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 <stdlib.h>
   6 #include <string.h>
   7 #include <unistd.h>
   8 #include <inttypes.h>
   9
  10 #include "map.h"
  11 #include "map_groups.h"
  12 #include "symbol.h"
  13 #include "demangle-java.h"
  14 #include "demangle-rust.h"
  15 #include "machine.h"
  16 #include "vdso.h"
  17 #include "debug.h"
  18 #include "util.h"
  19 #include <linux/ctype.h>
  20 #include <symbol/kallsyms.h>
  21
  22 #ifndef EM_AARCH64
  23 #define EM_AARCH64      183  /* ARM 64 bit */
  24 #endif
  25
  26 #ifndef ELF32_ST_VISIBILITY
  27 #define ELF32_ST_VISIBILITY(o)  ((o) & 0x03)
  28 #endif
  29
  30 /* For ELF64 the definitions are the same.  */
  31 #ifndef ELF64_ST_VISIBILITY
  32 #define ELF64_ST_VISIBILITY(o)  ELF32_ST_VISIBILITY (o)
  33 #endif
  34
  35 /* How to extract information held in the st_other field.  */
  36 #ifndef GELF_ST_VISIBILITY
  37 #define GELF_ST_VISIBILITY(val) ELF64_ST_VISIBILITY (val)
  38 #endif
  39
  40 typedef Elf64_Nhdr GElf_Nhdr;
  41
  42 #ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
  43 extern char *cplus_demangle(const char *, int);
  44
  45 static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
  46 {
  47         return cplus_demangle(c, i);
  48 }
  49 #else
  50 #ifdef NO_DEMANGLE
  51 static inline char *bfd_demangle(void __maybe_unused *v,
  52                                  const char __maybe_unused *c,
  53                                  int __maybe_unused i)
  54 {
  55         return NULL;
  56 }
  57 #else
  58 #define PACKAGE 'perf'
  59 #include <bfd.h>
  60 #endif
  61 #endif
  62
  63 #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
  64 static int elf_getphdrnum(Elf *elf, size_t *dst)
  65 {
  66         GElf_Ehdr gehdr;
  67         GElf_Ehdr *ehdr;
  68
  69         ehdr = gelf_getehdr(elf, &gehdr);
  70         if (!ehdr)
  71                 return -1;
  72
  73         *dst = ehdr->e_phnum;
  74
  75         return 0;
  76 }
  77 #endif
  78
  79 #ifndef HAVE_ELF_GETSHDRSTRNDX_SUPPORT
  80 static int elf_getshdrstrndx(Elf *elf __maybe_unused, size_t *dst __maybe_unused)
  81 {
  82         pr_err("%s: update your libelf to > 0.140, this one lacks elf_getshdrstrndx().\n", __func__);
  83         return -1;
  84 }
  85 #endif
  86
  87 #ifndef NT_GNU_BUILD_ID
  88 #define NT_GNU_BUILD_ID 3
  89 #endif
  90
  91 /**
  92  * elf_symtab__for_each_symbol - iterate thru all the symbols
  93  *
  94  * @syms: struct elf_symtab instance to iterate
  95  * @idx: uint32_t idx
  96  * @sym: GElf_Sym iterator
  97  */
  98 #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
  99         for (idx = 0, gelf_getsym(syms, idx, &sym);\
 100              idx < nr_syms; \
 101              idx++, gelf_getsym(syms, idx, &sym))
 102
 103 static inline uint8_t elf_sym__type(const GElf_Sym *sym)
 104 {
 105         return GELF_ST_TYPE(sym->st_info);
 106 }
 107
 108 static inline uint8_t elf_sym__visibility(const GElf_Sym *sym)
 109 {
 110         return GELF_ST_VISIBILITY(sym->st_other);
 111 }
 112
 113 #ifndef STT_GNU_IFUNC
 114 #define STT_GNU_IFUNC 10
 115 #endif
 116
 117 static inline int elf_sym__is_function(const GElf_Sym *sym)
 118 {
 119         return (elf_sym__type(sym) == STT_FUNC ||
 120                 elf_sym__type(sym) == STT_GNU_IFUNC) &&
 121                sym->st_name != 0 &&
 122                sym->st_shndx != SHN_UNDEF;
 123 }
 124
 125 static inline bool elf_sym__is_object(const GElf_Sym *sym)
 126 {
 127         return elf_sym__type(sym) == STT_OBJECT &&
 128                 sym->st_name != 0 &&
 129                 sym->st_shndx != SHN_UNDEF;
 130 }
 131
 132 static inline int elf_sym__is_label(const GElf_Sym *sym)
 133 {
 134         return elf_sym__type(sym) == STT_NOTYPE &&
 135                 sym->st_name != 0 &&
 136                 sym->st_shndx != SHN_UNDEF &&
 137                 sym->st_shndx != SHN_ABS &&
 138                 elf_sym__visibility(sym) != STV_HIDDEN &&
 139                 elf_sym__visibility(sym) != STV_INTERNAL;
 140 }
 141
 142 static bool elf_sym__filter(GElf_Sym *sym)
 143 {
 144         return elf_sym__is_function(sym) || elf_sym__is_object(sym);
 145 }
 146
 147 static inline const char *elf_sym__name(const GElf_Sym *sym,
 148                                         const Elf_Data *symstrs)
 149 {
 150         return symstrs->d_buf + sym->st_name;
 151 }
 152
 153 static inline const char *elf_sec__name(const GElf_Shdr *shdr,
 154                                         const Elf_Data *secstrs)
 155 {
 156         return secstrs->d_buf + shdr->sh_name;
 157 }
 158
 159 static inline int elf_sec__is_text(const GElf_Shdr *shdr,
 160                                         const Elf_Data *secstrs)
 161 {
 162         return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
 163 }
 164
 165 static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
 166                                     const Elf_Data *secstrs)
 167 {
 168         return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
 169 }
 170
 171 static bool elf_sec__filter(GElf_Shdr *shdr, Elf_Data *secstrs)
 172 {
 173         return elf_sec__is_text(shdr, secstrs) ||
 174                elf_sec__is_data(shdr, secstrs);
 175 }
 176
 177 static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
 178 {
 179         Elf_Scn *sec = NULL;
 180         GElf_Shdr shdr;
 181         size_t cnt = 1;
 182
 183         while ((sec = elf_nextscn(elf, sec)) != NULL) {
 184                 gelf_getshdr(sec, &shdr);
 185
 186                 if ((addr >= shdr.sh_addr) &&
 187                     (addr < (shdr.sh_addr + shdr.sh_size)))
 188                         return cnt;
 189
 190                 ++cnt;
 191         }
 192
 193         return -1;
 194 }
 195
 196 Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
 197                              GElf_Shdr *shp, const char *name, size_t *idx)
 198 {
 199         Elf_Scn *sec = NULL;
 200         size_t cnt = 1;
 201
 202         /* Elf is corrupted/truncated, avoid calling elf_strptr. */
 203         if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
 204                 return NULL;
 205
 206         while ((sec = elf_nextscn(elf, sec)) != NULL) {
 207                 char *str;
 208
 209                 gelf_getshdr(sec, shp);
 210                 str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
 211                 if (str && !strcmp(name, str)) {
 212                         if (idx)
 213                                 *idx = cnt;
 214                         return sec;
 215                 }
 216                 ++cnt;
 217         }
 218
 219         return NULL;
 220 }
 221
 222 static bool want_demangle(bool is_kernel_sym)
 223 {
 224         return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
 225 }
 226
 227 static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
 228 {
 229         int demangle_flags = verbose > 0 ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS;
 230         char *demangled = NULL;
 231
 232         /*
 233          * We need to figure out if the object was created from C++ sources
 234          * DWARF DW_compile_unit has this, but we don't always have access
 235          * to it...
