tools/perf/util/symbol-elf.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <fcntl.h>
   3 #include <stdio.h>
   4 #include <errno.h>
   5 #include <string.h>
   6 #include <unistd.h>
   7 #include <inttypes.h>
   8
   9 #include "symbol.h"
  10 #include "demangle-java.h"
  11 #include "demangle-rust.h"
  12 #include "machine.h"
  13 #include "vdso.h"
  14 #include "debug.h"
  15 #include "sane_ctype.h"
  16 #include <symbol/kallsyms.h>
  17
  18 #ifndef EM_AARCH64
  19 #define EM_AARCH64      183  /* ARM 64 bit */
  20 #endif
  21
  22 typedef Elf64_Nhdr GElf_Nhdr;
  23
  24 #ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
  25 extern char *cplus_demangle(const char *, int);
  26
  27 static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
  28 {
  29         return cplus_demangle(c, i);
  30 }
  31 #else
  32 #ifdef NO_DEMANGLE
  33 static inline char *bfd_demangle(void __maybe_unused *v,
  34                                  const char __maybe_unused *c,
  35                                  int __maybe_unused i)
  36 {
  37         return NULL;
  38 }
  39 #else
  40 #define PACKAGE 'perf'
  41 #include <bfd.h>
  42 #endif
  43 #endif
  44
  45 #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
  46 static int elf_getphdrnum(Elf *elf, size_t *dst)
  47 {
  48         GElf_Ehdr gehdr;
  49         GElf_Ehdr *ehdr;
  50
  51         ehdr = gelf_getehdr(elf, &gehdr);
  52         if (!ehdr)
  53                 return -1;
  54
  55         *dst = ehdr->e_phnum;
  56
  57         return 0;
  58 }
  59 #endif
  60
  61 #ifndef HAVE_ELF_GETSHDRSTRNDX_SUPPORT
  62 static int elf_getshdrstrndx(Elf *elf __maybe_unused, size_t *dst __maybe_unused)
  63 {
  64         pr_err("%s: update your libelf to > 0.140, this one lacks elf_getshdrstrndx().\n", __func__);
  65         return -1;
  66 }
  67 #endif
  68
  69 #ifndef NT_GNU_BUILD_ID
  70 #define NT_GNU_BUILD_ID 3
  71 #endif
  72
  73 /**
  74  * elf_symtab__for_each_symbol - iterate thru all the symbols
  75  *
  76  * @syms: struct elf_symtab instance to iterate
  77  * @idx: uint32_t idx
  78  * @sym: GElf_Sym iterator
  79  */
  80 #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
  81         for (idx = 0, gelf_getsym(syms, idx, &sym);\
  82              idx < nr_syms; \
  83              idx++, gelf_getsym(syms, idx, &sym))
  84
  85 static inline uint8_t elf_sym__type(const GElf_Sym *sym)
  86 {
  87         return GELF_ST_TYPE(sym->st_info);
  88 }
  89
  90 #ifndef STT_GNU_IFUNC
  91 #define STT_GNU_IFUNC 10
  92 #endif
  93
  94 static inline int elf_sym__is_function(const GElf_Sym *sym)
  95 {
  96         return (elf_sym__type(sym) == STT_FUNC ||
  97                 elf_sym__type(sym) == STT_GNU_IFUNC) &&
  98                sym->st_name != 0 &&
  99                sym->st_shndx != SHN_UNDEF;
 100 }
 101
 102 static inline bool elf_sym__is_object(const GElf_Sym *sym)
 103 {
 104         return elf_sym__type(sym) == STT_OBJECT &&
 105                 sym->st_name != 0 &&
 106                 sym->st_shndx != SHN_UNDEF;
 107 }
 108
 109 static inline int elf_sym__is_label(const GElf_Sym *sym)
 110 {
 111         return elf_sym__type(sym) == STT_NOTYPE &&
 112                 sym->st_name != 0 &&
 113                 sym->st_shndx != SHN_UNDEF &&
 114                 sym->st_shndx != SHN_ABS;
 115 }
 116
 117 static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
 118 {
 119         switch (type) {
 120         case MAP__FUNCTION:
 121                 return elf_sym__is_function(sym);
 122         case MAP__VARIABLE:
 123                 return elf_sym__is_object(sym);
 124         default:
 125                 return false;
 126         }
 127 }
 128
 129 static inline const char *elf_sym__name(const GElf_Sym *sym,
 130                                         const Elf_Data *symstrs)
 131 {
 132         return symstrs->d_buf + sym->st_name;
 133 }
 134
 135 static inline const char *elf_sec__name(const GElf_Shdr *shdr,
 136                                         const Elf_Data *secstrs)
 137 {
 138         return secstrs->d_buf + shdr->sh_name;
 139 }
 140
 141 static inline int elf_sec__is_text(const GElf_Shdr *shdr,
 142                                         const Elf_Data *secstrs)
 143 {
 144         return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
 145 }
 146
 147 static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
 148                                     const Elf_Data *secstrs)
 149 {
 150         return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
 151 }
 152
 153 static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs,
 154                           enum map_type type)
 155 {
 156         switch (type) {
 157         case MAP__FUNCTION:
 158                 return elf_sec__is_text(shdr, secstrs);
 159         case MAP__VARIABLE:
 160                 return elf_sec__is_data(shdr, secstrs);
 161         default:
 162                 return false;
 163         }
 164 }
 165
 166 static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
 167 {
 168         Elf_Scn *sec = NULL;
 169         GElf_Shdr shdr;
 170         size_t cnt = 1;
 171
 172         while ((sec = elf_nextscn(elf, sec)) != NULL) {
 173                 gelf_getshdr(sec, &shdr);
 174
 175                 if ((addr >= shdr.sh_addr) &&
 176                     (addr < (shdr.sh_addr + shdr.sh_size)))
 177                         return cnt;
 178
 179                 ++cnt;
 180         }
 181
 182         return -1;
 183 }
 184
 185 Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
 186                              GElf_Shdr *shp, const char *name, size_t *idx)
 187 {
 188         Elf_Scn *sec = NULL;
 189         size_t cnt = 1;
 190
 191         /* Elf is corrupted/truncated, avoid calling elf_strptr. */
 192         if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
 193                 return NULL;
 194
 195         while ((sec = elf_nextscn(elf, sec)) != NULL) {
 196                 char *str;
 197
 198                 gelf_getshdr(sec, shp);
 199                 str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
 200                 if (str && !strcmp(name, str)) {
 201                         if (idx)
 202                                 *idx = cnt;
 203                         return sec;
 204                 }
 205                 ++cnt;
 206         }
 207
 208         return NULL;
 209 }
 210
 211 static bool want_demangle(bool is_kernel_sym)
 212 {
 213         return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
 214 }
 215
 216 static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
 217 {
 218         int demangle_flags = verbose > 0 ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS;
 219         char *demangled = NULL;
 220
 221         /*
 222          * We need to figure out if the object was created from C++ sources
 223          * DWARF DW_compile_unit has this, but we don't always have access
 224          * to it...
 225          */
 226         if (!want_demangle(dso->kernel || kmodule))
 227             return demangled;
 228
 229         demangled = bfd_demangle(NULL, elf_name, demangle_flags);
 230         if (demangled == NULL)
 231                 demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);
 232         else if (rust_is_mangled(demangled))
 233                 /*
 234                     * Input to Rust demangling is the BFD-demangled
 235                     * name which it Rust-demangles in place.
 236                     */
 237                 rust_demangle_sym(demangled);
 238
 239         return demangled;
 240 }
 241
 242 #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
 243         for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
 244              idx < nr_entries; \
 245              ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
 246
 247 #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
 248         for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
 249              idx < nr_entries; \
 250              ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
 251
 252 /*
 253  * We need to check if we have a .dynsym, so that we can handle the
 254  * .plt, synthesizing its symbols, that aren't on the symtabs (be it
 255  * .dynsym or .symtab).
