tools/perf/util/symbol.c

   1 #include "util.h"
   2 #include "../perf.h"
   3 #include "string.h"
   4 #include "symbol.h"
   5
   6 #include <libelf.h>
   7 #include <gelf.h>
   8 #include <elf.h>
   9
  10 const char *sym_hist_filter;
  11
  12 static struct symbol *symbol__new(u64 start, u64 len,
  13                                   const char *name, unsigned int priv_size,
  14                                   u64 obj_start, int verbose)
  15 {
  16         size_t namelen = strlen(name) + 1;
  17         struct symbol *self = calloc(1, priv_size + sizeof(*self) + namelen);
  18
  19         if (!self)
  20                 return NULL;
  21
  22         if (verbose >= 2)
  23                 printf("new symbol: %016Lx [%08lx]: %s, hist: %p, obj_start: %p\n",
  24                         (u64)start, (unsigned long)len, name, self->hist, (void *)(unsigned long)obj_start);
  25
  26         self->obj_start= obj_start;
  27         self->hist = NULL;
  28         self->hist_sum = 0;
  29
  30         if (sym_hist_filter && !strcmp(name, sym_hist_filter))
  31                 self->hist = calloc(sizeof(u64), len);
  32
  33         if (priv_size) {
  34                 memset(self, 0, priv_size);
  35                 self = ((void *)self) + priv_size;
  36         }
  37         self->start = start;
  38         self->end   = len ? start + len - 1 : start;
  39         memcpy(self->name, name, namelen);
  40
  41         return self;
  42 }
  43
  44 static void symbol__delete(struct symbol *self, unsigned int priv_size)
  45 {
  46         free(((void *)self) - priv_size);
  47 }
  48
  49 static size_t symbol__fprintf(struct symbol *self, FILE *fp)
  50 {
  51         if (!self->module)
  52                 return fprintf(fp, " %llx-%llx %s\n",
  53                        self->start, self->end, self->name);
  54         else
  55                 return fprintf(fp, " %llx-%llx %s \t[%s]\n",
  56                        self->start, self->end, self->name, self->module->name);
  57 }
  58
  59 struct dso *dso__new(const char *name, unsigned int sym_priv_size)
  60 {
  61         struct dso *self = malloc(sizeof(*self) + strlen(name) + 1);
  62
  63         if (self != NULL) {
  64                 strcpy(self->name, name);
  65                 self->syms = RB_ROOT;
  66                 self->sym_priv_size = sym_priv_size;
  67                 self->find_symbol = dso__find_symbol;
  68         }
  69
  70         return self;
  71 }
  72
  73 static void dso__delete_symbols(struct dso *self)
  74 {
  75         struct symbol *pos;
  76         struct rb_node *next = rb_first(&self->syms);
  77
  78         while (next) {
  79                 pos = rb_entry(next, struct symbol, rb_node);
  80                 next = rb_next(&pos->rb_node);
  81                 rb_erase(&pos->rb_node, &self->syms);
  82                 symbol__delete(pos, self->sym_priv_size);
  83         }
  84 }
  85
  86 void dso__delete(struct dso *self)
  87 {
  88         dso__delete_symbols(self);
  89         free(self);
  90 }
  91
  92 static void dso__insert_symbol(struct dso *self, struct symbol *sym)
  93 {
  94         struct rb_node **p = &self->syms.rb_node;
  95         struct rb_node *parent = NULL;
  96         const u64 ip = sym->start;
  97         struct symbol *s;
  98
  99         while (*p != NULL) {
 100                 parent = *p;
 101                 s = rb_entry(parent, struct symbol, rb_node);
 102                 if (ip < s->start)
 103                         p = &(*p)->rb_left;
 104                 else
 105                         p = &(*p)->rb_right;
 106         }
 107         rb_link_node(&sym->rb_node, parent, p);
 108         rb_insert_color(&sym->rb_node, &self->syms);
 109 }
 110
 111 struct symbol *dso__find_symbol(struct dso *self, u64 ip)
 112 {
 113         struct rb_node *n;
 114
 115         if (self == NULL)
 116                 return NULL;
 117
 118         n = self->syms.rb_node;
 119
 120         while (n) {
 121                 struct symbol *s = rb_entry(n, struct symbol, rb_node);
 122
 123                 if (ip < s->start)
 124                         n = n->rb_left;
 125                 else if (ip > s->end)
 126                         n = n->rb_right;
 127                 else
 128                         return s;
 129         }
 130
 131         return NULL;
 132 }
 133
 134 size_t dso__fprintf(struct dso *self, FILE *fp)
 135 {
 136         size_t ret = fprintf(fp, "dso: %s\n", self->name);
 137
 138         struct rb_node *nd;
 139         for (nd = rb_first(&self->syms); nd; nd = rb_next(nd)) {
