tools/perf/util/symbol.c

   1 #include "util.h"
   2 #include "../perf.h"
   3 #include "string.h"
   4 #include "symbol.h"
   5 #include "thread.h"
   6
   7 #include "debug.h"
   8
   9 #include <asm/bug.h>
  10 #include <libelf.h>
  11 #include <gelf.h>
  12 #include <elf.h>
  13 #include <limits.h>
  14 #include <sys/utsname.h>
  15
  16 #ifndef NT_GNU_BUILD_ID
  17 #define NT_GNU_BUILD_ID 3
  18 #endif
  19
  20 enum dso_origin {
  21         DSO__ORIG_KERNEL = 0,
  22         DSO__ORIG_JAVA_JIT,
  23         DSO__ORIG_FEDORA,
  24         DSO__ORIG_UBUNTU,
  25         DSO__ORIG_BUILDID,
  26         DSO__ORIG_DSO,
  27         DSO__ORIG_KMODULE,
  28         DSO__ORIG_NOT_FOUND,
  29 };
  30
  31 static void dsos__add(struct list_head *head, struct dso *dso);
  32 static struct map *map__new2(u64 start, struct dso *dso, enum map_type type);
  33 static void kernel_maps__insert(struct map *map);
  34 struct symbol *dso__find_symbol(struct dso *self, enum map_type type, u64 addr);
  35 static int dso__load_kernel_sym(struct dso *self, struct map *map,
  36                                 symbol_filter_t filter);
  37 unsigned int symbol__priv_size;
  38 static int vmlinux_path__nr_entries;
  39 static char **vmlinux_path;
  40
  41 static struct symbol_conf symbol_conf__defaults = {
  42         .use_modules      = true,
  43         .try_vmlinux_path = true,
  44 };
  45
  46 static struct rb_root kernel_maps__functions;
  47
  48 bool dso__loaded(const struct dso *self, enum map_type type)
  49 {
  50         return self->loaded & (1 << type);
  51 }
  52
  53 static void dso__set_loaded(struct dso *self, enum map_type type)
  54 {
  55         self->loaded |= (1 << type);
  56 }
  57
  58 static void symbols__fixup_end(struct rb_root *self)
  59 {
  60         struct rb_node *nd, *prevnd = rb_first(self);
  61         struct symbol *curr, *prev;
  62
  63         if (prevnd == NULL)
  64                 return;
  65
  66         curr = rb_entry(prevnd, struct symbol, rb_node);
  67
  68         for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
  69                 prev = curr;
  70                 curr = rb_entry(nd, struct symbol, rb_node);
  71
  72                 if (prev->end == prev->start)
  73                         prev->end = curr->start - 1;
  74         }
  75
  76         /* Last entry */
  77         if (curr->end == curr->start)
  78                 curr->end = roundup(curr->start, 4096);
  79 }
  80
  81 static void kernel_maps__fixup_end(void)
  82 {
  83         struct map *prev, *curr;
  84         struct rb_node *nd, *prevnd = rb_first(&kernel_maps__functions);
  85
  86         if (prevnd == NULL)
  87                 return;
  88
  89         curr = rb_entry(prevnd, struct map, rb_node);
  90
  91         for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
  92                 prev = curr;
  93                 curr = rb_entry(nd, struct map, rb_node);
  94                 prev->end = curr->start - 1;
  95         }
  96
  97         /*
  98          * We still haven't the actual symbols, so guess the
  99          * last map final address.
 100          */
 101         curr->end = ~0UL;
 102 }
 103
 104 static struct symbol *symbol__new(u64 start, u64 len, const char *name)
 105 {
 106         size_t namelen = strlen(name) + 1;
 107         struct symbol *self = zalloc(symbol__priv_size +
 108                                      sizeof(*self) + namelen);
 109         if (self == NULL)
 110                 return NULL;
 111
 112         if (symbol__priv_size)
 113                 self = ((void *)self) + symbol__priv_size;
 114
 115         self->start = start;
 116         self->end   = len ? start + len - 1 : start;
 117
 118         pr_debug3("%s: %s %#Lx-%#Lx\n", __func__, name, start, self->end);
 119
 120         memcpy(self->name, name, namelen);
 121
 122         return self;
 123 }
 124
 125 static void symbol__delete(struct symbol *self)
 126 {
 127         free(((void *)self) - symbol__priv_size);
 128 }
 129
 130 static size_t symbol__fprintf(struct symbol *self, FILE *fp)
 131 {
 132         return fprintf(fp, " %llx-%llx %s\n",
 133                        self->start, self->end, self->name);
 134 }
 135
 136 static void dso__set_long_name(struct dso *self, char *name)
 137 {
 138         if (name == NULL)
 139                 return;
 140         self->long_name = name;
 141         self->long_name_len = strlen(name);
 142 }
 143
 144 static void dso__set_basename(struct dso *self)
 145 {
 146         self->short_name = basename(self->long_name);
 147 }
 148
 149 struct dso *dso__new(const char *name)
 150 {
 151         struct dso *self = malloc(sizeof(*self) + strlen(name) + 1);
 152
 153         if (self != NULL) {
 154                 int i;
 155                 strcpy(self->name, name);
 156                 dso__set_long_name(self, self->name);
 157                 self->short_name = self->name;
 158                 for (i = 0; i < MAP__NR_TYPES; ++i)
 159                         self->symbols[i] = RB_ROOT;
 160                 self->find_symbol = dso__find_symbol;
 161                 self->slen_calculated = 0;
 162                 self->origin = DSO__ORIG_NOT_FOUND;
 163                 self->loaded = 0;
 164                 self->has_build_id = 0;
 165         }
 166
 167         return self;
 168 }
 169
 170 static void symbols__delete(struct rb_root *self)
 171 {
 172         struct symbol *pos;
 173         struct rb_node *next = rb_first(self);
 174
 175         while (next) {
 176                 pos = rb_entry(next, struct symbol, rb_node);
 177                 next = rb_next(&pos->rb_node);
 178                 rb_erase(&pos->rb_node, self);
 179                 symbol__delete(pos);
 180         }
 181 }
 182
 183 void dso__delete(struct dso *self)
 184 {
 185         int i;
 186         for (i = 0; i < MAP__NR_TYPES; ++i)
 187                 symbols__delete(&self->symbols[i]);
 188         if (self->long_name != self->name)
 189                 free(self->long_name);
 190         free(self);
 191 }
 192
 193 void dso__set_build_id(struct dso *self, void *build_id)
 194 {
 195         memcpy(self->build_id, build_id, sizeof(self->build_id));
 196         self->has_build_id = 1;
 197 }
 198
 199 static void symbols__insert(struct rb_root *self, struct symbol *sym)
 200 {
 201         struct rb_node **p = &self->rb_node;
 202         struct rb_node *parent = NULL;
 203         const u64 ip = sym->start;
 204         struct symbol *s;
 205
 206         while (*p != NULL) {