 256  * And always look at the original dso, not at debuginfo packages, that
 257  * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
 258  */
 259 int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map)
 260 {
 261         uint32_t nr_rel_entries, idx;
 262         GElf_Sym sym;
 263         u64 plt_offset, plt_header_size, plt_entry_size;
 264         GElf_Shdr shdr_plt;
 265         struct symbol *f;
 266         GElf_Shdr shdr_rel_plt, shdr_dynsym;
 267         Elf_Data *reldata, *syms, *symstrs;
 268         Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
 269         size_t dynsym_idx;
 270         GElf_Ehdr ehdr;
 271         char sympltname[1024];
 272         Elf *elf;
 273         int nr = 0, symidx, err = 0;
 274
 275         if (!ss->dynsym)
 276                 return 0;
 277
 278         elf = ss->elf;
 279         ehdr = ss->ehdr;
 280
 281         scn_dynsym = ss->dynsym;
 282         shdr_dynsym = ss->dynshdr;
 283         dynsym_idx = ss->dynsym_idx;
 284
 285         if (scn_dynsym == NULL)
 286                 goto out_elf_end;
 287
 288         scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
 289                                           ".rela.plt", NULL);
 290         if (scn_plt_rel == NULL) {
 291                 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
 292                                                   ".rel.plt", NULL);
 293                 if (scn_plt_rel == NULL)
 294                         goto out_elf_end;
 295         }
 296
 297         err = -1;
 298
 299         if (shdr_rel_plt.sh_link != dynsym_idx)
 300                 goto out_elf_end;
 301
 302         if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
 303                 goto out_elf_end;
 304
 305         /*
 306          * Fetch the relocation section to find the idxes to the GOT
 307          * and the symbols in the .dynsym they refer to.
 308          */
 309         reldata = elf_getdata(scn_plt_rel, NULL);
 310         if (reldata == NULL)
 311                 goto out_elf_end;
 312
 313         syms = elf_getdata(scn_dynsym, NULL);
 314         if (syms == NULL)
 315                 goto out_elf_end;
 316
 317         scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
 318         if (scn_symstrs == NULL)
 319                 goto out_elf_end;
 320
 321         symstrs = elf_getdata(scn_symstrs, NULL);
 322         if (symstrs == NULL)
 323                 goto out_elf_end;
 324
 325         if (symstrs->d_size == 0)
 326                 goto out_elf_end;
 327
 328         nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
 329         plt_offset = shdr_plt.sh_offset;
 330         switch (ehdr.e_machine) {
 331                 case EM_ARM:
 332                         plt_header_size = 20;
 333                         plt_entry_size = 12;
 334                         break;
 335
 336                 case EM_AARCH64:
 337                         plt_header_size = 32;
 338                         plt_entry_size = 16;
 339                         break;
 340
 341                 default: /* FIXME: s390/alpha/mips/parisc/poperpc/sh/sparc/xtensa need to be checked */
 342                         plt_header_size = shdr_plt.sh_entsize;
 343                         plt_entry_size = shdr_plt.sh_entsize;
 344                         break;
 345         }
 346         plt_offset += plt_header_size;
 347
 348         if (shdr_rel_plt.sh_type == SHT_RELA) {
 349                 GElf_Rela pos_mem, *pos;
 350
 351                 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
 352                                            nr_rel_entries) {
 353                         const char *elf_name = NULL;
 354                         char *demangled = NULL;
 355                         symidx = GELF_R_SYM(pos->r_info);
 356                         gelf_getsym(syms, symidx, &sym);
 357
 358                         elf_name = elf_sym__name(&sym, symstrs);
 359                         demangled = demangle_sym(dso, 0, elf_name);
 360                         if (demangled != NULL)
 361                                 elf_name = demangled;
 362                         snprintf(sympltname, sizeof(sympltname),
 363                                  "%s@plt", elf_name);
 364                         free(demangled);
 365
 366                         f = symbol__new(plt_offset, plt_entry_size,
 367                                         STB_GLOBAL, sympltname);
 368                         if (!f)
 369                                 goto out_elf_end;
 370
 371                         plt_offset += plt_entry_size;
 372                         symbols__insert(&dso->symbols[map->type], f);
 373                         ++nr;
 374                 }
 375         } else if (shdr_rel_plt.sh_type == SHT_REL) {
 376                 GElf_Rel pos_mem, *pos;
 377                 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
 378                                           nr_rel_entries) {
 379                         const char *elf_name = NULL;
 380                         char *demangled = NULL;
 381                         symidx = GELF_R_SYM(pos->r_info);
 382                         gelf_getsym(syms, symidx, &sym);
 383
 384                         elf_name = elf_sym__name(&sym, symstrs);
 385                         demangled = demangle_sym(dso, 0, elf_name);
 386                         if (demangled != NULL)
 387                                 elf_name = demangled;
 388                         snprintf(sympltname, sizeof(sympltname),
 389                                  "%s@plt", elf_name);
 390                         free(demangled);
 391
 392                         f = symbol__new(plt_offset, plt_entry_size,
 393                                         STB_GLOBAL, sympltname);
 394                         if (!f)
 395                                 goto out_elf_end;
 396
 397                         plt_offset += plt_entry_size;
 398                         symbols__insert(&dso->symbols[map->type], f);
 399                         ++nr;
 400                 }
 401         }
 402
 403         err = 0;
 404 out_elf_end:
 405         if (err == 0)
 406                 return nr;
 407         pr_debug("%s: problems reading %s PLT info.\n",
 408                  __func__, dso->long_name);
 409         return 0;
 410 }
 411
 412 char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
 413 {
 414         return demangle_sym(dso, kmodule, elf_name);
 415 }
 416
 417 /*
 418  * Align offset to 4 bytes as needed for note name and descriptor data.
 419  */
 420 #define NOTE_ALIGN(n) (((n) + 3) & -4U)
 421
 422 static int elf_read_build_id(Elf *elf, void *bf, size_t size)
 423 {
 424         int err = -1;
 425         GElf_Ehdr ehdr;
 426         GElf_Shdr shdr;
 427         Elf_Data *data;
 428         Elf_Scn *sec;
 429         Elf_Kind ek;
 430         void *ptr;
 431
 432         if (size < BUILD_ID_SIZE)
 433                 goto out;
 434
 435         ek = elf_kind(elf);
 436         if (ek != ELF_K_ELF)
 437                 goto out;
 438
 439         if (gelf_getehdr(elf, &ehdr) == NULL) {
 440                 pr_err("%s: cannot get elf header.\n", __func__);
 441                 goto out;
 442         }
 443
 444         /*
 445          * Check following sections for notes:
 446          *   '.note.gnu.build-id'
 447          *   '.notes'
 448          *   '.note' (VDSO specific)
 449          */
 450         do {
 451                 sec = elf_section_by_name(elf, &ehdr, &shdr,
 452                                           ".note.gnu.build-id", NULL);
 453                 if (sec)
 454                         break;
 455
 456                 sec = elf_section_by_name(elf, &ehdr, &shdr,
 457                                           ".notes", NULL);
 458                 if (sec)
 459                         break;
 460
 461                 sec = elf_section_by_name(elf, &ehdr, &shdr,
 462                                           ".note", NULL);
 463                 if (sec)
 464                         break;
 465
 466                 return err;
 467
 468         } while (0);
 469
 470         data = elf_getdata(sec, NULL);
 471         if (data == NULL)
 472                 goto out;
 473
 474         ptr = data->d_buf;
 475         while (ptr < (data->d_buf + data->d_size)) {
 476                 GElf_Nhdr *nhdr = ptr;
 477                 size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
 478                        descsz = NOTE_ALIGN(nhdr->n_descsz);
 479                 const char *name;
 480
 481                 ptr += sizeof(*nhdr);
 482                 name = ptr;
 483                 ptr += namesz;
 484                 if (nhdr->n_type == NT_GNU_BUILD_ID &&
 485                     nhdr->n_namesz == sizeof("GNU")) {
 486                         if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
 487                                 size_t sz = min(size, descsz);
 488                                 memcpy(bf, ptr, sz);
 489                                 memset(bf + sz, 0, size - sz);
 490                                 err = descsz;
 491                                 break;
 492                         }
 493                 }
 494                 ptr += descsz;
 495         }
 496
 497 out:
 498         return err;
 499 }
 500
 501 int filename__read_build_id(const char *filename, void *bf, size_t size)
 502 {
 503         int fd, err = -1;
 504         Elf *elf;
 505
 506         if (size < BUILD_ID_SIZE)
 507                 goto out;
 508
 509         fd = open(filename, O_RDONLY);
 510         if (fd < 0)
 511                 goto out;
 512
 513         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
 514         if (elf == NULL) {
 515                 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