 236          */
 237         if (!want_demangle(dso->kernel || kmodule))
 238             return demangled;
 239
 240         demangled = bfd_demangle(NULL, elf_name, demangle_flags);
 241         if (demangled == NULL)
 242                 demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);
 243         else if (rust_is_mangled(demangled))
 244                 /*
 245                     * Input to Rust demangling is the BFD-demangled
 246                     * name which it Rust-demangles in place.
 247                     */
 248                 rust_demangle_sym(demangled);
 249
 250         return demangled;
 251 }
 252
 253 #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
 254         for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
 255              idx < nr_entries; \
 256              ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
 257
 258 #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
 259         for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
 260              idx < nr_entries; \
 261              ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
 262
 263 /*
 264  * We need to check if we have a .dynsym, so that we can handle the
 265  * .plt, synthesizing its symbols, that aren't on the symtabs (be it
 266  * .dynsym or .symtab).
 267  * And always look at the original dso, not at debuginfo packages, that
 268  * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
 269  */
 270 int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss)
 271 {
 272         uint32_t nr_rel_entries, idx;
 273         GElf_Sym sym;
 274         u64 plt_offset, plt_header_size, plt_entry_size;
 275         GElf_Shdr shdr_plt;
 276         struct symbol *f;
 277         GElf_Shdr shdr_rel_plt, shdr_dynsym;
 278         Elf_Data *reldata, *syms, *symstrs;
 279         Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
 280         size_t dynsym_idx;
 281         GElf_Ehdr ehdr;
 282         char sympltname[1024];
 283         Elf *elf;
 284         int nr = 0, symidx, err = 0;
 285
 286         if (!ss->dynsym)
 287                 return 0;
 288
 289         elf = ss->elf;
 290         ehdr = ss->ehdr;
 291
 292         scn_dynsym = ss->dynsym;
 293         shdr_dynsym = ss->dynshdr;
 294         dynsym_idx = ss->dynsym_idx;
 295
 296         if (scn_dynsym == NULL)
 297                 goto out_elf_end;
 298
 299         scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
 300                                           ".rela.plt", NULL);
 301         if (scn_plt_rel == NULL) {
 302                 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
 303                                                   ".rel.plt", NULL);
 304                 if (scn_plt_rel == NULL)
 305                         goto out_elf_end;
 306         }
 307
 308         err = -1;
 309
 310         if (shdr_rel_plt.sh_link != dynsym_idx)
 311                 goto out_elf_end;
 312
 313         if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
 314                 goto out_elf_end;
 315
 316         /*
 317          * Fetch the relocation section to find the idxes to the GOT
 318          * and the symbols in the .dynsym they refer to.
 319          */
 320         reldata = elf_getdata(scn_plt_rel, NULL);
 321         if (reldata == NULL)
 322                 goto out_elf_end;
 323
 324         syms = elf_getdata(scn_dynsym, NULL);
 325         if (syms == NULL)
 326                 goto out_elf_end;
 327
 328         scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
 329         if (scn_symstrs == NULL)
 330                 goto out_elf_end;
 331
 332         symstrs = elf_getdata(scn_symstrs, NULL);
 333         if (symstrs == NULL)
 334                 goto out_elf_end;
 335
 336         if (symstrs->d_size == 0)
 337                 goto out_elf_end;
 338
 339         nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
 340         plt_offset = shdr_plt.sh_offset;
 341         switch (ehdr.e_machine) {
 342                 case EM_ARM:
 343                         plt_header_size = 20;
 344                         plt_entry_size = 12;
 345                         break;
 346
 347                 case EM_AARCH64:
 348                         plt_header_size = 32;
 349                         plt_entry_size = 16;
 350                         break;
 351
 352                 case EM_SPARC:
 353                         plt_header_size = 48;
 354                         plt_entry_size = 12;
 355                         break;
 356
 357                 case EM_SPARCV9:
 358                         plt_header_size = 128;
 359                         plt_entry_size = 32;
 360                         break;
 361
 362                 default: /* FIXME: s390/alpha/mips/parisc/poperpc/sh/xtensa need to be checked */
 363                         plt_header_size = shdr_plt.sh_entsize;
 364                         plt_entry_size = shdr_plt.sh_entsize;
 365                         break;
 366         }
 367         plt_offset += plt_header_size;
 368
 369         if (shdr_rel_plt.sh_type == SHT_RELA) {
 370                 GElf_Rela pos_mem, *pos;
 371
 372                 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
 373                                            nr_rel_entries) {
 374                         const char *elf_name = NULL;
 375                         char *demangled = NULL;
 376                         symidx = GELF_R_SYM(pos->r_info);
 377                         gelf_getsym(syms, symidx, &sym);
 378
 379                         elf_name = elf_sym__name(&sym, symstrs);
 380                         demangled = demangle_sym(dso, 0, elf_name);
 381                         if (demangled != NULL)
 382                                 elf_name = demangled;
 383                         snprintf(sympltname, sizeof(sympltname),
 384                                  "%s@plt", elf_name);
 385                         free(demangled);
 386
 387                         f = symbol__new(plt_offset, plt_entry_size,
 388                                         STB_GLOBAL, STT_FUNC, sympltname);
 389                         if (!f)
 390                                 goto out_elf_end;
 391
 392                         plt_offset += plt_entry_size;
 393                         symbols__insert(&dso->symbols, f);
 394                         ++nr;
 395                 }
 396         } else if (shdr_rel_plt.sh_type == SHT_REL) {
 397                 GElf_Rel pos_mem, *pos;
 398                 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
 399                                           nr_rel_entries) {
 400                         const char *elf_name = NULL;
 401                         char *demangled = NULL;
 402                         symidx = GELF_R_SYM(pos->r_info);
 403                         gelf_getsym(syms, symidx, &sym);
 404
 405                         elf_name = elf_sym__name(&sym, symstrs);
 406                         demangled = demangle_sym(dso, 0, elf_name);
 407                         if (demangled != NULL)
 408                                 elf_name = demangled;
 409                         snprintf(sympltname, sizeof(sympltname),
 410                                  "%s@plt", elf_name);
 411                         free(demangled);
 412
 413                         f = symbol__new(plt_offset, plt_entry_size,
 414                                         STB_GLOBAL, STT_FUNC, sympltname);
 415                         if (!f)
 416                                 goto out_elf_end;
 417
 418                         plt_offset += plt_entry_size;
 419                         symbols__insert(&dso->symbols, f);
 420                         ++nr;
 421                 }
 422         }
 423
 424         err = 0;
 425 out_elf_end:
 426         if (err == 0)
 427                 return nr;
 428         pr_debug("%s: problems reading %s PLT info.\n",
 429                  __func__, dso->long_name);
 430         return 0;
 431 }
 432
 433 char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
 434 {
 435         return demangle_sym(dso, kmodule, elf_name);
 436 }
 437
 438 /*
 439  * Align offset to 4 bytes as needed for note name and descriptor data.