 207                 parent = *p;
 208                 s = rb_entry(parent, struct symbol, rb_node);
 209                 if (ip < s->start)
 210                         p = &(*p)->rb_left;
 211                 else
 212                         p = &(*p)->rb_right;
 213         }
 214         rb_link_node(&sym->rb_node, parent, p);
 215         rb_insert_color(&sym->rb_node, self);
 216 }
 217
 218 static struct symbol *symbols__find(struct rb_root *self, u64 ip)
 219 {
 220         struct rb_node *n;
 221
 222         if (self == NULL)
 223                 return NULL;
 224
 225         n = self->rb_node;
 226
 227         while (n) {
 228                 struct symbol *s = rb_entry(n, struct symbol, rb_node);
 229
 230                 if (ip < s->start)
 231                         n = n->rb_left;
 232                 else if (ip > s->end)
 233                         n = n->rb_right;
 234                 else
 235                         return s;
 236         }
 237
 238         return NULL;
 239 }
 240
 241 struct symbol *dso__find_symbol(struct dso *self, enum map_type type, u64 addr)
 242 {
 243         return symbols__find(&self->symbols[type], addr);
 244 }
 245
 246 int build_id__sprintf(u8 *self, int len, char *bf)
 247 {
 248         char *bid = bf;
 249         u8 *raw = self;
 250         int i;
 251
 252         for (i = 0; i < len; ++i) {
 253                 sprintf(bid, "%02x", *raw);
 254                 ++raw;
 255                 bid += 2;
 256         }
 257
 258         return raw - self;
 259 }
 260
 261 size_t dso__fprintf_buildid(struct dso *self, FILE *fp)
 262 {
 263         char sbuild_id[BUILD_ID_SIZE * 2 + 1];
 264
 265         build_id__sprintf(self->build_id, sizeof(self->build_id), sbuild_id);
 266         return fprintf(fp, "%s", sbuild_id);
 267 }
 268
 269 static const char * map_type__name[MAP__NR_TYPES] = {
 270         [MAP__FUNCTION] = "Functions",
 271 };
 272
 273 size_t dso__fprintf(struct dso *self, FILE *fp)
 274 {
 275         int i;
 276         struct rb_node *nd;
 277         size_t ret = fprintf(fp, "dso: %s (", self->short_name);
 278
 279         ret += dso__fprintf_buildid(self, fp);
 280         ret += fprintf(fp, ")\n");
 281         for (i = 0; i < MAP__NR_TYPES; ++i) {
 282                 ret += fprintf(fp, "%s:\n", map_type__name[i]);
 283
 284                 for (nd = rb_first(&self->symbols[i]); nd; nd = rb_next(nd)) {
 285                         struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
 286                         ret += symbol__fprintf(pos, fp);
 287                 }
 288         }
 289
 290         return ret;
 291 }
 292
 293 /*
 294  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
 295  * so that we can in the next step set the symbol ->end address and then
 296  * call kernel_maps__split_kallsyms.
 297  */
 298 static int dso__load_all_kallsyms(struct dso *self, struct map *map)
 299 {
 300         char *line = NULL;
 301         size_t n;
 302         struct rb_root *root = &self->symbols[map->type];
 303         FILE *file = fopen("/proc/kallsyms", "r");
 304
 305         if (file == NULL)
 306                 goto out_failure;
 307
 308         while (!feof(file)) {
 309                 u64 start;
 310                 struct symbol *sym;
 311                 int line_len, len;
 312                 char symbol_type;
 313                 char *symbol_name;
 314
 315                 line_len = getline(&line, &n, file);
 316                 if (line_len < 0)
 317                         break;
 318
 319                 if (!line)
 320                         goto out_failure;
 321
 322                 line[--line_len] = '\0'; /* \n */
 323
 324                 len = hex2u64(line, &start);
 325
 326                 len++;
 327                 if (len + 2 >= line_len)
 328                         continue;
 329
 330                 symbol_type = toupper(line[len]);
 331                 /*
 332                  * We're interested only in code ('T'ext)
 333                  */
 334                 if (symbol_type != 'T' && symbol_type != 'W')
 335                         continue;
 336
 337                 symbol_name = line + len + 2;
 338                 /*
 339                  * Will fix up the end later, when we have all symbols sorted.
 340                  */
 341                 sym = symbol__new(start, 0, symbol_name);
 342
 343                 if (sym == NULL)
 344                         goto out_delete_line;
 345                 /*
 346                  * We will pass the symbols to the filter later, in
 347                  * map__split_kallsyms, when we have split the maps per module
 348                  */
 349                 symbols__insert(root, sym);
 350         }
 351
 352         free(line);
 353         fclose(file);
 354
 355         return 0;
 356
 357 out_delete_line:
 358         free(line);
 359 out_failure:
 360         return -1;
 361 }
 362
 363 /*
 364  * Split the symbols into maps, making sure there are no overlaps, i.e. the
 365  * kernel range is broken in several maps, named [kernel].N, as we don't have
 366  * the original ELF section names vmlinux have.
 367  */
 368 static int dso__split_kallsyms(struct dso *self, struct map *map,
 369                                symbol_filter_t filter)
 370 {
 371         struct map *curr_map = map;
 372         struct symbol *pos;
 373         int count = 0;
 374         struct rb_root *root = &self->symbols[map->type];
 375         struct rb_node *next = rb_first(root);
 376         int kernel_range = 0;
 377
 378         while (next) {
 379                 char *module;
 380
 381                 pos = rb_entry(next, struct symbol, rb_node);
 382                 next = rb_next(&pos->rb_node);
 383
 384                 module = strchr(pos->name, '\t');
 385                 if (module) {
 386                         *module++ = '\0';
 387
 388                         if (strcmp(self->name, module)) {
 389                                 curr_map = kernel_maps__find_by_dso_name(module);
 390                                 if (curr_map == NULL) {
 391                                         pr_err("/proc/{kallsyms,modules} "
 392                                                "inconsistency!\n");
 393                                         return -1;
 394                                 }
 395                         }
 396                         /*
 397                          * So that we look just like we get from .ko files,
 398                          * i.e. not prelinked, relative to map->start.