 516                 goto out_close;
 517         }
 518
 519         err = elf_read_build_id(elf, bf, size);
 520
 521         elf_end(elf);
 522 out_close:
 523         close(fd);
 524 out:
 525         return err;
 526 }
 527
 528 int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
 529 {
 530         int fd, err = -1;
 531
 532         if (size < BUILD_ID_SIZE)
 533                 goto out;
 534
 535         fd = open(filename, O_RDONLY);
 536         if (fd < 0)
 537                 goto out;
 538
 539         while (1) {
 540                 char bf[BUFSIZ];
 541                 GElf_Nhdr nhdr;
 542                 size_t namesz, descsz;
 543
 544                 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
 545                         break;
 546
 547                 namesz = NOTE_ALIGN(nhdr.n_namesz);
 548                 descsz = NOTE_ALIGN(nhdr.n_descsz);
 549                 if (nhdr.n_type == NT_GNU_BUILD_ID &&
 550                     nhdr.n_namesz == sizeof("GNU")) {
 551                         if (read(fd, bf, namesz) != (ssize_t)namesz)
 552                                 break;
 553                         if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
 554                                 size_t sz = min(descsz, size);
 555                                 if (read(fd, build_id, sz) == (ssize_t)sz) {
 556                                         memset(build_id + sz, 0, size - sz);
 557                                         err = 0;
 558                                         break;
 559                                 }
 560                         } else if (read(fd, bf, descsz) != (ssize_t)descsz)
 561                                 break;
 562                 } else {
 563                         int n = namesz + descsz;
 564
 565                         if (n > (int)sizeof(bf)) {
 566                                 n = sizeof(bf);
 567                                 pr_debug("%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n",
 568                                          __func__, filename, nhdr.n_namesz, nhdr.n_descsz);
 569                         }
 570                         if (read(fd, bf, n) != n)
 571                                 break;
 572                 }
 573         }
 574         close(fd);
 575 out:
 576         return err;
 577 }
 578
 579 int filename__read_debuglink(const char *filename, char *debuglink,
 580                              size_t size)
 581 {
 582         int fd, err = -1;
 583         Elf *elf;
 584         GElf_Ehdr ehdr;
 585         GElf_Shdr shdr;
 586         Elf_Data *data;
 587         Elf_Scn *sec;
 588         Elf_Kind ek;
 589
 590         fd = open(filename, O_RDONLY);
 591         if (fd < 0)
 592                 goto out;
 593
 594         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
 595         if (elf == NULL) {
 596                 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
 597                 goto out_close;
 598         }
 599
 600         ek = elf_kind(elf);
 601         if (ek != ELF_K_ELF)
 602                 goto out_elf_end;
 603
 604         if (gelf_getehdr(elf, &ehdr) == NULL) {
 605                 pr_err("%s: cannot get elf header.\n", __func__);
 606                 goto out_elf_end;
 607         }
 608
 609         sec = elf_section_by_name(elf, &ehdr, &shdr,
 610                                   ".gnu_debuglink", NULL);
 611         if (sec == NULL)
 612                 goto out_elf_end;
 613
 614         data = elf_getdata(sec, NULL);
 615         if (data == NULL)
 616                 goto out_elf_end;
 617
 618         /* the start of this section is a zero-terminated string */
 619         strncpy(debuglink, data->d_buf, size);
 620
 621         err = 0;
 622
 623 out_elf_end:
 624         elf_end(elf);
 625 out_close:
 626         close(fd);
 627 out:
 628         return err;
 629 }
 630
 631 static int dso__swap_init(struct dso *dso, unsigned char eidata)
 632 {
 633         static unsigned int const endian = 1;
 634
 635         dso->needs_swap = DSO_SWAP__NO;
 636
 637         switch (eidata) {
 638         case ELFDATA2LSB:
 639                 /* We are big endian, DSO is little endian. */
 640                 if (*(unsigned char const *)&endian != 1)
 641                         dso->needs_swap = DSO_SWAP__YES;
 642                 break;
 643
 644         case ELFDATA2MSB:
 645                 /* We are little endian, DSO is big endian. */
 646                 if (*(unsigned char const *)&endian != 0)
 647                         dso->needs_swap = DSO_SWAP__YES;
 648                 break;
 649
 650         default:
 651                 pr_err("unrecognized DSO data encoding %d\n", eidata);
 652                 return -EINVAL;
 653         }
 654
 655         return 0;
 656 }
 657
 658 bool symsrc__possibly_runtime(struct symsrc *ss)
 659 {
 660         return ss->dynsym || ss->opdsec;
 661 }
 662
 663 bool symsrc__has_symtab(struct symsrc *ss)
 664 {
 665         return ss->symtab != NULL;
 666 }
 667
 668 void symsrc__destroy(struct symsrc *ss)
 669 {
 670         zfree(&ss->name);
 671         elf_end(ss->elf);
 672         close(ss->fd);
 673 }
 674
 675 bool __weak elf__needs_adjust_symbols(GElf_Ehdr ehdr)
 676 {
 677         return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL;
 678 }
 679
 680 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
 681                  enum dso_binary_type type)
 682 {
 683         int err = -1;
 684         GElf_Ehdr ehdr;
 685         Elf *elf;
 686         int fd;
 687
 688         if (dso__needs_decompress(dso)) {
 689                 fd = dso__decompress_kmodule_fd(dso, name);
 690                 if (fd < 0)
 691                         return -1;
 692
 693                 type = dso->symtab_type;
 694         } else {
 695                 fd = open(name, O_RDONLY);
 696                 if (fd < 0) {
 697                         dso->load_errno = errno;
 698                         return -1;
 699                 }
 700         }
 701
 702         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
 703         if (elf == NULL) {
 704                 pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
 705                 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
 706                 goto out_close;
 707         }
 708
 709         if (gelf_getehdr(elf, &ehdr) == NULL) {
 710                 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
 711                 pr_debug("%s: cannot get elf header.\n", __func__);
 712                 goto out_elf_end;
 713         }
 714
 715         if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) {
 716                 dso->load_errno = DSO_LOAD_ERRNO__INTERNAL_ERROR;
 717                 goto out_elf_end;
 718         }
 719
 720         /* Always reject images with a mismatched build-id: */
 721         if (dso->has_build_id && !symbol_conf.ignore_vmlinux_buildid) {
 722                 u8 build_id[BUILD_ID_SIZE];
 723
 724                 if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) {
 725                         dso->load_errno = DSO_LOAD_ERRNO__CANNOT_READ_BUILDID;
 726                         goto out_elf_end;
 727                 }
 728
 729                 if (!dso__build_id_equal(dso, build_id)) {
 730                         pr_debug("%s: build id mismatch for %s.\n", __func__, name);
 731                         dso->load_errno = DSO_LOAD_ERRNO__MISMATCHING_BUILDID;
 732                         goto out_elf_end;
 733                 }
 734         }
 735
 736         ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
 737
 738         ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
 739                         NULL);
 740         if (ss->symshdr.sh_type != SHT_SYMTAB)
 741                 ss->symtab = NULL;
 742
 743         ss->dynsym_idx = 0;
 744         ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
 745                         &ss->dynsym_idx);
 746         if (ss->dynshdr.sh_type != SHT_DYNSYM)
 747                 ss->dynsym = NULL;
 748
 749         ss->opdidx = 0;
 750         ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
 751                         &ss->opdidx);
 752         if (ss->opdshdr.sh_type != SHT_PROGBITS)
 753                 ss->opdsec = NULL;
 754
 755         if (dso->kernel == DSO_TYPE_USER)
 756                 ss->adjust_symbols = true;
 757         else
 758                 ss->adjust_symbols = elf__needs_adjust_symbols(ehdr);
 759
 760         ss->name   = strdup(name);
 761         if (!ss->name) {
 762                 dso->load_errno = errno;
 763                 goto out_elf_end;
 764         }
 765
 766         ss->elf    = elf;
 767         ss->fd     = fd;
 768         ss->ehdr   = ehdr;
 769         ss->type   = type;
 770
 771         return 0;
 772
 773 out_elf_end:
 774         elf_end(elf);
 775 out_close:
 776         close(fd);
 777         return err;
 778 }
 779
 780 /**
 781  * ref_reloc_sym_not_found - has kernel relocation symbol been found.
 782  * @kmap: kernel maps and relocation reference symbol
 783  *
 784  * This function returns %true if we are dealing with the kernel maps and the
 785  * relocation reference symbol has not yet been found.  Otherwise %false is
 786  * returned.
 787  */
 788 static bool ref_reloc_sym_not_found(struct kmap *kmap)
 789 {
 790         return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
 791                !kmap->ref_reloc_sym->unrelocated_addr;
 792 }
 793
 794 /**
 795  * ref_reloc - kernel relocation offset.
 796  * @kmap: kernel maps and relocation reference symbol
 797  *
 798  * This function returns the offset of kernel addresses as determined by using
 799  * the relocation reference symbol i.e. if the kernel has not been relocated
 800  * then the return value is zero.
