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 static inline uint8_t elf_sym__visibility(const GElf_Sym *sym)
  89 {
  90         return GELF_ST_VISIBILITY(sym->st_other);
  91 }
  92
  93 #ifndef STT_GNU_IFUNC
  94 #define STT_GNU_IFUNC 10
  95 #endif
  96
  97 static inline int elf_sym__is_function(const GElf_Sym *sym)
  98 {
  99         return (elf_sym__type(sym) == STT_FUNC ||
 100                 elf_sym__type(sym) == STT_GNU_IFUNC) &&
 101                sym->st_name != 0 &&
 102                sym->st_shndx != SHN_UNDEF;
 103 }
 104
 105 static inline bool elf_sym__is_object(const GElf_Sym *sym)
 106 {
 107         return elf_sym__type(sym) == STT_OBJECT &&
 108                 sym->st_name != 0 &&
 109                 sym->st_shndx != SHN_UNDEF;
 110 }
 111
 112 static inline int elf_sym__is_label(const GElf_Sym *sym)
 113 {
 114         return elf_sym__type(sym) == STT_NOTYPE &&
 115                 sym->st_name != 0 &&
 116                 sym->st_shndx != SHN_UNDEF &&
 117                 sym->st_shndx != SHN_ABS &&
 118                 elf_sym__visibility(sym) != STV_HIDDEN &&
 119                 elf_sym__visibility(sym) != STV_INTERNAL;
 120 }
 121
 122 static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
 123 {
 124         switch (type) {
 125         case MAP__FUNCTION:
 126                 return elf_sym__is_function(sym);
 127         case MAP__VARIABLE:
 128                 return elf_sym__is_object(sym);
 129         default:
 130                 return false;
 131         }
 132 }
 133
 134 static inline const char *elf_sym__name(const GElf_Sym *sym,
 135                                         const Elf_Data *symstrs)
 136 {
 137         return symstrs->d_buf + sym->st_name;
 138 }
 139
 140 static inline const char *elf_sec__name(const GElf_Shdr *shdr,
 141                                         const Elf_Data *secstrs)
 142 {
 143         return secstrs->d_buf + shdr->sh_name;
 144 }
 145
 146 static inline int elf_sec__is_text(const GElf_Shdr *shdr,
 147                                         const Elf_Data *secstrs)
 148 {
 149         return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
 150 }
 151
 152 static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
 153                                     const Elf_Data *secstrs)
 154 {
 155         return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
 156 }
 157
 158 static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs,
 159                           enum map_type type)
 160 {
 161         switch (type) {
 162         case MAP__FUNCTION:
 163                 return elf_sec__is_text(shdr, secstrs);
 164         case MAP__VARIABLE:
 165                 return elf_sec__is_data(shdr, secstrs);
 166         default:
 167                 return false;
 168         }
 169 }
 170
 171 static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
 172 {
 173         Elf_Scn *sec = NULL;
 174         GElf_Shdr shdr;
 175         size_t cnt = 1;
 176
 177         while ((sec = elf_nextscn(elf, sec)) != NULL) {
 178                 gelf_getshdr(sec, &shdr);
 179
 180                 if ((addr >= shdr.sh_addr) &&
 181                     (addr < (shdr.sh_addr + shdr.sh_size)))
 182                         return cnt;
 183
 184                 ++cnt;
 185         }
 186
 187         return -1;
 188 }
 189
 190 Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
 191                              GElf_Shdr *shp, const char *name, size_t *idx)
 192 {
 193         Elf_Scn *sec = NULL;
 194         size_t cnt = 1;
 195
 196         /* Elf is corrupted/truncated, avoid calling elf_strptr. */
 197         if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
 198                 return NULL;
 199
 200         while ((sec = elf_nextscn(elf, sec)) != NULL) {
 201                 char *str;
 202
 203                 gelf_getshdr(sec, shp);
 204                 str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
 205                 if (str && !strcmp(name, str)) {
 206                         if (idx)
 207                                 *idx = cnt;
 208                         return sec;
 209                 }
 210                 ++cnt;
 211         }
 212
 213         return NULL;
 214 }
 215
 216 static bool want_demangle(bool is_kernel_sym)
 217 {
 218         return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
 219 }
 220
 221 static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
 222 {
 223         int demangle_flags = verbose ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS;
 224         char *demangled = NULL;
 225
 226         /*
 227          * We need to figure out if the object was created from C++ sources
 228          * DWARF DW_compile_unit has this, but we don't always have access
 229          * to it...
 230          */
 231         if (!want_demangle(dso->kernel || kmodule))
 232             return demangled;
 233
 234         demangled = bfd_demangle(NULL, elf_name, demangle_flags);
 235         if (demangled == NULL)
 236                 demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);
 237         else if (rust_is_mangled(demangled))
 238                 /*
 239                     * Input to Rust demangling is the BFD-demangled
 240                     * name which it Rust-demangles in place.
 241                     */
 242                 rust_demangle_sym(demangled);
 243
 244         return demangled;
 245 }
 246
 247 #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
 248         for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
 249              idx < nr_entries; \
 250              ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
 251
 252 #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
 253         for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
 254              idx < nr_entries; \
 255              ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
 256
 257 /*
 258  * We need to check if we have a .dynsym, so that we can handle the
 259  * .plt, synthesizing its symbols, that aren't on the symtabs (be it
 260  * .dynsym or .symtab).
 261  * And always look at the original dso, not at debuginfo packages, that
 262  * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
 263  */
 264 int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map)
 265 {
 266         uint32_t nr_rel_entries, idx;
 267         GElf_Sym sym;
 268         u64 plt_offset;
 269         GElf_Shdr shdr_plt;
 270         struct symbol *f;
 271         GElf_Shdr shdr_rel_plt, shdr_dynsym;
 272         Elf_Data *reldata, *syms, *symstrs;
 273         Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
 274         size_t dynsym_idx;
 275         GElf_Ehdr ehdr;
 276         char sympltname[1024];
 277         Elf *elf;
 278         int nr = 0, symidx, err = 0;
 279
 280         if (!ss->dynsym)
 281                 return 0;
 282
 283         elf = ss->elf;
 284         ehdr = ss->ehdr;
 285
 286         scn_dynsym = ss->dynsym;
 287         shdr_dynsym = ss->dynshdr;
 288         dynsym_idx = ss->dynsym_idx;
 289
 290         if (scn_dynsym == NULL)
 291                 goto out_elf_end;
 292
 293         scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
 294                                           ".rela.plt", NULL);
 295         if (scn_plt_rel == NULL) {
 296                 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
 297                                                   ".rel.plt", NULL);
 298                 if (scn_plt_rel == NULL)
 299                         goto out_elf_end;
 300         }
 301
 302         err = -1;
 303
 304         if (shdr_rel_plt.sh_link != dynsym_idx)
 305                 goto out_elf_end;
 306
 307         if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
 308                 goto out_elf_end;
 309
 310         /*
 311          * Fetch the relocation section to find the idxes to the GOT
 312          * and the symbols in the .dynsym they refer to.
