tools/perf/util/symbol-elf.c

   1 #include <fcntl.h>
   2 #include <stdio.h>
   3 #include <errno.h>
   4 #include <string.h>
   5 #include <unistd.h>
   6 #include <inttypes.h>
   7
   8 #include "symbol.h"
   9 #include "demangle-java.h"
  10 #include "demangle-rust.h"
  11 #include "machine.h"
  12 #include "vdso.h"
  13 #include <symbol/kallsyms.h>
  14 #include "debug.h"
  15
  16 #ifndef EM_AARCH64
  17 #define EM_AARCH64      183  /* ARM 64 bit */
  18 #endif
  19
  20 typedef Elf64_Nhdr GElf_Nhdr;
  21
  22 #ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
  23 extern char *cplus_demangle(const char *, int);
  24
  25 static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
  26 {
  27         return cplus_demangle(c, i);
  28 }
  29 #else
  30 #ifdef NO_DEMANGLE
  31 static inline char *bfd_demangle(void __maybe_unused *v,
  32                                  const char __maybe_unused *c,
  33                                  int __maybe_unused i)
  34 {
  35         return NULL;
  36 }
  37 #else
  38 #define PACKAGE 'perf'
  39 #include <bfd.h>
  40 #endif
  41 #endif
  42
  43 #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
  44 static int elf_getphdrnum(Elf *elf, size_t *dst)
  45 {
  46         GElf_Ehdr gehdr;
  47         GElf_Ehdr *ehdr;
  48
  49         ehdr = gelf_getehdr(elf, &gehdr);
  50         if (!ehdr)
  51                 return -1;
  52
  53         *dst = ehdr->e_phnum;
  54
  55         return 0;
  56 }
  57 #endif
  58
  59 #ifndef HAVE_ELF_GETSHDRSTRNDX_SUPPORT
  60 static int elf_getshdrstrndx(Elf *elf __maybe_unused, size_t *dst __maybe_unused)
  61 {
  62         pr_err("%s: update your libelf to > 0.140, this one lacks elf_getshdrstrndx().\n", __func__);
  63         return -1;
  64 }
  65 #endif
  66
  67 #ifndef NT_GNU_BUILD_ID
  68 #define NT_GNU_BUILD_ID 3
  69 #endif
  70
  71 /**
  72  * elf_symtab__for_each_symbol - iterate thru all the symbols
  73  *
  74  * @syms: struct elf_symtab instance to iterate
  75  * @idx: uint32_t idx
  76  * @sym: GElf_Sym iterator
  77  */
  78 #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
  79         for (idx = 0, gelf_getsym(syms, idx, &sym);\
  80              idx < nr_syms; \
  81              idx++, gelf_getsym(syms, idx, &sym))
  82
  83 static inline uint8_t elf_sym__type(const GElf_Sym *sym)
  84 {
  85         return GELF_ST_TYPE(sym->st_info);
  86 }
  87
  88 #ifndef STT_GNU_IFUNC
  89 #define STT_GNU_IFUNC 10
  90 #endif
  91
  92 static inline int elf_sym__is_function(const GElf_Sym *sym)
  93 {
  94         return (elf_sym__type(sym) == STT_FUNC ||
  95                 elf_sym__type(sym) == STT_GNU_IFUNC) &&
  96                sym->st_name != 0 &&
  97                sym->st_shndx != SHN_UNDEF;
  98 }
  99
 100 static inline bool elf_sym__is_object(const GElf_Sym *sym)
 101 {
 102         return elf_sym__type(sym) == STT_OBJECT &&
 103                 sym->st_name != 0 &&
 104                 sym->st_shndx != SHN_UNDEF;
 105 }
 106
 107 static inline int elf_sym__is_label(const GElf_Sym *sym)
 108 {
 109         return elf_sym__type(sym) == STT_NOTYPE &&
 110                 sym->st_name != 0 &&
 111                 sym->st_shndx != SHN_UNDEF &&
 112                 sym->st_shndx != SHN_ABS;
 113 }
 114
 115 static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
 116 {
 117         switch (type) {
 118         case MAP__FUNCTION:
 119                 return elf_sym__is_function(sym);
 120         case MAP__VARIABLE:
 121                 return elf_sym__is_object(sym);
 122         default:
 123                 return false;
 124         }
 125 }
 126
 127 static inline const char *elf_sym__name(const GElf_Sym *sym,
 128                                         const Elf_Data *symstrs)
 129 {
 130         return symstrs->d_buf + sym->st_name;
 131 }
 132
 133 static inline const char *elf_sec__name(const GElf_Shdr *shdr,
 134                                         const Elf_Data *secstrs)
 135 {
 136         return secstrs->d_buf + shdr->sh_name;
 137 }
 138
 139 static inline int elf_sec__is_text(const GElf_Shdr *shdr,
 140                                         const Elf_Data *secstrs)
 141 {
 142         return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
 143 }
 144
 145 static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
 146                                     const Elf_Data *secstrs)
 147 {
 148         return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
 149 }
 150
 151 static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs,
 152                           enum map_type type)
 153 {
 154         switch (type) {
 155         case MAP__FUNCTION:
 156                 return elf_sec__is_text(shdr, secstrs);
 157         case MAP__VARIABLE:
 158                 return elf_sec__is_data(shdr, secstrs);
 159         default:
 160                 return false;
 161         }
 162 }
 163
 164 static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
 165 {
 166         Elf_Scn *sec = NULL;
 167         GElf_Shdr shdr;
 168         size_t cnt = 1;
 169
 170         while ((sec = elf_nextscn(elf, sec)) != NULL) {
 171                 gelf_getshdr(sec, &shdr);
 172
 173                 if ((addr >= shdr.sh_addr) &&
 174                     (addr < (shdr.sh_addr + shdr.sh_size)))
 175                         return cnt;
 176
 177                 ++cnt;
 178         }
 179
 180         return -1;
 181 }
 182
 183 Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
 184                              GElf_Shdr *shp, const char *name, size_t *idx)
 185 {
 186         Elf_Scn *sec = NULL;
 187         size_t cnt = 1;
 188
 189         /* Elf is corrupted/truncated, avoid calling elf_strptr. */
 190         if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
 191                 return NULL;
 192
 193         while ((sec = elf_nextscn(elf, sec)) != NULL) {
 194                 char *str;
 195
 196                 gelf_getshdr(sec, shp);
 197                 str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
 198                 if (str && !strcmp(name, str)) {
 199                         if (idx)
 200                                 *idx = cnt;
 201                         return sec;
 202                 }
 203                 ++cnt;
 204         }
 205
 206         return NULL;
 207 }
 208
 209 #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
 210         for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
 211              idx < nr_entries; \
 212              ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
 213
 214 #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
 215         for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
 216              idx < nr_entries; \
 217              ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
 218
 219 /*
 220  * We need to check if we have a .dynsym, so that we can handle the
 221  * .plt, synthesizing its symbols, that aren't on the symtabs (be it
 222  * .dynsym or .symtab).
 223  * And always look at the original dso, not at debuginfo packages, that
 224  * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
 225  */
 226 int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map,
 227                                 symbol_filter_t filter)
 228 {
 229         uint32_t nr_rel_entries, idx;
 230         GElf_Sym sym;
 231         u64 plt_offset;
 232         GElf_Shdr shdr_plt;
 233         struct symbol *f;
 234         GElf_Shdr shdr_rel_plt, shdr_dynsym;
 235         Elf_Data *reldata, *syms, *symstrs;
 236         Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
 237         size_t dynsym_idx;
 238         GElf_Ehdr ehdr;
 239         char sympltname[1024];
 240         Elf *elf;
 241         int nr = 0, symidx, err = 0;
 242
 243         if (!ss->dynsym)
 244                 return 0;
 245
 246         elf = ss->elf;
 247         ehdr = ss->ehdr;
 248
 249         scn_dynsym = ss->dynsym;
 250         shdr_dynsym = ss->dynshdr;
 251         dynsym_idx = ss->dynsym_idx;
 252
 253         if (scn_dynsym == NULL)
 254                 goto out_elf_end;
 255
 256         scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
 257                                           ".rela.plt", NULL);
 258         if (scn_plt_rel == NULL) {
 259                 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
 260                                                   ".rel.plt", NULL);
 261                 if (scn_plt_rel == NULL)
 262                         goto out_elf_end;
 263         }
 264
 265         err = -1;
 266
 267         if (shdr_rel_plt.sh_link != dynsym_idx)
 268                 goto out_elf_end;
 269
 270         if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
 271                 goto out_elf_end;
 272
 273         /*
 274          * Fetch the relocation section to find the idxes to the GOT
 275          * and the symbols in the .dynsym they refer to.