 801  */
 802 static u64 ref_reloc(struct kmap *kmap)
 803 {
 804         if (kmap && kmap->ref_reloc_sym &&
 805             kmap->ref_reloc_sym->unrelocated_addr)
 806                 return kmap->ref_reloc_sym->addr -
 807                        kmap->ref_reloc_sym->unrelocated_addr;
 808         return 0;
 809 }
 810
 811 void __weak arch__sym_update(struct symbol *s __maybe_unused,
 812                 GElf_Sym *sym __maybe_unused) { }
 813
 814 int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
 815                   struct symsrc *runtime_ss, int kmodule)
 816 {
 817         struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
 818         struct map_groups *kmaps = kmap ? map__kmaps(map) : NULL;
 819         struct map *curr_map = map;
 820         struct dso *curr_dso = dso;
 821         Elf_Data *symstrs, *secstrs;
 822         uint32_t nr_syms;
 823         int err = -1;
 824         uint32_t idx;
 825         GElf_Ehdr ehdr;
 826         GElf_Shdr shdr;
 827         GElf_Shdr tshdr;
 828         Elf_Data *syms, *opddata = NULL;
 829         GElf_Sym sym;
 830         Elf_Scn *sec, *sec_strndx;
 831         Elf *elf;
 832         int nr = 0;
 833         bool remap_kernel = false, adjust_kernel_syms = false;
 834
 835         if (kmap && !kmaps)
 836                 return -1;
 837
 838         dso->symtab_type = syms_ss->type;
 839         dso->is_64_bit = syms_ss->is_64_bit;
 840         dso->rel = syms_ss->ehdr.e_type == ET_REL;
 841
 842         /*
 843          * Modules may already have symbols from kallsyms, but those symbols
 844          * have the wrong values for the dso maps, so remove them.
 845          */
 846         if (kmodule && syms_ss->symtab)
 847                 symbols__delete(&dso->symbols[map->type]);
 848
 849         if (!syms_ss->symtab) {
 850                 /*
 851                  * If the vmlinux is stripped, fail so we will fall back
 852                  * to using kallsyms. The vmlinux runtime symbols aren't
 853                  * of much use.
 854                  */
 855                 if (dso->kernel)
 856                         goto out_elf_end;
 857
 858                 syms_ss->symtab  = syms_ss->dynsym;
 859                 syms_ss->symshdr = syms_ss->dynshdr;
 860         }
 861
 862         elf = syms_ss->elf;
 863         ehdr = syms_ss->ehdr;
 864         sec = syms_ss->symtab;
 865         shdr = syms_ss->symshdr;
 866
 867         if (elf_section_by_name(runtime_ss->elf, &runtime_ss->ehdr, &tshdr,
 868                                 ".text", NULL))
 869                 dso->text_offset = tshdr.sh_addr - tshdr.sh_offset;
 870
 871         if (runtime_ss->opdsec)
 872                 opddata = elf_rawdata(runtime_ss->opdsec, NULL);
 873
 874         syms = elf_getdata(sec, NULL);
 875         if (syms == NULL)
 876                 goto out_elf_end;
 877
 878         sec = elf_getscn(elf, shdr.sh_link);
 879         if (sec == NULL)
 880                 goto out_elf_end;
 881
 882         symstrs = elf_getdata(sec, NULL);
 883         if (symstrs == NULL)
 884                 goto out_elf_end;
 885
 886         sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx);
 887         if (sec_strndx == NULL)
 888                 goto out_elf_end;
 889
 890         secstrs = elf_getdata(sec_strndx, NULL);
 891         if (secstrs == NULL)
 892                 goto out_elf_end;
 893
 894         nr_syms = shdr.sh_size / shdr.sh_entsize;
 895
 896         memset(&sym, 0, sizeof(sym));
 897
 898         /*
 899          * The kernel relocation symbol is needed in advance in order to adjust
 900          * kernel maps correctly.
 901          */
 902         if (ref_reloc_sym_not_found(kmap)) {
 903                 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
 904                         const char *elf_name = elf_sym__name(&sym, symstrs);
 905
 906                         if (strcmp(elf_name, kmap->ref_reloc_sym->name))
 907                                 continue;
 908                         kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
 909                         map->reloc = kmap->ref_reloc_sym->addr -
 910                                      kmap->ref_reloc_sym->unrelocated_addr;
 911                         break;
 912                 }
 913         }
 914
 915         /*
 916          * Handle any relocation of vdso necessary because older kernels
 917          * attempted to prelink vdso to its virtual address.
 918          */
 919         if (dso__is_vdso(dso))
 920                 map->reloc = map->start - dso->text_offset;
 921
 922         dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
 923         /*
 924          * Initial kernel and module mappings do not map to the dso.  For
 925          * function mappings, flag the fixups.
 926          */
 927         if (map->type == MAP__FUNCTION && (dso->kernel || kmodule)) {
 928                 remap_kernel = true;
 929                 adjust_kernel_syms = dso->adjust_symbols;
 930         }
 931         elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
 932                 struct symbol *f;
 933                 const char *elf_name = elf_sym__name(&sym, symstrs);
 934                 char *demangled = NULL;
 935                 int is_label = elf_sym__is_label(&sym);
 936                 const char *section_name;
 937                 bool used_opd = false;
 938
 939                 if (!is_label && !elf_sym__is_a(&sym, map->type))
 940                         continue;
 941
 942                 /* Reject ARM ELF "mapping symbols": these aren't unique and
 943                  * don't identify functions, so will confuse the profile
 944                  * output: */
 945                 if (ehdr.e_machine == EM_ARM || ehdr.e_machine == EM_AARCH64) {
 946                         if (elf_name[0] == '$' && strchr("adtx", elf_name[1])
 947                             && (elf_name[2] == '\0' || elf_name[2] == '.'))
 948                                 continue;
 949                 }
 950
 951                 if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
 952                         u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
 953                         u64 *opd = opddata->d_buf + offset;
 954                         sym.st_value = DSO__SWAP(dso, u64, *opd);
 955                         sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
 956                                         sym.st_value);
 957                         used_opd = true;
 958                 }
 959                 /*
 960                  * When loading symbols in a data mapping, ABS symbols (which
 961                  * has a value of SHN_ABS in its st_shndx) failed at
 962                  * elf_getscn().  And it marks the loading as a failure so
 963                  * already loaded symbols cannot be fixed up.
 964                  *
 965                  * I'm not sure what should be done. Just ignore them for now.
 966                  * - Namhyung Kim
 967                  */
 968                 if (sym.st_shndx == SHN_ABS)
 969                         continue;
 970
 971                 sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
 972                 if (!sec)
 973                         goto out_elf_end;
 974
 975                 gelf_getshdr(sec, &shdr);
 976
 977                 if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
 978                         continue;
 979
 980                 section_name = elf_sec__name(&shdr, secstrs);
 981
 982                 /* On ARM, symbols for thumb functions have 1 added to
 983                  * the symbol address as a flag - remove it */
 984                 if ((ehdr.e_machine == EM_ARM) &&
 985                     (map->type == MAP__FUNCTION) &&
 986                     (sym.st_value & 1))
 987                         --sym.st_value;
 988
 989                 if (dso->kernel || kmodule) {
 990                         char dso_name[PATH_MAX];
 991
 992                         /* Adjust symbol to map to file offset */
 993                         if (adjust_kernel_syms)
 994                                 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
 995
 996                         if (strcmp(section_name,
 997                                    (curr_dso->short_name +
 998                                     dso->short_name_len)) == 0)
 999                                 goto new_symbol;
1000
1001                         if (strcmp(section_name, ".text") == 0) {
1002                                 /*
1003                                  * The initial kernel mapping is based on
1004                                  * kallsyms and identity maps.  Overwrite it to
1005                                  * map to the kernel dso.
1006                                  */
1007                                 if (remap_kernel && dso->kernel) {
1008                                         remap_kernel = false;
1009                                         map->start = shdr.sh_addr +
1010                                                      ref_reloc(kmap);
1011                                         map->end = map->start + shdr.sh_size;
1012                                         map->pgoff = shdr.sh_offset;
1013                                         map->map_ip = map__map_ip;
1014                                         map->unmap_ip = map__unmap_ip;
1015                                         /* Ensure maps are correctly ordered */
1016                                         if (kmaps) {
1017                                                 map__get(map);
1018                                                 map_groups__remove(kmaps, map);
1019                                                 map_groups__insert(kmaps, map);
1020                                                 map__put(map);
1021                                         }
1022                                 }
1023
1024                                 /*
1025                                  * The initial module mapping is based on
1026                                  * /proc/modules mapped to offset zero.
