		symsrc__destroy(&ss_[ss_pos - 1]);
out_free:
1357
	free(name);
1358
	if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1359
		return 0;
1360 1361 1362
	return ret;
}

1363
struct map *map_groups__find_by_name(struct map_groups *mg,
1364
				     enum map_type type, const char *name)
1365 1366 1367
{
	struct rb_node *nd;

1368
	for (nd = rb_first(&mg->maps[type]); nd; nd = rb_next(nd)) {
1369 1370
		struct map *map = rb_entry(nd, struct map, rb_node);

1371
		if (map->dso && strcmp(map->dso->short_name, name) == 0)
1372 1373 1374 1375 1376 1377
			return map;
	}

	return NULL;
}

1378
int dso__load_vmlinux(struct dso *dso, struct map *map,
1379
		      const char *vmlinux, symbol_filter_t filter)
1380
{
1381 1382
	int err = -1;
	struct symsrc ss;
1383
	char symfs_vmlinux[PATH_MAX];
1384
	enum dso_binary_type symtab_type;
1385

1386 1387 1388 1389 1390
	if (vmlinux[0] == '/')
		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
	else
		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s",
			 symbol_conf.symfs, vmlinux);
1391

1392
	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1393
		symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1394
	else
1395
		symtab_type = DSO_BINARY_TYPE__VMLINUX;
1396

1397
	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
1398 1399
		return -1;

1400
	err = dso__load_sym(dso, map, &ss, &ss, filter, 0);
1401
	symsrc__destroy(&ss);
1402

1403
	if (err > 0) {
1404 1405 1406 1407
		if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
			dso->data_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
		else
			dso->data_type = DSO_BINARY_TYPE__VMLINUX;
1408 1409
		dso__set_long_name(dso, (char *)vmlinux);
		dso__set_loaded(dso, map->type);
1410
		pr_debug("Using %s for symbols\n", symfs_vmlinux);
1411
	}
1412

1413 1414 1415
	return err;
}

1416
int dso__load_vmlinux_path(struct dso *dso, struct map *map,
1417
			   symbol_filter_t filter)
1418 1419
{
	int i, err = 0;
1420
	char *filename;
1421 1422

	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
1423 1424
		 vmlinux_path__nr_entries + 1);

1425
	filename = dso__build_id_filename(dso, NULL, 0);
1426
	if (filename != NULL) {
1427
		err = dso__load_vmlinux(dso, map, filename, filter);
1428 1429
		if (err > 0) {
			dso->lname_alloc = 1;
1430
			goto out;
1431
		}
1432 1433
		free(filename);
	}
1434 1435

	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
1436
		err = dso__load_vmlinux(dso, map, vmlinux_path[i], filter);
1437
		if (err > 0) {
1438
			dso__set_long_name(dso, strdup(vmlinux_path[i]));
1439
			dso->lname_alloc = 1;
1440 1441 1442
			break;
		}
	}
1443
out:
1444 1445 1446
	return err;
}

1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545
static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
{
	char kallsyms_filename[PATH_MAX];
	struct dirent *dent;
	int ret = -1;
	DIR *d;

	d = opendir(dir);
	if (!d)
		return -1;

	while (1) {
		dent = readdir(d);
		if (!dent)
			break;
		if (dent->d_type != DT_DIR)
			continue;
		scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
			  "%s/%s/kallsyms", dir, dent->d_name);
		if (!validate_kcore_modules(kallsyms_filename, map)) {
			strlcpy(dir, kallsyms_filename, dir_sz);
			ret = 0;
			break;
		}
	}

	closedir(d);

	return ret;
}

static char *dso__find_kallsyms(struct dso *dso, struct map *map)
{
	u8 host_build_id[BUILD_ID_SIZE];
	char sbuild_id[BUILD_ID_SIZE * 2 + 1];
	bool is_host = false;
	char path[PATH_MAX];

	if (!dso->has_build_id) {
		/*
		 * Last resort, if we don't have a build-id and couldn't find
		 * any vmlinux file, try the running kernel kallsyms table.
		 */
		goto proc_kallsyms;
	}

	if (sysfs__read_build_id("/sys/kernel/notes", host_build_id,
				 sizeof(host_build_id)) == 0)
		is_host = dso__build_id_equal(dso, host_build_id);

	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);

	/* Use /proc/kallsyms if possible */
	if (is_host) {
		DIR *d;
		int fd;

		/* If no cached kcore go with /proc/kallsyms */
		scnprintf(path, sizeof(path), "%s/[kernel.kcore]/%s",
			  buildid_dir, sbuild_id);
		d = opendir(path);
		if (!d)
			goto proc_kallsyms;
		closedir(d);