 276          */
 277         reldata = elf_getdata(scn_plt_rel, NULL);
 278         if (reldata == NULL)
 279                 goto out_elf_end;
 280
 281         syms = elf_getdata(scn_dynsym, NULL);
 282         if (syms == NULL)
 283                 goto out_elf_end;
 284
 285         scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
 286         if (scn_symstrs == NULL)
 287                 goto out_elf_end;
 288
 289         symstrs = elf_getdata(scn_symstrs, NULL);
 290         if (symstrs == NULL)
 291                 goto out_elf_end;
 292
 293         if (symstrs->d_size == 0)
 294                 goto out_elf_end;
 295
 296         nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
 297         plt_offset = shdr_plt.sh_offset;
 298
 299         if (shdr_rel_plt.sh_type == SHT_RELA) {
 300                 GElf_Rela pos_mem, *pos;
 301
 302                 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
 303                                            nr_rel_entries) {
 304                         symidx = GELF_R_SYM(pos->r_info);
 305                         plt_offset += shdr_plt.sh_entsize;
 306                         gelf_getsym(syms, symidx, &sym);
 307                         snprintf(sympltname, sizeof(sympltname),
 308                                  "%s@plt", elf_sym__name(&sym, symstrs));
 309
 310                         f = symbol__new(plt_offset, shdr_plt.sh_entsize,
 311                                         STB_GLOBAL, sympltname);
 312                         if (!f)
 313                                 goto out_elf_end;
 314
 315                         if (filter && filter(map, f))
 316                                 symbol__delete(f);
 317                         else {
 318                                 symbols__insert(&dso->symbols[map->type], f);
 319                                 ++nr;
 320                         }
 321                 }
 322         } else if (shdr_rel_plt.sh_type == SHT_REL) {
 323                 GElf_Rel pos_mem, *pos;
 324                 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
 325                                           nr_rel_entries) {
 326                         symidx = GELF_R_SYM(pos->r_info);
 327                         plt_offset += shdr_plt.sh_entsize;
 328                         gelf_getsym(syms, symidx, &sym);
 329                         snprintf(sympltname, sizeof(sympltname),
 330                                  "%s@plt", elf_sym__name(&sym, symstrs));
 331
 332                         f = symbol__new(plt_offset, shdr_plt.sh_entsize,
 333                                         STB_GLOBAL, sympltname);
 334                         if (!f)
 335                                 goto out_elf_end;
 336
 337                         if (filter && filter(map, f))
 338                                 symbol__delete(f);
 339                         else {
 340                                 symbols__insert(&dso->symbols[map->type], f);
 341                                 ++nr;
 342                         }
 343                 }
 344         }
 345
 346         err = 0;
 347 out_elf_end:
 348         if (err == 0)
 349                 return nr;
 350         pr_debug("%s: problems reading %s PLT info.\n",
 351                  __func__, dso->long_name);
 352         return 0;
 353 }
 354
 355 /*
 356  * Align offset to 4 bytes as needed for note name and descriptor data.
 357  */
 358 #define NOTE_ALIGN(n) (((n) + 3) & -4U)
 359
 360 static int elf_read_build_id(Elf *elf, void *bf, size_t size)
 361 {
 362         int err = -1;
 363         GElf_Ehdr ehdr;
 364         GElf_Shdr shdr;
 365         Elf_Data *data;
 366         Elf_Scn *sec;
 367         Elf_Kind ek;
 368         void *ptr;
 369
 370         if (size < BUILD_ID_SIZE)
 371                 goto out;
 372
 373         ek = elf_kind(elf);
 374         if (ek != ELF_K_ELF)
 375                 goto out;
 376
 377         if (gelf_getehdr(elf, &ehdr) == NULL) {
 378                 pr_err("%s: cannot get elf header.\n", __func__);
 379                 goto out;
 380         }
 381
 382         /*
 383          * Check following sections for notes:
 384          *   '.note.gnu.build-id'
 385          *   '.notes'
 386          *   '.note' (VDSO specific)
 387          */
 388         do {
 389                 sec = elf_section_by_name(elf, &ehdr, &shdr,
 390                                           ".note.gnu.build-id", NULL);
 391                 if (sec)
 392                         break;
 393
 394                 sec = elf_section_by_name(elf, &ehdr, &shdr,
 395                                           ".notes", NULL);
 396                 if (sec)
 397                         break;
 398
 399                 sec = elf_section_by_name(elf, &ehdr, &shdr,
 400                                           ".note", NULL);
 401                 if (sec)
 402                         break;
 403
 404                 return err;
 405
 406         } while (0);
 407
 408         data = elf_getdata(sec, NULL);
 409         if (data == NULL)
 410                 goto out;
 411
 412         ptr = data->d_buf;
 413         while (ptr < (data->d_buf + data->d_size)) {
 414                 GElf_Nhdr *nhdr = ptr;
 415                 size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
 416                        descsz = NOTE_ALIGN(nhdr->n_descsz);
 417                 const char *name;
 418
 419                 ptr += sizeof(*nhdr);
 420                 name = ptr;
 421                 ptr += namesz;
 422                 if (nhdr->n_type == NT_GNU_BUILD_ID &&
 423                     nhdr->n_namesz == sizeof("GNU")) {
 424                         if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
 425                                 size_t sz = min(size, descsz);
 426                                 memcpy(bf, ptr, sz);
 427                                 memset(bf + sz, 0, size - sz);
 428                                 err = descsz;
 429                                 break;
 430                         }
 431                 }
 432                 ptr += descsz;
 433         }
 434
 435 out:
 436         return err;
 437 }
 438
 439 int filename__read_build_id(const char *filename, void *bf, size_t size)
 440 {
 441         int fd, err = -1;
 442         Elf *elf;
 443
 444         if (size < BUILD_ID_SIZE)
 445                 goto out;
 446
 447         fd = open(filename, O_RDONLY);
 448         if (fd < 0)
 449                 goto out;
 450
 451         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
 452         if (elf == NULL) {
 453                 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
 454                 goto out_close;
 455         }
 456
 457         err = elf_read_build_id(elf, bf, size);
 458
 459         elf_end(elf);
 460 out_close:
 461         close(fd);
 462 out:
 463         return err;
 464 }
 465
 466 int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
 467 {
 468         int fd, err = -1;
 469
 470         if (size < BUILD_ID_SIZE)
 471                 goto out;
 472
 473         fd = open(filename, O_RDONLY);
 474         if (fd < 0)
 475                 goto out;
 476
 477         while (1) {
 478                 char bf[BUFSIZ];
 479                 GElf_Nhdr nhdr;
 480                 size_t namesz, descsz;
 481
 482                 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
 483                         break;
 484
 485                 namesz = NOTE_ALIGN(nhdr.n_namesz);
 486                 descsz = NOTE_ALIGN(nhdr.n_descsz);
 487                 if (nhdr.n_type == NT_GNU_BUILD_ID &&
 488                     nhdr.n_namesz == sizeof("GNU")) {
 489                         if (read(fd, bf, namesz) != (ssize_t)namesz)
 490                                 break;
 491                         if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
 492                                 size_t sz = min(descsz, size);
 493                                 if (read(fd, build_id, sz) == (ssize_t)sz) {
 494                                         memset(build_id + sz, 0, size - sz);
 495                                         err = 0;
 496                                         break;
 497                                 }
 498                         } else if (read(fd, bf, descsz) != (ssize_t)descsz)
 499                                 break;
 500                 } else {
 501                         int n = namesz + descsz;
 502                         if (read(fd, bf, n) != n)
 503                                 break;
 504                 }
 505         }
 506         close(fd);