1027                                  * Overwrite it to map to the module dso.
1028                                  */
1029                                 if (remap_kernel && kmodule) {
1030                                         remap_kernel = false;
1031                                         map->pgoff = shdr.sh_offset;
1032                                 }
1033
1034                                 curr_map = map;
1035                                 curr_dso = dso;
1036                                 goto new_symbol;
1037                         }
1038
1039                         if (!kmap)
1040                                 goto new_symbol;
1041
1042                         snprintf(dso_name, sizeof(dso_name),
1043                                  "%s%s", dso->short_name, section_name);
1044
1045                         curr_map = map_groups__find_by_name(kmaps, map->type, dso_name);
1046                         if (curr_map == NULL) {
1047                                 u64 start = sym.st_value;
1048
1049                                 if (kmodule)
1050                                         start += map->start + shdr.sh_offset;
1051
1052                                 curr_dso = dso__new(dso_name);
1053                                 if (curr_dso == NULL)
1054                                         goto out_elf_end;
1055                                 curr_dso->kernel = dso->kernel;
1056                                 curr_dso->long_name = dso->long_name;
1057                                 curr_dso->long_name_len = dso->long_name_len;
1058                                 curr_map = map__new2(start, curr_dso,
1059                                                      map->type);
1060                                 dso__put(curr_dso);
1061                                 if (curr_map == NULL) {
1062                                         goto out_elf_end;
1063                                 }
1064                                 if (adjust_kernel_syms) {
1065                                         curr_map->start = shdr.sh_addr +
1066                                                           ref_reloc(kmap);
1067                                         curr_map->end = curr_map->start +
1068                                                         shdr.sh_size;
1069                                         curr_map->pgoff = shdr.sh_offset;
1070                                 } else {
1071                                         curr_map->map_ip = identity__map_ip;
1072                                         curr_map->unmap_ip = identity__map_ip;
1073                                 }
1074                                 curr_dso->symtab_type = dso->symtab_type;
1075                                 map_groups__insert(kmaps, curr_map);
1076                                 /*
1077                                  * Add it before we drop the referece to curr_map,
1078                                  * i.e. while we still are sure to have a reference
1079                                  * to this DSO via curr_map->dso.
1080                                  */
1081                                 dsos__add(&map->groups->machine->dsos, curr_dso);
1082                                 /* kmaps already got it */
1083                                 map__put(curr_map);
1084                                 dso__set_loaded(curr_dso, map->type);
1085                         } else
1086                                 curr_dso = curr_map->dso;
1087
1088                         goto new_symbol;
1089                 }
1090
1091                 if ((used_opd && runtime_ss->adjust_symbols)
1092                                 || (!used_opd && syms_ss->adjust_symbols)) {
1093                         pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
1094                                   "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
1095                                   (u64)sym.st_value, (u64)shdr.sh_addr,
1096                                   (u64)shdr.sh_offset);
1097                         sym.st_value -= shdr.sh_addr - shdr.sh_offset;
1098                 }
1099 new_symbol:
1100                 demangled = demangle_sym(dso, kmodule, elf_name);
1101                 if (demangled != NULL)
1102                         elf_name = demangled;
1103
1104                 f = symbol__new(sym.st_value, sym.st_size,
1105                                 GELF_ST_BIND(sym.st_info), elf_name);
1106                 free(demangled);
1107                 if (!f)
1108                         goto out_elf_end;
1109
1110                 arch__sym_update(f, &sym);
1111
1112                 __symbols__insert(&curr_dso->symbols[curr_map->type], f, dso->kernel);
1113                 nr++;
1114         }
1115
1116         /*
1117          * For misannotated, zeroed, ASM function sizes.
1118          */
1119         if (nr > 0) {
1120                 symbols__fixup_end(&dso->symbols[map->type]);
1121                 symbols__fixup_duplicate(&dso->symbols[map->type]);
1122                 if (kmap) {
1123                         /*
1124                          * We need to fixup this here too because we create new
1125                          * maps here, for things like vsyscall sections.
1126                          */
1127                         __map_groups__fixup_end(kmaps, map->type);
1128                 }
1129         }
1130         err = nr;
1131 out_elf_end:
1132         return err;
1133 }
1134
1135 static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
1136 {
1137         GElf_Phdr phdr;
1138         size_t i, phdrnum;
1139         int err;
1140         u64 sz;
1141
1142         if (elf_getphdrnum(elf, &phdrnum))
1143                 return -1;
1144
1145         for (i = 0; i < phdrnum; i++) {
1146                 if (gelf_getphdr(elf, i, &phdr) == NULL)
1147                         return -1;
1148                 if (phdr.p_type != PT_LOAD)
1149                         continue;
1150                 if (exe) {
1151                         if (!(phdr.p_flags & PF_X))
1152                                 continue;
1153                 } else {
1154                         if (!(phdr.p_flags & PF_R))
1155                                 continue;
1156                 }
1157                 sz = min(phdr.p_memsz, phdr.p_filesz);
1158                 if (!sz)
1159                         continue;
1160                 err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
1161                 if (err)
1162                         return err;
1163         }
1164         return 0;
1165 }
1166
1167 int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
1168                     bool *is_64_bit)
1169 {
1170         int err;
1171         Elf *elf;
1172
1173         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1174         if (elf == NULL)
1175                 return -1;
1176
1177         if (is_64_bit)
1178                 *is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
1179
1180         err = elf_read_maps(elf, exe, mapfn, data);
1181
1182         elf_end(elf);
1183         return err;
1184 }
1185
1186 enum dso_type dso__type_fd(int fd)
1187 {
1188         enum dso_type dso_type = DSO__TYPE_UNKNOWN;
1189         GElf_Ehdr ehdr;
1190         Elf_Kind ek;
1191         Elf *elf;
1192
1193         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1194         if (elf == NULL)
1195                 goto out;
1196
1197         ek = elf_kind(elf);
1198         if (ek != ELF_K_ELF)
1199                 goto out_end;
1200
1201         if (gelf_getclass(elf) == ELFCLASS64) {
1202                 dso_type = DSO__TYPE_64BIT;
1203                 goto out_end;
1204         }
1205
1206         if (gelf_getehdr(elf, &ehdr) == NULL)
1207                 goto out_end;
1208
1209         if (ehdr.e_machine == EM_X86_64)
1210                 dso_type = DSO__TYPE_X32BIT;
1211         else
1212                 dso_type = DSO__TYPE_32BIT;
1213 out_end:
1214         elf_end(elf);
1215 out:
1216         return dso_type;
1217 }
1218
1219 static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
1220 {
1221         ssize_t r;
1222         size_t n;
1223         int err = -1;
1224         char *buf = malloc(page_size);
1225
1226         if (buf == NULL)
1227                 return -1;
1228
1229         if (lseek(to, to_offs, SEEK_SET) != to_offs)
1230                 goto out;
1231
1232         if (lseek(from, from_offs, SEEK_SET) != from_offs)
1233                 goto out;
1234
1235         while (len) {
1236                 n = page_size;
1237                 if (len < n)
1238                         n = len;
1239                 /* Use read because mmap won't work on proc files */
1240                 r = read(from, buf, n);
1241                 if (r < 0)
1242                         goto out;
1243                 if (!r)
1244                         break;
1245                 n = r;
1246                 r = write(to, buf, n);
1247                 if (r < 0)
1248                         goto out;
1249                 if ((size_t)r != n)
1250                         goto out;
1251                 len -= n;
1252         }
1253
1254         err = 0;
1255 out:
1256         free(buf);
1257         return err;
1258 }
1259
1260 struct kcore {
1261         int fd;
1262         int elfclass;
1263         Elf *elf;
1264         GElf_Ehdr ehdr;
1265 };
1266
1267 static int kcore__open(struct kcore *kcore, const char *filename)
1268 {
1269         GElf_Ehdr *ehdr;
1270
1271         kcore->fd = open(filename, O_RDONLY);
1272         if (kcore->fd == -1)
1273                 return -1;
1274
1275         kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
1276         if (!kcore->elf)
1277                 goto out_close;
1278
1279         kcore->elfclass = gelf_getclass(kcore->elf);
1280         if (kcore->elfclass == ELFCLASSNONE)
1281                 goto out_end;
1282
1283         ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1284         if (!ehdr)
1285                 goto out_end;
1286
1287         return 0;
1288
1289 out_end:
1290         elf_end(kcore->elf);
1291 out_close:
1292         close(kcore->fd);
1293         return -1;
1294 }
1295
1296 static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
1297                        bool temp)
1298 {
1299         kcore->elfclass = elfclass;
1300
1301         if (temp)
1302                 kcore->fd = mkstemp(filename);
1303         else
1304                 kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
1305         if (kcore->fd == -1)
1306                 return -1;
1307
1308         kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
1309         if (!kcore->elf)
1310                 goto out_close;
1311
1312         if (!gelf_newehdr(kcore->elf, elfclass))
1313                 goto out_end;
1314
1315         memset(&kcore->ehdr, 0, sizeof(GElf_Ehdr));
1316
1317         return 0;
1318
1319 out_end:
1320         elf_end(kcore->elf);
1321 out_close:
1322         close(kcore->fd);
1323         unlink(filename);
1324         return -1;