		/*
		 * Do not check the build-id cache, until we know we cannot use
		 * /proc/kcore.
		 */
		fd = open("/proc/kcore", O_RDONLY);
		if (fd != -1) {
			close(fd);
			/* If module maps match go with /proc/kallsyms */
			if (!validate_kcore_modules("/proc/kallsyms", map))
				goto proc_kallsyms;
		}

		/* Find kallsyms in build-id cache with kcore */
		if (!find_matching_kcore(map, path, sizeof(path)))
			return strdup(path);

		goto proc_kallsyms;
	}

	scnprintf(path, sizeof(path), "%s/[kernel.kallsyms]/%s",
		  buildid_dir, sbuild_id);

	if (access(path, F_OK)) {
		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
		       sbuild_id);
		return NULL;
	}

	return strdup(path);

proc_kallsyms:
	return strdup("/proc/kallsyms");
}

1546
static int dso__load_kernel_sym(struct dso *dso, struct map *map,
1547
				symbol_filter_t filter)
1548
{
1549
	int err;
1550 1551
	const char *kallsyms_filename = NULL;
	char *kallsyms_allocated_filename = NULL;
1552
	/*
1553 1554
	 * Step 1: if the user specified a kallsyms or vmlinux filename, use
	 * it and only it, reporting errors to the user if it cannot be used.
1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566
	 *
	 * For instance, try to analyse an ARM perf.data file _without_ a
	 * build-id, or if the user specifies the wrong path to the right
	 * vmlinux file, obviously we can't fallback to another vmlinux (a
	 * x86_86 one, on the machine where analysis is being performed, say),
	 * or worse, /proc/kallsyms.
	 *
	 * If the specified file _has_ a build-id and there is a build-id
	 * section in the perf.data file, we will still do the expected
	 * validation in dso__load_vmlinux and will bail out if they don't
	 * match.
	 */
1567 1568 1569 1570 1571
	if (symbol_conf.kallsyms_name != NULL) {
		kallsyms_filename = symbol_conf.kallsyms_name;
		goto do_kallsyms;
	}

1572
	if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
1573
		err = dso__load_vmlinux(dso, map,
1574
					symbol_conf.vmlinux_name, filter);
1575
		if (err > 0) {
1576
			dso__set_long_name(dso,
1577
					   strdup(symbol_conf.vmlinux_name));
1578
			dso->lname_alloc = 1;
1579
			return err;
1580 1581
		}
		return err;
1582
	}
1583

1584
	if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
1585
		err = dso__load_vmlinux_path(dso, map, filter);
1586
		if (err > 0)
1587
			return err;
1588 1589
	}

1590 1591 1592 1593
	/* do not try local files if a symfs was given */
	if (symbol_conf.symfs[0] != 0)
		return -1;

1594 1595 1596
	kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
	if (!kallsyms_allocated_filename)
		return -1;
1597

1598
	kallsyms_filename = kallsyms_allocated_filename;
1599

1600
do_kallsyms:
1601
	err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1602 1603
	if (err > 0)
		pr_debug("Using %s for symbols\n", kallsyms_filename);
1604
	free(kallsyms_allocated_filename);
1605

1606
	if (err > 0 && !dso__is_kcore(dso)) {
1607
		dso__set_long_name(dso, strdup("[kernel.kallsyms]"));
1608 1609
		map__fixup_start(map);
		map__fixup_end(map);
1610
	}
1611

1612 1613 1614
	return err;
}

1615 1616
static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
				      symbol_filter_t filter)
1617 1618 1619
{
	int err;
	const char *kallsyms_filename = NULL;
1620
	struct machine *machine;
1621 1622 1623 1624 1625 1626
	char path[PATH_MAX];

	if (!map->groups) {
		pr_debug("Guest kernel map hasn't the point to groups\n");
		return -1;
	}
1627
	machine = map->groups->machine;
1628

1629
	if (machine__is_default_guest(machine)) {
1630 1631 1632 1633 1634 1635
		/*
		 * if the user specified a vmlinux filename, use it and only
		 * it, reporting errors to the user if it cannot be used.
		 * Or use file guest_kallsyms inputted by user on commandline
		 */
		if (symbol_conf.default_guest_vmlinux_name != NULL) {
1636
			err = dso__load_vmlinux(dso, map,
1637
				symbol_conf.default_guest_vmlinux_name, filter);
1638
			return err;
1639 1640 1641 1642 1643 1644
		}

		kallsyms_filename = symbol_conf.default_guest_kallsyms;
		if (!kallsyms_filename)
			return -1;
	} else {
1645
		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
1646 1647 1648
		kallsyms_filename = path;
	}