 399                          */
 400                         pos->start = curr_map->map_ip(curr_map, pos->start);
 401                         pos->end   = curr_map->map_ip(curr_map, pos->end);
 402                 } else if (curr_map != map) {
 403                         char dso_name[PATH_MAX];
 404                         struct dso *dso;
 405
 406                         snprintf(dso_name, sizeof(dso_name), "[kernel].%d",
 407                                  kernel_range++);
 408
 409                         dso = dso__new(dso_name);
 410                         if (dso == NULL)
 411                                 return -1;
 412
 413                         curr_map = map__new2(pos->start, dso, map->type);
 414                         if (map == NULL) {
 415                                 dso__delete(dso);
 416                                 return -1;
 417                         }
 418
 419                         curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
 420                         kernel_maps__insert(curr_map);
 421                         ++kernel_range;
 422                 }
 423
 424                 if (filter && filter(curr_map, pos)) {
 425                         rb_erase(&pos->rb_node, root);
 426                         symbol__delete(pos);
 427                 } else {
 428                         if (curr_map != map) {
 429                                 rb_erase(&pos->rb_node, root);
 430                                 symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
 431                         }
 432                         count++;
 433                 }
 434         }
 435
 436         return count;
 437 }
 438
 439
 440 static int dso__load_kallsyms(struct dso *self, struct map *map,
 441                               symbol_filter_t filter)
 442 {
 443         if (dso__load_all_kallsyms(self, map) < 0)
 444                 return -1;
 445
 446         symbols__fixup_end(&self->symbols[map->type]);
 447         self->origin = DSO__ORIG_KERNEL;
 448
 449         return dso__split_kallsyms(self, map, filter);
 450 }
 451
 452 size_t kernel_maps__fprintf(FILE *fp)
 453 {
 454         size_t printed = fprintf(fp, "Kernel maps:\n");
 455         struct rb_node *nd;
 456
 457         for (nd = rb_first(&kernel_maps__functions); nd; nd = rb_next(nd)) {
 458                 struct map *pos = rb_entry(nd, struct map, rb_node);
 459
 460                 printed += fprintf(fp, "Map:");
 461                 printed += map__fprintf(pos, fp);
 462                 if (verbose > 1) {
 463                         printed += dso__fprintf(pos->dso, fp);
 464                         printed += fprintf(fp, "--\n");
 465                 }
 466         }
 467
 468         return printed + fprintf(fp, "END kernel maps\n");
 469 }
 470
 471 static int dso__load_perf_map(struct dso *self, struct map *map,
 472                               symbol_filter_t filter)
 473 {
 474         char *line = NULL;
 475         size_t n;
 476         FILE *file;
 477         int nr_syms = 0;
 478
 479         file = fopen(self->long_name, "r");
 480         if (file == NULL)
 481                 goto out_failure;
 482
 483         while (!feof(file)) {
 484                 u64 start, size;
 485                 struct symbol *sym;
 486                 int line_len, len;
 487
 488                 line_len = getline(&line, &n, file);
 489                 if (line_len < 0)
 490                         break;
 491
 492                 if (!line)
 493                         goto out_failure;
 494
 495                 line[--line_len] = '\0'; /* \n */
 496
 497                 len = hex2u64(line, &start);
 498
 499                 len++;
 500                 if (len + 2 >= line_len)
 501                         continue;
 502
 503                 len += hex2u64(line + len, &size);
 504
 505                 len++;
 506                 if (len + 2 >= line_len)
 507                         continue;
 508
 509                 sym = symbol__new(start, size, line + len);
 510
 511                 if (sym == NULL)
 512                         goto out_delete_line;
 513
 514                 if (filter && filter(map, sym))
 515                         symbol__delete(sym);
 516                 else {
 517                         symbols__insert(&self->symbols[map->type], sym);
 518                         nr_syms++;
 519                 }
 520         }
 521
 522         free(line);
 523         fclose(file);
 524
 525         return nr_syms;
 526
 527 out_delete_line:
 528         free(line);
 529 out_failure:
 530         return -1;
 531 }
 532
 533 /**
 534  * elf_symtab__for_each_symbol - iterate thru all the symbols
 535  *
 536  * @self: struct elf_symtab instance to iterate
 537  * @idx: uint32_t idx
 538  * @sym: GElf_Sym iterator
 539  */
 540 #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
 541         for (idx = 0, gelf_getsym(syms, idx, &sym);\
 542              idx < nr_syms; \
 543              idx++, gelf_getsym(syms, idx, &sym))
 544
 545 static inline uint8_t elf_sym__type(const GElf_Sym *sym)
 546 {
 547         return GELF_ST_TYPE(sym->st_info);
 548 }
 549
 550 static inline int elf_sym__is_function(const GElf_Sym *sym)
 551 {
 552         return elf_sym__type(sym) == STT_FUNC &&
 553                sym->st_name != 0 &&
 554                sym->st_shndx != SHN_UNDEF;
 555 }
 556
 557 static inline int elf_sym__is_label(const GElf_Sym *sym)
 558 {
 559         return elf_sym__type(sym) == STT_NOTYPE &&
 560                 sym->st_name != 0 &&
 561                 sym->st_shndx != SHN_UNDEF &&
 562                 sym->st_shndx != SHN_ABS;
 563 }
 564
 565 static inline const char *elf_sec__name(const GElf_Shdr *shdr,
 566                                         const Elf_Data *secstrs)
 567 {
 568         return secstrs->d_buf + shdr->sh_name;
 569 }
 570
 571 static inline int elf_sec__is_text(const GElf_Shdr *shdr,
 572                                         const Elf_Data *secstrs)
 573 {
 574         return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
 575 }
 576
 577 static inline const char *elf_sym__name(const GElf_Sym *sym,
 578                                         const Elf_Data *symstrs)
 579 {
 580         return symstrs->d_buf + sym->st_name;
 581 }
 582
 583 static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
 584                                     GElf_Shdr *shp, const char *name,
 585                                     size_t *idx)
 586 {
 587         Elf_Scn *sec = NULL;
 588         size_t cnt = 1;
 589
 590         while ((sec = elf_nextscn(elf, sec)) != NULL) {
 591                 char *str;
 592
 593                 gelf_getshdr(sec, shp);
 594                 str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
 595                 if (!strcmp(name, str)) {
 596                         if (idx)
 597                                 *idx = cnt;
 598                         break;
 599                 }
 600                 ++cnt;
 601         }
 602
 603         return sec;
 604 }
 605
 606 #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
 607         for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
 608              idx < nr_entries; \
 609              ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
 610
 611 #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
 612         for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
 613              idx < nr_entries; \
 614              ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
 615
 616 /*
 617  * We need to check if we have a .dynsym, so that we can handle the
 618  * .plt, synthesizing its symbols, that aren't on the symtabs (be it
 619  * .dynsym or .symtab).
 620  * And always look at the original dso, not at debuginfo packages, that
 621  * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
 622  */
 623 static int dso__synthesize_plt_symbols(struct  dso *self, struct map *map,
 624                                        symbol_filter_t filter)
 625 {
 626         uint32_t nr_rel_entries, idx;
 627         GElf_Sym sym;
 628         u64 plt_offset;
 629         GElf_Shdr shdr_plt;
 630         struct symbol *f;
 631         GElf_Shdr shdr_rel_plt, shdr_dynsym;
 632         Elf_Data *reldata, *syms, *symstrs;
 633         Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
 634         size_t dynsym_idx;
 635         GElf_Ehdr ehdr;
 636         char sympltname[1024];
 637         Elf *elf;
 638         int nr = 0, symidx, fd, err = 0;
 639
 640         fd = open(self->long_name, O_RDONLY);
 641         if (fd < 0)
 642                 goto out;
 643
 644         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
 645         if (elf == NULL)
 646                 goto out_close;
 647
 648         if (gelf_getehdr(elf, &ehdr) == NULL)
 649                 goto out_elf_end;
 650
 651         scn_dynsym = elf_section_by_name(elf, &ehdr, &shdr_dynsym,
 652                                          ".dynsym", &dynsym_idx);
 653         if (scn_dynsym == NULL)
 654                 goto out_elf_end;
 655
 656         scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
 657                                           ".rela.plt", NULL);
 658         if (scn_plt_rel == NULL) {
 659                 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
 660                                                   ".rel.plt", NULL);
 661                 if (scn_plt_rel == NULL)
 662                         goto out_elf_end;
 663         }
 664
 665         err = -1;
 666
 667         if (shdr_rel_plt.sh_link != dynsym_idx)
 668                 goto out_elf_end;
 669
 670         if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
 671                 goto out_elf_end;
 672
 673         /*
 674          * Fetch the relocation section to find the idxes to the GOT
 675          * and the symbols in the .dynsym they refer to.