1325 }
1326
1327 static void kcore__close(struct kcore *kcore)
1328 {
1329         elf_end(kcore->elf);
1330         close(kcore->fd);
1331 }
1332
1333 static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
1334 {
1335         GElf_Ehdr *ehdr = &to->ehdr;
1336         GElf_Ehdr *kehdr = &from->ehdr;
1337
1338         memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
1339         ehdr->e_type      = kehdr->e_type;
1340         ehdr->e_machine   = kehdr->e_machine;
1341         ehdr->e_version   = kehdr->e_version;
1342         ehdr->e_entry     = 0;
1343         ehdr->e_shoff     = 0;
1344         ehdr->e_flags     = kehdr->e_flags;
1345         ehdr->e_phnum     = count;
1346         ehdr->e_shentsize = 0;
1347         ehdr->e_shnum     = 0;
1348         ehdr->e_shstrndx  = 0;
1349
1350         if (from->elfclass == ELFCLASS32) {
1351                 ehdr->e_phoff     = sizeof(Elf32_Ehdr);
1352                 ehdr->e_ehsize    = sizeof(Elf32_Ehdr);
1353                 ehdr->e_phentsize = sizeof(Elf32_Phdr);
1354         } else {
1355                 ehdr->e_phoff     = sizeof(Elf64_Ehdr);
1356                 ehdr->e_ehsize    = sizeof(Elf64_Ehdr);
1357                 ehdr->e_phentsize = sizeof(Elf64_Phdr);
1358         }
1359
1360         if (!gelf_update_ehdr(to->elf, ehdr))
1361                 return -1;
1362
1363         if (!gelf_newphdr(to->elf, count))
1364                 return -1;
1365
1366         return 0;
1367 }
1368
1369 static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
1370                            u64 addr, u64 len)
1371 {
1372         GElf_Phdr phdr = {
1373                 .p_type         = PT_LOAD,
1374                 .p_flags        = PF_R | PF_W | PF_X,
1375                 .p_offset       = offset,
1376                 .p_vaddr        = addr,
1377                 .p_paddr        = 0,
1378                 .p_filesz       = len,
1379                 .p_memsz        = len,
1380                 .p_align        = page_size,
1381         };
1382
1383         if (!gelf_update_phdr(kcore->elf, idx, &phdr))
1384                 return -1;
1385
1386         return 0;
1387 }
1388
1389 static off_t kcore__write(struct kcore *kcore)
1390 {
1391         return elf_update(kcore->elf, ELF_C_WRITE);
1392 }
1393
1394 struct phdr_data {
1395         off_t offset;
1396         u64 addr;
1397         u64 len;
1398 };
1399
1400 struct kcore_copy_info {
1401         u64 stext;
1402         u64 etext;
1403         u64 first_symbol;
1404         u64 last_symbol;
1405         u64 first_module;
1406         u64 last_module_symbol;
1407         struct phdr_data kernel_map;
1408         struct phdr_data modules_map;
1409 };
1410
1411 static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
1412                                         u64 start)
1413 {
1414         struct kcore_copy_info *kci = arg;
1415
1416         if (!symbol_type__is_a(type, MAP__FUNCTION))
1417                 return 0;
1418
1419         if (strchr(name, '[')) {
1420                 if (start > kci->last_module_symbol)
1421                         kci->last_module_symbol = start;
1422                 return 0;
1423         }
1424
1425         if (!kci->first_symbol || start < kci->first_symbol)
1426                 kci->first_symbol = start;
1427
1428         if (!kci->last_symbol || start > kci->last_symbol)
1429                 kci->last_symbol = start;
1430
1431         if (!strcmp(name, "_stext")) {
1432                 kci->stext = start;
1433                 return 0;
1434         }
1435
1436         if (!strcmp(name, "_etext")) {
1437                 kci->etext = start;
1438                 return 0;
1439         }
1440
1441         return 0;
1442 }
1443
1444 static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
1445                                       const char *dir)
1446 {
1447         char kallsyms_filename[PATH_MAX];
1448
1449         scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);
1450
1451         if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
1452                 return -1;
1453
1454         if (kallsyms__parse(kallsyms_filename, kci,
1455                             kcore_copy__process_kallsyms) < 0)
1456                 return -1;
1457
1458         return 0;
1459 }
1460
1461 static int kcore_copy__process_modules(void *arg,
1462                                        const char *name __maybe_unused,
1463                                        u64 start, u64 size __maybe_unused)
1464 {
1465         struct kcore_copy_info *kci = arg;
1466
1467         if (!kci->first_module || start < kci->first_module)
1468                 kci->first_module = start;
1469
1470         return 0;
1471 }
1472
1473 static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
1474                                      const char *dir)
1475 {
1476         char modules_filename[PATH_MAX];
1477
1478         scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);
1479
1480         if (symbol__restricted_filename(modules_filename, "/proc/modules"))
1481                 return -1;
1482
1483         if (modules__parse(modules_filename, kci,
1484                            kcore_copy__process_modules) < 0)
1485                 return -1;
1486
1487         return 0;
1488 }
1489
1490 static void kcore_copy__map(struct phdr_data *p, u64 start, u64 end, u64 pgoff,
1491                             u64 s, u64 e)
1492 {
1493         if (p->addr || s < start || s >= end)
1494                 return;
1495
1496         p->addr = s;
1497         p->offset = (s - start) + pgoff;
1498         p->len = e < end ? e - s : end - s;
1499 }
1500
1501 static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
1502 {
1503         struct kcore_copy_info *kci = data;
1504         u64 end = start + len;
1505
1506         kcore_copy__map(&kci->kernel_map, start, end, pgoff, kci->stext,
1507                         kci->etext);
1508
1509         kcore_copy__map(&kci->modules_map, start, end, pgoff, kci->first_module,
1510                         kci->last_module_symbol);
1511
1512         return 0;
1513 }
1514
1515 static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
1516 {
1517         if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
1518                 return -1;
1519
1520         return 0;
1521 }
1522
1523 static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
1524                                  Elf *elf)
1525 {
1526         if (kcore_copy__parse_kallsyms(kci, dir))
1527                 return -1;
1528
1529         if (kcore_copy__parse_modules(kci, dir))
1530                 return -1;
1531
1532         if (kci->stext)
1533                 kci->stext = round_down(kci->stext, page_size);
1534         else
1535                 kci->stext = round_down(kci->first_symbol, page_size);
1536
1537         if (kci->etext) {
1538                 kci->etext = round_up(kci->etext, page_size);
1539         } else if (kci->last_symbol) {
1540                 kci->etext = round_up(kci->last_symbol, page_size);
1541                 kci->etext += page_size;
1542         }
1543
1544         kci->first_module = round_down(kci->first_module, page_size);
1545
1546         if (kci->last_module_symbol) {
1547                 kci->last_module_symbol = round_up(kci->last_module_symbol,
1548                                                    page_size);
1549                 kci->last_module_symbol += page_size;
1550         }
1551
1552         if (!kci->stext || !kci->etext)
1553                 return -1;
1554
1555         if (kci->first_module && !kci->last_module_symbol)
1556                 return -1;
1557
1558         return kcore_copy__read_maps(kci, elf);
1559 }
1560
1561 static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
1562                                  const char *name)
1563 {
1564         char from_filename[PATH_MAX];
1565         char to_filename[PATH_MAX];
1566
1567         scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1568         scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1569
1570         return copyfile_mode(from_filename, to_filename, 0400);
1571 }
1572
1573 static int kcore_copy__unlink(const char *dir, const char *name)
1574 {
1575         char filename[PATH_MAX];
1576
1577         scnprintf(filename, PATH_MAX, "%s/%s", dir, name);
1578
1579         return unlink(filename);
1580 }
1581
1582 static int kcore_copy__compare_fds(int from, int to)
1583 {
1584         char *buf_from;
1585         char *buf_to;
1586         ssize_t ret;
1587         size_t len;
1588         int err = -1;
1589
1590         buf_from = malloc(page_size);
1591         buf_to = malloc(page_size);
1592         if (!buf_from || !buf_to)
1593                 goto out;
1594
1595         while (1) {
1596                 /* Use read because mmap won't work on proc files */
1597                 ret = read(from, buf_from, page_size);
1598                 if (ret < 0)
1599                         goto out;
1600
1601                 if (!ret)
1602                         break;
1603
1604                 len = ret;
1605
1606                 if (readn(to, buf_to, len) != (int)len)
1607                         goto out;
1608
1609                 if (memcmp(buf_from, buf_to, len))
1610                         goto out;
1611         }
1612
1613         err = 0;
1614 out:
1615         free(buf_to);
1616         free(buf_from);
1617         return err;
1618 }
1619
1620 static int kcore_copy__compare_files(const char *from_filename,
1621                                      const char *to_filename)
1622 {
1623         int from, to, err = -1;
1624
1625         from = open(from_filename, O_RDONLY);
1626         if (from < 0)
1627                 return -1;
1628
1629         to = open(to_filename, O_RDONLY);
1630         if (to < 0)
1631                 goto out_close_from;
1632
1633         err = kcore_copy__compare_fds(from, to);
1634
1635         close(to);
1636 out_close_from:
1637         close(from);
1638         return err;
1639 }
1640
1641 static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
1642                                     const char *name)
1643 {
1644         char from_filename[PATH_MAX];
1645         char to_filename[PATH_MAX];
1646
1647         scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1648         scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1649
1650         return kcore_copy__compare_files(from_filename, to_filename);
1651 }
1652
1653 /**
1654  * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
1655  * @from_dir: from directory
1656  * @to_dir: to directory
1657  *
1658  * This function copies kallsyms, modules and kcore files from one directory to
1659  * another.  kallsyms and modules are copied entirely.  Only code segments are
1660  * copied from kcore.  It is assumed that two segments suffice: one for the
1661  * kernel proper and one for all the modules.  The code segments are determined
1662  * from kallsyms and modules files.  The kernel map starts at _stext or the
1663  * lowest function symbol, and ends at _etext or the highest function symbol.