 313          */
 314         reldata = elf_getdata(scn_plt_rel, NULL);
 315         if (reldata == NULL)
 316                 goto out_elf_end;
 317
 318         syms = elf_getdata(scn_dynsym, NULL);
 319         if (syms == NULL)
 320                 goto out_elf_end;
 321
 322         scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
 323         if (scn_symstrs == NULL)
 324                 goto out_elf_end;
 325
 326         symstrs = elf_getdata(scn_symstrs, NULL);
 327         if (symstrs == NULL)
 328                 goto out_elf_end;
 329
 330         if (symstrs->d_size == 0)
 331                 goto out_elf_end;
 332
 333         nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
 334         plt_offset = shdr_plt.sh_offset;
 335
 336         if (shdr_rel_plt.sh_type == SHT_RELA) {
 337                 GElf_Rela pos_mem, *pos;
 338
 339                 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
 340                                            nr_rel_entries) {
 341                         const char *elf_name = NULL;
 342                         char *demangled = NULL;
 343                         symidx = GELF_R_SYM(pos->r_info);
 344                         plt_offset += shdr_plt.sh_entsize;
 345                         gelf_getsym(syms, symidx, &sym);
 346
 347                         elf_name = elf_sym__name(&sym, symstrs);
 348                         demangled = demangle_sym(dso, 0, elf_name);
 349                         if (demangled != NULL)
 350                                 elf_name = demangled;
 351                         snprintf(sympltname, sizeof(sympltname),
 352                                  "%s@plt", elf_name);
 353                         free(demangled);
 354
 355                         f = symbol__new(plt_offset, shdr_plt.sh_entsize,
 356                                         STB_GLOBAL, sympltname);
 357                         if (!f)
 358                                 goto out_elf_end;
 359
 360                         symbols__insert(&dso->symbols[map->type], f);
 361                         ++nr;
 362                 }
 363         } else if (shdr_rel_plt.sh_type == SHT_REL) {
 364                 GElf_Rel pos_mem, *pos;
 365                 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
 366                                           nr_rel_entries) {
 367                         const char *elf_name = NULL;
 368                         char *demangled = NULL;
 369                         symidx = GELF_R_SYM(pos->r_info);
 370                         plt_offset += shdr_plt.sh_entsize;
 371                         gelf_getsym(syms, symidx, &sym);
 372
 373                         elf_name = elf_sym__name(&sym, symstrs);
 374                         demangled = demangle_sym(dso, 0, elf_name);
 375                         if (demangled != NULL)
 376                                 elf_name = demangled;
 377                         snprintf(sympltname, sizeof(sympltname),
 378                                  "%s@plt", elf_name);
 379                         free(demangled);
 380
 381                         f = symbol__new(plt_offset, shdr_plt.sh_entsize,
 382                                         STB_GLOBAL, sympltname);
 383                         if (!f)
 384                                 goto out_elf_end;
 385
 386                         symbols__insert(&dso->symbols[map->type], f);
 387                         ++nr;
 388                 }
 389         }
 390
 391         err = 0;
 392 out_elf_end:
 393         if (err == 0)
 394                 return nr;
 395         pr_debug("%s: problems reading %s PLT info.\n",
 396                  __func__, dso->long_name);
 397         return 0;
 398 }
 399
 400 /*
 401  * Align offset to 4 bytes as needed for note name and descriptor data.
 402  */
 403 #define NOTE_ALIGN(n) (((n) + 3) & -4U)
 404
 405 static int elf_read_build_id(Elf *elf, void *bf, size_t size)
 406 {
 407         int err = -1;
 408         GElf_Ehdr ehdr;
 409         GElf_Shdr shdr;
 410         Elf_Data *data;
 411         Elf_Scn *sec;
 412         Elf_Kind ek;
 413         void *ptr;
 414
 415         if (size < BUILD_ID_SIZE)
 416                 goto out;
 417
 418         ek = elf_kind(elf);
 419         if (ek != ELF_K_ELF)
 420                 goto out;
 421
 422         if (gelf_getehdr(elf, &ehdr) == NULL) {
 423                 pr_err("%s: cannot get elf header.\n", __func__);
 424                 goto out;
 425         }
 426
 427         /*
 428          * Check following sections for notes:
 429          *   '.note.gnu.build-id'
 430          *   '.notes'
 431          *   '.note' (VDSO specific)
 432          */
 433         do {
 434                 sec = elf_section_by_name(elf, &ehdr, &shdr,
 435                                           ".note.gnu.build-id", NULL);
 436                 if (sec)
 437                         break;
 438
 439                 sec = elf_section_by_name(elf, &ehdr, &shdr,
 440                                           ".notes", NULL);
 441                 if (sec)
 442                         break;
 443
 444                 sec = elf_section_by_name(elf, &ehdr, &shdr,
 445                                           ".note", NULL);
 446                 if (sec)
 447                         break;
 448
 449                 return err;
 450
 451         } while (0);
 452
 453         data = elf_getdata(sec, NULL);
 454         if (data == NULL)
 455                 goto out;
 456
 457         ptr = data->d_buf;
 458         while (ptr < (data->d_buf + data->d_size)) {
 459                 GElf_Nhdr *nhdr = ptr;
 460                 size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
 461                        descsz = NOTE_ALIGN(nhdr->n_descsz);
 462                 const char *name;
 463
 464                 ptr += sizeof(*nhdr);
 465                 name = ptr;
 466                 ptr += namesz;
 467                 if (nhdr->n_type == NT_GNU_BUILD_ID &&
 468                     nhdr->n_namesz == sizeof("GNU")) {
 469                         if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
 470                                 size_t sz = min(size, descsz);
 471                                 memcpy(bf, ptr, sz);
 472                                 memset(bf + sz, 0, size - sz);
 473                                 err = descsz;
 474                                 break;
 475                         }
 476                 }
 477                 ptr += descsz;
 478         }
 479
 480 out:
 481         return err;
 482 }
 483
 484 int filename__read_build_id(const char *filename, void *bf, size_t size)
 485 {
 486         int fd, err = -1;
 487         Elf *elf;
 488
 489         if (size < BUILD_ID_SIZE)
 490                 goto out;
 491
 492         fd = open(filename, O_RDONLY);
 493         if (fd < 0)
 494                 goto out;
 495
 496         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
 497         if (elf == NULL) {
 498                 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
 499                 goto out_close;
 500         }
 501
 502         err = elf_read_build_id(elf, bf, size);
 503
 504         elf_end(elf);
 505 out_close:
 506         close(fd);
 507 out:
 508         return err;
 509 }
 510
 511 int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
 512 {
 513         int fd, err = -1;
 514
 515         if (size < BUILD_ID_SIZE)
 516                 goto out;
 517
 518         fd = open(filename, O_RDONLY);
 519         if (fd < 0)
 520                 goto out;
 521
 522         while (1) {
 523                 char bf[BUFSIZ];
 524                 GElf_Nhdr nhdr;
 525                 size_t namesz, descsz;
 526
 527                 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
 528                         break;
 529
 530                 namesz = NOTE_ALIGN(nhdr.n_namesz);
 531                 descsz = NOTE_ALIGN(nhdr.n_descsz);
 532                 if (nhdr.n_type == NT_GNU_BUILD_ID &&
 533                     nhdr.n_namesz == sizeof("GNU")) {
 534                         if (read(fd, bf, namesz) != (ssize_t)namesz)
 535                                 break;
 536                         if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
 537                                 size_t sz = min(descsz, size);
 538                                 if (read(fd, build_id, sz) == (ssize_t)sz) {
 539                                         memset(build_id + sz, 0, size - sz);
 540                                         err = 0;
 541                                         break;
 542                                 }
 543                         } else if (read(fd, bf, descsz) != (ssize_t)descsz)
 544                                 break;
 545                 } else {
 546                         int n = namesz + descsz;
 547
 548                         if (n > (int)sizeof(bf)) {
 549                                 n = sizeof(bf);
 550                                 pr_debug("%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n",
 551                                          __func__, filename, nhdr.n_namesz, nhdr.n_descsz);
 552                         }
 553                         if (read(fd, bf, n) != n)
 554                                 break;
 555                 }
 556         }
 557         close(fd);
 558 out:
 559         return err;
 560 }
 561
 562 int filename__read_debuglink(const char *filename, char *debuglink,
 563                              size_t size)
 564 {
 565         int fd, err = -1;
 566         Elf *elf;
 567         GElf_Ehdr ehdr;
 568         GElf_Shdr shdr;
 569         Elf_Data *data;
 570         Elf_Scn *sec;
 571         Elf_Kind ek;
 572
 573         fd = open(filename, O_RDONLY);
 574         if (fd < 0)
 575                 goto out;
