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