1664  * The module map starts at the lowest module address and ends at the highest
1665  * module symbol.  Start addresses are rounded down to the nearest page.  End
1666  * addresses are rounded up to the nearest page.  An extra page is added to the
1667  * highest kernel symbol and highest module symbol to, hopefully, encompass that
1668  * symbol too.  Because it contains only code sections, the resulting kcore is
1669  * unusual.  One significant peculiarity is that the mapping (start -> pgoff)
1670  * is not the same for the kernel map and the modules map.  That happens because
1671  * the data is copied adjacently whereas the original kcore has gaps.  Finally,
1672  * kallsyms and modules files are compared with their copies to check that
1673  * modules have not been loaded or unloaded while the copies were taking place.
1674  *
1675  * Return: %0 on success, %-1 on failure.
1676  */
1677 int kcore_copy(const char *from_dir, const char *to_dir)
1678 {
1679         struct kcore kcore;
1680         struct kcore extract;
1681         size_t count = 2;
1682         int idx = 0, err = -1;
1683         off_t offset = page_size, sz, modules_offset = 0;
1684         struct kcore_copy_info kci = { .stext = 0, };
1685         char kcore_filename[PATH_MAX];
1686         char extract_filename[PATH_MAX];
1687
1688         if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
1689                 return -1;
1690
1691         if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
1692                 goto out_unlink_kallsyms;
1693
1694         scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
1695         scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);
1696
1697         if (kcore__open(&kcore, kcore_filename))
1698                 goto out_unlink_modules;
1699
1700         if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
1701                 goto out_kcore_close;
1702
1703         if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
1704                 goto out_kcore_close;
1705
1706         if (!kci.modules_map.addr)
1707                 count -= 1;
1708
1709         if (kcore__copy_hdr(&kcore, &extract, count))
1710                 goto out_extract_close;
1711
1712         if (kcore__add_phdr(&extract, idx++, offset, kci.kernel_map.addr,
1713                             kci.kernel_map.len))
1714                 goto out_extract_close;
1715
1716         if (kci.modules_map.addr) {
1717                 modules_offset = offset + kci.kernel_map.len;
1718                 if (kcore__add_phdr(&extract, idx, modules_offset,
1719                                     kci.modules_map.addr, kci.modules_map.len))
1720                         goto out_extract_close;
1721         }
1722
1723         sz = kcore__write(&extract);
1724         if (sz < 0 || sz > offset)
1725                 goto out_extract_close;
1726
1727         if (copy_bytes(kcore.fd, kci.kernel_map.offset, extract.fd, offset,
1728                        kci.kernel_map.len))
1729                 goto out_extract_close;
1730
1731         if (modules_offset && copy_bytes(kcore.fd, kci.modules_map.offset,
1732                                          extract.fd, modules_offset,
1733                                          kci.modules_map.len))
1734                 goto out_extract_close;
1735
1736         if (kcore_copy__compare_file(from_dir, to_dir, "modules"))
1737                 goto out_extract_close;
1738
1739         if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
1740                 goto out_extract_close;
1741
1742         err = 0;
1743
1744 out_extract_close:
1745         kcore__close(&extract);
1746         if (err)
1747                 unlink(extract_filename);
1748 out_kcore_close:
1749         kcore__close(&kcore);
1750 out_unlink_modules:
1751         if (err)
1752                 kcore_copy__unlink(to_dir, "modules");
1753 out_unlink_kallsyms:
1754         if (err)
1755                 kcore_copy__unlink(to_dir, "kallsyms");
1756
1757         return err;
1758 }
1759
1760 int kcore_extract__create(struct kcore_extract *kce)
1761 {
1762         struct kcore kcore;
1763         struct kcore extract;
1764         size_t count = 1;
1765         int idx = 0, err = -1;
1766         off_t offset = page_size, sz;
1767
1768         if (kcore__open(&kcore, kce->kcore_filename))
1769                 return -1;
1770
1771         strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
1772         if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
1773                 goto out_kcore_close;
1774
1775         if (kcore__copy_hdr(&kcore, &extract, count))
1776                 goto out_extract_close;
1777
1778         if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
1779                 goto out_extract_close;
1780
1781         sz = kcore__write(&extract);
1782         if (sz < 0 || sz > offset)
1783                 goto out_extract_close;
1784
1785         if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
1786                 goto out_extract_close;
1787
1788         err = 0;
1789
1790 out_extract_close:
1791         kcore__close(&extract);
1792         if (err)
1793                 unlink(kce->extract_filename);
1794 out_kcore_close:
1795         kcore__close(&kcore);
1796
1797         return err;
1798 }
1799
1800 void kcore_extract__delete(struct kcore_extract *kce)
1801 {
1802         unlink(kce->extract_filename);
1803 }
1804
1805 #ifdef HAVE_GELF_GETNOTE_SUPPORT
1806 /**
1807  * populate_sdt_note : Parse raw data and identify SDT note
1808  * @elf: elf of the opened file
1809  * @data: raw data of a section with description offset applied
1810  * @len: note description size
1811  * @type: type of the note
1812  * @sdt_notes: List to add the SDT note
1813  *
1814  * Responsible for parsing the @data in section .note.stapsdt in @elf and
1815  * if its an SDT note, it appends to @sdt_notes list.