 576
 577         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
 578         if (elf == NULL) {
 579                 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
 580                 goto out_close;
 581         }
 582
 583         ek = elf_kind(elf);
 584         if (ek != ELF_K_ELF)
 585                 goto out_elf_end;
 586
 587         if (gelf_getehdr(elf, &ehdr) == NULL) {
 588                 pr_err("%s: cannot get elf header.\n", __func__);
 589                 goto out_elf_end;
 590         }
 591
 592         sec = elf_section_by_name(elf, &ehdr, &shdr,
 593                                   ".gnu_debuglink", NULL);
 594         if (sec == NULL)
 595                 goto out_elf_end;
 596
 597         data = elf_getdata(sec, NULL);
 598         if (data == NULL)
 599                 goto out_elf_end;
 600
 601         /* the start of this section is a zero-terminated string */
 602         strncpy(debuglink, data->d_buf, size);
 603
 604         err = 0;
 605
 606 out_elf_end:
 607         elf_end(elf);
 608 out_close:
 609         close(fd);
 610 out:
 611         return err;
 612 }
 613
 614 static int dso__swap_init(struct dso *dso, unsigned char eidata)
 615 {
 616         static unsigned int const endian = 1;
 617
 618         dso->needs_swap = DSO_SWAP__NO;
 619
 620         switch (eidata) {
 621         case ELFDATA2LSB:
 622                 /* We are big endian, DSO is little endian. */
 623                 if (*(unsigned char const *)&endian != 1)
 624                         dso->needs_swap = DSO_SWAP__YES;
 625                 break;
 626
 627         case ELFDATA2MSB:
 628                 /* We are little endian, DSO is big endian. */
 629                 if (*(unsigned char const *)&endian != 0)
 630                         dso->needs_swap = DSO_SWAP__YES;
 631                 break;
 632
 633         default:
 634                 pr_err("unrecognized DSO data encoding %d\n", eidata);
 635                 return -EINVAL;
 636         }
 637
 638         return 0;
 639 }
 640
 641 static int decompress_kmodule(struct dso *dso, const char *name,
 642                               enum dso_binary_type type)
 643 {
 644         int fd = -1;
 645         char tmpbuf[] = "/tmp/perf-kmod-XXXXXX";
 646         struct kmod_path m;
 647
 648         if (type != DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP &&
 649             type != DSO_BINARY_TYPE__GUEST_KMODULE_COMP &&
 650             type != DSO_BINARY_TYPE__BUILD_ID_CACHE)
 651                 return -1;
 652
 653         if (type == DSO_BINARY_TYPE__BUILD_ID_CACHE)
 654                 name = dso->long_name;
 655
 656         if (kmod_path__parse_ext(&m, name) || !m.comp)
 657                 return -1;
 658
 659         fd = mkstemp(tmpbuf);
 660         if (fd < 0) {
 661                 dso->load_errno = errno;
 662                 goto out;
 663         }
 664
 665         if (!decompress_to_file(m.ext, name, fd)) {
 666                 dso->load_errno = DSO_LOAD_ERRNO__DECOMPRESSION_FAILURE;
 667                 close(fd);
 668                 fd = -1;
 669         }
 670
 671         unlink(tmpbuf);
 672
 673 out:
 674         free(m.ext);
 675         return fd;
 676 }
 677
 678 bool symsrc__possibly_runtime(struct symsrc *ss)
 679 {
 680         return ss->dynsym || ss->opdsec;
 681 }
 682
 683 bool symsrc__has_symtab(struct symsrc *ss)
 684 {
 685         return ss->symtab != NULL;
 686 }
 687
 688 void symsrc__destroy(struct symsrc *ss)
 689 {
 690         zfree(&ss->name);
 691         elf_end(ss->elf);
 692         close(ss->fd);
 693 }
 694
 695 bool __weak elf__needs_adjust_symbols(GElf_Ehdr ehdr)
 696 {
 697         return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL;
 698 }
 699
 700 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
 701                  enum dso_binary_type type)
 702 {
 703         int err = -1;
 704         GElf_Ehdr ehdr;
 705         Elf *elf;
 706         int fd;
 707
 708         if (dso__needs_decompress(dso)) {
 709                 fd = decompress_kmodule(dso, name, type);
 710                 if (fd < 0)
 711                         return -1;
 712         } else {
 713                 fd = open(name, O_RDONLY);
 714                 if (fd < 0) {
 715                         dso->load_errno = errno;
 716                         return -1;
 717                 }
 718         }
 719
 720         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
 721         if (elf == NULL) {
 722                 pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
 723                 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
 724                 goto out_close;
 725         }
 726
 727         if (gelf_getehdr(elf, &ehdr) == NULL) {
 728                 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
 729                 pr_debug("%s: cannot get elf header.\n", __func__);
 730                 goto out_elf_end;
 731         }
 732
 733         if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) {
 734                 dso->load_errno = DSO_LOAD_ERRNO__INTERNAL_ERROR;
 735                 goto out_elf_end;
 736         }
 737
 738         /* Always reject images with a mismatched build-id: */
 739         if (dso->has_build_id && !symbol_conf.ignore_vmlinux_buildid) {
 740                 u8 build_id[BUILD_ID_SIZE];
 741
 742                 if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) {
 743                         dso->load_errno = DSO_LOAD_ERRNO__CANNOT_READ_BUILDID;
 744                         goto out_elf_end;
 745                 }
 746
 747                 if (!dso__build_id_equal(dso, build_id)) {
 748                         pr_debug("%s: build id mismatch for %s.\n", __func__, name);
 749                         dso->load_errno = DSO_LOAD_ERRNO__MISMATCHING_BUILDID;
 750                         goto out_elf_end;
 751                 }
 752         }
 753
 754         ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
 755
 756         ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
 757                         NULL);
 758         if (ss->symshdr.sh_type != SHT_SYMTAB)
 759                 ss->symtab = NULL;
 760
 761         ss->dynsym_idx = 0;
 762         ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
 763                         &ss->dynsym_idx);
 764         if (ss->dynshdr.sh_type != SHT_DYNSYM)
 765                 ss->dynsym = NULL;
 766
 767         ss->opdidx = 0;
 768         ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
 769                         &ss->opdidx);
 770         if (ss->opdshdr.sh_type != SHT_PROGBITS)
 771                 ss->opdsec = NULL;
 772
 773         if (dso->kernel == DSO_TYPE_USER)
 774                 ss->adjust_symbols = true;
 775         else
 776                 ss->adjust_symbols = elf__needs_adjust_symbols(ehdr);
 777
 778         ss->name   = strdup(name);
 779         if (!ss->name) {
 780                 dso->load_errno = errno;
 781                 goto out_elf_end;
 782         }
 783
 784         ss->elf    = elf;
 785         ss->fd     = fd;
 786         ss->ehdr   = ehdr;
 787         ss->type   = type;
 788
 789         return 0;
 790
 791 out_elf_end:
 792         elf_end(elf);
 793 out_close:
 794         close(fd);
 795         return err;
 796 }
 797
 798 /**
 799  * ref_reloc_sym_not_found - has kernel relocation symbol been found.
 800  * @kmap: kernel maps and relocation reference symbol
 801  *
 802  * This function returns %true if we are dealing with the kernel maps and the
 803  * relocation reference symbol has not yet been found.  Otherwise %false is
 804  * returned.
 805  */
 806 static bool ref_reloc_sym_not_found(struct kmap *kmap)
 807 {
 808         return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
 809                !kmap->ref_reloc_sym->unrelocated_addr;
 810 }
 811
 812 /**
 813  * ref_reloc - kernel relocation offset.
 814  * @kmap: kernel maps and relocation reference symbol
 815  *
 816  * This function returns the offset of kernel addresses as determined by using
 817  * the relocation reference symbol i.e. if the kernel has not been relocated
 818  * then the return value is zero.
 819  */
 820 static u64 ref_reloc(struct kmap *kmap)
 821 {
 822         if (kmap && kmap->ref_reloc_sym &&
 823             kmap->ref_reloc_sym->unrelocated_addr)
 824                 return kmap->ref_reloc_sym->addr -
 825                        kmap->ref_reloc_sym->unrelocated_addr;
 826         return 0;
 827 }
 828
 829 void __weak arch__sym_update(struct symbol *s __maybe_unused,
 830                 GElf_Sym *sym __maybe_unused) { }
 831
 832 int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
 833                   struct symsrc *runtime_ss, int kmodule)
 834 {
 835         struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
 836         struct map_groups *kmaps = kmap ? map__kmaps(map) : NULL;
 837         struct map *curr_map = map;
 838         struct dso *curr_dso = dso;
 839         Elf_Data *symstrs, *secstrs;
 840         uint32_t nr_syms;
 841         int err = -1;
 842         uint32_t idx;
 843         GElf_Ehdr ehdr;
 844         GElf_Shdr shdr;
 845         GElf_Shdr tshdr;
 846         Elf_Data *syms, *opddata = NULL;
 847         GElf_Sym sym;
 848         Elf_Scn *sec, *sec_strndx;
 849         Elf *elf;
 850         int nr = 0;
 851         bool remap_kernel = false, adjust_kernel_syms = false;
 852
 853         if (kmap && !kmaps)
 854                 return -1;
 855
 856         dso->symtab_type = syms_ss->type;
 857         dso->is_64_bit = syms_ss->is_64_bit;
 858         dso->rel = syms_ss->ehdr.e_type == ET_REL;
 859
 860         /*
 861          * Modules may already have symbols from kallsyms, but those symbols
 862          * have the wrong values for the dso maps, so remove them.