 507 out:
 508         return err;
 509 }
 510
 511 int filename__read_debuglink(const char *filename, char *debuglink,
 512                              size_t size)
 513 {
 514         int fd, err = -1;
 515         Elf *elf;
 516         GElf_Ehdr ehdr;
 517         GElf_Shdr shdr;
 518         Elf_Data *data;
 519         Elf_Scn *sec;
 520         Elf_Kind ek;
 521
 522         fd = open(filename, O_RDONLY);
 523         if (fd < 0)
 524                 goto out;
 525
 526         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
 527         if (elf == NULL) {
 528                 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
 529                 goto out_close;
 530         }
 531
 532         ek = elf_kind(elf);
 533         if (ek != ELF_K_ELF)
 534                 goto out_elf_end;
 535
 536         if (gelf_getehdr(elf, &ehdr) == NULL) {
 537                 pr_err("%s: cannot get elf header.\n", __func__);
 538                 goto out_elf_end;
 539         }
 540
 541         sec = elf_section_by_name(elf, &ehdr, &shdr,
 542                                   ".gnu_debuglink", NULL);
 543         if (sec == NULL)
 544                 goto out_elf_end;
 545
 546         data = elf_getdata(sec, NULL);
 547         if (data == NULL)
 548                 goto out_elf_end;
 549
 550         /* the start of this section is a zero-terminated string */
 551         strncpy(debuglink, data->d_buf, size);
 552
 553         err = 0;
 554
 555 out_elf_end:
 556         elf_end(elf);
 557 out_close:
 558         close(fd);
 559 out:
 560         return err;
 561 }
 562
 563 static int dso__swap_init(struct dso *dso, unsigned char eidata)
 564 {
 565         static unsigned int const endian = 1;
 566
 567         dso->needs_swap = DSO_SWAP__NO;
 568
 569         switch (eidata) {
 570         case ELFDATA2LSB:
 571                 /* We are big endian, DSO is little endian. */
 572                 if (*(unsigned char const *)&endian != 1)
 573                         dso->needs_swap = DSO_SWAP__YES;
 574                 break;
 575
 576         case ELFDATA2MSB:
 577                 /* We are little endian, DSO is big endian. */
 578                 if (*(unsigned char const *)&endian != 0)
 579                         dso->needs_swap = DSO_SWAP__YES;
 580                 break;
 581
 582         default:
 583                 pr_err("unrecognized DSO data encoding %d\n", eidata);
 584                 return -EINVAL;
 585         }
 586
 587         return 0;
 588 }
 589
 590 static int decompress_kmodule(struct dso *dso, const char *name,
 591                               enum dso_binary_type type)
 592 {
 593         int fd = -1;
 594         char tmpbuf[] = "/tmp/perf-kmod-XXXXXX";
 595         struct kmod_path m;
 596
 597         if (type != DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP &&
 598             type != DSO_BINARY_TYPE__GUEST_KMODULE_COMP &&
 599             type != DSO_BINARY_TYPE__BUILD_ID_CACHE)
 600                 return -1;
 601
 602         if (type == DSO_BINARY_TYPE__BUILD_ID_CACHE)
 603                 name = dso->long_name;
 604
 605         if (kmod_path__parse_ext(&m, name) || !m.comp)
 606                 return -1;
 607
 608         fd = mkstemp(tmpbuf);
 609         if (fd < 0) {
 610                 dso->load_errno = errno;
 611                 goto out;
 612         }
 613
 614         if (!decompress_to_file(m.ext, name, fd)) {
 615                 dso->load_errno = DSO_LOAD_ERRNO__DECOMPRESSION_FAILURE;
 616                 close(fd);
 617                 fd = -1;
 618         }
 619
 620         unlink(tmpbuf);
 621
 622 out:
 623         free(m.ext);
 624         return fd;
 625 }
 626
 627 bool symsrc__possibly_runtime(struct symsrc *ss)
 628 {
 629         return ss->dynsym || ss->opdsec;
 630 }
 631
 632 bool symsrc__has_symtab(struct symsrc *ss)
 633 {
 634         return ss->symtab != NULL;
 635 }
 636
 637 void symsrc__destroy(struct symsrc *ss)
 638 {
 639         zfree(&ss->name);
 640         elf_end(ss->elf);
 641         close(ss->fd);
 642 }
 643
 644 bool __weak elf__needs_adjust_symbols(GElf_Ehdr ehdr)
 645 {
 646         return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL;
 647 }
 648
 649 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
 650                  enum dso_binary_type type)
 651 {
 652         int err = -1;
 653         GElf_Ehdr ehdr;
 654         Elf *elf;
 655         int fd;
 656
 657         if (dso__needs_decompress(dso)) {
 658                 fd = decompress_kmodule(dso, name, type);
 659                 if (fd < 0)
 660                         return -1;
 661         } else {
 662                 fd = open(name, O_RDONLY);
 663                 if (fd < 0) {
 664                         dso->load_errno = errno;
 665                         return -1;
 666                 }
 667         }
 668
 669         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
 670         if (elf == NULL) {
 671                 pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
 672                 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
 673                 goto out_close;
 674         }
 675
 676         if (gelf_getehdr(elf, &ehdr) == NULL) {
 677                 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
 678                 pr_debug("%s: cannot get elf header.\n", __func__);
 679                 goto out_elf_end;
 680         }
 681
 682         if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) {
 683                 dso->load_errno = DSO_LOAD_ERRNO__INTERNAL_ERROR;
 684                 goto out_elf_end;
 685         }
 686
 687         /* Always reject images with a mismatched build-id: */
 688         if (dso->has_build_id) {
 689                 u8 build_id[BUILD_ID_SIZE];
 690
 691                 if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) {
 692                         dso->load_errno = DSO_LOAD_ERRNO__CANNOT_READ_BUILDID;
 693                         goto out_elf_end;
 694                 }
 695
 696                 if (!dso__build_id_equal(dso, build_id)) {
 697                         pr_debug("%s: build id mismatch for %s.\n", __func__, name);
 698                         dso->load_errno = DSO_LOAD_ERRNO__MISMATCHING_BUILDID;
 699                         goto out_elf_end;
 700                 }
 701         }
 702
 703         ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
 704
 705         ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
 706                         NULL);
 707         if (ss->symshdr.sh_type != SHT_SYMTAB)
 708                 ss->symtab = NULL;
 709
 710         ss->dynsym_idx = 0;
 711         ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
 712                         &ss->dynsym_idx);
 713         if (ss->dynshdr.sh_type != SHT_DYNSYM)
 714                 ss->dynsym = NULL;
 715
 716         ss->opdidx = 0;
 717         ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
 718                         &ss->opdidx);
 719         if (ss->opdshdr.sh_type != SHT_PROGBITS)
 720                 ss->opdsec = NULL;
 721
 722         if (dso->kernel == DSO_TYPE_USER)
 723                 ss->adjust_symbols = true;
 724         else
 725                 ss->adjust_symbols = elf__needs_adjust_symbols(ehdr);
 726
 727         ss->name   = strdup(name);
 728         if (!ss->name) {
 729                 dso->load_errno = errno;
 730                 goto out_elf_end;
 731         }
 732
 733         ss->elf    = elf;
 734         ss->fd     = fd;
 735         ss->ehdr   = ehdr;
 736         ss->type   = type;
 737
 738         return 0;
 739
 740 out_elf_end:
 741         elf_end(elf);
 742 out_close:
 743         close(fd);
 744         return err;
 745 }
 746
 747 /**
 748  * ref_reloc_sym_not_found - has kernel relocation symbol been found.
 749  * @kmap: kernel maps and relocation reference symbol
 750  *
 751  * This function returns %true if we are dealing with the kernel maps and the
 752  * relocation reference symbol has not yet been found.  Otherwise %false is
 753  * returned.
 754  */
 755 static bool ref_reloc_sym_not_found(struct kmap *kmap)
 756 {
 757         return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
 758                !kmap->ref_reloc_sym->unrelocated_addr;
 759 }
 760
 761 /**
 762  * ref_reloc - kernel relocation offset.
 763  * @kmap: kernel maps and relocation reference symbol
 764  *
 765  * This function returns the offset of kernel addresses as determined by using
 766  * the relocation reference symbol i.e. if the kernel has not been relocated
 767  * then the return value is zero.