 440  */
 441 #define NOTE_ALIGN(n) (((n) + 3) & -4U)
 442
 443 static int elf_read_build_id(Elf *elf, void *bf, size_t size)
 444 {
 445         int err = -1;
 446         GElf_Ehdr ehdr;
 447         GElf_Shdr shdr;
 448         Elf_Data *data;
 449         Elf_Scn *sec;
 450         Elf_Kind ek;
 451         void *ptr;
 452
 453         if (size < BUILD_ID_SIZE)
 454                 goto out;
 455
 456         ek = elf_kind(elf);
 457         if (ek != ELF_K_ELF)
 458                 goto out;
 459
 460         if (gelf_getehdr(elf, &ehdr) == NULL) {
 461                 pr_err("%s: cannot get elf header.\n", __func__);
 462                 goto out;
 463         }
 464
 465         /*
 466          * Check following sections for notes:
 467          *   '.note.gnu.build-id'
 468          *   '.notes'
 469          *   '.note' (VDSO specific)
 470          */
 471         do {
 472                 sec = elf_section_by_name(elf, &ehdr, &shdr,
 473                                           ".note.gnu.build-id", NULL);
 474                 if (sec)
 475                         break;
 476
 477                 sec = elf_section_by_name(elf, &ehdr, &shdr,
 478                                           ".notes", NULL);
 479                 if (sec)
 480                         break;
 481
 482                 sec = elf_section_by_name(elf, &ehdr, &shdr,
 483                                           ".note", NULL);
 484                 if (sec)
 485                         break;
 486
 487                 return err;
 488
 489         } while (0);
 490
 491         data = elf_getdata(sec, NULL);
 492         if (data == NULL)
 493                 goto out;
 494
 495         ptr = data->d_buf;
 496         while (ptr < (data->d_buf + data->d_size)) {
 497                 GElf_Nhdr *nhdr = ptr;
 498                 size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
 499                        descsz = NOTE_ALIGN(nhdr->n_descsz);
 500                 const char *name;
 501
 502                 ptr += sizeof(*nhdr);
 503                 name = ptr;
 504                 ptr += namesz;
 505                 if (nhdr->n_type == NT_GNU_BUILD_ID &&
 506                     nhdr->n_namesz == sizeof("GNU")) {
 507                         if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
 508                                 size_t sz = min(size, descsz);
 509                                 memcpy(bf, ptr, sz);
 510                                 memset(bf + sz, 0, size - sz);
 511                                 err = descsz;
 512                                 break;
 513                         }
 514                 }
 515                 ptr += descsz;
 516         }
 517
 518 out:
 519         return err;
 520 }
 521
 522 int filename__read_build_id(const char *filename, void *bf, size_t size)
 523 {
 524         int fd, err = -1;
 525         Elf *elf;
 526
 527         if (size < BUILD_ID_SIZE)
 528                 goto out;
 529
 530         fd = open(filename, O_RDONLY);
 531         if (fd < 0)
 532                 goto out;
 533
 534         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
 535         if (elf == NULL) {
 536                 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
 537                 goto out_close;
 538         }
 539
 540         err = elf_read_build_id(elf, bf, size);
 541
 542         elf_end(elf);
 543 out_close:
 544         close(fd);
 545 out:
 546         return err;
 547 }
 548
 549 int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
 550 {
 551         int fd, err = -1;
 552
 553         if (size < BUILD_ID_SIZE)
 554                 goto out;
 555
 556         fd = open(filename, O_RDONLY);
 557         if (fd < 0)
 558                 goto out;
 559
 560         while (1) {
 561                 char bf[BUFSIZ];
 562                 GElf_Nhdr nhdr;
 563                 size_t namesz, descsz;
 564
 565                 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
 566                         break;
 567
 568                 namesz = NOTE_ALIGN(nhdr.n_namesz);
 569                 descsz = NOTE_ALIGN(nhdr.n_descsz);
 570                 if (nhdr.n_type == NT_GNU_BUILD_ID &&
 571                     nhdr.n_namesz == sizeof("GNU")) {
 572                         if (read(fd, bf, namesz) != (ssize_t)namesz)
 573                                 break;
 574                         if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
 575                                 size_t sz = min(descsz, size);
 576                                 if (read(fd, build_id, sz) == (ssize_t)sz) {
 577                                         memset(build_id + sz, 0, size - sz);
 578                                         err = 0;
 579                                         break;
 580                                 }
 581                         } else if (read(fd, bf, descsz) != (ssize_t)descsz)
 582                                 break;
 583                 } else {
 584                         int n = namesz + descsz;
 585
 586                         if (n > (int)sizeof(bf)) {
 587                                 n = sizeof(bf);
 588                                 pr_debug("%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n",
 589                                          __func__, filename, nhdr.n_namesz, nhdr.n_descsz);
 590                         }
 591                         if (read(fd, bf, n) != n)
 592                                 break;
 593                 }
 594         }
 595         close(fd);
 596 out:
 597         return err;
 598 }
 599
 600 int filename__read_debuglink(const char *filename, char *debuglink,
 601                              size_t size)
 602 {
 603         int fd, err = -1;
 604         Elf *elf;
 605         GElf_Ehdr ehdr;
 606         GElf_Shdr shdr;
 607         Elf_Data *data;
 608         Elf_Scn *sec;
 609         Elf_Kind ek;
 610
 611         fd = open(filename, O_RDONLY);
 612         if (fd < 0)
 613                 goto out;
 614
 615         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
 616         if (elf == NULL) {
 617                 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
 618                 goto out_close;
 619         }
 620
 621         ek = elf_kind(elf);
 622         if (ek != ELF_K_ELF)
 623                 goto out_elf_end;
 624
 625         if (gelf_getehdr(elf, &ehdr) == NULL) {
 626                 pr_err("%s: cannot get elf header.\n", __func__);
 627                 goto out_elf_end;