1649
	err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1650
	if (err > 0)
1651
		pr_debug("Using %s for symbols\n", kallsyms_filename);
1652
	if (err > 0 && !dso__is_kcore(dso)) {
1653 1654
		machine__mmap_name(machine, path, sizeof(path));
		dso__set_long_name(dso, strdup(path));
1655 1656 1657 1658 1659 1660
		map__fixup_start(map);
		map__fixup_end(map);
	}

	return err;
}
1661

1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689
static void vmlinux_path__exit(void)
{
	while (--vmlinux_path__nr_entries >= 0) {
		free(vmlinux_path[vmlinux_path__nr_entries]);
		vmlinux_path[vmlinux_path__nr_entries] = NULL;
	}

	free(vmlinux_path);
	vmlinux_path = NULL;
}

static int vmlinux_path__init(void)
{
	struct utsname uts;
	char bf[PATH_MAX];

	vmlinux_path = malloc(sizeof(char *) * 5);
	if (vmlinux_path == NULL)
		return -1;

	vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux");
	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
		goto out_fail;
	++vmlinux_path__nr_entries;
	vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux");
	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
		goto out_fail;
	++vmlinux_path__nr_entries;
1690 1691 1692 1693 1694 1695 1696 1697

	/* only try running kernel version if no symfs was given */
	if (symbol_conf.symfs[0] != 0)
		return 0;

	if (uname(&uts) < 0)
		return -1;

1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721
	snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release);
	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
		goto out_fail;
	++vmlinux_path__nr_entries;
	snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", uts.release);
	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
		goto out_fail;
	++vmlinux_path__nr_entries;
	snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
		 uts.release);
	vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
		goto out_fail;
	++vmlinux_path__nr_entries;

	return 0;

out_fail:
	vmlinux_path__exit();
	return -1;
}

1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735
static int setup_list(struct strlist **list, const char *list_str,
		      const char *list_name)
{
	if (list_str == NULL)
		return 0;

	*list = strlist__new(true, list_str);
	if (!*list) {
		pr_err("problems parsing %s list\n", list_name);
		return -1;
	}
	return 0;
}

1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754
static bool symbol__read_kptr_restrict(void)
{
	bool value = false;

	if (geteuid() != 0) {
		FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
		if (fp != NULL) {
			char line[8];

			if (fgets(line, sizeof(line), fp) != NULL)
				value = atoi(line) != 0;

			fclose(fp);
		}
	}

	return value;
}

1755
int symbol__init(void)
1756
{
1757 1758
	const char *symfs;

1759 1760 1761
	if (symbol_conf.initialized)
		return 0;

1762
	symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
1763

1764 1765
	symbol__elf_init();

1766 1767 1768
	if (symbol_conf.sort_by_name)
		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
					  sizeof(struct symbol));
1769

1770
	if (symbol_conf.try_vmlinux_path && vmlinux_path__init() < 0)
1771 1772
		return -1;

1773 1774 1775 1776 1777
	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
		pr_err("'.' is the only non valid --field-separator argument\n");
		return -1;
	}

1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789
	if (setup_list(&symbol_conf.dso_list,
		       symbol_conf.dso_list_str, "dso") < 0)
		return -1;

	if (setup_list(&symbol_conf.comm_list,
		       symbol_conf.comm_list_str, "comm") < 0)
		goto out_free_dso_list;

	if (setup_list(&symbol_conf.sym_list,
		       symbol_conf.sym_list_str, "symbol") < 0)
		goto out_free_comm_list;

1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801
	/*
	 * A path to symbols of "/" is identical to ""
	 * reset here for simplicity.
	 */
	symfs = realpath(symbol_conf.symfs, NULL);
	if (symfs == NULL)
		symfs = symbol_conf.symfs;
	if (strcmp(symfs, "/") == 0)
		symbol_conf.symfs = "";
	if (symfs != symbol_conf.symfs)
		free((void *)symfs);

1802 1803
	symbol_conf.kptr_restrict = symbol__read_kptr_restrict();

1804
	symbol_conf.initialized = true;
1805
	return 0;
1806 1807 1808

out_free_comm_list:
	strlist__delete(symbol_conf.comm_list);
1809 1810
out_free_dso_list:
	strlist__delete(symbol_conf.dso_list);
1811
	return -1;
1812 1813
}

1814 1815
void symbol__exit(void)
{
1816 1817
	if (!symbol_conf.initialized)
		return;
1818 1819 1820 1821 1822
	strlist__delete(symbol_conf.sym_list);
	strlist__delete(symbol_conf.dso_list);
	strlist__delete(symbol_conf.comm_list);
	vmlinux_path__exit();
	symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
1823
	symbol_conf.initialized = false;
1824
}