 140                 struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
 141                 ret += symbol__fprintf(pos, fp);
 142         }
 143
 144         return ret;
 145 }
 146
 147 static int dso__load_kallsyms(struct dso *self, symbol_filter_t filter, int verbose)
 148 {
 149         struct rb_node *nd, *prevnd;
 150         char *line = NULL;
 151         size_t n;
 152         FILE *file = fopen("/proc/kallsyms", "r");
 153         int count = 0;
 154
 155         if (file == NULL)
 156                 goto out_failure;
 157
 158         while (!feof(file)) {
 159                 u64 start;
 160                 struct symbol *sym;
 161                 int line_len, len;
 162                 char symbol_type;
 163
 164                 line_len = getline(&line, &n, file);
 165                 if (line_len < 0)
 166                         break;
 167
 168                 if (!line)
 169                         goto out_failure;
 170
 171                 line[--line_len] = '\0'; /* \n */
 172
 173                 len = hex2u64(line, &start);
 174
 175                 len++;
 176                 if (len + 2 >= line_len)
 177                         continue;
 178
 179                 symbol_type = toupper(line[len]);
 180                 /*
 181                  * We're interested only in code ('T'ext)
 182                  */
 183                 if (symbol_type != 'T' && symbol_type != 'W')
 184                         continue;
 185                 /*
 186                  * Well fix up the end later, when we have all sorted.
 187                  */
 188                 sym = symbol__new(start, 0xdead, line + len + 2,
 189                                   self->sym_priv_size, 0, verbose);
 190
 191                 if (sym == NULL)
 192                         goto out_delete_line;
 193
 194                 if (filter && filter(self, sym))
 195                         symbol__delete(sym, self->sym_priv_size);
 196                 else {
 197                         dso__insert_symbol(self, sym);
 198                         count++;
 199                 }
 200         }
 201
 202         /*
 203          * Now that we have all sorted out, just set the ->end of all
 204          * symbols
 205          */
 206         prevnd = rb_first(&self->syms);
 207
 208         if (prevnd == NULL)
 209                 goto out_delete_line;
 210
 211         for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
 212                 struct symbol *prev = rb_entry(prevnd, struct symbol, rb_node),
 213                               *curr = rb_entry(nd, struct symbol, rb_node);
 214
 215                 prev->end = curr->start - 1;
 216                 prevnd = nd;
 217         }
 218
 219         free(line);
 220         fclose(file);
 221
 222         return count;
 223
 224 out_delete_line:
 225         free(line);
 226 out_failure:
 227         return -1;
 228 }
 229
 230 static int dso__load_perf_map(struct dso *self, symbol_filter_t filter, int verbose)
 231 {
 232         char *line = NULL;
 233         size_t n;
 234         FILE *file;
 235         int nr_syms = 0;
 236
 237         file = fopen(self->name, "r");
 238         if (file == NULL)
 239                 goto out_failure;
 240
 241         while (!feof(file)) {
 242                 u64 start, size;
 243                 struct symbol *sym;
 244                 int line_len, len;
 245
 246                 line_len = getline(&line, &n, file);
 247                 if (line_len < 0)
 248                         break;
 249
 250                 if (!line)
 251                         goto out_failure;
 252
 253                 line[--line_len] = '\0'; /* \n */
 254
 255                 len = hex2u64(line, &start);
 256
 257                 len++;
 258                 if (len + 2 >= line_len)
 259                         continue;
 260
 261                 len += hex2u64(line + len, &size);
 262
 263                 len++;
 264                 if (len + 2 >= line_len)
 265                         continue;
 266
 267                 sym = symbol__new(start, size, line + len,
 268                                   self->sym_priv_size, start, verbose);
 269
 270                 if (sym == NULL)
 271                         goto out_delete_line;
 272
 273                 if (filter && filter(self, sym))
 274                         symbol__delete(sym, self->sym_priv_size);
 275                 else {
 276                         dso__insert_symbol(self, sym);
 277                         nr_syms++;
 278                 }
 279         }
 280
 281         free(line);
 282         fclose(file);
 283