 768  */
 769 static u64 ref_reloc(struct kmap *kmap)
 770 {
 771         if (kmap && kmap->ref_reloc_sym &&
 772             kmap->ref_reloc_sym->unrelocated_addr)
 773                 return kmap->ref_reloc_sym->addr -
 774                        kmap->ref_reloc_sym->unrelocated_addr;
 775         return 0;
 776 }
 777
 778 static bool want_demangle(bool is_kernel_sym)
 779 {
 780         return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
 781 }
 782
 783 void __weak arch__sym_update(struct symbol *s __maybe_unused,
 784                 GElf_Sym *sym __maybe_unused) { }
 785
 786 int dso__load_sym(struct dso *dso, struct map *map,
 787                   struct symsrc *syms_ss, struct symsrc *runtime_ss,
 788                   symbol_filter_t filter, int kmodule)
 789 {
 790         struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
 791         struct map_groups *kmaps = kmap ? map__kmaps(map) : NULL;
 792         struct map *curr_map = map;
 793         struct dso *curr_dso = dso;
 794         Elf_Data *symstrs, *secstrs;
 795         uint32_t nr_syms;
 796         int err = -1;
 797         uint32_t idx;
 798         GElf_Ehdr ehdr;
 799         GElf_Shdr shdr;
 800         GElf_Shdr tshdr;
 801         Elf_Data *syms, *opddata = NULL;
 802         GElf_Sym sym;
 803         Elf_Scn *sec, *sec_strndx;
 804         Elf *elf;
 805         int nr = 0;
 806         bool remap_kernel = false, adjust_kernel_syms = false;
 807
 808         if (kmap && !kmaps)
 809                 return -1;
 810
 811         dso->symtab_type = syms_ss->type;
 812         dso->is_64_bit = syms_ss->is_64_bit;
 813         dso->rel = syms_ss->ehdr.e_type == ET_REL;
 814
 815         /*
 816          * Modules may already have symbols from kallsyms, but those symbols
 817          * have the wrong values for the dso maps, so remove them.
 818          */
 819         if (kmodule && syms_ss->symtab)
 820                 symbols__delete(&dso->symbols[map->type]);
 821
 822         if (!syms_ss->symtab) {
 823                 /*
 824                  * If the vmlinux is stripped, fail so we will fall back
 825                  * to using kallsyms. The vmlinux runtime symbols aren't
 826                  * of much use.
 827                  */
 828                 if (dso->kernel)
 829                         goto out_elf_end;
 830
 831                 syms_ss->symtab  = syms_ss->dynsym;
 832                 syms_ss->symshdr = syms_ss->dynshdr;
 833         }
 834
 835         elf = syms_ss->elf;
 836         ehdr = syms_ss->ehdr;
 837         sec = syms_ss->symtab;
 838         shdr = syms_ss->symshdr;
 839
 840         if (elf_section_by_name(elf, &ehdr, &tshdr, ".text", NULL))
 841                 dso->text_offset = tshdr.sh_addr - tshdr.sh_offset;
 842
 843         if (runtime_ss->opdsec)
 844                 opddata = elf_rawdata(runtime_ss->opdsec, NULL);
 845
 846         syms = elf_getdata(sec, NULL);
 847         if (syms == NULL)
 848                 goto out_elf_end;
 849
 850         sec = elf_getscn(elf, shdr.sh_link);
 851         if (sec == NULL)
 852                 goto out_elf_end;
 853
 854         symstrs = elf_getdata(sec, NULL);
 855         if (symstrs == NULL)
 856                 goto out_elf_end;
 857
 858         sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx);
 859         if (sec_strndx == NULL)
 860                 goto out_elf_end;
 861
 862         secstrs = elf_getdata(sec_strndx, NULL);
 863         if (secstrs == NULL)
 864                 goto out_elf_end;
 865
 866         nr_syms = shdr.sh_size / shdr.sh_entsize;
 867
 868         memset(&sym, 0, sizeof(sym));
 869
 870         /*
 871          * The kernel relocation symbol is needed in advance in order to adjust
 872          * kernel maps correctly.
 873          */
 874         if (ref_reloc_sym_not_found(kmap)) {
 875                 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
 876                         const char *elf_name = elf_sym__name(&sym, symstrs);
 877
 878                         if (strcmp(elf_name, kmap->ref_reloc_sym->name))
 879                                 continue;
 880                         kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
 881                         map->reloc = kmap->ref_reloc_sym->addr -
 882                                      kmap->ref_reloc_sym->unrelocated_addr;
 883                         break;
 884                 }
 885         }
 886
 887         /*
 888          * Handle any relocation of vdso necessary because older kernels
 889          * attempted to prelink vdso to its virtual address.
 890          */
 891         if (dso__is_vdso(dso))
 892                 map->reloc = map->start - dso->text_offset;
 893
 894         dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
 895         /*
 896          * Initial kernel and module mappings do not map to the dso.  For
 897          * function mappings, flag the fixups.
 898          */
 899         if (map->type == MAP__FUNCTION && (dso->kernel || kmodule)) {
 900                 remap_kernel = true;
 901                 adjust_kernel_syms = dso->adjust_symbols;
 902         }
 903         elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
 904                 struct symbol *f;
 905                 const char *elf_name = elf_sym__name(&sym, symstrs);
 906                 char *demangled = NULL;
 907                 int is_label = elf_sym__is_label(&sym);
 908                 const char *section_name;
 909                 bool used_opd = false;
 910
 911                 if (!is_label && !elf_sym__is_a(&sym, map->type))
 912                         continue;
 913
 914                 /* Reject ARM ELF "mapping symbols": these aren't unique and
 915                  * don't identify functions, so will confuse the profile
 916                  * output: */
 917                 if (ehdr.e_machine == EM_ARM || ehdr.e_machine == EM_AARCH64) {
 918                         if (elf_name[0] == '$' && strchr("adtx", elf_name[1])
 919                             && (elf_name[2] == '\0' || elf_name[2] == '.'))
 920                                 continue;
 921                 }
 922
 923                 if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
 924                         u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
 925                         u64 *opd = opddata->d_buf + offset;
 926                         sym.st_value = DSO__SWAP(dso, u64, *opd);
 927                         sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
 928                                         sym.st_value);
 929                         used_opd = true;
 930                 }
 931                 /*
 932                  * When loading symbols in a data mapping, ABS symbols (which
 933                  * has a value of SHN_ABS in its st_shndx) failed at
 934                  * elf_getscn().  And it marks the loading as a failure so
 935                  * already loaded symbols cannot be fixed up.
 936                  *
 937                  * I'm not sure what should be done. Just ignore them for now.
 938                  * - Namhyung Kim
 939                  */
 940                 if (sym.st_shndx == SHN_ABS)
 941                         continue;
 942
 943                 sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
 944                 if (!sec)
 945                         goto out_elf_end;
 946
 947                 gelf_getshdr(sec, &shdr);
 948
 949                 if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
 950                         continue;
 951
 952                 section_name = elf_sec__name(&shdr, secstrs);
 953
 954                 /* On ARM, symbols for thumb functions have 1 added to
 955                  * the symbol address as a flag - remove it */
 956                 if ((ehdr.e_machine == EM_ARM) &&
 957                     (map->type == MAP__FUNCTION) &&
 958                     (sym.st_value & 1))
 959                         --sym.st_value;
 960
 961                 if (dso->kernel || kmodule) {
 962                         char dso_name[PATH_MAX];
 963
 964                         /* Adjust symbol to map to file offset */
 965                         if (adjust_kernel_syms)
 966                                 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
 967
 968                         if (strcmp(section_name,
 969                                    (curr_dso->short_name +
 970                                     dso->short_name_len)) == 0)
 971                                 goto new_symbol;
 972
 973                         if (strcmp(section_name, ".text") == 0) {
 974                                 /*
 975                                  * The initial kernel mapping is based on
 976                                  * kallsyms and identity maps.  Overwrite it to
 977                                  * map to the kernel dso.
 978                                  */
 979                                 if (remap_kernel && dso->kernel) {
 980                                         remap_kernel = false;
 981                                         map->start = shdr.sh_addr +
 982                                                      ref_reloc(kmap);
 983                                         map->end = map->start + shdr.sh_size;
 984                                         map->pgoff = shdr.sh_offset;
 985                                         map->map_ip = map__map_ip;
 986                                         map->unmap_ip = map__unmap_ip;
 987                                         /* Ensure maps are correctly ordered */
 988                                         if (kmaps) {
 989                                                 map__get(map);
 990                                                 map_groups__remove(kmaps, map);
 991                                                 map_groups__insert(kmaps, map);
 992                                                 map__put(map);
 993                                         }
 994                                 }
 995
 996                                 /*
 997                                  * The initial module mapping is based on
 998                                  * /proc/modules mapped to offset zero.
 999                                  * Overwrite it to map to the module dso.