 863          */
 864         if (kmodule && syms_ss->symtab)
 865                 symbols__delete(&dso->symbols[map->type]);
 866
 867         if (!syms_ss->symtab) {
 868                 /*
 869                  * If the vmlinux is stripped, fail so we will fall back
 870                  * to using kallsyms. The vmlinux runtime symbols aren't
 871                  * of much use.
 872                  */
 873                 if (dso->kernel)
 874                         goto out_elf_end;
 875
 876                 syms_ss->symtab  = syms_ss->dynsym;
 877                 syms_ss->symshdr = syms_ss->dynshdr;
 878         }
 879
 880         elf = syms_ss->elf;
 881         ehdr = syms_ss->ehdr;
 882         sec = syms_ss->symtab;
 883         shdr = syms_ss->symshdr;
 884
 885         if (elf_section_by_name(runtime_ss->elf, &runtime_ss->ehdr, &tshdr,
 886                                 ".text", NULL))
 887                 dso->text_offset = tshdr.sh_addr - tshdr.sh_offset;
 888
 889         if (runtime_ss->opdsec)
 890                 opddata = elf_rawdata(runtime_ss->opdsec, NULL);
 891
 892         syms = elf_getdata(sec, NULL);
 893         if (syms == NULL)
 894                 goto out_elf_end;
 895
 896         sec = elf_getscn(elf, shdr.sh_link);
 897         if (sec == NULL)
 898                 goto out_elf_end;
 899
 900         symstrs = elf_getdata(sec, NULL);
 901         if (symstrs == NULL)
 902                 goto out_elf_end;
 903
 904         sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx);
 905         if (sec_strndx == NULL)
 906                 goto out_elf_end;
 907
 908         secstrs = elf_getdata(sec_strndx, NULL);
 909         if (secstrs == NULL)
 910                 goto out_elf_end;
 911
 912         nr_syms = shdr.sh_size / shdr.sh_entsize;
 913
 914         memset(&sym, 0, sizeof(sym));
 915
 916         /*
 917          * The kernel relocation symbol is needed in advance in order to adjust
 918          * kernel maps correctly.
 919          */
 920         if (ref_reloc_sym_not_found(kmap)) {
 921                 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
 922                         const char *elf_name = elf_sym__name(&sym, symstrs);
 923
 924                         if (strcmp(elf_name, kmap->ref_reloc_sym->name))
 925                                 continue;
 926                         kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
 927                         map->reloc = kmap->ref_reloc_sym->addr -
 928                                      kmap->ref_reloc_sym->unrelocated_addr;
 929                         break;
 930                 }
 931         }
 932
 933         /*
 934          * Handle any relocation of vdso necessary because older kernels
 935          * attempted to prelink vdso to its virtual address.
 936          */
 937         if (dso__is_vdso(dso))
 938                 map->reloc = map->start - dso->text_offset;
 939
 940         dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
 941         /*
 942          * Initial kernel and module mappings do not map to the dso.  For
 943          * function mappings, flag the fixups.
 944          */
 945         if (map->type == MAP__FUNCTION && (dso->kernel || kmodule)) {
 946                 remap_kernel = true;
 947                 adjust_kernel_syms = dso->adjust_symbols;
 948         }
 949         elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
 950                 struct symbol *f;
 951                 const char *elf_name = elf_sym__name(&sym, symstrs);
 952                 char *demangled = NULL;
 953                 int is_label = elf_sym__is_label(&sym);
 954                 const char *section_name;
 955                 bool used_opd = false;
 956
 957                 if (!is_label && !elf_sym__is_a(&sym, map->type))
 958                         continue;
 959
 960                 /* Reject ARM ELF "mapping symbols": these aren't unique and
 961                  * don't identify functions, so will confuse the profile
 962                  * output: */
 963                 if (ehdr.e_machine == EM_ARM || ehdr.e_machine == EM_AARCH64) {
 964                         if (elf_name[0] == '$' && strchr("adtx", elf_name[1])
 965                             && (elf_name[2] == '\0' || elf_name[2] == '.'))
 966                                 continue;
 967                 }
 968
 969                 if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
 970                         u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
 971                         u64 *opd = opddata->d_buf + offset;
 972                         sym.st_value = DSO__SWAP(dso, u64, *opd);
 973                         sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
 974                                         sym.st_value);
 975                         used_opd = true;
 976                 }
 977                 /*
 978                  * When loading symbols in a data mapping, ABS symbols (which
 979                  * has a value of SHN_ABS in its st_shndx) failed at
 980                  * elf_getscn().  And it marks the loading as a failure so
 981                  * already loaded symbols cannot be fixed up.
 982                  *
 983                  * I'm not sure what should be done. Just ignore them for now.
 984                  * - Namhyung Kim
 985                  */
 986                 if (sym.st_shndx == SHN_ABS)
 987                         continue;
 988
 989                 sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
 990                 if (!sec)
 991                         goto out_elf_end;
 992
 993                 gelf_getshdr(sec, &shdr);
 994
 995                 if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
 996                         continue;
 997
 998                 section_name = elf_sec__name(&shdr, secstrs);
 999
1000                 /* On ARM, symbols for thumb functions have 1 added to
1001                  * the symbol address as a flag - remove it */
1002                 if ((ehdr.e_machine == EM_ARM) &&
1003                     (map->type == MAP__FUNCTION) &&
1004                     (sym.st_value & 1))
1005                         --sym.st_value;
1006
1007                 if (dso->kernel || kmodule) {
1008                         char dso_name[PATH_MAX];
1009
1010                         /* Adjust symbol to map to file offset */
1011                         if (adjust_kernel_syms)
1012                                 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
1013
1014                         if (strcmp(section_name,
1015                                    (curr_dso->short_name +
1016                                     dso->short_name_len)) == 0)
1017                                 goto new_symbol;
1018
1019                         if (strcmp(section_name, ".text") == 0) {
1020                                 /*
1021                                  * The initial kernel mapping is based on
1022                                  * kallsyms and identity maps.  Overwrite it to
1023                                  * map to the kernel dso.
1024                                  */
1025                                 if (remap_kernel && dso->kernel) {
1026                                         remap_kernel = false;
1027                                         map->start = shdr.sh_addr +
1028                                                      ref_reloc(kmap);
1029                                         map->end = map->start + shdr.sh_size;
1030                                         map->pgoff = shdr.sh_offset;
1031                                         map->map_ip = map__map_ip;
1032                                         map->unmap_ip = map__unmap_ip;
1033                                         /* Ensure maps are correctly ordered */
1034                                         if (kmaps) {
1035                                                 map__get(map);
1036                                                 map_groups__remove(kmaps, map);
1037                                                 map_groups__insert(kmaps, map);
1038                                                 map__put(map);
1039                                         }
1040                                 }
1041
1042                                 /*
1043                                  * The initial module mapping is based on
1044                                  * /proc/modules mapped to offset zero.
1045                                  * Overwrite it to map to the module dso.