 676          */
 677         reldata = elf_getdata(scn_plt_rel, NULL);
 678         if (reldata == NULL)
 679                 goto out_elf_end;
 680
 681         syms = elf_getdata(scn_dynsym, NULL);
 682         if (syms == NULL)
 683                 goto out_elf_end;
 684
 685         scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
 686         if (scn_symstrs == NULL)
 687                 goto out_elf_end;
 688
 689         symstrs = elf_getdata(scn_symstrs, NULL);
 690         if (symstrs == NULL)
 691                 goto out_elf_end;
 692
 693         nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
 694         plt_offset = shdr_plt.sh_offset;
 695
 696         if (shdr_rel_plt.sh_type == SHT_RELA) {
 697                 GElf_Rela pos_mem, *pos;
 698
 699                 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
 700                                            nr_rel_entries) {
 701                         symidx = GELF_R_SYM(pos->r_info);
 702                         plt_offset += shdr_plt.sh_entsize;
 703                         gelf_getsym(syms, symidx, &sym);
 704                         snprintf(sympltname, sizeof(sympltname),
 705                                  "%s@plt", elf_sym__name(&sym, symstrs));
 706
 707                         f = symbol__new(plt_offset, shdr_plt.sh_entsize,
 708                                         sympltname);
 709                         if (!f)
 710                                 goto out_elf_end;
 711
 712                         if (filter && filter(map, f))
 713                                 symbol__delete(f);
 714                         else {
 715                                 symbols__insert(&self->symbols[map->type], f);
 716                                 ++nr;
 717                         }
 718                 }
 719         } else if (shdr_rel_plt.sh_type == SHT_REL) {
 720                 GElf_Rel pos_mem, *pos;
 721                 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
 722                                           nr_rel_entries) {
 723                         symidx = GELF_R_SYM(pos->r_info);
 724                         plt_offset += shdr_plt.sh_entsize;
 725                         gelf_getsym(syms, symidx, &sym);
 726                         snprintf(sympltname, sizeof(sympltname),
 727                                  "%s@plt", elf_sym__name(&sym, symstrs));
 728
 729                         f = symbol__new(plt_offset, shdr_plt.sh_entsize,
 730                                         sympltname);
 731                         if (!f)
 732                                 goto out_elf_end;
 733
 734                         if (filter && filter(map, f))
 735                                 symbol__delete(f);
 736                         else {
 737                                 symbols__insert(&self->symbols[map->type], f);
 738                                 ++nr;
 739                         }
 740                 }
 741         }
 742
 743         err = 0;
 744 out_elf_end:
 745         elf_end(elf);
 746 out_close:
 747         close(fd);
 748
 749         if (err == 0)
 750                 return nr;
 751 out:
 752         pr_warning("%s: problems reading %s PLT info.\n",
 753                    __func__, self->long_name);
 754         return 0;
 755 }
 756
 757 static int dso__load_sym(struct dso *self, struct map *map, const char *name,
 758                          int fd, symbol_filter_t filter, int kernel,
 759                          int kmodule)
 760 {
 761         struct map *curr_map = map;
 762         struct dso *curr_dso = self;
 763         size_t dso_name_len = strlen(self->short_name);
 764         Elf_Data *symstrs, *secstrs;
 765         uint32_t nr_syms;
 766         int err = -1;
 767         uint32_t idx;
 768         GElf_Ehdr ehdr;
 769         GElf_Shdr shdr;
 770         Elf_Data *syms;
 771         GElf_Sym sym;
 772         Elf_Scn *sec, *sec_strndx;
 773         Elf *elf;
 774         int nr = 0;
 775
 776         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
 777         if (elf == NULL) {
 778                 pr_err("%s: cannot read %s ELF file.\n", __func__, name);
 779                 goto out_close;
 780         }
 781
 782         if (gelf_getehdr(elf, &ehdr) == NULL) {
 783                 pr_err("%s: cannot get elf header.\n", __func__);
 784                 goto out_elf_end;
 785         }
 786
 787         sec = elf_section_by_name(elf, &ehdr, &shdr, ".symtab", NULL);
 788         if (sec == NULL) {
 789                 sec = elf_section_by_name(elf, &ehdr, &shdr, ".dynsym", NULL);
 790                 if (sec == NULL)
 791                         goto out_elf_end;
 792         }
 793
 794         syms = elf_getdata(sec, NULL);
 795         if (syms == NULL)
 796                 goto out_elf_end;
 797
 798         sec = elf_getscn(elf, shdr.sh_link);
 799         if (sec == NULL)
 800                 goto out_elf_end;
 801
 802         symstrs = elf_getdata(sec, NULL);
 803         if (symstrs == NULL)
 804                 goto out_elf_end;
 805
 806         sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
 807         if (sec_strndx == NULL)
 808                 goto out_elf_end;
 809
 810         secstrs = elf_getdata(sec_strndx, NULL);
 811         if (secstrs == NULL)
 812                 goto out_elf_end;
 813
 814         nr_syms = shdr.sh_size / shdr.sh_entsize;
 815
 816         memset(&sym, 0, sizeof(sym));
 817         if (!kernel) {
 818                 self->adjust_symbols = (ehdr.e_type == ET_EXEC ||
 819                                 elf_section_by_name(elf, &ehdr, &shdr,
 820                                                      ".gnu.prelink_undo",
 821                                                      NULL) != NULL);
 822         } else self->adjust_symbols = 0;
 823
 824         elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
 825                 struct symbol *f;
 826                 const char *elf_name;
 827                 char *demangled = NULL;
 828                 int is_label = elf_sym__is_label(&sym);
 829                 const char *section_name;
 830
 831                 if (!is_label && !elf_sym__is_function(&sym))
 832                         continue;
 833
 834                 sec = elf_getscn(elf, sym.st_shndx);
 835                 if (!sec)
 836                         goto out_elf_end;
 837
 838                 gelf_getshdr(sec, &shdr);
 839
 840                 if (is_label && !elf_sec__is_text(&shdr, secstrs))
 841                         continue;
 842
 843                 elf_name = elf_sym__name(&sym, symstrs);
 844                 section_name = elf_sec__name(&shdr, secstrs);
 845
 846                 if (kernel || kmodule) {
 847                         char dso_name[PATH_MAX];
 848
 849                         if (strcmp(section_name,
 850                                    curr_dso->short_name + dso_name_len) == 0)
 851                                 goto new_symbol;
 852
 853                         if (strcmp(section_name, ".text") == 0) {
 854                                 curr_map = map;
 855                                 curr_dso = self;
 856                                 goto new_symbol;
 857                         }
 858
 859                         snprintf(dso_name, sizeof(dso_name),