 628         }
 629
 630         sec = elf_section_by_name(elf, &ehdr, &shdr,
 631                                   ".gnu_debuglink", NULL);
 632         if (sec == NULL)
 633                 goto out_elf_end;
 634
 635         data = elf_getdata(sec, NULL);
 636         if (data == NULL)
 637                 goto out_elf_end;
 638
 639         /* the start of this section is a zero-terminated string */
 640         strncpy(debuglink, data->d_buf, size);
 641
 642         err = 0;
 643
 644 out_elf_end:
 645         elf_end(elf);
 646 out_close:
 647         close(fd);
 648 out:
 649         return err;
 650 }
 651
 652 static int dso__swap_init(struct dso *dso, unsigned char eidata)
 653 {
 654         static unsigned int const endian = 1;
 655
 656         dso->needs_swap = DSO_SWAP__NO;
 657
 658         switch (eidata) {
 659         case ELFDATA2LSB:
 660                 /* We are big endian, DSO is little endian. */
 661                 if (*(unsigned char const *)&endian != 1)
 662                         dso->needs_swap = DSO_SWAP__YES;
 663                 break;
 664
 665         case ELFDATA2MSB:
 666                 /* We are little endian, DSO is big endian. */
 667                 if (*(unsigned char const *)&endian != 0)
 668                         dso->needs_swap = DSO_SWAP__YES;
 669                 break;
 670
 671         default:
 672                 pr_err("unrecognized DSO data encoding %d\n", eidata);
 673                 return -EINVAL;
 674         }
 675
 676         return 0;
 677 }
 678
 679 bool symsrc__possibly_runtime(struct symsrc *ss)
 680 {
 681         return ss->dynsym || ss->opdsec;
 682 }
 683
 684 bool symsrc__has_symtab(struct symsrc *ss)
 685 {
 686         return ss->symtab != NULL;
 687 }
 688
 689 void symsrc__destroy(struct symsrc *ss)
 690 {
 691         zfree(&ss->name);
 692         elf_end(ss->elf);
 693         close(ss->fd);
 694 }
 695
 696 bool __weak elf__needs_adjust_symbols(GElf_Ehdr ehdr)
 697 {
 698         return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL;
 699 }
 700
 701 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
 702                  enum dso_binary_type type)
 703 {
 704         GElf_Ehdr ehdr;
 705         Elf *elf;
 706         int fd;
 707
 708         if (dso__needs_decompress(dso)) {
 709                 fd = dso__decompress_kmodule_fd(dso, name);
 710                 if (fd < 0)
 711                         return -1;
 712
 713                 type = dso->symtab_type;
 714         } else {
 715                 fd = open(name, O_RDONLY);
 716                 if (fd < 0) {
 717                         dso->load_errno = errno;
 718                         return -1;
 719                 }
 720         }
 721
 722         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
 723         if (elf == NULL) {
 724                 pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
 725                 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
 726                 goto out_close;
 727         }
 728
 729         if (gelf_getehdr(elf, &ehdr) == NULL) {
 730                 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
 731                 pr_debug("%s: cannot get elf header.\n", __func__);
 732                 goto out_elf_end;
 733         }
 734
 735         if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) {
 736                 dso->load_errno = DSO_LOAD_ERRNO__INTERNAL_ERROR;
 737                 goto out_elf_end;
 738         }
 739
 740         /* Always reject images with a mismatched build-id: */
 741         if (dso->has_build_id && !symbol_conf.ignore_vmlinux_buildid) {
 742                 u8 build_id[BUILD_ID_SIZE];
 743
 744                 if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) {
 745                         dso->load_errno = DSO_LOAD_ERRNO__CANNOT_READ_BUILDID;
 746                         goto out_elf_end;
 747                 }
 748
 749                 if (!dso__build_id_equal(dso, build_id)) {
 750                         pr_debug("%s: build id mismatch for %s.\n", __func__, name);
 751                         dso->load_errno = DSO_LOAD_ERRNO__MISMATCHING_BUILDID;
 752                         goto out_elf_end;
 753                 }
 754         }
 755
 756         ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
 757
 758         ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
 759                         NULL);
 760         if (ss->symshdr.sh_type != SHT_SYMTAB)
 761                 ss->symtab = NULL;
 762
 763         ss->dynsym_idx = 0;
 764         ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
 765                         &ss->dynsym_idx);
 766         if (ss->dynshdr.sh_type != SHT_DYNSYM)
 767                 ss->dynsym = NULL;
 768
 769         ss->opdidx = 0;
 770         ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
 771                         &ss->opdidx);
 772         if (ss->opdshdr.sh_type != SHT_PROGBITS)
 773                 ss->opdsec = NULL;
 774
 775         if (dso->kernel == DSO_TYPE_USER)
 776                 ss->adjust_symbols = true;
 777         else
 778                 ss->adjust_symbols = elf__needs_adjust_symbols(ehdr);
 779
 780         ss->name   = strdup(name);
 781         if (!ss->name) {
 782                 dso->load_errno = errno;
 783                 goto out_elf_end;
 784         }
 785
 786         ss->elf    = elf;
 787         ss->fd     = fd;
 788         ss->ehdr   = ehdr;
 789         ss->type   = type;
 790
 791         return 0;
 792
 793 out_elf_end:
 794         elf_end(elf);
 795 out_close:
 796         close(fd);
 797         return -1;
 798 }
 799
 800 /**
 801  * ref_reloc_sym_not_found - has kernel relocation symbol been found.
 802  * @kmap: kernel maps and relocation reference symbol
 803  *
 804  * This function returns %true if we are dealing with the kernel maps and the
 805  * relocation reference symbol has not yet been found.  Otherwise %false is
 806  * returned.
 807  */
 808 static bool ref_reloc_sym_not_found(struct kmap *kmap)
 809 {
 810         return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
 811                !kmap->ref_reloc_sym->unrelocated_addr;
 812 }
 813
 814 /**
 815  * ref_reloc - kernel relocation offset.
 816  * @kmap: kernel maps and relocation reference symbol
 817  *
 818  * This function returns the offset of kernel addresses as determined by using
 819  * the relocation reference symbol i.e. if the kernel has not been relocated
 820  * then the return value is zero.