1046                                  */
1047                                 if (remap_kernel && kmodule) {
1048                                         remap_kernel = false;
1049                                         map->pgoff = shdr.sh_offset;
1050                                 }
1051
1052                                 curr_map = map;
1053                                 curr_dso = dso;
1054                                 goto new_symbol;
1055                         }
1056
1057                         if (!kmap)
1058                                 goto new_symbol;
1059
1060                         snprintf(dso_name, sizeof(dso_name),
1061                                  "%s%s", dso->short_name, section_name);
1062
1063                         curr_map = map_groups__find_by_name(kmaps, map->type, dso_name);
1064                         if (curr_map == NULL) {
1065                                 u64 start = sym.st_value;
1066
1067                                 if (kmodule)
1068                                         start += map->start + shdr.sh_offset;
1069
1070                                 curr_dso = dso__new(dso_name);
1071                                 if (curr_dso == NULL)
1072                                         goto out_elf_end;
1073                                 curr_dso->kernel = dso->kernel;
1074                                 curr_dso->long_name = dso->long_name;
1075                                 curr_dso->long_name_len = dso->long_name_len;
1076                                 curr_map = map__new2(start, curr_dso,
1077                                                      map->type);
1078                                 dso__put(curr_dso);
1079                                 if (curr_map == NULL) {
1080                                         goto out_elf_end;
1081                                 }
1082                                 if (adjust_kernel_syms) {
1083                                         curr_map->start = shdr.sh_addr +
1084                                                           ref_reloc(kmap);
1085                                         curr_map->end = curr_map->start +
1086                                                         shdr.sh_size;
1087                                         curr_map->pgoff = shdr.sh_offset;
1088                                 } else {
1089                                         curr_map->map_ip = identity__map_ip;
1090                                         curr_map->unmap_ip = identity__map_ip;
1091                                 }
1092                                 curr_dso->symtab_type = dso->symtab_type;
1093                                 map_groups__insert(kmaps, curr_map);
1094                                 /*
1095                                  * Add it before we drop the referece to curr_map,
1096                                  * i.e. while we still are sure to have a reference
1097                                  * to this DSO via curr_map->dso.
1098                                  */
1099                                 dsos__add(&map->groups->machine->dsos, curr_dso);
1100                                 /* kmaps already got it */
1101                                 map__put(curr_map);
1102                                 dso__set_loaded(curr_dso, map->type);
1103                         } else
1104                                 curr_dso = curr_map->dso;
1105
1106                         goto new_symbol;
1107                 }
1108
1109                 if ((used_opd && runtime_ss->adjust_symbols)
1110                                 || (!used_opd && syms_ss->adjust_symbols)) {
1111                         pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
1112                                   "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
1113                                   (u64)sym.st_value, (u64)shdr.sh_addr,
1114                                   (u64)shdr.sh_offset);
1115                         sym.st_value -= shdr.sh_addr - shdr.sh_offset;
1116                 }
1117 new_symbol:
1118                 demangled = demangle_sym(dso, kmodule, elf_name);
1119                 if (demangled != NULL)
1120                         elf_name = demangled;
1121
1122                 f = symbol__new(sym.st_value, sym.st_size,
1123                                 GELF_ST_BIND(sym.st_info), elf_name);
1124                 free(demangled);
1125                 if (!f)
1126                         goto out_elf_end;
1127
1128                 arch__sym_update(f, &sym);
1129
1130                 __symbols__insert(&curr_dso->symbols[curr_map->type], f, dso->kernel);
1131                 nr++;
1132         }
1133
1134         /*
1135          * For misannotated, zeroed, ASM function sizes.
1136          */
1137         if (nr > 0) {
1138                 symbols__fixup_end(&dso->symbols[map->type]);
1139                 symbols__fixup_duplicate(&dso->symbols[map->type]);
1140                 if (kmap) {
1141                         /*
1142                          * We need to fixup this here too because we create new
1143                          * maps here, for things like vsyscall sections.
1144                          */
1145                         __map_groups__fixup_end(kmaps, map->type);
1146                 }
1147         }
1148         err = nr;
1149 out_elf_end:
1150         return err;
1151 }
1152
1153 static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
1154 {
1155         GElf_Phdr phdr;
1156         size_t i, phdrnum;
1157         int err;
1158         u64 sz;
1159
1160         if (elf_getphdrnum(elf, &phdrnum))
1161                 return -1;
1162
1163         for (i = 0; i < phdrnum; i++) {
1164                 if (gelf_getphdr(elf, i, &phdr) == NULL)
1165                         return -1;
1166                 if (phdr.p_type != PT_LOAD)
1167                         continue;
1168                 if (exe) {
1169                         if (!(phdr.p_flags & PF_X))
1170                                 continue;
1171                 } else {
1172                         if (!(phdr.p_flags & PF_R))
1173                                 continue;
1174                 }
1175                 sz = min(phdr.p_memsz, phdr.p_filesz);
1176                 if (!sz)
1177                         continue;
1178                 err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
1179                 if (err)
1180                         return err;
1181         }
1182         return 0;
1183 }
1184
1185 int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
1186                     bool *is_64_bit)
1187 {
1188         int err;
1189         Elf *elf;
1190
1191         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1192         if (elf == NULL)
1193                 return -1;
1194
1195         if (is_64_bit)
1196                 *is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
1197
1198         err = elf_read_maps(elf, exe, mapfn, data);
1199
1200         elf_end(elf);
1201         return err;
1202 }
1203
1204 enum dso_type dso__type_fd(int fd)
1205 {
1206         enum dso_type dso_type = DSO__TYPE_UNKNOWN;
1207         GElf_Ehdr ehdr;
1208         Elf_Kind ek;
1209         Elf *elf;
1210
1211         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1212         if (elf == NULL)
1213                 goto out;
1214
1215         ek = elf_kind(elf);
1216         if (ek != ELF_K_ELF)
1217                 goto out_end;
1218
1219         if (gelf_getclass(elf) == ELFCLASS64) {
1220                 dso_type = DSO__TYPE_64BIT;
1221                 goto out_end;
1222         }
1223
1224         if (gelf_getehdr(elf, &ehdr) == NULL)
1225                 goto out_end;
1226
1227         if (ehdr.e_machine == EM_X86_64)
1228                 dso_type = DSO__TYPE_X32BIT;
1229         else
1230                 dso_type = DSO__TYPE_32BIT;
1231 out_end:
1232         elf_end(elf);
1233 out:
1234         return dso_type;
1235 }
1236
1237 static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
1238 {
1239         ssize_t r;
1240         size_t n;
1241         int err = -1;
1242         char *buf = malloc(page_size);
1243
1244         if (buf == NULL)
1245                 return -1;
1246
1247         if (lseek(to, to_offs, SEEK_SET) != to_offs)
1248                 goto out;
1249
1250         if (lseek(from, from_offs, SEEK_SET) != from_offs)
1251                 goto out;
1252
1253         while (len) {
1254                 n = page_size;
1255                 if (len < n)
1256                         n = len;
1257                 /* Use read because mmap won't work on proc files */
1258                 r = read(from, buf, n);
1259                 if (r < 0)
1260                         goto out;
1261                 if (!r)
1262                         break;
1263                 n = r;
1264                 r = write(to, buf, n);
1265                 if (r < 0)
1266                         goto out;
1267                 if ((size_t)r != n)
1268                         goto out;
1269                 len -= n;
1270         }
1271
1272         err = 0;
1273 out:
1274         free(buf);
1275         return err;
1276 }
1277
1278 struct kcore {
1279         int fd;
1280         int elfclass;
1281         Elf *elf;
1282         GElf_Ehdr ehdr;
1283 };
1284
1285 static int kcore__open(struct kcore *kcore, const char *filename)
1286 {
1287         GElf_Ehdr *ehdr;
1288
1289         kcore->fd = open(filename, O_RDONLY);
1290         if (kcore->fd == -1)
1291                 return -1;
1292
1293         kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
1294         if (!kcore->elf)
1295                 goto out_close;
1296
1297         kcore->elfclass = gelf_getclass(kcore->elf);
1298         if (kcore->elfclass == ELFCLASSNONE)
1299                 goto out_end;
1300
1301         ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1302         if (!ehdr)
1303                 goto out_end;
1304
1305         return 0;
1306
1307 out_end:
1308         elf_end(kcore->elf);
1309 out_close:
1310         close(kcore->fd);
1311         return -1;
1312 }
1313
1314 static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
1315                        bool temp)
1316 {
1317         kcore->elfclass = elfclass;
1318
1319         if (temp)
1320                 kcore->fd = mkstemp(filename);
1321         else
1322                 kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
1323         if (kcore->fd == -1)
1324                 return -1;
1325
1326         kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
1327         if (!kcore->elf)
1328                 goto out_close;
1329
1330         if (!gelf_newehdr(kcore->elf, elfclass))
1331                 goto out_end;
1332
1333         memset(&kcore->ehdr, 0, sizeof(GElf_Ehdr));
1334
1335         return 0;
1336
1337 out_end:
1338         elf_end(kcore->elf);
1339 out_close:
1340         close(kcore->fd);
1341         unlink(filename);
1342         return -1;
1343 }
1344
1345 static void kcore__close(struct kcore *kcore)
1346 {
1347         elf_end(kcore->elf);
1348         close(kcore->fd);
1349 }
1350
1351 static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
1352 {