 284         return nr_syms;
 285
 286 out_delete_line:
 287         free(line);
 288 out_failure:
 289         return -1;
 290 }
 291
 292 /**
 293  * elf_symtab__for_each_symbol - iterate thru all the symbols
 294  *
 295  * @self: struct elf_symtab instance to iterate
 296  * @index: uint32_t index
 297  * @sym: GElf_Sym iterator
 298  */
 299 #define elf_symtab__for_each_symbol(syms, nr_syms, index, sym) \
 300         for (index = 0, gelf_getsym(syms, index, &sym);\
 301              index < nr_syms; \
 302              index++, gelf_getsym(syms, index, &sym))
 303
 304 static inline uint8_t elf_sym__type(const GElf_Sym *sym)
 305 {
 306         return GELF_ST_TYPE(sym->st_info);
 307 }
 308
 309 static inline int elf_sym__is_function(const GElf_Sym *sym)
 310 {
 311         return elf_sym__type(sym) == STT_FUNC &&
 312                sym->st_name != 0 &&
 313                sym->st_shndx != SHN_UNDEF &&
 314                sym->st_size != 0;
 315 }
 316
 317 static inline int elf_sym__is_label(const GElf_Sym *sym)
 318 {
 319         return elf_sym__type(sym) == STT_NOTYPE &&
 320                 sym->st_name != 0 &&
 321                 sym->st_shndx != SHN_UNDEF &&
 322                 sym->st_shndx != SHN_ABS;
 323 }
 324
 325 static inline const char *elf_sec__name(const GElf_Shdr *shdr,
 326                                         const Elf_Data *secstrs)
 327 {
 328         return secstrs->d_buf + shdr->sh_name;
 329 }
 330
 331 static inline int elf_sec__is_text(const GElf_Shdr *shdr,
 332                                         const Elf_Data *secstrs)
 333 {
 334         return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
 335 }
 336
 337 static inline const char *elf_sym__name(const GElf_Sym *sym,
 338                                         const Elf_Data *symstrs)
 339 {
 340         return symstrs->d_buf + sym->st_name;
 341 }
 342
 343 static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
 344                                     GElf_Shdr *shp, const char *name,
 345                                     size_t *index)
 346 {
 347         Elf_Scn *sec = NULL;
 348         size_t cnt = 1;
 349
 350         while ((sec = elf_nextscn(elf, sec)) != NULL) {
 351                 char *str;
 352
 353                 gelf_getshdr(sec, shp);
 354                 str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
 355                 if (!strcmp(name, str)) {
 356                         if (index)
 357                                 *index = cnt;
 358                         break;
 359                 }
 360                 ++cnt;
 361         }
 362
 363         return sec;
 364 }
 365
 366 #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
 367         for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
 368              idx < nr_entries; \
 369              ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
 370
 371 #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
 372         for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
 373              idx < nr_entries; \
 374              ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
 375
 376 static int dso__synthesize_plt_symbols(struct  dso *self, Elf *elf,
 377                                        GElf_Ehdr *ehdr, Elf_Scn *scn_dynsym,
 378                                        GElf_Shdr *shdr_dynsym,
 379                                        size_t dynsym_idx, int verbose)
 380 {
 381         uint32_t nr_rel_entries, idx;
 382         GElf_Sym sym;
 383         u64 plt_offset;
 384         GElf_Shdr shdr_plt;
 385         struct symbol *f;
 386         GElf_Shdr shdr_rel_plt;
 387         Elf_Data *reldata, *syms, *symstrs;
 388         Elf_Scn *scn_plt_rel, *scn_symstrs;
 389         char sympltname[1024];
 390         int nr = 0, symidx;
 391
 392         scn_plt_rel = elf_section_by_name(elf, ehdr, &shdr_rel_plt,
 393                                           ".rela.plt", NULL);
 394         if (scn_plt_rel == NULL) {
 395                 scn_plt_rel = elf_section_by_name(elf, ehdr, &shdr_rel_plt,
 396                                                   ".rel.plt", NULL);
 397                 if (scn_plt_rel == NULL)
 398                         return 0;
 399         }
 400
 401         if (shdr_rel_plt.sh_link != dynsym_idx)
 402                 return 0;
 403
 404         if (elf_section_by_name(elf, ehdr, &shdr_plt, ".plt", NULL) == NULL)
 405                 return 0;
 406
 407         /*
 408          * Fetch the relocation section to find the indexes to the GOT
 409          * and the symbols in the .dynsym they refer to.