 860                                  "%s%s", self->short_name, section_name);
 861
 862                         curr_map = kernel_maps__find_by_dso_name(dso_name);
 863                         if (curr_map == NULL) {
 864                                 u64 start = sym.st_value;
 865
 866                                 if (kmodule)
 867                                         start += map->start + shdr.sh_offset;
 868
 869                                 curr_dso = dso__new(dso_name);
 870                                 if (curr_dso == NULL)
 871                                         goto out_elf_end;
 872                                 curr_map = map__new2(start, curr_dso,
 873                                                      MAP__FUNCTION);
 874                                 if (curr_map == NULL) {
 875                                         dso__delete(curr_dso);
 876                                         goto out_elf_end;
 877                                 }
 878                                 curr_map->map_ip = identity__map_ip;
 879                                 curr_map->unmap_ip = identity__map_ip;
 880                                 curr_dso->origin = DSO__ORIG_KERNEL;
 881                                 kernel_maps__insert(curr_map);
 882                                 dsos__add(&dsos__kernel, curr_dso);
 883                         } else
 884                                 curr_dso = curr_map->dso;
 885
 886                         goto new_symbol;
 887                 }
 888
 889                 if (curr_dso->adjust_symbols) {
 890                         pr_debug2("adjusting symbol: st_value: %Lx sh_addr: "
 891                                   "%Lx sh_offset: %Lx\n", (u64)sym.st_value,
 892                                   (u64)shdr.sh_addr, (u64)shdr.sh_offset);
 893                         sym.st_value -= shdr.sh_addr - shdr.sh_offset;
 894                 }
 895                 /*
 896                  * We need to figure out if the object was created from C++ sources
 897                  * DWARF DW_compile_unit has this, but we don't always have access
 898                  * to it...
 899                  */
 900                 demangled = bfd_demangle(NULL, elf_name, DMGL_PARAMS | DMGL_ANSI);
 901                 if (demangled != NULL)
 902                         elf_name = demangled;
 903 new_symbol:
 904                 f = symbol__new(sym.st_value, sym.st_size, elf_name);
 905                 free(demangled);
 906                 if (!f)
 907                         goto out_elf_end;
 908
 909                 if (filter && filter(curr_map, f))
 910                         symbol__delete(f);
 911                 else {
 912                         symbols__insert(&curr_dso->symbols[curr_map->type], f);
 913                         nr++;
 914                 }
 915         }
 916
 917         /*
 918          * For misannotated, zeroed, ASM function sizes.
 919          */
 920         if (nr > 0)
 921                 symbols__fixup_end(&self->symbols[map->type]);
 922         err = nr;
 923 out_elf_end:
 924         elf_end(elf);
 925 out_close:
 926         return err;
 927 }
 928
 929 static bool dso__build_id_equal(const struct dso *self, u8 *build_id)
 930 {
 931         return memcmp(self->build_id, build_id, sizeof(self->build_id)) == 0;
 932 }
 933
 934 static bool __dsos__read_build_ids(struct list_head *head)
 935 {
 936         bool have_build_id = false;
 937         struct dso *pos;
 938
 939         list_for_each_entry(pos, head, node)
 940                 if (filename__read_build_id(pos->long_name, pos->build_id,
 941                                             sizeof(pos->build_id)) > 0) {
 942                         have_build_id     = true;
 943                         pos->has_build_id = true;
 944                 }
 945
 946         return have_build_id;
 947 }
 948
 949 bool dsos__read_build_ids(void)
 950 {
 951         return __dsos__read_build_ids(&dsos__kernel) ||
 952                __dsos__read_build_ids(&dsos__user);
 953 }
 954
 955 /*
 956  * Align offset to 4 bytes as needed for note name and descriptor data.
 957  */
 958 #define NOTE_ALIGN(n) (((n) + 3) & -4U)
 959
 960 int filename__read_build_id(const char *filename, void *bf, size_t size)
 961 {
 962         int fd, err = -1;
 963         GElf_Ehdr ehdr;
 964         GElf_Shdr shdr;
 965         Elf_Data *data;
 966         Elf_Scn *sec;
 967         Elf_Kind ek;
 968         void *ptr;
 969         Elf *elf;
 970
 971         if (size < BUILD_ID_SIZE)
 972                 goto out;
 973
 974         fd = open(filename, O_RDONLY);
 975         if (fd < 0)
 976                 goto out;
 977
 978         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
 979         if (elf == NULL) {
 980                 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
 981                 goto out_close;
 982         }
 983
 984         ek = elf_kind(elf);
 985         if (ek != ELF_K_ELF)
 986                 goto out_elf_end;
 987
 988         if (gelf_getehdr(elf, &ehdr) == NULL) {
 989                 pr_err("%s: cannot get elf header.\n", __func__);
 990                 goto out_elf_end;
 991         }
 992
 993         sec = elf_section_by_name(elf, &ehdr, &shdr,
 994                                   ".note.gnu.build-id", NULL);
 995         if (sec == NULL) {
 996                 sec = elf_section_by_name(elf, &ehdr, &shdr,
 997                                           ".notes", NULL);
 998                 if (sec == NULL)
 999                         goto out_elf_end;
1000         }
1001
1002         data = elf_getdata(sec, NULL);
1003         if (data == NULL)
1004                 goto out_elf_end;
1005
1006         ptr = data->d_buf;
1007         while (ptr < (data->d_buf + data->d_size)) {
1008                 GElf_Nhdr *nhdr = ptr;
1009                 int namesz = NOTE_ALIGN(nhdr->n_namesz),
1010                     descsz = NOTE_ALIGN(nhdr->n_descsz);
1011                 const char *name;
1012
1013                 ptr += sizeof(*nhdr);
1014                 name = ptr;
1015                 ptr += namesz;
1016                 if (nhdr->n_type == NT_GNU_BUILD_ID &&
1017                     nhdr->n_namesz == sizeof("GNU")) {
1018                         if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
1019                                 memcpy(bf, ptr, BUILD_ID_SIZE);
1020                                 err = BUILD_ID_SIZE;
1021                                 break;
1022                         }
1023                 }
1024                 ptr += descsz;
1025         }
1026 out_elf_end:
1027         elf_end(elf);
1028 out_close:
1029         close(fd);
1030 out:
1031         return err;
1032 }
1033
1034 int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
1035 {
1036         int fd, err = -1;
1037
1038         if (size < BUILD_ID_SIZE)
1039                 goto out;
1040
1041         fd = open(filename, O_RDONLY);
1042         if (fd < 0)
1043                 goto out;
1044
1045         while (1) {
1046                 char bf[BUFSIZ];
1047                 GElf_Nhdr nhdr;
1048                 int namesz, descsz;
1049
1050                 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
1051                         break;