1353         GElf_Ehdr *ehdr = &to->ehdr;
1354         GElf_Ehdr *kehdr = &from->ehdr;
1355
1356         memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
1357         ehdr->e_type      = kehdr->e_type;
1358         ehdr->e_machine   = kehdr->e_machine;
1359         ehdr->e_version   = kehdr->e_version;
1360         ehdr->e_entry     = 0;
1361         ehdr->e_shoff     = 0;
1362         ehdr->e_flags     = kehdr->e_flags;
1363         ehdr->e_phnum     = count;
1364         ehdr->e_shentsize = 0;
1365         ehdr->e_shnum     = 0;
1366         ehdr->e_shstrndx  = 0;
1367
1368         if (from->elfclass == ELFCLASS32) {
1369                 ehdr->e_phoff     = sizeof(Elf32_Ehdr);
1370                 ehdr->e_ehsize    = sizeof(Elf32_Ehdr);
1371                 ehdr->e_phentsize = sizeof(Elf32_Phdr);
1372         } else {
1373                 ehdr->e_phoff     = sizeof(Elf64_Ehdr);
1374                 ehdr->e_ehsize    = sizeof(Elf64_Ehdr);
1375                 ehdr->e_phentsize = sizeof(Elf64_Phdr);
1376         }
1377
1378         if (!gelf_update_ehdr(to->elf, ehdr))
1379                 return -1;
1380
1381         if (!gelf_newphdr(to->elf, count))
1382                 return -1;
1383
1384         return 0;
1385 }
1386
1387 static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
1388                            u64 addr, u64 len)
1389 {
1390         GElf_Phdr phdr = {
1391                 .p_type         = PT_LOAD,
1392                 .p_flags        = PF_R | PF_W | PF_X,
1393                 .p_offset       = offset,
1394                 .p_vaddr        = addr,
1395                 .p_paddr        = 0,
1396                 .p_filesz       = len,
1397                 .p_memsz        = len,
1398                 .p_align        = page_size,
1399         };
1400
1401         if (!gelf_update_phdr(kcore->elf, idx, &phdr))
1402                 return -1;
1403
1404         return 0;
1405 }
1406
1407 static off_t kcore__write(struct kcore *kcore)
1408 {
1409         return elf_update(kcore->elf, ELF_C_WRITE);
1410 }
1411
1412 struct phdr_data {
1413         off_t offset;
1414         u64 addr;
1415         u64 len;
1416 };
1417
1418 struct kcore_copy_info {
1419         u64 stext;
1420         u64 etext;
1421         u64 first_symbol;
1422         u64 last_symbol;
1423         u64 first_module;
1424         u64 first_module_symbol;
1425         u64 last_module_symbol;
1426         struct phdr_data kernel_map;
1427         struct phdr_data modules_map;
1428 };
1429
1430 static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
1431                                         u64 start)
1432 {
1433         struct kcore_copy_info *kci = arg;
1434
1435         if (!symbol_type__is_a(type, MAP__FUNCTION))
1436                 return 0;
1437
1438         if (strchr(name, '[')) {
1439                 if (!kci->first_module_symbol || start < kci->first_module_symbol)
1440                         kci->first_module_symbol = start;
1441                 if (start > kci->last_module_symbol)
1442                         kci->last_module_symbol = start;
1443                 return 0;
1444         }
1445
1446         if (!kci->first_symbol || start < kci->first_symbol)
1447                 kci->first_symbol = start;
1448
1449         if (!kci->last_symbol || start > kci->last_symbol)
1450                 kci->last_symbol = start;
1451
1452         if (!strcmp(name, "_stext")) {
1453                 kci->stext = start;
1454                 return 0;
1455         }
1456
1457         if (!strcmp(name, "_etext")) {
1458                 kci->etext = start;
1459                 return 0;
1460         }
1461
1462         return 0;
1463 }
1464
1465 static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
1466                                       const char *dir)
1467 {
1468         char kallsyms_filename[PATH_MAX];
1469
1470         scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);
1471
1472         if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
1473                 return -1;
1474
1475         if (kallsyms__parse(kallsyms_filename, kci,
1476                             kcore_copy__process_kallsyms) < 0)
1477                 return -1;
1478
1479         return 0;
1480 }
1481
1482 static int kcore_copy__process_modules(void *arg,
1483                                        const char *name __maybe_unused,
1484                                        u64 start, u64 size __maybe_unused)
1485 {
1486         struct kcore_copy_info *kci = arg;
1487
1488         if (!kci->first_module || start < kci->first_module)
1489                 kci->first_module = start;
1490
1491         return 0;
1492 }
1493
1494 static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
1495                                      const char *dir)
1496 {
1497         char modules_filename[PATH_MAX];
1498
1499         scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);
1500
1501         if (symbol__restricted_filename(modules_filename, "/proc/modules"))
1502                 return -1;
1503
1504         if (modules__parse(modules_filename, kci,
1505                            kcore_copy__process_modules) < 0)
1506                 return -1;
1507
1508         return 0;
1509 }
1510
1511 static void kcore_copy__map(struct phdr_data *p, u64 start, u64 end, u64 pgoff,
1512                             u64 s, u64 e)
1513 {
1514         if (p->addr || s < start || s >= end)
1515                 return;
1516
1517         p->addr = s;
1518         p->offset = (s - start) + pgoff;
1519         p->len = e < end ? e - s : end - s;
1520 }
1521
1522 static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
1523 {
1524         struct kcore_copy_info *kci = data;
1525         u64 end = start + len;
1526
1527         kcore_copy__map(&kci->kernel_map, start, end, pgoff, kci->stext,
1528                         kci->etext);
1529
1530         kcore_copy__map(&kci->modules_map, start, end, pgoff, kci->first_module,
1531                         kci->last_module_symbol);
1532
1533         return 0;
1534 }
1535
1536 static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
1537 {
1538         if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
1539                 return -1;
1540
1541         return 0;
1542 }
1543
1544 static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
1545                                  Elf *elf)
1546 {
1547         if (kcore_copy__parse_kallsyms(kci, dir))
1548                 return -1;
1549
1550         if (kcore_copy__parse_modules(kci, dir))
1551                 return -1;
1552
1553         if (kci->stext)
1554                 kci->stext = round_down(kci->stext, page_size);
1555         else
1556                 kci->stext = round_down(kci->first_symbol, page_size);
1557
1558         if (kci->etext) {
1559                 kci->etext = round_up(kci->etext, page_size);
1560         } else if (kci->last_symbol) {
1561                 kci->etext = round_up(kci->last_symbol, page_size);
1562                 kci->etext += page_size;
1563         }
1564
1565         if (kci->first_module_symbol &&
1566             (!kci->first_module || kci->first_module_symbol < kci->first_module))
1567                 kci->first_module = kci->first_module_symbol;
1568
1569         kci->first_module = round_down(kci->first_module, page_size);
1570
1571         if (kci->last_module_symbol) {
1572                 kci->last_module_symbol = round_up(kci->last_module_symbol,
1573                                                    page_size);
1574                 kci->last_module_symbol += page_size;
1575         }
1576
1577         if (!kci->stext || !kci->etext)
1578                 return -1;
1579
1580         if (kci->first_module && !kci->last_module_symbol)
1581                 return -1;
1582
1583         return kcore_copy__read_maps(kci, elf);
1584 }
1585
1586 static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
1587                                  const char *name)
1588 {
1589         char from_filename[PATH_MAX];
1590         char to_filename[PATH_MAX];
1591
1592         scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1593         scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1594
1595         return copyfile_mode(from_filename, to_filename, 0400);
1596 }
1597
1598 static int kcore_copy__unlink(const char *dir, const char *name)
1599 {
1600         char filename[PATH_MAX];
1601
1602         scnprintf(filename, PATH_MAX, "%s/%s", dir, name);
1603
1604         return unlink(filename);
1605 }
1606
1607 static int kcore_copy__compare_fds(int from, int to)
1608 {
1609         char *buf_from;
1610         char *buf_to;
1611         ssize_t ret;
1612         size_t len;
1613         int err = -1;
1614
1615         buf_from = malloc(page_size);
1616         buf_to = malloc(page_size);
1617         if (!buf_from || !buf_to)
1618                 goto out;
1619
1620         while (1) {
1621                 /* Use read because mmap won't work on proc files */
1622                 ret = read(from, buf_from, page_size);
1623                 if (ret < 0)
1624                         goto out;
1625
1626                 if (!ret)
1627                         break;
1628
1629                 len = ret;
1630
1631                 if (readn(to, buf_to, len) != (int)len)
1632                         goto out;
1633
1634                 if (memcmp(buf_from, buf_to, len))
1635                         goto out;
1636         }
1637
1638         err = 0;
1639 out:
1640         free(buf_to);
1641         free(buf_from);
1642         return err;
1643 }
1644
1645 static int kcore_copy__compare_files(const char *from_filename,
1646                                      const char *to_filename)
1647 {
1648         int from, to, err = -1;
1649
1650         from = open(from_filename, O_RDONLY);
1651         if (from < 0)
1652                 return -1;
1653
1654         to = open(to_filename, O_RDONLY);
1655         if (to < 0)
1656                 goto out_close_from;
1657
1658         err = kcore_copy__compare_fds(from, to);
1659
1660         close(to);
1661 out_close_from:
1662         close(from);
1663         return err;
1664 }
1665
1666 static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
1667                                     const char *name)
1668 {
1669         char from_filename[PATH_MAX];
1670         char to_filename[PATH_MAX];
1671
1672         scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1673         scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1674
1675         return kcore_copy__compare_files(from_filename, to_filename);
1676 }
1677
1678 /**
1679  * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
1680  * @from_dir: from directory
1681  * @to_dir: to directory
1682  *
1683  * This function copies kallsyms, modules and kcore files from one directory to
1684  * another.  kallsyms and modules are copied entirely.  Only code segments are
1685  * copied from kcore.  It is assumed that two segments suffice: one for the
1686  * kernel proper and one for all the modules.  The code segments are determined
1687  * from kallsyms and modules files.  The kernel map starts at _stext or the
1688  * lowest function symbol, and ends at _etext or the highest function symbol.