 410          */
 411         reldata = elf_getdata(scn_plt_rel, NULL);
 412         if (reldata == NULL)
 413                 return -1;
 414
 415         syms = elf_getdata(scn_dynsym, NULL);
 416         if (syms == NULL)
 417                 return -1;
 418
 419         scn_symstrs = elf_getscn(elf, shdr_dynsym->sh_link);
 420         if (scn_symstrs == NULL)
 421                 return -1;
 422
 423         symstrs = elf_getdata(scn_symstrs, NULL);
 424         if (symstrs == NULL)
 425                 return -1;
 426
 427         nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
 428         plt_offset = shdr_plt.sh_offset;
 429
 430         if (shdr_rel_plt.sh_type == SHT_RELA) {
 431                 GElf_Rela pos_mem, *pos;
 432
 433                 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
 434                                            nr_rel_entries) {
 435                         symidx = GELF_R_SYM(pos->r_info);
 436                         plt_offset += shdr_plt.sh_entsize;
 437                         gelf_getsym(syms, symidx, &sym);
 438                         snprintf(sympltname, sizeof(sympltname),
 439                                  "%s@plt", elf_sym__name(&sym, symstrs));
 440
 441                         f = symbol__new(plt_offset, shdr_plt.sh_entsize,
 442                                         sympltname, self->sym_priv_size, 0, verbose);
 443                         if (!f)
 444                                 return -1;
 445
 446                         dso__insert_symbol(self, f);
 447                         ++nr;
 448                 }
 449         } else if (shdr_rel_plt.sh_type == SHT_REL) {
 450                 GElf_Rel pos_mem, *pos;
 451                 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
 452                                           nr_rel_entries) {
 453                         symidx = GELF_R_SYM(pos->r_info);
 454                         plt_offset += shdr_plt.sh_entsize;
 455                         gelf_getsym(syms, symidx, &sym);
 456                         snprintf(sympltname, sizeof(sympltname),
 457                                  "%s@plt", elf_sym__name(&sym, symstrs));
 458
 459                         f = symbol__new(plt_offset, shdr_plt.sh_entsize,
 460                                         sympltname, self->sym_priv_size, 0, verbose);
 461                         if (!f)
 462                                 return -1;
 463
 464                         dso__insert_symbol(self, f);
 465                         ++nr;
 466                 }
 467         } else {
 468                 /*
 469                  * TODO: There are still one more shdr_rel_plt.sh_type
 470                  * I have to investigate, but probably should be ignored.
 471                  */
 472         }
 473
 474         return nr;
 475 }
 476
 477 static int dso__load_sym(struct dso *self, int fd, const char *name,
 478                          symbol_filter_t filter, int verbose, struct module *mod)
 479 {
 480         Elf_Data *symstrs, *secstrs;
 481         uint32_t nr_syms;
 482         int err = -1;
 483         uint32_t index;
 484         GElf_Ehdr ehdr;
 485         GElf_Shdr shdr;
 486         Elf_Data *syms;
 487         GElf_Sym sym;
 488         Elf_Scn *sec, *sec_dynsym, *sec_strndx;
 489         Elf *elf;
 490         size_t dynsym_idx;
 491         int nr = 0;
 492
 493         elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
 494         if (elf == NULL) {
 495                 if (verbose)
 496                         fprintf(stderr, "%s: cannot read %s ELF file.\n",
 497                                 __func__, name);
 498                 goto out_close;
 499         }
 500
 501         if (gelf_getehdr(elf, &ehdr) == NULL) {
 502                 if (verbose)
 503                         fprintf(stderr, "%s: cannot get elf header.\n", __func__);
 504                 goto out_elf_end;
 505         }
 506
 507         /*
 508          * We need to check if we have a .dynsym, so that we can handle the
 509          * .plt, synthesizing its symbols, that aren't on the symtabs (be it
 510          * .dynsym or .symtab)
 511          */
 512         sec_dynsym = elf_section_by_name(elf, &ehdr, &shdr,
 513                                          ".dynsym", &dynsym_idx);
 514         if (sec_dynsym != NULL) {
 515                 nr = dso__synthesize_plt_symbols(self, elf, &ehdr,
 516                                                  sec_dynsym, &shdr,
 517                                                  dynsym_idx, verbose);
 518                 if (nr < 0)
 519                         goto out_elf_end;
 520         }
 521
 522         /*
 523          * But if we have a full .symtab (that is a superset of .dynsym) we
 524          * should add the symbols not in the .dynsyn
 525          */
 526         sec = elf_section_by_name(elf, &ehdr, &shdr, ".symtab", NULL);
 527         if (sec == NULL) {
 528                 if (sec_dynsym == NULL)
 529                         goto out_elf_end;
 530
 531                 sec = sec_dynsym;
 532                 gelf_getshdr(sec, &shdr);