 821  */
 822 static u64 ref_reloc(struct kmap *kmap)
 823 {
 824         if (kmap && kmap->ref_reloc_sym &&
 825             kmap->ref_reloc_sym->unrelocated_addr)
 826                 return kmap->ref_reloc_sym->addr -
 827                        kmap->ref_reloc_sym->unrelocated_addr;
 828         return 0;
 829 }
 830
 831 void __weak arch__sym_update(struct symbol *s __maybe_unused,
 832                 GElf_Sym *sym __maybe_unused) { }
 833
 834 static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
 835                                       GElf_Sym *sym, GElf_Shdr *shdr,
 836                                       struct map_groups *kmaps, struct kmap *kmap,
 837                                       struct dso **curr_dsop, struct map **curr_mapp,
 838                                       const char *section_name,
 839                                       bool adjust_kernel_syms, bool kmodule, bool *remap_kernel)
 840 {
 841         struct dso *curr_dso = *curr_dsop;
 842         struct map *curr_map;
 843         char dso_name[PATH_MAX];
 844
 845         /* Adjust symbol to map to file offset */
 846         if (adjust_kernel_syms)
 847                 sym->st_value -= shdr->sh_addr - shdr->sh_offset;
 848
 849         if (strcmp(section_name, (curr_dso->short_name + dso->short_name_len)) == 0)
 850                 return 0;
 851
 852         if (strcmp(section_name, ".text") == 0) {
 853                 /*
 854                  * The initial kernel mapping is based on
 855                  * kallsyms and identity maps.  Overwrite it to
 856                  * map to the kernel dso.
 857                  */
 858                 if (*remap_kernel && dso->kernel) {
 859                         *remap_kernel = false;
 860                         map->start = shdr->sh_addr + ref_reloc(kmap);
 861                         map->end = map->start + shdr->sh_size;
 862                         map->pgoff = shdr->sh_offset;
 863                         map->map_ip = map__map_ip;
 864                         map->unmap_ip = map__unmap_ip;
 865                         /* Ensure maps are correctly ordered */
 866                         if (kmaps) {
 867                                 map__get(map);
 868                                 map_groups__remove(kmaps, map);
 869                                 map_groups__insert(kmaps, map);
 870                                 map__put(map);
 871                         }
 872                 }
 873
 874                 /*
 875                  * The initial module mapping is based on
 876                  * /proc/modules mapped to offset zero.
 877                  * Overwrite it to map to the module dso.
 878                  */
 879                 if (*remap_kernel && kmodule) {
 880                         *remap_kernel = false;
 881                         map->pgoff = shdr->sh_offset;
 882                 }
 883
 884                 *curr_mapp = map;
 885                 *curr_dsop = dso;
 886                 return 0;
 887         }
 888
 889         if (!kmap)
 890                 return 0;
 891
 892         snprintf(dso_name, sizeof(dso_name), "%s%s", dso->short_name, section_name);
 893
 894         curr_map = map_groups__find_by_name(kmaps, dso_name);
 895         if (curr_map == NULL) {
 896                 u64 start = sym->st_value;
 897
 898                 if (kmodule)
 899                         start += map->start + shdr->sh_offset;
 900
 901                 curr_dso = dso__new(dso_name);
 902                 if (curr_dso == NULL)
 903                         return -1;
 904                 curr_dso->kernel = dso->kernel;
 905                 curr_dso->long_name = dso->long_name;
 906                 curr_dso->long_name_len = dso->long_name_len;
 907                 curr_map = map__new2(start, curr_dso);
 908                 dso__put(curr_dso);
 909                 if (curr_map == NULL)
 910                         return -1;
 911
 912                 if (adjust_kernel_syms) {
 913                         curr_map->start  = shdr->sh_addr + ref_reloc(kmap);
 914                         curr_map->end    = curr_map->start + shdr->sh_size;
 915                         curr_map->pgoff  = shdr->sh_offset;
 916                 } else {
 917                         curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
 918                 }
 919                 curr_dso->symtab_type = dso->symtab_type;
 920                 map_groups__insert(kmaps, curr_map);
 921                 /*
 922                  * Add it before we drop the referece to curr_map, i.e. while
 923                  * we still are sure to have a reference to this DSO via
 924                  * *curr_map->dso.
 925                  */
 926                 dsos__add(&map->groups->machine->dsos, curr_dso);
 927                 /* kmaps already got it */
 928                 map__put(curr_map);
 929                 dso__set_loaded(curr_dso);
 930                 *curr_mapp = curr_map;
 931                 *curr_dsop = curr_dso;
 932         } else
 933                 *curr_dsop = curr_map->dso;
 934
 935         return 0;
 936 }
 937
 938 int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
 939                   struct symsrc *runtime_ss, int kmodule)
 940 {
 941         struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
 942         struct map_groups *kmaps = kmap ? map__kmaps(map) : NULL;
 943         struct map *curr_map = map;
 944         struct dso *curr_dso = dso;
 945         Elf_Data *symstrs, *secstrs;
 946         uint32_t nr_syms;
 947         int err = -1;
 948         uint32_t idx;
 949         GElf_Ehdr ehdr;
 950         GElf_Shdr shdr;
 951         GElf_Shdr tshdr;
 952         Elf_Data *syms, *opddata = NULL;
 953         GElf_Sym sym;
 954         Elf_Scn *sec, *sec_strndx;
 955         Elf *elf;
 956         int nr = 0;
 957         bool remap_kernel = false, adjust_kernel_syms = false;
 958
 959         if (kmap && !kmaps)
 960                 return -1;
 961
 962         dso->symtab_type = syms_ss->type;
 963         dso->is_64_bit = syms_ss->is_64_bit;
 964         dso->rel = syms_ss->ehdr.e_type == ET_REL;
 965
 966         /*
 967          * Modules may already have symbols from kallsyms, but those symbols
 968          * have the wrong values for the dso maps, so remove them.
 969          */
 970         if (kmodule && syms_ss->symtab)
 971                 symbols__delete(&dso->symbols);
 972
 973         if (!syms_ss->symtab) {
 974                 /*
 975                  * If the vmlinux is stripped, fail so we will fall back
 976                  * to using kallsyms. The vmlinux runtime symbols aren't
 977                  * of much use.