1052
1053                 namesz = NOTE_ALIGN(nhdr.n_namesz);
1054                 descsz = NOTE_ALIGN(nhdr.n_descsz);
1055                 if (nhdr.n_type == NT_GNU_BUILD_ID &&
1056                     nhdr.n_namesz == sizeof("GNU")) {
1057                         if (read(fd, bf, namesz) != namesz)
1058                                 break;
1059                         if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
1060                                 if (read(fd, build_id,
1061                                     BUILD_ID_SIZE) == BUILD_ID_SIZE) {
1062                                         err = 0;
1063                                         break;
1064                                 }
1065                         } else if (read(fd, bf, descsz) != descsz)
1066                                 break;
1067                 } else {
1068                         int n = namesz + descsz;
1069                         if (read(fd, bf, n) != n)
1070                                 break;
1071                 }
1072         }
1073         close(fd);
1074 out:
1075         return err;
1076 }
1077
1078 char dso__symtab_origin(const struct dso *self)
1079 {
1080         static const char origin[] = {
1081                 [DSO__ORIG_KERNEL] =   'k',
1082                 [DSO__ORIG_JAVA_JIT] = 'j',
1083                 [DSO__ORIG_FEDORA] =   'f',
1084                 [DSO__ORIG_UBUNTU] =   'u',
1085                 [DSO__ORIG_BUILDID] =  'b',
1086                 [DSO__ORIG_DSO] =      'd',
1087                 [DSO__ORIG_KMODULE] =  'K',
1088         };
1089
1090         if (self == NULL || self->origin == DSO__ORIG_NOT_FOUND)
1091                 return '!';
1092         return origin[self->origin];
1093 }
1094
1095 int dso__load(struct dso *self, struct map *map, symbol_filter_t filter)
1096 {
1097         int size = PATH_MAX;
1098         char *name;
1099         u8 build_id[BUILD_ID_SIZE];
1100         int ret = -1;
1101         int fd;
1102
1103         dso__set_loaded(self, map->type);
1104
1105         if (self->kernel)
1106                 return dso__load_kernel_sym(self, map, filter);
1107
1108         name = malloc(size);
1109         if (!name)
1110                 return -1;
1111
1112         self->adjust_symbols = 0;
1113
1114         if (strncmp(self->name, "/tmp/perf-", 10) == 0) {
1115                 ret = dso__load_perf_map(self, map, filter);
1116                 self->origin = ret > 0 ? DSO__ORIG_JAVA_JIT :
1117                                          DSO__ORIG_NOT_FOUND;
1118                 return ret;
1119         }
1120
1121         self->origin = DSO__ORIG_FEDORA - 1;
1122
1123 more:
1124         do {
1125                 self->origin++;
1126                 switch (self->origin) {
1127                 case DSO__ORIG_FEDORA:
1128                         snprintf(name, size, "/usr/lib/debug%s.debug",
1129                                  self->long_name);
1130                         break;
1131                 case DSO__ORIG_UBUNTU:
1132                         snprintf(name, size, "/usr/lib/debug%s",
1133                                  self->long_name);
1134                         break;
1135                 case DSO__ORIG_BUILDID:
1136                         if (filename__read_build_id(self->long_name, build_id,
1137                                                     sizeof(build_id))) {
1138                                 char build_id_hex[BUILD_ID_SIZE * 2 + 1];
1139
1140                                 build_id__sprintf(build_id, sizeof(build_id),
1141                                                   build_id_hex);
1142                                 snprintf(name, size,
1143                                          "/usr/lib/debug/.build-id/%.2s/%s.debug",
1144                                         build_id_hex, build_id_hex + 2);
1145                                 if (self->has_build_id)
1146                                         goto compare_build_id;
1147                                 break;
1148                         }
1149                         self->origin++;
1150                         /* Fall thru */
1151                 case DSO__ORIG_DSO:
1152                         snprintf(name, size, "%s", self->long_name);
1153                         break;
1154
1155                 default:
1156                         goto out;
1157                 }
1158
1159                 if (self->has_build_id) {
1160                         if (filename__read_build_id(name, build_id,
1161                                                     sizeof(build_id)) < 0)
1162                                 goto more;
1163 compare_build_id:
1164                         if (!dso__build_id_equal(self, build_id))
1165                                 goto more;
1166                 }
1167
1168                 fd = open(name, O_RDONLY);
1169         } while (fd < 0);
1170
1171         ret = dso__load_sym(self, map, name, fd, filter, 0, 0);
1172         close(fd);
1173
1174         /*
1175          * Some people seem to have debuginfo files _WITHOUT_ debug info!?!?
1176          */
1177         if (!ret)
1178                 goto more;
1179
1180         if (ret > 0) {
1181                 int nr_plt = dso__synthesize_plt_symbols(self, map, filter);
1182                 if (nr_plt > 0)
1183                         ret += nr_plt;
1184         }
1185 out:
1186         free(name);
1187         if (ret < 0 && strstr(self->name, " (deleted)") != NULL)
1188                 return 0;
1189         return ret;
1190 }
1191
1192 static void kernel_maps__insert(struct map *map)
1193 {
1194         maps__insert(&kernel_maps__functions, map);
1195 }
1196
1197 struct symbol *kernel_maps__find_function(u64 ip, struct map **mapp,
1198                                           symbol_filter_t filter)
1199 {
1200         struct map *map = maps__find(&kernel_maps__functions, ip);
1201
1202         if (mapp)
1203                 *mapp = map;
1204
1205         if (map) {
1206                 ip = map->map_ip(map, ip);
1207                 return map__find_symbol(map, ip, filter);
1208         } else
1209                 WARN_ONCE(RB_EMPTY_ROOT(&kernel_maps__functions),
1210                           "Empty kernel_maps, was symbol__init() called?\n");
1211
1212         return NULL;
1213 }
1214
1215 struct map *kernel_maps__find_by_dso_name(const char *name)
1216 {
1217         struct rb_node *nd;
1218
1219         for (nd = rb_first(&kernel_maps__functions); nd; nd = rb_next(nd)) {
1220                 struct map *map = rb_entry(nd, struct map, rb_node);
1221
1222                 if (map->dso && strcmp(map->dso->name, name) == 0)
1223                         return map;
1224         }
1225
1226         return NULL;
1227 }
1228
1229 static int dsos__set_modules_path_dir(char *dirname)
1230 {
1231         struct dirent *dent;
1232         DIR *dir = opendir(dirname);
1233
1234         if (!dir) {
1235                 pr_debug("%s: cannot open %s dir\n", __func__, dirname);
1236                 return -1;
1237         }
1238
1239         while ((dent = readdir(dir)) != NULL) {
1240                 char path[PATH_MAX];
1241
1242                 if (dent->d_type == DT_DIR) {
1243                         if (!strcmp(dent->d_name, ".") ||
1244                             !strcmp(dent->d_name, ".."))