 533         }
 534
 535         syms = elf_getdata(sec, NULL);
 536         if (syms == NULL)
 537                 goto out_elf_end;
 538
 539         sec = elf_getscn(elf, shdr.sh_link);
 540         if (sec == NULL)
 541                 goto out_elf_end;
 542
 543         symstrs = elf_getdata(sec, NULL);
 544         if (symstrs == NULL)
 545                 goto out_elf_end;
 546
 547         sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
 548         if (sec_strndx == NULL)
 549                 goto out_elf_end;
 550
 551         secstrs = elf_getdata(sec_strndx, NULL);
 552         if (symstrs == NULL)
 553                 goto out_elf_end;
 554
 555         nr_syms = shdr.sh_size / shdr.sh_entsize;
 556
 557         memset(&sym, 0, sizeof(sym));
 558         self->adjust_symbols = (ehdr.e_type == ET_EXEC ||
 559                                 elf_section_by_name(elf, &ehdr, &shdr,
 560                                                      ".gnu.prelink_undo",
 561                                                      NULL) != NULL);
 562         elf_symtab__for_each_symbol(syms, nr_syms, index, sym) {
 563                 struct symbol *f;
 564                 u64 obj_start;
 565                 struct section *section = NULL;
 566                 int is_label = elf_sym__is_label(&sym);
 567                 const char *section_name;
 568
 569                 if (!is_label && !elf_sym__is_function(&sym))
 570                         continue;
 571
 572                 sec = elf_getscn(elf, sym.st_shndx);
 573                 if (!sec)
 574                         goto out_elf_end;
 575
 576                 gelf_getshdr(sec, &shdr);
 577
 578                 if (is_label && !elf_sec__is_text(&shdr, secstrs))
 579                         continue;
 580
 581                 section_name = elf_sec__name(&shdr, secstrs);
 582                 obj_start = sym.st_value;
 583
 584                 if (self->adjust_symbols) {
 585                         if (verbose >= 2)
 586                                 printf("adjusting symbol: st_value: %Lx sh_addr: %Lx sh_offset: %Lx\n",
 587                                         (u64)sym.st_value, (u64)shdr.sh_addr, (u64)shdr.sh_offset);
 588
 589                         sym.st_value -= shdr.sh_addr - shdr.sh_offset;
 590                 }
 591
 592                 if (mod) {
 593                         section = mod->sections->find_section(mod->sections, section_name);
 594                         if (section)
 595                                 sym.st_value += section->vma;
 596                         else {
 597                                 fprintf(stderr, "dso__load_sym() module %s lookup of %s failed\n",
 598                                         mod->name, section_name);
 599                                 goto out_elf_end;
 600                         }
 601                 }
 602
 603                 f = symbol__new(sym.st_value, sym.st_size,
 604                                 elf_sym__name(&sym, symstrs),
 605                                 self->sym_priv_size, obj_start, verbose);
 606                 if (!f)
 607                         goto out_elf_end;
 608
 609                 if (filter && filter(self, f))
 610                         symbol__delete(f, self->sym_priv_size);
 611                 else {
 612                         f->module = mod;
 613                         dso__insert_symbol(self, f);
 614                         nr++;
 615                 }
 616         }
 617
 618         err = nr;
 619 out_elf_end:
 620         elf_end(elf);
 621 out_close:
 622         return err;
 623 }
 624
 625 int dso__load(struct dso *self, symbol_filter_t filter, int verbose)
 626 {
 627         int size = strlen(self->name) + sizeof("/usr/lib/debug%s.debug");
 628         char *name = malloc(size);
 629         int variant = 0;
 630         int ret = -1;
 631         int fd;
 632
 633         if (!name)
 634                 return -1;
 635
 636         self->adjust_symbols = 0;
 637
 638         if (strncmp(self->name, "/tmp/perf-", 10) == 0)
 639                 return dso__load_perf_map(self, filter, verbose);
 640
 641 more:
 642         do {
 643                 switch (variant) {
 644                 case 0: /* Fedora */
 645                         snprintf(name, size, "/usr/lib/debug%s.debug", self->name);
 646                         break;
 647                 case 1: /* Ubuntu */
 648                         snprintf(name, size, "/usr/lib/debug%s", self->name);
 649                         break;
 650                 case 2: /* Sane people */
 651                         snprintf(name, size, "%s", self->name);
 652                         break;
 653
 654                 default:
 655                         goto out;
 656                 }
 657                 variant++;
 658
 659                 fd = open(name, O_RDONLY);
 660         } while (fd < 0);
 661
 662         ret = dso__load_sym(self, fd, name, filter, verbose, NULL);
 663         close(fd);
 664
 665         /*
 666          * Some people seem to have debuginfo files _WITHOUT_ debug info!?!?