 978                  */
 979                 if (dso->kernel)
 980                         goto out_elf_end;
 981
 982                 syms_ss->symtab  = syms_ss->dynsym;
 983                 syms_ss->symshdr = syms_ss->dynshdr;
 984         }
 985
 986         elf = syms_ss->elf;
 987         ehdr = syms_ss->ehdr;
 988         sec = syms_ss->symtab;
 989         shdr = syms_ss->symshdr;
 990
 991         if (elf_section_by_name(runtime_ss->elf, &runtime_ss->ehdr, &tshdr,
 992                                 ".text", NULL))
 993                 dso->text_offset = tshdr.sh_addr - tshdr.sh_offset;
 994
 995         if (runtime_ss->opdsec)
 996                 opddata = elf_rawdata(runtime_ss->opdsec, NULL);
 997
 998         syms = elf_getdata(sec, NULL);
 999         if (syms == NULL)
1000                 goto out_elf_end;
1001
1002         sec = elf_getscn(elf, shdr.sh_link);
1003         if (sec == NULL)
1004                 goto out_elf_end;
1005
1006         symstrs = elf_getdata(sec, NULL);
1007         if (symstrs == NULL)
1008                 goto out_elf_end;
1009
1010         sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx);
1011         if (sec_strndx == NULL)
1012                 goto out_elf_end;
1013
1014         secstrs = elf_getdata(sec_strndx, NULL);
1015         if (secstrs == NULL)
1016                 goto out_elf_end;
1017
1018         nr_syms = shdr.sh_size / shdr.sh_entsize;
1019
1020         memset(&sym, 0, sizeof(sym));
1021
1022         /*
1023          * The kernel relocation symbol is needed in advance in order to adjust
1024          * kernel maps correctly.
1025          */
1026         if (ref_reloc_sym_not_found(kmap)) {
1027                 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
1028                         const char *elf_name = elf_sym__name(&sym, symstrs);
1029
1030                         if (strcmp(elf_name, kmap->ref_reloc_sym->name))
1031                                 continue;
1032                         kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
1033                         map->reloc = kmap->ref_reloc_sym->addr -
1034                                      kmap->ref_reloc_sym->unrelocated_addr;
1035                         break;
1036                 }
1037         }
1038
1039         /*
1040          * Handle any relocation of vdso necessary because older kernels
1041          * attempted to prelink vdso to its virtual address.
1042          */
1043         if (dso__is_vdso(dso))
1044                 map->reloc = map->start - dso->text_offset;
1045
1046         dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
1047         /*
1048          * Initial kernel and module mappings do not map to the dso.
1049          * Flag the fixups.
1050          */
1051         if (dso->kernel || kmodule) {
1052                 remap_kernel = true;
1053                 adjust_kernel_syms = dso->adjust_symbols;
1054         }
1055         elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
1056                 struct symbol *f;
1057                 const char *elf_name = elf_sym__name(&sym, symstrs);
1058                 char *demangled = NULL;
1059                 int is_label = elf_sym__is_label(&sym);
1060                 const char *section_name;
1061                 bool used_opd = false;
1062
1063                 if (!is_label && !elf_sym__filter(&sym))
1064                         continue;
1065
1066                 /* Reject ARM ELF "mapping symbols": these aren't unique and
1067                  * don't identify functions, so will confuse the profile
1068                  * output: */
1069                 if (ehdr.e_machine == EM_ARM || ehdr.e_machine == EM_AARCH64) {
1070                         if (elf_name[0] == '$' && strchr("adtx", elf_name[1])
1071                             && (elf_name[2] == '\0' || elf_name[2] == '.'))
1072                                 continue;
1073                 }
1074
1075                 if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
1076                         u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
1077                         u64 *opd = opddata->d_buf + offset;
1078                         sym.st_value = DSO__SWAP(dso, u64, *opd);
1079                         sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
1080                                         sym.st_value);
1081                         used_opd = true;
1082                 }
1083                 /*
1084                  * When loading symbols in a data mapping, ABS symbols (which
1085                  * has a value of SHN_ABS in its st_shndx) failed at
1086                  * elf_getscn().  And it marks the loading as a failure so
1087                  * already loaded symbols cannot be fixed up.
1088                  *
1089                  * I'm not sure what should be done. Just ignore them for now.
1090                  * - Namhyung Kim
1091                  */
1092                 if (sym.st_shndx == SHN_ABS)
1093                         continue;
1094
1095                 sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
1096                 if (!sec)
1097                         goto out_elf_end;
1098
1099                 gelf_getshdr(sec, &shdr);
1100
1101                 if (is_label && !elf_sec__filter(&shdr, secstrs))
1102                         continue;
1103
1104                 section_name = elf_sec__name(&shdr, secstrs);
1105
1106                 /* On ARM, symbols for thumb functions have 1 added to
1107                  * the symbol address as a flag - remove it */
1108                 if ((ehdr.e_machine == EM_ARM) &&
1109                     (GELF_ST_TYPE(sym.st_info) == STT_FUNC) &&
1110                     (sym.st_value & 1))
1111                         --sym.st_value;
1112
1113                 if (dso->kernel || kmodule) {
1114                         if (dso__process_kernel_symbol(dso, map, &sym, &shdr, kmaps, kmap, &curr_dso, &curr_map,
1115                                                        section_name, adjust_kernel_syms, kmodule, &remap_kernel))
1116                                 goto out_elf_end;
1117                 } else if ((used_opd && runtime_ss->adjust_symbols) ||
1118                            (!used_opd && syms_ss->adjust_symbols)) {
1119                         pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
1120                                   "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
1121                                   (u64)sym.st_value, (u64)shdr.sh_addr,
1122                                   (u64)shdr.sh_offset);
1123                         sym.st_value -= shdr.sh_addr - shdr.sh_offset;
1124                 }
1125
1126                 demangled = demangle_sym(dso, kmodule, elf_name);
1127                 if (demangled != NULL)
1128                         elf_name = demangled;
1129
1130                 f = symbol__new(sym.st_value, sym.st_size,
1131                                 GELF_ST_BIND(sym.st_info),
1132                                 GELF_ST_TYPE(sym.st_info), elf_name);
1133                 free(demangled);
1134                 if (!f)
1135                         goto out_elf_end;
1136
1137                 arch__sym_update(f, &sym);
1138
1139                 __symbols__insert(&curr_dso->symbols, f, dso->kernel);
1140                 nr++;
1141         }
1142
1143         /*
1144          * For misannotated, zeroed, ASM function sizes.
1145          */
1146         if (nr > 0) {
1147                 symbols__fixup_end(&dso->symbols);
1148                 symbols__fixup_duplicate(&dso->symbols);
1149                 if (kmap) {
1150                         /*
1151                          * We need to fixup this here too because we create new
1152                          * maps here, for things like vsyscall sections.