1245                                 continue;
1246
1247                         snprintf(path, sizeof(path), "%s/%s",
1248                                  dirname, dent->d_name);
1249                         if (dsos__set_modules_path_dir(path) < 0)
1250                                 goto failure;
1251                 } else {
1252                         char *dot = strrchr(dent->d_name, '.'),
1253                              dso_name[PATH_MAX];
1254                         struct map *map;
1255                         char *long_name;
1256
1257                         if (dot == NULL || strcmp(dot, ".ko"))
1258                                 continue;
1259                         snprintf(dso_name, sizeof(dso_name), "[%.*s]",
1260                                  (int)(dot - dent->d_name), dent->d_name);
1261
1262                         strxfrchar(dso_name, '-', '_');
1263                         map = kernel_maps__find_by_dso_name(dso_name);
1264                         if (map == NULL)
1265                                 continue;
1266
1267                         snprintf(path, sizeof(path), "%s/%s",
1268                                  dirname, dent->d_name);
1269
1270                         long_name = strdup(path);
1271                         if (long_name == NULL)
1272                                 goto failure;
1273                         dso__set_long_name(map->dso, long_name);
1274                 }
1275         }
1276
1277         return 0;
1278 failure:
1279         closedir(dir);
1280         return -1;
1281 }
1282
1283 static int dsos__set_modules_path(void)
1284 {
1285         struct utsname uts;
1286         char modules_path[PATH_MAX];
1287
1288         if (uname(&uts) < 0)
1289                 return -1;
1290
1291         snprintf(modules_path, sizeof(modules_path), "/lib/modules/%s/kernel",
1292                  uts.release);
1293
1294         return dsos__set_modules_path_dir(modules_path);
1295 }
1296
1297 /*
1298  * Constructor variant for modules (where we know from /proc/modules where
1299  * they are loaded) and for vmlinux, where only after we load all the
1300  * symbols we'll know where it starts and ends.
1301  */
1302 static struct map *map__new2(u64 start, struct dso *dso, enum map_type type)
1303 {
1304         struct map *self = malloc(sizeof(*self));
1305
1306         if (self != NULL) {
1307                 /*
1308                  * ->end will be filled after we load all the symbols
1309                  */
1310                 map__init(self, type, start, 0, 0, dso);
1311         }
1312
1313         return self;
1314 }
1315
1316 static int kernel_maps__create_module_maps(void)
1317 {
1318         char *line = NULL;
1319         size_t n;
1320         FILE *file = fopen("/proc/modules", "r");
1321         struct map *map;
1322
1323         if (file == NULL)
1324                 return -1;
1325
1326         while (!feof(file)) {
1327                 char name[PATH_MAX];
1328                 u64 start;
1329                 struct dso *dso;
1330                 char *sep;
1331                 int line_len;
1332
1333                 line_len = getline(&line, &n, file);
1334                 if (line_len < 0)
1335                         break;
1336
1337                 if (!line)
1338                         goto out_failure;
1339
1340                 line[--line_len] = '\0'; /* \n */
1341
1342                 sep = strrchr(line, 'x');
1343                 if (sep == NULL)
1344                         continue;
1345
1346                 hex2u64(sep + 1, &start);
1347
1348                 sep = strchr(line, ' ');
1349                 if (sep == NULL)
1350                         continue;
1351
1352                 *sep = '\0';
1353
1354                 snprintf(name, sizeof(name), "[%s]", line);
1355                 dso = dso__new(name);
1356
1357                 if (dso == NULL)
1358                         goto out_delete_line;
1359
1360                 map = map__new2(start, dso, MAP__FUNCTION);
1361                 if (map == NULL) {
1362                         dso__delete(dso);
1363                         goto out_delete_line;
1364                 }
1365
1366                 snprintf(name, sizeof(name),
1367                          "/sys/module/%s/notes/.note.gnu.build-id", line);
1368                 if (sysfs__read_build_id(name, dso->build_id,
1369                                          sizeof(dso->build_id)) == 0)
1370                         dso->has_build_id = true;
1371
1372                 dso->origin = DSO__ORIG_KMODULE;
1373                 kernel_maps__insert(map);
1374                 dsos__add(&dsos__kernel, dso);
1375         }
1376
1377         free(line);
1378         fclose(file);
1379
1380         return dsos__set_modules_path();
1381
1382 out_delete_line:
1383         free(line);
1384 out_failure:
1385         return -1;
1386 }
1387
1388 static int dso__load_vmlinux(struct dso *self, struct map *map,
1389                              const char *vmlinux, symbol_filter_t filter)
1390 {
1391         int err = -1, fd;
1392
1393         if (self->has_build_id) {
1394                 u8 build_id[BUILD_ID_SIZE];
1395
1396                 if (filename__read_build_id(vmlinux, build_id,
1397                                             sizeof(build_id)) < 0) {
1398                         pr_debug("No build_id in %s, ignoring it\n", vmlinux);
1399                         return -1;
1400                 }
1401                 if (!dso__build_id_equal(self, build_id)) {
1402                         char expected_build_id[BUILD_ID_SIZE * 2 + 1],
1403                              vmlinux_build_id[BUILD_ID_SIZE * 2 + 1];
1404
1405                         build_id__sprintf(self->build_id,
1406                                           sizeof(self->build_id),
1407                                           expected_build_id);
1408                         build_id__sprintf(build_id, sizeof(build_id),
1409                                           vmlinux_build_id);
1410                         pr_debug("build_id in %s is %s while expected is %s, "
1411                                  "ignoring it\n", vmlinux, vmlinux_build_id,
1412                                  expected_build_id);
1413                         return -1;
1414                 }
1415         }
1416
1417         fd = open(vmlinux, O_RDONLY);
1418         if (fd < 0)
1419                 return -1;
1420
1421         dso__set_loaded(self, map->type);
1422         err = dso__load_sym(self, map, self->long_name, fd, filter, 1, 0);
1423
1424         close(fd);
1425
1426         return err;
1427 }
1428
1429 static int dso__load_kernel_sym(struct dso *self, struct map *map,
1430                                 symbol_filter_t filter)
1431 {
1432         int err;
1433         bool is_kallsyms;
1434
1435         if (vmlinux_path != NULL) {
1436                 int i;
1437                 pr_debug("Looking at the vmlinux_path (%d entries long)\n",
1438                          vmlinux_path__nr_entries);
1439                 for (i = 0; i < vmlinux_path__nr_entries; ++i) {
1440                         err = dso__load_vmlinux(self, map, vmlinux_path[i],
1441                                                 filter);
1442                         if (err > 0) {
1443                                 pr_debug("Using %s for symbols\n",