 667          */
 668         if (!ret)
 669                 goto more;
 670
 671 out:
 672         free(name);
 673         return ret;
 674 }
 675
 676 static int dso__load_module(struct dso *self, struct mod_dso *mods, const char *name,
 677                              symbol_filter_t filter, int verbose)
 678 {
 679         struct module *mod = mod_dso__find_module(mods, name);
 680         int err = 0, fd;
 681
 682         if (mod == NULL || !mod->active)
 683                 return err;
 684
 685         fd = open(mod->path, O_RDONLY);
 686
 687         if (fd < 0)
 688                 return err;
 689
 690         err = dso__load_sym(self, fd, name, filter, verbose, mod);
 691         close(fd);
 692
 693         return err;
 694 }
 695
 696 int dso__load_modules(struct dso *self, symbol_filter_t filter, int verbose)
 697 {
 698         struct mod_dso *mods = mod_dso__new_dso("modules");
 699         struct module *pos;
 700         struct rb_node *next;
 701         int err;
 702
 703         err = mod_dso__load_modules(mods);
 704
 705         if (err <= 0)
 706                 return err;
 707
 708         /*
 709          * Iterate over modules, and load active symbols.
 710          */
 711         next = rb_first(&mods->mods);
 712         while (next) {
 713                 pos = rb_entry(next, struct module, rb_node);
 714                 err = dso__load_module(self, mods, pos->name, filter, verbose);
 715
 716                 if (err < 0)
 717                         break;
 718
 719                 next = rb_next(&pos->rb_node);
 720         }
 721
 722         if (err < 0) {
 723                 mod_dso__delete_modules(mods);
 724                 mod_dso__delete_self(mods);
 725         }
 726
 727         return err;
 728 }
 729
 730 static inline void dso__fill_symbol_holes(struct dso *self)
 731 {
 732         struct symbol *prev = NULL;
 733         struct rb_node *nd;
 734
 735         for (nd = rb_last(&self->syms); nd; nd = rb_prev(nd)) {
 736                 struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
 737
 738                 if (prev) {
 739                         u64 hole = 0;
 740                         int alias = pos->start == prev->start;
 741
 742                         if (!alias)
 743                                 hole = prev->start - pos->end - 1;
 744
 745                         if (hole || alias) {
 746                                 if (alias)
 747                                         pos->end = prev->end;
 748                                 else if (hole)
 749                                         pos->end = prev->start - 1;
 750                         }
 751                 }
 752                 prev = pos;
 753         }
 754 }
 755
 756 static int dso__load_vmlinux(struct dso *self, const char *vmlinux,
 757                              symbol_filter_t filter, int verbose)
 758 {
 759         int err, fd = open(vmlinux, O_RDONLY);
 760
 761         if (fd < 0)
 762                 return -1;
 763
 764         err = dso__load_sym(self, fd, vmlinux, filter, verbose, NULL);
 765
 766         if (err > 0)
 767                 dso__fill_symbol_holes(self);
 768
 769         close(fd);
 770
 771         return err;
 772 }
 773
 774 int dso__load_kernel(struct dso *self, const char *vmlinux,
 775                      symbol_filter_t filter, int verbose, int modules)
 776 {
 777         int err = -1;
 778
 779         if (vmlinux) {
 780                 err = dso__load_vmlinux(self, vmlinux, filter, verbose);
 781                 if (err > 0 && modules)
 782                         err = dso__load_modules(self, filter, verbose);
 783         }
 784
 785         if (err <= 0)
 786                 err = dso__load_kallsyms(self, filter, verbose);
 787
 788         return err;
 789 }
 790
 791 void symbol__init(void)
 792 {
 793         elf_version(EV_CURRENT);
 794 }