1000                                  */
1001                                 if (remap_kernel && kmodule) {
1002                                         remap_kernel = false;
1003                                         map->pgoff = shdr.sh_offset;
1004                                 }
1005
1006                                 curr_map = map;
1007                                 curr_dso = dso;
1008                                 goto new_symbol;
1009                         }
1010
1011                         if (!kmap)
1012                                 goto new_symbol;
1013
1014                         snprintf(dso_name, sizeof(dso_name),
1015                                  "%s%s", dso->short_name, section_name);
1016
1017                         curr_map = map_groups__find_by_name(kmaps, map->type, dso_name);
1018                         if (curr_map == NULL) {
1019                                 u64 start = sym.st_value;
1020
1021                                 if (kmodule)
1022                                         start += map->start + shdr.sh_offset;
1023
1024                                 curr_dso = dso__new(dso_name);
1025                                 if (curr_dso == NULL)
1026                                         goto out_elf_end;
1027                                 curr_dso->kernel = dso->kernel;
1028                                 curr_dso->long_name = dso->long_name;
1029                                 curr_dso->long_name_len = dso->long_name_len;
1030                                 curr_map = map__new2(start, curr_dso,
1031                                                      map->type);
1032                                 dso__put(curr_dso);
1033                                 if (curr_map == NULL) {
1034                                         goto out_elf_end;
1035                                 }
1036                                 if (adjust_kernel_syms) {
1037                                         curr_map->start = shdr.sh_addr +
1038                                                           ref_reloc(kmap);
1039                                         curr_map->end = curr_map->start +
1040                                                         shdr.sh_size;
1041                                         curr_map->pgoff = shdr.sh_offset;
1042                                 } else {
1043                                         curr_map->map_ip = identity__map_ip;
1044                                         curr_map->unmap_ip = identity__map_ip;
1045                                 }
1046                                 curr_dso->symtab_type = dso->symtab_type;
1047                                 map_groups__insert(kmaps, curr_map);
1048                                 /*
1049                                  * Add it before we drop the referece to curr_map,
1050                                  * i.e. while we still are sure to have a reference
1051                                  * to this DSO via curr_map->dso.
1052                                  */
1053                                 dsos__add(&map->groups->machine->dsos, curr_dso);
1054                                 /* kmaps already got it */
1055                                 map__put(curr_map);
1056                                 dso__set_loaded(curr_dso, map->type);
1057                         } else
1058                                 curr_dso = curr_map->dso;
1059
1060                         goto new_symbol;
1061                 }
1062
1063                 if ((used_opd && runtime_ss->adjust_symbols)
1064                                 || (!used_opd && syms_ss->adjust_symbols)) {
1065                         pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
1066                                   "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
1067                                   (u64)sym.st_value, (u64)shdr.sh_addr,
1068                                   (u64)shdr.sh_offset);
1069                         sym.st_value -= shdr.sh_addr - shdr.sh_offset;
1070                 }
1071 new_symbol:
1072                 /*
1073                  * We need to figure out if the object was created from C++ sources
1074                  * DWARF DW_compile_unit has this, but we don't always have access
1075                  * to it...
1076                  */
1077                 if (want_demangle(dso->kernel || kmodule)) {
1078                         int demangle_flags = DMGL_NO_OPTS;
1079                         if (verbose)
1080                                 demangle_flags = DMGL_PARAMS | DMGL_ANSI;
1081
1082                         demangled = bfd_demangle(NULL, elf_name, demangle_flags);
1083                         if (demangled == NULL)
1084                                 demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);
1085                         else if (rust_is_mangled(demangled))
1086                                 /*
1087                                  * Input to Rust demangling is the BFD-demangled
1088                                  * name which it Rust-demangles in place.
1089                                  */
1090                                 rust_demangle_sym(demangled);
1091
1092                         if (demangled != NULL)
1093                                 elf_name = demangled;
1094                 }
1095                 f = symbol__new(sym.st_value, sym.st_size,
1096                                 GELF_ST_BIND(sym.st_info), elf_name);
1097                 free(demangled);
1098                 if (!f)
1099                         goto out_elf_end;
1100
1101                 arch__sym_update(f, &sym);
1102
1103                 if (filter && filter(curr_map, f))
1104                         symbol__delete(f);
1105                 else {
1106                         symbols__insert(&curr_dso->symbols[curr_map->type], f);
1107                         nr++;
1108                 }
1109         }
1110
1111         /*
1112          * For misannotated, zeroed, ASM function sizes.
1113          */
1114         if (nr > 0) {
1115                 if (!symbol_conf.allow_aliases)
1116                         symbols__fixup_duplicate(&dso->symbols[map->type]);
1117                 symbols__fixup_end(&dso->symbols[map->type]);
1118                 if (kmap) {
1119                         /*
1120                          * We need to fixup this here too because we create new
1121                          * maps here, for things like vsyscall sections.
1122                          */
1123                         __map_groups__fixup_end(kmaps, map->type);
1124                 }
1125         }
1126         err = nr;
1127 out_elf_end:
1128         return err;
1129 }
1130
1131 static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
1132 {
1133         GElf_Phdr phdr;
1134         size_t i, phdrnum;
1135         int err;
1136         u64 sz;
1137
1138         if (elf_getphdrnum(elf, &phdrnum))
1139                 return -1;
1140
1141         for (i = 0; i < phdrnum; i++) {
1142                 if (gelf_getphdr(elf, i, &phdr) == NULL)
1143                         return -1;
1144                 if (phdr.p_type != PT_LOAD)
1145                         continue;
1146                 if (exe) {
1147                         if (!(phdr.p_flags & PF_X))
1148                                 continue;
1149                 } else {
1150                         if (!(phdr.p_flags & PF_R))
1151                                 continue;
1152                 }
1153                 sz = min(phdr.p_memsz, phdr.p_filesz);
1154                 if (!sz)
1155                         continue;
1156                 err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
1157                 if (err)
1158                         return err;
1159         }
1160         return 0;
1161 }
1162
1163 int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
1164                     bool *is_64_bit)
1165 {
1166         int err;
1167         Elf *elf;
1168
1169         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1170         if (elf == NULL)
1171                 return -1;
1172
1173         if (is_64_bit)
1174                 *is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
1175
1176         err = elf_read_maps(elf, exe, mapfn, data);
1177
1178         elf_end(elf);
1179         return err;
1180 }
1181
1182 enum dso_type dso__type_fd(int fd)
1183 {
1184         enum dso_type dso_type = DSO__TYPE_UNKNOWN;
1185         GElf_Ehdr ehdr;
1186         Elf_Kind ek;
1187         Elf *elf;
1188
1189         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1190         if (elf == NULL)
1191                 goto out;
1192
1193         ek = elf_kind(elf);
1194         if (ek != ELF_K_ELF)
1195                 goto out_end;
1196
1197         if (gelf_getclass(elf) == ELFCLASS64) {
1198                 dso_type = DSO__TYPE_64BIT;
1199                 goto out_end;
1200         }
1201
1202         if (gelf_getehdr(elf, &ehdr) == NULL)
1203                 goto out_end;
1204
1205         if (ehdr.e_machine == EM_X86_64)
1206                 dso_type = DSO__TYPE_X32BIT;
1207         else
1208                 dso_type = DSO__TYPE_32BIT;
1209 out_end:
1210         elf_end(elf);
1211 out:
1212         return dso_type;
1213 }
1214
1215 static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
1216 {
1217         ssize_t r;
1218         size_t n;
1219         int err = -1;
1220         char *buf = malloc(page_size);
1221
1222         if (buf == NULL)
1223                 return -1;
1224
1225         if (lseek(to, to_offs, SEEK_SET) != to_offs)
1226                 goto out;
1227
1228         if (lseek(from, from_offs, SEEK_SET) != from_offs)
1229                 goto out;
1230