1689  * The module map starts at the lowest module address and ends at the highest
1690  * module symbol.  Start addresses are rounded down to the nearest page.  End
1691  * addresses are rounded up to the nearest page.  An extra page is added to the
1692  * highest kernel symbol and highest module symbol to, hopefully, encompass that
1693  * symbol too.  Because it contains only code sections, the resulting kcore is
1694  * unusual.  One significant peculiarity is that the mapping (start -> pgoff)
1695  * is not the same for the kernel map and the modules map.  That happens because
1696  * the data is copied adjacently whereas the original kcore has gaps.  Finally,
1697  * kallsyms and modules files are compared with their copies to check that
1698  * modules have not been loaded or unloaded while the copies were taking place.
1699  *
1700  * Return: %0 on success, %-1 on failure.
1701  */
1702 int kcore_copy(const char *from_dir, const char *to_dir)
1703 {
1704         struct kcore kcore;
1705         struct kcore extract;
1706         size_t count = 2;
1707         int idx = 0, err = -1;
1708         off_t offset = page_size, sz, modules_offset = 0;
1709         struct kcore_copy_info kci = { .stext = 0, };
1710         char kcore_filename[PATH_MAX];
1711         char extract_filename[PATH_MAX];
1712
1713         if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
1714                 return -1;
1715
1716         if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
1717                 goto out_unlink_kallsyms;
1718
1719         scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
1720         scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);
1721
1722         if (kcore__open(&kcore, kcore_filename))
1723                 goto out_unlink_modules;
1724
1725         if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
1726                 goto out_kcore_close;
1727
1728         if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
1729                 goto out_kcore_close;
1730
1731         if (!kci.modules_map.addr)
1732                 count -= 1;
1733
1734         if (kcore__copy_hdr(&kcore, &extract, count))
1735                 goto out_extract_close;
1736
1737         if (kcore__add_phdr(&extract, idx++, offset, kci.kernel_map.addr,
1738                             kci.kernel_map.len))
1739                 goto out_extract_close;
1740
1741         if (kci.modules_map.addr) {
1742                 modules_offset = offset + kci.kernel_map.len;
1743                 if (kcore__add_phdr(&extract, idx, modules_offset,
1744                                     kci.modules_map.addr, kci.modules_map.len))
1745                         goto out_extract_close;
1746         }
1747
1748         sz = kcore__write(&extract);
1749         if (sz < 0 || sz > offset)
1750                 goto out_extract_close;
1751
1752         if (copy_bytes(kcore.fd, kci.kernel_map.offset, extract.fd, offset,
1753                        kci.kernel_map.len))
1754                 goto out_extract_close;
1755
1756         if (modules_offset && copy_bytes(kcore.fd, kci.modules_map.offset,
1757                                          extract.fd, modules_offset,
1758                                          kci.modules_map.len))
1759                 goto out_extract_close;
1760
1761         if (kcore_copy__compare_file(from_dir, to_dir, "modules"))
1762                 goto out_extract_close;
1763
1764         if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
1765                 goto out_extract_close;
1766
1767         err = 0;
1768
1769 out_extract_close:
1770         kcore__close(&extract);
1771         if (err)
1772                 unlink(extract_filename);
1773 out_kcore_close:
1774         kcore__close(&kcore);
1775 out_unlink_modules:
1776         if (err)
1777                 kcore_copy__unlink(to_dir, "modules");
1778 out_unlink_kallsyms:
1779         if (err)
1780                 kcore_copy__unlink(to_dir, "kallsyms");
1781
1782         return err;
1783 }
1784
1785 int kcore_extract__create(struct kcore_extract *kce)
1786 {
1787         struct kcore kcore;
1788         struct kcore extract;
1789         size_t count = 1;
1790         int idx = 0, err = -1;
1791         off_t offset = page_size, sz;
1792
1793         if (kcore__open(&kcore, kce->kcore_filename))
1794                 return -1;
1795
1796         strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
1797         if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
1798                 goto out_kcore_close;
1799
1800         if (kcore__copy_hdr(&kcore, &extract, count))
1801                 goto out_extract_close;
1802
1803         if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
1804                 goto out_extract_close;
1805
1806         sz = kcore__write(&extract);
1807         if (sz < 0 || sz > offset)
1808                 goto out_extract_close;
1809
1810         if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
1811                 goto out_extract_close;
1812
1813         err = 0;
1814
1815 out_extract_close:
1816         kcore__close(&extract);
1817         if (err)
1818                 unlink(kce->extract_filename);
1819 out_kcore_close:
1820         kcore__close(&kcore);
1821
1822         return err;
1823 }
1824
1825 void kcore_extract__delete(struct kcore_extract *kce)
1826 {
1827         unlink(kce->extract_filename);
1828 }
1829
1830 #ifdef HAVE_GELF_GETNOTE_SUPPORT
1831 /**
1832  * populate_sdt_note : Parse raw data and identify SDT note
1833  * @elf: elf of the opened file
1834  * @data: raw data of a section with description offset applied
1835  * @len: note description size
1836  * @type: type of the note
1837  * @sdt_notes: List to add the SDT note
1838  *
1839  * Responsible for parsing the @data in section .note.stapsdt in @elf and
1840  * if its an SDT note, it appends to @sdt_notes list.