1816  */
1817 static int populate_sdt_note(Elf **elf, const char *data, size_t len,
1818                              struct list_head *sdt_notes)
1819 {
1820         const char *provider, *name, *args;
1821         struct sdt_note *tmp = NULL;
1822         GElf_Ehdr ehdr;
1823         GElf_Addr base_off = 0;
1824         GElf_Shdr shdr;
1825         int ret = -EINVAL;
1826
1827         union {
1828                 Elf64_Addr a64[NR_ADDR];
1829                 Elf32_Addr a32[NR_ADDR];
1830         } buf;
1831
1832         Elf_Data dst = {
1833                 .d_buf = &buf, .d_type = ELF_T_ADDR, .d_version = EV_CURRENT,
1834                 .d_size = gelf_fsize((*elf), ELF_T_ADDR, NR_ADDR, EV_CURRENT),
1835                 .d_off = 0, .d_align = 0
1836         };
1837         Elf_Data src = {
1838                 .d_buf = (void *) data, .d_type = ELF_T_ADDR,
1839                 .d_version = EV_CURRENT, .d_size = dst.d_size, .d_off = 0,
1840                 .d_align = 0
1841         };
1842
1843         tmp = (struct sdt_note *)calloc(1, sizeof(struct sdt_note));
1844         if (!tmp) {
1845                 ret = -ENOMEM;
1846                 goto out_err;
1847         }
1848
1849         INIT_LIST_HEAD(&tmp->note_list);
1850
1851         if (len < dst.d_size + 3)
1852                 goto out_free_note;
1853
1854         /* Translation from file representation to memory representation */
1855         if (gelf_xlatetom(*elf, &dst, &src,
1856                           elf_getident(*elf, NULL)[EI_DATA]) == NULL) {
1857                 pr_err("gelf_xlatetom : %s\n", elf_errmsg(-1));
1858                 goto out_free_note;
1859         }
1860
1861         /* Populate the fields of sdt_note */
1862         provider = data + dst.d_size;
1863
1864         name = (const char *)memchr(provider, '\0', data + len - provider);
1865         if (name++ == NULL)
1866                 goto out_free_note;
1867
1868         tmp->provider = strdup(provider);
1869         if (!tmp->provider) {
1870                 ret = -ENOMEM;
1871                 goto out_free_note;
1872         }
1873         tmp->name = strdup(name);
1874         if (!tmp->name) {
1875                 ret = -ENOMEM;
1876                 goto out_free_prov;
1877         }
1878
1879         args = memchr(name, '\0', data + len - name);
1880
1881         /*
1882          * There is no argument if:
1883          * - We reached the end of the note;
1884          * - There is not enough room to hold a potential string;
1885          * - The argument string is empty or just contains ':'.
1886          */
1887         if (args == NULL || data + len - args < 2 ||
1888                 args[1] == ':' || args[1] == '\0')
1889                 tmp->args = NULL;
1890         else {
1891                 tmp->args = strdup(++args);
1892                 if (!tmp->args) {
1893                         ret = -ENOMEM;
1894                         goto out_free_name;
1895                 }
1896         }
1897
1898         if (gelf_getclass(*elf) == ELFCLASS32) {
1899                 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr));
1900                 tmp->bit32 = true;
1901         } else {
1902                 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf64_Addr));
1903                 tmp->bit32 = false;
1904         }
1905
1906         if (!gelf_getehdr(*elf, &ehdr)) {
1907                 pr_debug("%s : cannot get elf header.\n", __func__);
1908                 ret = -EBADF;
1909                 goto out_free_args;
1910         }
1911
1912         /* Adjust the prelink effect :
1913          * Find out the .stapsdt.base section.
1914          * This scn will help us to handle prelinking (if present).
1915          * Compare the retrieved file offset of the base section with the
1916          * base address in the description of the SDT note. If its different,
1917          * then accordingly, adjust the note location.
1918          */
1919         if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL)) {
1920                 base_off = shdr.sh_offset;
1921                 if (base_off) {
1922                         if (tmp->bit32)
1923                                 tmp->addr.a32[0] = tmp->addr.a32[0] + base_off -
1924                                         tmp->addr.a32[1];
1925                         else
1926                                 tmp->addr.a64[0] = tmp->addr.a64[0] + base_off -
1927                                         tmp->addr.a64[1];
1928                 }
1929         }
1930
1931         list_add_tail(&tmp->note_list, sdt_notes);
1932         return 0;
1933
1934 out_free_args:
1935         free(tmp->args);
1936 out_free_name:
1937         free(tmp->name);
1938 out_free_prov:
1939         free(tmp->provider);
1940 out_free_note:
1941         free(tmp);
1942 out_err:
1943         return ret;
1944 }
1945
1946 /**
1947  * construct_sdt_notes_list : constructs a list of SDT notes
1948  * @elf : elf to look into
1949  * @sdt_notes : empty list_head
1950  *
1951  * Scans the sections in 'elf' for the section
1952  * .note.stapsdt. It, then calls populate_sdt_note to find
1953  * out the SDT events and populates the 'sdt_notes'.
1954  */
1955 static int construct_sdt_notes_list(Elf *elf, struct list_head *sdt_notes)
1956 {
1957         GElf_Ehdr ehdr;
1958         Elf_Scn *scn = NULL;
1959         Elf_Data *data;
1960         GElf_Shdr shdr;
1961         size_t shstrndx, next;
1962         GElf_Nhdr nhdr;
1963         size_t name_off, desc_off, offset;
1964         int ret = 0;
1965
1966         if (gelf_getehdr(elf, &ehdr) == NULL) {
1967                 ret = -EBADF;
1968                 goto out_ret;
1969         }
1970         if (elf_getshdrstrndx(elf, &shstrndx) != 0) {
1971                 ret = -EBADF;
1972                 goto out_ret;
1973         }
1974
1975         /* Look for the required section */
1976         scn = elf_section_by_name(elf, &ehdr, &shdr, SDT_NOTE_SCN, NULL);
1977         if (!scn) {
1978                 ret = -ENOENT;
1979                 goto out_ret;
1980         }
1981
1982         if ((shdr.sh_type != SHT_NOTE) || (shdr.sh_flags & SHF_ALLOC)) {
1983                 ret = -ENOENT;
1984                 goto out_ret;
1985         }
1986
1987         data = elf_getdata(scn, NULL);
1988
1989         /* Get the SDT notes */
1990         for (offset = 0; (next = gelf_getnote(data, offset, &nhdr, &name_off,
1991                                               &desc_off)) > 0; offset = next) {
1992                 if (nhdr.n_namesz == sizeof(SDT_NOTE_NAME) &&
1993                     !memcmp(data->d_buf + name_off, SDT_NOTE_NAME,
1994                             sizeof(SDT_NOTE_NAME))) {
1995                         /* Check the type of the note */
1996                         if (nhdr.n_type != SDT_NOTE_TYPE)
1997                                 goto out_ret;
1998
1999                         ret = populate_sdt_note(&elf, ((data->d_buf) + desc_off),
2000                                                 nhdr.n_descsz, sdt_notes);
2001                         if (ret < 0)
2002                                 goto out_ret;
2003                 }
2004         }
2005         if (list_empty(sdt_notes))
2006                 ret = -ENOENT;
2007
2008 out_ret:
2009         return ret;
2010 }
2011
2012 /**
2013  * get_sdt_note_list : Wrapper to construct a list of sdt notes
2014  * @head : empty list_head
2015  * @target : file to find SDT notes from
2016  *
2017  * This opens the file, initializes
2018  * the ELF and then calls construct_sdt_notes_list.
2019  */
2020 int get_sdt_note_list(struct list_head *head, const char *target)
2021 {
2022         Elf *elf;
2023         int fd, ret;
2024
2025         fd = open(target, O_RDONLY);
2026         if (fd < 0)
2027                 return -EBADF;
2028
2029         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
2030         if (!elf) {
2031                 ret = -EBADF;
2032                 goto out_close;
2033         }
2034         ret = construct_sdt_notes_list(elf, head);
2035         elf_end(elf);
2036 out_close:
2037         close(fd);
2038         return ret;
2039 }
2040
2041 /**
2042  * cleanup_sdt_note_list : free the sdt notes' list
2043  * @sdt_notes: sdt notes' list
2044  *
2045  * Free up the SDT notes in @sdt_notes.
2046  * Returns the number of SDT notes free'd.
2047  */
2048 int cleanup_sdt_note_list(struct list_head *sdt_notes)
2049 {
2050         struct sdt_note *tmp, *pos;
2051         int nr_free = 0;
2052
2053         list_for_each_entry_safe(pos, tmp, sdt_notes, note_list) {
2054                 list_del(&pos->note_list);
2055                 free(pos->name);
2056                 free(pos->provider);
2057                 free(pos);
2058                 nr_free++;
2059         }
2060         return nr_free;
2061 }
2062
2063 /**
2064  * sdt_notes__get_count: Counts the number of sdt events
2065  * @start: list_head to sdt_notes list
2066  *
2067  * Returns the number of SDT notes in a list
2068  */
2069 int sdt_notes__get_count(struct list_head *start)
2070 {
2071         struct sdt_note *sdt_ptr;
2072         int count = 0;
2073
2074         list_for_each_entry(sdt_ptr, start, note_list)
2075                 count++;
2076         return count;
2077 }
2078 #endif
2079
2080 void symbol__elf_init(void)
2081 {
2082         elf_version(EV_CURRENT);
2083 }