1231         while (len) {
1232                 n = page_size;
1233                 if (len < n)
1234                         n = len;
1235                 /* Use read because mmap won't work on proc files */
1236                 r = read(from, buf, n);
1237                 if (r < 0)
1238                         goto out;
1239                 if (!r)
1240                         break;
1241                 n = r;
1242                 r = write(to, buf, n);
1243                 if (r < 0)
1244                         goto out;
1245                 if ((size_t)r != n)
1246                         goto out;
1247                 len -= n;
1248         }
1249
1250         err = 0;
1251 out:
1252         free(buf);
1253         return err;
1254 }
1255
1256 struct kcore {
1257         int fd;
1258         int elfclass;
1259         Elf *elf;
1260         GElf_Ehdr ehdr;
1261 };
1262
1263 static int kcore__open(struct kcore *kcore, const char *filename)
1264 {
1265         GElf_Ehdr *ehdr;
1266
1267         kcore->fd = open(filename, O_RDONLY);
1268         if (kcore->fd == -1)
1269                 return -1;
1270
1271         kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
1272         if (!kcore->elf)
1273                 goto out_close;
1274
1275         kcore->elfclass = gelf_getclass(kcore->elf);
1276         if (kcore->elfclass == ELFCLASSNONE)
1277                 goto out_end;
1278
1279         ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1280         if (!ehdr)
1281                 goto out_end;
1282
1283         return 0;
1284
1285 out_end:
1286         elf_end(kcore->elf);
1287 out_close:
1288         close(kcore->fd);
1289         return -1;
1290 }
1291
1292 static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
1293                        bool temp)
1294 {
1295         kcore->elfclass = elfclass;
1296
1297         if (temp)
1298                 kcore->fd = mkstemp(filename);
1299         else
1300                 kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
1301         if (kcore->fd == -1)
1302                 return -1;
1303
1304         kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
1305         if (!kcore->elf)
1306                 goto out_close;
1307
1308         if (!gelf_newehdr(kcore->elf, elfclass))
1309                 goto out_end;
1310
1311         memset(&kcore->ehdr, 0, sizeof(GElf_Ehdr));
1312
1313         return 0;
1314
1315 out_end:
1316         elf_end(kcore->elf);
1317 out_close:
1318         close(kcore->fd);
1319         unlink(filename);
1320         return -1;
1321 }
1322
1323 static void kcore__close(struct kcore *kcore)
1324 {
1325         elf_end(kcore->elf);
1326         close(kcore->fd);
1327 }
1328
1329 static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
1330 {
1331         GElf_Ehdr *ehdr = &to->ehdr;
1332         GElf_Ehdr *kehdr = &from->ehdr;
1333
1334         memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
1335         ehdr->e_type      = kehdr->e_type;
1336         ehdr->e_machine   = kehdr->e_machine;
1337         ehdr->e_version   = kehdr->e_version;
1338         ehdr->e_entry     = 0;
1339         ehdr->e_shoff     = 0;
1340         ehdr->e_flags     = kehdr->e_flags;
1341         ehdr->e_phnum     = count;
1342         ehdr->e_shentsize = 0;
1343         ehdr->e_shnum     = 0;
1344         ehdr->e_shstrndx  = 0;
1345
1346         if (from->elfclass == ELFCLASS32) {
1347                 ehdr->e_phoff     = sizeof(Elf32_Ehdr);
1348                 ehdr->e_ehsize    = sizeof(Elf32_Ehdr);
1349                 ehdr->e_phentsize = sizeof(Elf32_Phdr);
1350         } else {
1351                 ehdr->e_phoff     = sizeof(Elf64_Ehdr);
1352                 ehdr->e_ehsize    = sizeof(Elf64_Ehdr);
1353                 ehdr->e_phentsize = sizeof(Elf64_Phdr);
1354         }
1355
1356         if (!gelf_update_ehdr(to->elf, ehdr))
1357                 return -1;
1358
1359         if (!gelf_newphdr(to->elf, count))
1360                 return -1;
1361
1362         return 0;
1363 }
1364
1365 static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
1366                            u64 addr, u64 len)
1367 {
1368         GElf_Phdr phdr = {
1369                 .p_type         = PT_LOAD,
1370                 .p_flags        = PF_R | PF_W | PF_X,
1371                 .p_offset       = offset,
1372                 .p_vaddr        = addr,
1373                 .p_paddr        = 0,
1374                 .p_filesz       = len,
1375                 .p_memsz        = len,
1376                 .p_align        = page_size,
1377         };
1378
1379         if (!gelf_update_phdr(kcore->elf, idx, &phdr))
1380                 return -1;
1381
1382         return 0;
1383 }
1384
1385 static off_t kcore__write(struct kcore *kcore)
1386 {
1387         return elf_update(kcore->elf, ELF_C_WRITE);
1388 }
1389
1390 struct phdr_data {
1391         off_t offset;
1392         u64 addr;
1393         u64 len;
1394 };
1395
1396 struct kcore_copy_info {
1397         u64 stext;
1398         u64 etext;
1399         u64 first_symbol;
1400         u64 last_symbol;
1401         u64 first_module;
1402         u64 last_module_symbol;
1403         struct phdr_data kernel_map;
1404         struct phdr_data modules_map;
1405 };
1406
1407 static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
1408                                         u64 start)
1409 {
1410         struct kcore_copy_info *kci = arg;
1411
1412         if (!symbol_type__is_a(type, MAP__FUNCTION))
1413                 return 0;
1414
1415         if (strchr(name, '[')) {
1416                 if (start > kci->last_module_symbol)
1417                         kci->last_module_symbol = start;
1418                 return 0;
1419         }
1420
1421         if (!kci->first_symbol || start < kci->first_symbol)
1422                 kci->first_symbol = start;
1423
1424         if (!kci->last_symbol || start > kci->last_symbol)
1425                 kci->last_symbol = start;
1426
1427         if (!strcmp(name, "_stext")) {
1428                 kci->stext = start;
1429                 return 0;
1430         }
1431
1432         if (!strcmp(name, "_etext")) {
1433                 kci->etext = start;
1434                 return 0;
1435         }
1436
1437         return 0;
1438 }
1439
1440 static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
1441                                       const char *dir)
1442 {
1443         char kallsyms_filename[PATH_MAX];
1444
1445         scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);
1446
1447         if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
1448                 return -1;
1449
1450         if (kallsyms__parse(kallsyms_filename, kci,
1451                             kcore_copy__process_kallsyms) < 0)
1452                 return -1;
1453
1454         return 0;
1455 }
1456
1457 static int kcore_copy__process_modules(void *arg,
1458                                        const char *name __maybe_unused,
1459                                        u64 start)
1460 {
1461         struct kcore_copy_info *kci = arg;
1462
1463         if (!kci->first_module || start < kci->first_module)
1464                 kci->first_module = start;
1465
1466         return 0;
1467 }
1468
1469 static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
1470                                      const char *dir)
1471 {
1472         char modules_filename[PATH_MAX];
1473
1474         scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);
1475
1476         if (symbol__restricted_filename(modules_filename, "/proc/modules"))
1477                 return -1;
1478
1479         if (modules__parse(modules_filename, kci,
1480                            kcore_copy__process_modules) < 0)
1481                 return -1;
1482
1483         return 0;
1484 }
1485
1486 static void kcore_copy__map(struct phdr_data *p, u64 start, u64 end, u64 pgoff,
1487                             u64 s, u64 e)
1488 {
1489         if (p->addr || s < start || s >= end)
1490                 return;
1491
1492         p->addr = s;
1493         p->offset = (s - start) + pgoff;
1494         p->len = e < end ? e - s : end - s;
1495 }
1496
1497 static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
1498 {
1499         struct kcore_copy_info *kci = data;
1500         u64 end = start + len;
1501
1502         kcore_copy__map(&kci->kernel_map, start, end, pgoff, kci->stext,
1503                         kci->etext);
1504
1505         kcore_copy__map(&kci->modules_map, start, end, pgoff, kci->first_module,
1506                         kci->last_module_symbol);
1507
1508         return 0;
1509 }
1510
1511 static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
1512 {
1513         if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
1514                 return -1;
1515
1516         return 0;
1517 }
1518
1519 static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
1520                                  Elf *elf)
1521 {
1522         if (kcore_copy__parse_kallsyms(kci, dir))
1523                 return -1;
1524
1525         if (kcore_copy__parse_modules(kci, dir))
1526                 return -1;
1527
1528         if (kci->stext)
1529                 kci->stext = round_down(kci->stext, page_size);
1530         else
1531                 kci->stext = round_down(kci->first_symbol, page_size);
1532
1533         if (kci->etext) {
1534                 kci->etext = round_up(kci->etext, page_size);
1535         } else if (kci->last_symbol) {
1536                 kci->etext = round_up(kci->last_symbol, page_size);
1537                 kci->etext += page_size;
1538         }
1539
1540         kci->first_module = round_down(kci->first_module, page_size);
1541
1542         if (kci->last_module_symbol) {