1841  */
1842 static int populate_sdt_note(Elf **elf, const char *data, size_t len,
1843                              struct list_head *sdt_notes)
1844 {
1845         const char *provider, *name;
1846         struct sdt_note *tmp = NULL;
1847         GElf_Ehdr ehdr;
1848         GElf_Addr base_off = 0;
1849         GElf_Shdr shdr;
1850         int ret = -EINVAL;
1851
1852         union {
1853                 Elf64_Addr a64[NR_ADDR];
1854                 Elf32_Addr a32[NR_ADDR];
1855         } buf;
1856
1857         Elf_Data dst = {
1858                 .d_buf = &buf, .d_type = ELF_T_ADDR, .d_version = EV_CURRENT,
1859                 .d_size = gelf_fsize((*elf), ELF_T_ADDR, NR_ADDR, EV_CURRENT),
1860                 .d_off = 0, .d_align = 0
1861         };
1862         Elf_Data src = {
1863                 .d_buf = (void *) data, .d_type = ELF_T_ADDR,
1864                 .d_version = EV_CURRENT, .d_size = dst.d_size, .d_off = 0,
1865                 .d_align = 0
1866         };
1867
1868         tmp = (struct sdt_note *)calloc(1, sizeof(struct sdt_note));
1869         if (!tmp) {
1870                 ret = -ENOMEM;
1871                 goto out_err;
1872         }
1873
1874         INIT_LIST_HEAD(&tmp->note_list);
1875
1876         if (len < dst.d_size + 3)
1877                 goto out_free_note;
1878
1879         /* Translation from file representation to memory representation */
1880         if (gelf_xlatetom(*elf, &dst, &src,
1881                           elf_getident(*elf, NULL)[EI_DATA]) == NULL) {
1882                 pr_err("gelf_xlatetom : %s\n", elf_errmsg(-1));
1883                 goto out_free_note;
1884         }
1885
1886         /* Populate the fields of sdt_note */
1887         provider = data + dst.d_size;
1888
1889         name = (const char *)memchr(provider, '\0', data + len - provider);
1890         if (name++ == NULL)
1891                 goto out_free_note;
1892
1893         tmp->provider = strdup(provider);
1894         if (!tmp->provider) {
1895                 ret = -ENOMEM;
1896                 goto out_free_note;
1897         }
1898         tmp->name = strdup(name);
1899         if (!tmp->name) {
1900                 ret = -ENOMEM;
1901                 goto out_free_prov;
1902         }
1903
1904         if (gelf_getclass(*elf) == ELFCLASS32) {
1905                 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr));
1906                 tmp->bit32 = true;
1907         } else {
1908                 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf64_Addr));
1909                 tmp->bit32 = false;
1910         }
1911
1912         if (!gelf_getehdr(*elf, &ehdr)) {
1913                 pr_debug("%s : cannot get elf header.\n", __func__);
1914                 ret = -EBADF;
1915                 goto out_free_name;
1916         }
1917
1918         /* Adjust the prelink effect :
1919          * Find out the .stapsdt.base section.
1920          * This scn will help us to handle prelinking (if present).
1921          * Compare the retrieved file offset of the base section with the
1922          * base address in the description of the SDT note. If its different,
1923          * then accordingly, adjust the note location.
1924          */
1925         if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL)) {
1926                 base_off = shdr.sh_offset;
1927                 if (base_off) {
1928                         if (tmp->bit32)
1929                                 tmp->addr.a32[0] = tmp->addr.a32[0] + base_off -
1930                                         tmp->addr.a32[1];
1931                         else
1932                                 tmp->addr.a64[0] = tmp->addr.a64[0] + base_off -
1933                                         tmp->addr.a64[1];
1934                 }
1935         }
1936
1937         list_add_tail(&tmp->note_list, sdt_notes);
1938         return 0;
1939
1940 out_free_name:
1941         free(tmp->name);
1942 out_free_prov:
1943         free(tmp->provider);
1944 out_free_note:
1945         free(tmp);
1946 out_err:
1947         return ret;
1948 }
1949
1950 /**
1951  * construct_sdt_notes_list : constructs a list of SDT notes
1952  * @elf : elf to look into
1953  * @sdt_notes : empty list_head
1954  *
1955  * Scans the sections in 'elf' for the section
1956  * .note.stapsdt. It, then calls populate_sdt_note to find
1957  * out the SDT events and populates the 'sdt_notes'.
1958  */
1959 static int construct_sdt_notes_list(Elf *elf, struct list_head *sdt_notes)
1960 {
1961         GElf_Ehdr ehdr;
1962         Elf_Scn *scn = NULL;
1963         Elf_Data *data;
1964         GElf_Shdr shdr;
1965         size_t shstrndx, next;
1966         GElf_Nhdr nhdr;
1967         size_t name_off, desc_off, offset;
1968         int ret = 0;
1969
1970         if (gelf_getehdr(elf, &ehdr) == NULL) {
1971                 ret = -EBADF;
1972                 goto out_ret;
1973         }
1974         if (elf_getshdrstrndx(elf, &shstrndx) != 0) {
1975                 ret = -EBADF;
1976                 goto out_ret;
1977         }
1978
1979         /* Look for the required section */
1980         scn = elf_section_by_name(elf, &ehdr, &shdr, SDT_NOTE_SCN, NULL);
1981         if (!scn) {
1982                 ret = -ENOENT;
1983                 goto out_ret;
1984         }
1985
1986         if ((shdr.sh_type != SHT_NOTE) || (shdr.sh_flags & SHF_ALLOC)) {
1987                 ret = -ENOENT;
1988                 goto out_ret;
1989         }
1990
1991         data = elf_getdata(scn, NULL);
1992
1993         /* Get the SDT notes */
1994         for (offset = 0; (next = gelf_getnote(data, offset, &nhdr, &name_off,
1995                                               &desc_off)) > 0; offset = next) {
1996                 if (nhdr.n_namesz == sizeof(SDT_NOTE_NAME) &&
1997                     !memcmp(data->d_buf + name_off, SDT_NOTE_NAME,
1998                             sizeof(SDT_NOTE_NAME))) {
1999                         /* Check the type of the note */
2000                         if (nhdr.n_type != SDT_NOTE_TYPE)
2001                                 goto out_ret;
2002
2003                         ret = populate_sdt_note(&elf, ((data->d_buf) + desc_off),
2004                                                 nhdr.n_descsz, sdt_notes);
2005                         if (ret < 0)
2006                                 goto out_ret;
2007                 }
2008         }
2009         if (list_empty(sdt_notes))
2010                 ret = -ENOENT;
2011
2012 out_ret:
2013         return ret;
2014 }
2015
2016 /**
2017  * get_sdt_note_list : Wrapper to construct a list of sdt notes
2018  * @head : empty list_head
2019  * @target : file to find SDT notes from
2020  *
2021  * This opens the file, initializes
2022  * the ELF and then calls construct_sdt_notes_list.
2023  */
2024 int get_sdt_note_list(struct list_head *head, const char *target)
2025 {
2026         Elf *elf;
2027         int fd, ret;
2028
2029         fd = open(target, O_RDONLY);
2030         if (fd < 0)
2031                 return -EBADF;
2032
2033         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
2034         if (!elf) {
2035                 ret = -EBADF;
2036                 goto out_close;
2037         }
2038         ret = construct_sdt_notes_list(elf, head);
2039         elf_end(elf);
2040 out_close:
2041         close(fd);
2042         return ret;
2043 }
2044
2045 /**
2046  * cleanup_sdt_note_list : free the sdt notes' list
2047  * @sdt_notes: sdt notes' list
2048  *
2049  * Free up the SDT notes in @sdt_notes.
2050  * Returns the number of SDT notes free'd.
2051  */
2052 int cleanup_sdt_note_list(struct list_head *sdt_notes)
2053 {
2054         struct sdt_note *tmp, *pos;
2055         int nr_free = 0;
2056
2057         list_for_each_entry_safe(pos, tmp, sdt_notes, note_list) {
2058                 list_del(&pos->note_list);
2059                 free(pos->name);
2060                 free(pos->provider);
2061                 free(pos);
2062                 nr_free++;
2063         }
2064         return nr_free;
2065 }
2066
2067 /**
2068  * sdt_notes__get_count: Counts the number of sdt events
2069  * @start: list_head to sdt_notes list
2070  *
2071  * Returns the number of SDT notes in a list
2072  */
2073 int sdt_notes__get_count(struct list_head *start)
2074 {
2075         struct sdt_note *sdt_ptr;
2076         int count = 0;
2077
2078         list_for_each_entry(sdt_ptr, start, note_list)
2079                 count++;
2080         return count;
2081 }
2082 #endif
2083
2084 void symbol__elf_init(void)
2085 {
2086         elf_version(EV_CURRENT);
2087 }