1153                          */
1154                         map_groups__fixup_end(kmaps);
1155                 }
1156         }
1157         err = nr;
1158 out_elf_end:
1159         return err;
1160 }
1161
1162 static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
1163 {
1164         GElf_Phdr phdr;
1165         size_t i, phdrnum;
1166         int err;
1167         u64 sz;
1168
1169         if (elf_getphdrnum(elf, &phdrnum))
1170                 return -1;
1171
1172         for (i = 0; i < phdrnum; i++) {
1173                 if (gelf_getphdr(elf, i, &phdr) == NULL)
1174                         return -1;
1175                 if (phdr.p_type != PT_LOAD)
1176                         continue;
1177                 if (exe) {
1178                         if (!(phdr.p_flags & PF_X))
1179                                 continue;
1180                 } else {
1181                         if (!(phdr.p_flags & PF_R))
1182                                 continue;
1183                 }
1184                 sz = min(phdr.p_memsz, phdr.p_filesz);
1185                 if (!sz)
1186                         continue;
1187                 err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
1188                 if (err)
1189                         return err;
1190         }
1191         return 0;
1192 }
1193
1194 int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
1195                     bool *is_64_bit)
1196 {
1197         int err;
1198         Elf *elf;
1199
1200         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1201         if (elf == NULL)
1202                 return -1;
1203
1204         if (is_64_bit)
1205                 *is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
1206
1207         err = elf_read_maps(elf, exe, mapfn, data);
1208
1209         elf_end(elf);
1210         return err;
1211 }
1212
1213 enum dso_type dso__type_fd(int fd)
1214 {
1215         enum dso_type dso_type = DSO__TYPE_UNKNOWN;
1216         GElf_Ehdr ehdr;
1217         Elf_Kind ek;
1218         Elf *elf;
1219
1220         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1221         if (elf == NULL)
1222                 goto out;
1223
1224         ek = elf_kind(elf);
1225         if (ek != ELF_K_ELF)
1226                 goto out_end;
1227
1228         if (gelf_getclass(elf) == ELFCLASS64) {
1229                 dso_type = DSO__TYPE_64BIT;
1230                 goto out_end;
1231         }
1232
1233         if (gelf_getehdr(elf, &ehdr) == NULL)
1234                 goto out_end;
1235
1236         if (ehdr.e_machine == EM_X86_64)
1237                 dso_type = DSO__TYPE_X32BIT;
1238         else
1239                 dso_type = DSO__TYPE_32BIT;
1240 out_end:
1241         elf_end(elf);
1242 out:
1243         return dso_type;
1244 }
1245
1246 static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
1247 {
1248         ssize_t r;
1249         size_t n;
1250         int err = -1;
1251         char *buf = malloc(page_size);
1252
1253         if (buf == NULL)
1254                 return -1;
1255
1256         if (lseek(to, to_offs, SEEK_SET) != to_offs)
1257                 goto out;
1258
1259         if (lseek(from, from_offs, SEEK_SET) != from_offs)
1260                 goto out;
1261
1262         while (len) {
1263                 n = page_size;
1264                 if (len < n)
1265                         n = len;
1266                 /* Use read because mmap won't work on proc files */
1267                 r = read(from, buf, n);
1268                 if (r < 0)
1269                         goto out;
1270                 if (!r)
1271                         break;
1272                 n = r;
1273                 r = write(to, buf, n);
1274                 if (r < 0)
1275                         goto out;
1276                 if ((size_t)r != n)
1277                         goto out;
1278                 len -= n;
1279         }
1280
1281         err = 0;
1282 out:
1283         free(buf);
1284         return err;
1285 }
1286
1287 struct kcore {
1288         int fd;
1289         int elfclass;
1290         Elf *elf;
1291         GElf_Ehdr ehdr;
1292 };
1293
1294 static int kcore__open(struct kcore *kcore, const char *filename)
1295 {
1296         GElf_Ehdr *ehdr;
1297
1298         kcore->fd = open(filename, O_RDONLY);
1299         if (kcore->fd == -1)
1300                 return -1;
1301
1302         kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
1303         if (!kcore->elf)
1304                 goto out_close;
1305
1306         kcore->elfclass = gelf_getclass(kcore->elf);
1307         if (kcore->elfclass == ELFCLASSNONE)
1308                 goto out_end;
1309
1310         ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1311         if (!ehdr)
1312                 goto out_end;
1313
1314         return 0;
1315
1316 out_end:
1317         elf_end(kcore->elf);
1318 out_close:
1319         close(kcore->fd);
1320         return -1;
1321 }
1322
1323 static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
1324                        bool temp)
1325 {
1326         kcore->elfclass = elfclass;
1327
1328         if (temp)
1329                 kcore->fd = mkstemp(filename);
1330         else
1331                 kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
1332         if (kcore->fd == -1)
1333                 return -1;
1334
1335         kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
1336         if (!kcore->elf)
1337                 goto out_close;
1338
1339         if (!gelf_newehdr(kcore->elf, elfclass))
1340                 goto out_end;
1341
1342         memset(&kcore->ehdr, 0, sizeof(GElf_Ehdr));
1343
1344         return 0;
1345
1346 out_end:
1347         elf_end(kcore->elf);
1348 out_close:
1349         close(kcore->fd);
1350         unlink(filename);
1351         return -1;
1352 }
1353
1354 static void kcore__close(struct kcore *kcore)
1355 {
1356         elf_end(kcore->elf);
1357         close(kcore->fd);
1358 }
1359
1360 static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
1361 {
1362         GElf_Ehdr *ehdr = &to->ehdr;
1363         GElf_Ehdr *kehdr = &from->ehdr;
1364
1365         memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
1366         ehdr->e_type      = kehdr->e_type;
1367         ehdr->e_machine   = kehdr->e_machine;
1368         ehdr->e_version   = kehdr->e_version;
1369         ehdr->e_entry     = 0;
1370         ehdr->e_shoff     = 0;
1371         ehdr->e_flags     = kehdr->e_flags;
1372         ehdr->e_phnum     = count;
1373         ehdr->e_shentsize = 0;
1374         ehdr->e_shnum     = 0;
1375         ehdr->e_shstrndx  = 0;
1376
1377         if (from->elfclass == ELFCLASS32) {
1378                 ehdr->e_phoff     = sizeof(Elf32_Ehdr);
1379                 ehdr->e_ehsize    = sizeof(Elf32_Ehdr);
1380                 ehdr->e_phentsize = sizeof(Elf32_Phdr);
1381         } else {
1382                 ehdr->e_phoff     = sizeof(Elf64_Ehdr);
1383                 ehdr->e_ehsize    = sizeof(Elf64_Ehdr);
1384                 ehdr->e_phentsize = sizeof(Elf64_Phdr);
1385         }
1386
1387         if (!gelf_update_ehdr(to->elf, ehdr))
1388                 return -1;
1389
1390         if (!gelf_newphdr(to->elf, count))
1391                 return -1;
1392
1393         return 0;
1394 }
1395