1543                 kci->last_module_symbol = round_up(kci->last_module_symbol,
1544                                                    page_size);
1545                 kci->last_module_symbol += page_size;
1546         }
1547
1548         if (!kci->stext || !kci->etext)
1549                 return -1;
1550
1551         if (kci->first_module && !kci->last_module_symbol)
1552                 return -1;
1553
1554         return kcore_copy__read_maps(kci, elf);
1555 }
1556
1557 static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
1558                                  const char *name)
1559 {
1560         char from_filename[PATH_MAX];
1561         char to_filename[PATH_MAX];
1562
1563         scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1564         scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1565
1566         return copyfile_mode(from_filename, to_filename, 0400);
1567 }
1568
1569 static int kcore_copy__unlink(const char *dir, const char *name)
1570 {
1571         char filename[PATH_MAX];
1572
1573         scnprintf(filename, PATH_MAX, "%s/%s", dir, name);
1574
1575         return unlink(filename);
1576 }
1577
1578 static int kcore_copy__compare_fds(int from, int to)
1579 {
1580         char *buf_from;
1581         char *buf_to;
1582         ssize_t ret;
1583         size_t len;
1584         int err = -1;
1585
1586         buf_from = malloc(page_size);
1587         buf_to = malloc(page_size);
1588         if (!buf_from || !buf_to)
1589                 goto out;
1590
1591         while (1) {
1592                 /* Use read because mmap won't work on proc files */
1593                 ret = read(from, buf_from, page_size);
1594                 if (ret < 0)
1595                         goto out;
1596
1597                 if (!ret)
1598                         break;
1599
1600                 len = ret;
1601
1602                 if (readn(to, buf_to, len) != (int)len)
1603                         goto out;
1604
1605                 if (memcmp(buf_from, buf_to, len))
1606                         goto out;
1607         }
1608
1609         err = 0;
1610 out:
1611         free(buf_to);
1612         free(buf_from);
1613         return err;
1614 }
1615
1616 static int kcore_copy__compare_files(const char *from_filename,
1617                                      const char *to_filename)
1618 {
1619         int from, to, err = -1;
1620
1621         from = open(from_filename, O_RDONLY);
1622         if (from < 0)
1623                 return -1;
1624
1625         to = open(to_filename, O_RDONLY);
1626         if (to < 0)
1627                 goto out_close_from;
1628
1629         err = kcore_copy__compare_fds(from, to);
1630
1631         close(to);
1632 out_close_from:
1633         close(from);
1634         return err;
1635 }
1636
1637 static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
1638                                     const char *name)
1639 {
1640         char from_filename[PATH_MAX];
1641         char to_filename[PATH_MAX];
1642
1643         scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1644         scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1645
1646         return kcore_copy__compare_files(from_filename, to_filename);
1647 }
1648
1649 /**
1650  * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
1651  * @from_dir: from directory
1652  * @to_dir: to directory
1653  *
1654  * This function copies kallsyms, modules and kcore files from one directory to
1655  * another.  kallsyms and modules are copied entirely.  Only code segments are
1656  * copied from kcore.  It is assumed that two segments suffice: one for the
1657  * kernel proper and one for all the modules.  The code segments are determined
1658  * from kallsyms and modules files.  The kernel map starts at _stext or the
1659  * lowest function symbol, and ends at _etext or the highest function symbol.
1660  * The module map starts at the lowest module address and ends at the highest
1661  * module symbol.  Start addresses are rounded down to the nearest page.  End
1662  * addresses are rounded up to the nearest page.  An extra page is added to the
1663  * highest kernel symbol and highest module symbol to, hopefully, encompass that
1664  * symbol too.  Because it contains only code sections, the resulting kcore is
1665  * unusual.  One significant peculiarity is that the mapping (start -> pgoff)
1666  * is not the same for the kernel map and the modules map.  That happens because
1667  * the data is copied adjacently whereas the original kcore has gaps.  Finally,
1668  * kallsyms and modules files are compared with their copies to check that
1669  * modules have not been loaded or unloaded while the copies were taking place.
1670  *
1671  * Return: %0 on success, %-1 on failure.
1672  */
1673 int kcore_copy(const char *from_dir, const char *to_dir)
1674 {
1675         struct kcore kcore;
1676         struct kcore extract;
1677         size_t count = 2;
1678         int idx = 0, err = -1;
1679         off_t offset = page_size, sz, modules_offset = 0;
1680         struct kcore_copy_info kci = { .stext = 0, };
1681         char kcore_filename[PATH_MAX];
1682         char extract_filename[PATH_MAX];
1683
1684         if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
1685                 return -1;
1686
1687         if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
1688                 goto out_unlink_kallsyms;
1689
1690         scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
1691         scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);
1692
1693         if (kcore__open(&kcore, kcore_filename))
1694                 goto out_unlink_modules;
1695
1696         if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
1697                 goto out_kcore_close;
1698
1699         if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
1700                 goto out_kcore_close;
1701
1702         if (!kci.modules_map.addr)
1703                 count -= 1;
1704
1705         if (kcore__copy_hdr(&kcore, &extract, count))
1706                 goto out_extract_close;
1707
1708         if (kcore__add_phdr(&extract, idx++, offset, kci.kernel_map.addr,
1709                             kci.kernel_map.len))
1710                 goto out_extract_close;
1711
1712         if (kci.modules_map.addr) {
1713                 modules_offset = offset + kci.kernel_map.len;
1714                 if (kcore__add_phdr(&extract, idx, modules_offset,
1715                                     kci.modules_map.addr, kci.modules_map.len))
1716                         goto out_extract_close;
1717         }
1718
1719         sz = kcore__write(&extract);
1720         if (sz < 0 || sz > offset)
1721                 goto out_extract_close;
1722
1723         if (copy_bytes(kcore.fd, kci.kernel_map.offset, extract.fd, offset,
1724                        kci.kernel_map.len))
1725                 goto out_extract_close;
1726
1727         if (modules_offset && copy_bytes(kcore.fd, kci.modules_map.offset,
1728                                          extract.fd, modules_offset,
1729                                          kci.modules_map.len))
1730                 goto out_extract_close;
1731
1732         if (kcore_copy__compare_file(from_dir, to_dir, "modules"))
1733                 goto out_extract_close;
1734
1735         if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
1736                 goto out_extract_close;
1737
1738         err = 0;
1739
1740 out_extract_close:
1741         kcore__close(&extract);
1742         if (err)
1743                 unlink(extract_filename);
1744 out_kcore_close:
1745         kcore__close(&kcore);
1746 out_unlink_modules:
1747         if (err)
1748                 kcore_copy__unlink(to_dir, "modules");
1749 out_unlink_kallsyms:
1750         if (err)
1751                 kcore_copy__unlink(to_dir, "kallsyms");
1752
1753         return err;
1754 }
1755
1756 int kcore_extract__create(struct kcore_extract *kce)
1757 {
1758         struct kcore kcore;
1759         struct kcore extract;
1760         size_t count = 1;
1761         int idx = 0, err = -1;
1762         off_t offset = page_size, sz;
1763
1764         if (kcore__open(&kcore, kce->kcore_filename))
1765                 return -1;
1766
1767         strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
1768         if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
1769                 goto out_kcore_close;
1770
1771         if (kcore__copy_hdr(&kcore, &extract, count))
1772                 goto out_extract_close;
1773
1774         if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
1775                 goto out_extract_close;
1776
1777         sz = kcore__write(&extract);
1778         if (sz < 0 || sz > offset)
1779                 goto out_extract_close;
1780
1781         if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
1782                 goto out_extract_close;
1783
1784         err = 0;
1785
1786 out_extract_close:
1787         kcore__close(&extract);
1788         if (err)
1789                 unlink(kce->extract_filename);
1790 out_kcore_close:
1791         kcore__close(&kcore);
1792
1793         return err;
1794 }
1795
1796 void kcore_extract__delete(struct kcore_extract *kce)
1797 {
1798         unlink(kce->extract_filename);
1799 }
1800
1801 #ifdef HAVE_GELF_GETNOTE_SUPPORT
1802 /**
1803  * populate_sdt_note : Parse raw data and identify SDT note
1804  * @elf: elf of the opened file
1805  * @data: raw data of a section with description offset applied
1806  * @len: note description size
1807  * @type: type of the note
1808  * @sdt_notes: List to add the SDT note
1809  *
1810  * Responsible for parsing the @data in section .note.stapsdt in @elf and
1811  * if its an SDT note, it appends to @sdt_notes list.