1444                                          vmlinux_path[i]);
1445                                 dso__set_long_name(self,
1446                                                    strdup(vmlinux_path[i]));
1447                                 goto out_fixup;
1448                         }
1449                 }
1450         }
1451
1452         is_kallsyms = self->long_name[0] == '[';
1453         if (is_kallsyms)
1454                 goto do_kallsyms;
1455
1456         err = dso__load_vmlinux(self, map, self->long_name, filter);
1457         if (err <= 0) {
1458                 pr_info("The file %s cannot be used, "
1459                         "trying to use /proc/kallsyms...", self->long_name);
1460 do_kallsyms:
1461                 err = dso__load_kallsyms(self, map, filter);
1462                 if (err > 0 && !is_kallsyms)
1463                         dso__set_long_name(self, strdup("[kernel.kallsyms]"));
1464         }
1465
1466         if (err > 0) {
1467 out_fixup:
1468                 map__fixup_start(map);
1469                 map__fixup_end(map);
1470         }
1471
1472         return err;
1473 }
1474
1475 LIST_HEAD(dsos__user);
1476 LIST_HEAD(dsos__kernel);
1477 struct dso *vdso;
1478
1479 static void dsos__add(struct list_head *head, struct dso *dso)
1480 {
1481         list_add_tail(&dso->node, head);
1482 }
1483
1484 static struct dso *dsos__find(struct list_head *head, const char *name)
1485 {
1486         struct dso *pos;
1487
1488         list_for_each_entry(pos, head, node)
1489                 if (strcmp(pos->name, name) == 0)
1490                         return pos;
1491         return NULL;
1492 }
1493
1494 struct dso *dsos__findnew(const char *name)
1495 {
1496         struct dso *dso = dsos__find(&dsos__user, name);
1497
1498         if (!dso) {
1499                 dso = dso__new(name);
1500                 if (dso != NULL) {
1501                         dsos__add(&dsos__user, dso);
1502                         dso__set_basename(dso);
1503                 }
1504         }
1505
1506         return dso;
1507 }
1508
1509 static void __dsos__fprintf(struct list_head *head, FILE *fp)
1510 {
1511         struct dso *pos;
1512
1513         list_for_each_entry(pos, head, node)
1514                 dso__fprintf(pos, fp);
1515 }
1516
1517 void dsos__fprintf(FILE *fp)
1518 {
1519         __dsos__fprintf(&dsos__kernel, fp);
1520         __dsos__fprintf(&dsos__user, fp);
1521 }
1522
1523 static size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp)
1524 {
1525         struct dso *pos;
1526         size_t ret = 0;
1527
1528         list_for_each_entry(pos, head, node) {
1529                 ret += dso__fprintf_buildid(pos, fp);
1530                 ret += fprintf(fp, " %s\n", pos->long_name);
1531         }
1532         return ret;
1533 }
1534
1535 size_t dsos__fprintf_buildid(FILE *fp)
1536 {
1537         return (__dsos__fprintf_buildid(&dsos__kernel, fp) +
1538                 __dsos__fprintf_buildid(&dsos__user, fp));
1539 }
1540
1541 static int kernel_maps__create_kernel_map(const struct symbol_conf *conf)
1542 {
1543         struct map *kmap;
1544         struct dso *kernel = dso__new(conf->vmlinux_name ?: "[kernel.kallsyms]");
1545
1546         if (kernel == NULL)
1547                 return -1;
1548
1549         kmap = map__new2(0, kernel, MAP__FUNCTION);
1550         if (kmap == NULL)
1551                 goto out_delete_kernel_dso;
1552
1553         kmap->map_ip       = kmap->unmap_ip = identity__map_ip;
1554         kernel->short_name = "[kernel]";
1555         kernel->kernel     = 1;
1556
1557         vdso = dso__new("[vdso]");
1558         if (vdso == NULL)
1559                 goto out_delete_kernel_map;
1560         dso__set_loaded(vdso, MAP__FUNCTION);
1561
1562         if (sysfs__read_build_id("/sys/kernel/notes", kernel->build_id,
1563                                  sizeof(kernel->build_id)) == 0)
1564                 kernel->has_build_id = true;
1565
1566         kernel_maps__insert(kmap);
1567         dsos__add(&dsos__kernel, kernel);
1568         dsos__add(&dsos__user, vdso);
1569
1570         return 0;
1571
1572 out_delete_kernel_map:
1573         map__delete(kmap);
1574 out_delete_kernel_dso:
1575         dso__delete(kernel);
1576         return -1;
1577 }
1578
1579 static void vmlinux_path__exit(void)
1580 {
1581         while (--vmlinux_path__nr_entries >= 0) {
1582                 free(vmlinux_path[vmlinux_path__nr_entries]);
1583                 vmlinux_path[vmlinux_path__nr_entries] = NULL;
1584         }
1585
1586         free(vmlinux_path);
1587         vmlinux_path = NULL;
1588 }
1589
1590 static int vmlinux_path__init(void)
1591 {
1592         struct utsname uts;
1593         char bf[PATH_MAX];
1594
1595         if (uname(&uts) < 0)
1596                 return -1;
1597
1598         vmlinux_path = malloc(sizeof(char *) * 5);
1599         if (vmlinux_path == NULL)
1600                 return -1;
1601
1602         vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux");
1603         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1604                 goto out_fail;
1605         ++vmlinux_path__nr_entries;
1606         vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux");
1607         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1608                 goto out_fail;
1609         ++vmlinux_path__nr_entries;
1610         snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release);
1611         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1612         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1613                 goto out_fail;
1614         ++vmlinux_path__nr_entries;
1615         snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", uts.release);
1616         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1617         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1618                 goto out_fail;
1619         ++vmlinux_path__nr_entries;
1620         snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
1621                  uts.release);
1622         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1623         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1624                 goto out_fail;
1625         ++vmlinux_path__nr_entries;
1626
1627         return 0;
1628
1629 out_fail:
1630         vmlinux_path__exit();
1631         return -1;
1632 }
1633
1634 static int kernel_maps__init(const struct symbol_conf *conf)
1635 {
1636         const struct symbol_conf *pconf = conf ?: &symbol_conf__defaults;
1637
1638         symbol__priv_size = pconf->priv_size;
1639
1640         if (pconf->try_vmlinux_path && vmlinux_path__init() < 0)
1641                 return -1;
1642
1643         if (kernel_maps__create_kernel_map(pconf) < 0) {
1644                 vmlinux_path__exit();
1645                 return -1;
1646         }
1647
1648         if (pconf->use_modules && kernel_maps__create_module_maps() < 0)
1649                 pr_debug("Failed to load list of modules in use, "
1650                          "continuing...\n");
1651         /*
1652          * Now that we have all the maps created, just set the ->end of them:
1653          */
1654         kernel_maps__fixup_end();
1655         return 0;
1656 }
1657
1658 int symbol__init(struct symbol_conf *conf)
1659 {
1660         elf_version(EV_CURRENT);
1661         return kernel_maps__init(conf);
1662 }