1812  */
1813 static int populate_sdt_note(Elf **elf, const char *data, size_t len,
1814                              struct list_head *sdt_notes)
1815 {
1816         const char *provider, *name;
1817         struct sdt_note *tmp = NULL;
1818         GElf_Ehdr ehdr;
1819         GElf_Addr base_off = 0;
1820         GElf_Shdr shdr;
1821         int ret = -EINVAL;
1822
1823         union {
1824                 Elf64_Addr a64[NR_ADDR];
1825                 Elf32_Addr a32[NR_ADDR];
1826         } buf;
1827
1828         Elf_Data dst = {
1829                 .d_buf = &buf, .d_type = ELF_T_ADDR, .d_version = EV_CURRENT,
1830                 .d_size = gelf_fsize((*elf), ELF_T_ADDR, NR_ADDR, EV_CURRENT),
1831                 .d_off = 0, .d_align = 0
1832         };
1833         Elf_Data src = {
1834                 .d_buf = (void *) data, .d_type = ELF_T_ADDR,
1835                 .d_version = EV_CURRENT, .d_size = dst.d_size, .d_off = 0,
1836                 .d_align = 0
1837         };
1838
1839         tmp = (struct sdt_note *)calloc(1, sizeof(struct sdt_note));
1840         if (!tmp) {
1841                 ret = -ENOMEM;
1842                 goto out_err;
1843         }
1844
1845         INIT_LIST_HEAD(&tmp->note_list);
1846
1847         if (len < dst.d_size + 3)
1848                 goto out_free_note;
1849
1850         /* Translation from file representation to memory representation */
1851         if (gelf_xlatetom(*elf, &dst, &src,
1852                           elf_getident(*elf, NULL)[EI_DATA]) == NULL) {
1853                 pr_err("gelf_xlatetom : %s\n", elf_errmsg(-1));
1854                 goto out_free_note;
1855         }
1856
1857         /* Populate the fields of sdt_note */
1858         provider = data + dst.d_size;
1859
1860         name = (const char *)memchr(provider, '\0', data + len - provider);
1861         if (name++ == NULL)
1862                 goto out_free_note;
1863
1864         tmp->provider = strdup(provider);
1865         if (!tmp->provider) {
1866                 ret = -ENOMEM;
1867                 goto out_free_note;
1868         }
1869         tmp->name = strdup(name);
1870         if (!tmp->name) {
1871                 ret = -ENOMEM;
1872                 goto out_free_prov;
1873         }
1874
1875         if (gelf_getclass(*elf) == ELFCLASS32) {
1876                 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr));
1877                 tmp->bit32 = true;
1878         } else {
1879                 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf64_Addr));
1880                 tmp->bit32 = false;
1881         }
1882
1883         if (!gelf_getehdr(*elf, &ehdr)) {
1884                 pr_debug("%s : cannot get elf header.\n", __func__);
1885                 ret = -EBADF;
1886                 goto out_free_name;
1887         }
1888
1889         /* Adjust the prelink effect :
1890          * Find out the .stapsdt.base section.
1891          * This scn will help us to handle prelinking (if present).
1892          * Compare the retrieved file offset of the base section with the
1893          * base address in the description of the SDT note. If its different,
1894          * then accordingly, adjust the note location.
1895          */
1896         if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL)) {
1897                 base_off = shdr.sh_offset;
1898                 if (base_off) {
1899                         if (tmp->bit32)
1900                                 tmp->addr.a32[0] = tmp->addr.a32[0] + base_off -
1901                                         tmp->addr.a32[1];
1902                         else
1903                                 tmp->addr.a64[0] = tmp->addr.a64[0] + base_off -
1904                                         tmp->addr.a64[1];
1905                 }
1906         }
1907
1908         list_add_tail(&tmp->note_list, sdt_notes);
1909         return 0;
1910
1911 out_free_name:
1912         free(tmp->name);
1913 out_free_prov:
1914         free(tmp->provider);
1915 out_free_note:
1916         free(tmp);
1917 out_err:
1918         return ret;
1919 }
1920
1921 /**
1922  * construct_sdt_notes_list : constructs a list of SDT notes
1923  * @elf : elf to look into
1924  * @sdt_notes : empty list_head
1925  *
1926  * Scans the sections in 'elf' for the section
1927  * .note.stapsdt. It, then calls populate_sdt_note to find
1928  * out the SDT events and populates the 'sdt_notes'.
1929  */
1930 static int construct_sdt_notes_list(Elf *elf, struct list_head *sdt_notes)
1931 {
1932         GElf_Ehdr ehdr;
1933         Elf_Scn *scn = NULL;
1934         Elf_Data *data;
1935         GElf_Shdr shdr;
1936         size_t shstrndx, next;
1937         GElf_Nhdr nhdr;
1938         size_t name_off, desc_off, offset;
1939         int ret = 0;
1940
1941         if (gelf_getehdr(elf, &ehdr) == NULL) {
1942                 ret = -EBADF;
1943                 goto out_ret;
1944         }
1945         if (elf_getshdrstrndx(elf, &shstrndx) != 0) {
1946                 ret = -EBADF;
1947                 goto out_ret;
1948         }
1949
1950         /* Look for the required section */
1951         scn = elf_section_by_name(elf, &ehdr, &shdr, SDT_NOTE_SCN, NULL);
1952         if (!scn) {
1953                 ret = -ENOENT;
1954                 goto out_ret;
1955         }
1956
1957         if ((shdr.sh_type != SHT_NOTE) || (shdr.sh_flags & SHF_ALLOC)) {
1958                 ret = -ENOENT;
1959                 goto out_ret;
1960         }
1961
1962         data = elf_getdata(scn, NULL);
1963
1964         /* Get the SDT notes */
1965         for (offset = 0; (next = gelf_getnote(data, offset, &nhdr, &name_off,
1966                                               &desc_off)) > 0; offset = next) {
1967                 if (nhdr.n_namesz == sizeof(SDT_NOTE_NAME) &&
1968                     !memcmp(data->d_buf + name_off, SDT_NOTE_NAME,
1969                             sizeof(SDT_NOTE_NAME))) {
1970                         /* Check the type of the note */
1971                         if (nhdr.n_type != SDT_NOTE_TYPE)
1972                                 goto out_ret;
1973
1974                         ret = populate_sdt_note(&elf, ((data->d_buf) + desc_off),
1975                                                 nhdr.n_descsz, sdt_notes);
1976                         if (ret < 0)
1977                                 goto out_ret;
1978                 }
1979         }
1980         if (list_empty(sdt_notes))
1981                 ret = -ENOENT;
1982
1983 out_ret:
1984         return ret;
1985 }
1986
1987 /**
1988  * get_sdt_note_list : Wrapper to construct a list of sdt notes
1989  * @head : empty list_head
1990  * @target : file to find SDT notes from
1991  *
1992  * This opens the file, initializes
1993  * the ELF and then calls construct_sdt_notes_list.
1994  */
1995 int get_sdt_note_list(struct list_head *head, const char *target)
1996 {
1997         Elf *elf;
1998         int fd, ret;
1999
2000         fd = open(target, O_RDONLY);
2001         if (fd < 0)
2002                 return -EBADF;
2003
2004         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
2005         if (!elf) {
2006                 ret = -EBADF;
2007                 goto out_close;
2008         }
2009         ret = construct_sdt_notes_list(elf, head);
2010         elf_end(elf);
2011 out_close:
2012         close(fd);
2013         return ret;
2014 }
2015
2016 /**
2017  * cleanup_sdt_note_list : free the sdt notes' list
2018  * @sdt_notes: sdt notes' list
2019  *
2020  * Free up the SDT notes in @sdt_notes.
2021  * Returns the number of SDT notes free'd.
2022  */
2023 int cleanup_sdt_note_list(struct list_head *sdt_notes)
2024 {
2025         struct sdt_note *tmp, *pos;
2026         int nr_free = 0;
2027
2028         list_for_each_entry_safe(pos, tmp, sdt_notes, note_list) {
2029                 list_del(&pos->note_list);
2030                 free(pos->name);
2031                 free(pos->provider);
2032                 free(pos);
2033                 nr_free++;
2034         }
2035         return nr_free;
2036 }
2037
2038 /**
2039  * sdt_notes__get_count: Counts the number of sdt events
2040  * @start: list_head to sdt_notes list
2041  *
2042  * Returns the number of SDT notes in a list
2043  */
2044 int sdt_notes__get_count(struct list_head *start)
2045 {
2046         struct sdt_note *sdt_ptr;
2047         int count = 0;
2048
2049         list_for_each_entry(sdt_ptr, start, note_list)
2050                 count++;
2051         return count;
2052 }
2053 #endif
2054
2055 void symbol__elf_init(void)
2056 {
2057         elf_version(EV_CURRENT);
2058 }