1396 static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
1397                            u64 addr, u64 len)
1398 {
1399         GElf_Phdr phdr = {
1400                 .p_type         = PT_LOAD,
1401                 .p_flags        = PF_R | PF_W | PF_X,
1402                 .p_offset       = offset,
1403                 .p_vaddr        = addr,
1404                 .p_paddr        = 0,
1405                 .p_filesz       = len,
1406                 .p_memsz        = len,
1407                 .p_align        = page_size,
1408         };
1409
1410         if (!gelf_update_phdr(kcore->elf, idx, &phdr))
1411                 return -1;
1412
1413         return 0;
1414 }
1415
1416 static off_t kcore__write(struct kcore *kcore)
1417 {
1418         return elf_update(kcore->elf, ELF_C_WRITE);
1419 }
1420
1421 struct phdr_data {
1422         off_t offset;
1423         off_t rel;
1424         u64 addr;
1425         u64 len;
1426         struct list_head node;
1427         struct phdr_data *remaps;
1428 };
1429
1430 struct sym_data {
1431         u64 addr;
1432         struct list_head node;
1433 };
1434
1435 struct kcore_copy_info {
1436         u64 stext;
1437         u64 etext;
1438         u64 first_symbol;
1439         u64 last_symbol;
1440         u64 first_module;
1441         u64 last_module_symbol;
1442         size_t phnum;
1443         struct list_head phdrs;
1444         struct list_head syms;
1445 };
1446
1447 #define kcore_copy__for_each_phdr(k, p) \
1448         list_for_each_entry((p), &(k)->phdrs, node)
1449
1450 static struct phdr_data *phdr_data__new(u64 addr, u64 len, off_t offset)
1451 {
1452         struct phdr_data *p = zalloc(sizeof(*p));
1453
1454         if (p) {
1455                 p->addr   = addr;
1456                 p->len    = len;
1457                 p->offset = offset;
1458         }
1459
1460         return p;
1461 }
1462
1463 static struct phdr_data *kcore_copy_info__addnew(struct kcore_copy_info *kci,
1464                                                  u64 addr, u64 len,
1465                                                  off_t offset)
1466 {
1467         struct phdr_data *p = phdr_data__new(addr, len, offset);
1468
1469         if (p)
1470                 list_add_tail(&p->node, &kci->phdrs);
1471
1472         return p;
1473 }
1474
1475 static void kcore_copy__free_phdrs(struct kcore_copy_info *kci)
1476 {
1477         struct phdr_data *p, *tmp;
1478
1479         list_for_each_entry_safe(p, tmp, &kci->phdrs, node) {
1480                 list_del(&p->node);
1481                 free(p);
1482         }
1483 }
1484
1485 static struct sym_data *kcore_copy__new_sym(struct kcore_copy_info *kci,
1486                                             u64 addr)
1487 {
1488         struct sym_data *s = zalloc(sizeof(*s));
1489
1490         if (s) {
1491                 s->addr = addr;
1492                 list_add_tail(&s->node, &kci->syms);
1493         }
1494
1495         return s;
1496 }
1497
1498 static void kcore_copy__free_syms(struct kcore_copy_info *kci)
1499 {
1500         struct sym_data *s, *tmp;
1501
1502         list_for_each_entry_safe(s, tmp, &kci->syms, node) {
1503                 list_del(&s->node);
1504                 free(s);
1505         }
1506 }
1507
1508 static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
1509                                         u64 start)
1510 {
1511         struct kcore_copy_info *kci = arg;
1512
1513         if (!kallsyms__is_function(type))
1514                 return 0;
1515
1516         if (strchr(name, '[')) {
1517                 if (start > kci->last_module_symbol)
1518                         kci->last_module_symbol = start;
1519                 return 0;
1520         }
1521
1522         if (!kci->first_symbol || start < kci->first_symbol)
1523                 kci->first_symbol = start;
1524
1525         if (!kci->last_symbol || start > kci->last_symbol)
1526                 kci->last_symbol = start;
1527
1528         if (!strcmp(name, "_stext")) {
1529                 kci->stext = start;
1530                 return 0;
1531         }
1532
1533         if (!strcmp(name, "_etext")) {
1534                 kci->etext = start;
1535                 return 0;
1536         }
1537
1538         if (is_entry_trampoline(name) && !kcore_copy__new_sym(kci, start))
1539                 return -1;
1540
1541         return 0;
1542 }
1543
1544 static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
1545                                       const char *dir)
1546 {
1547         char kallsyms_filename[PATH_MAX];
1548
1549         scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);
1550
1551         if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
1552                 return -1;
1553
1554         if (kallsyms__parse(kallsyms_filename, kci,
1555                             kcore_copy__process_kallsyms) < 0)
1556                 return -1;
1557
1558         return 0;
1559 }
1560
1561 static int kcore_copy__process_modules(void *arg,
1562                                        const char *name __maybe_unused,
1563                                        u64 start, u64 size __maybe_unused)
1564 {
1565         struct kcore_copy_info *kci = arg;
1566
1567         if (!kci->first_module || start < kci->first_module)
1568                 kci->first_module = start;
1569
1570         return 0;
1571 }
1572
1573 static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
1574                                      const char *dir)
1575 {
1576         char modules_filename[PATH_MAX];
1577
1578         scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);
1579
1580         if (symbol__restricted_filename(modules_filename, "/proc/modules"))
1581                 return -1;
1582
1583         if (modules__parse(modules_filename, kci,
1584                            kcore_copy__process_modules) < 0)
1585                 return -1;
1586
1587         return 0;
1588 }
1589
1590 static int kcore_copy__map(struct kcore_copy_info *kci, u64 start, u64 end,
1591                            u64 pgoff, u64 s, u64 e)
1592 {
1593         u64 len, offset;
1594
1595         if (s < start || s >= end)
1596                 return 0;
1597
1598         offset = (s - start) + pgoff;
1599         len = e < end ? e - s : end - s;
1600
1601         return kcore_copy_info__addnew(kci, s, len, offset) ? 0 : -1;
1602 }
1603
1604 static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
1605 {
1606         struct kcore_copy_info *kci = data;
1607         u64 end = start + len;
1608         struct sym_data *sdat;
1609
1610         if (kcore_copy__map(kci, start, end, pgoff, kci->stext, kci->etext))
1611                 return -1;
1612
1613         if (kcore_copy__map(kci, start, end, pgoff, kci->first_module,
1614                             kci->last_module_symbol))
1615                 return -1;
1616
1617         list_for_each_entry(sdat, &kci->syms, node) {
1618                 u64 s = round_down(sdat->addr, page_size);
1619
1620                 if (kcore_copy__map(kci, start, end, pgoff, s, s + len))
1621                         return -1;
1622         }
1623
1624         return 0;
1625 }
1626
1627 static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
1628 {
1629         if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
1630                 return -1;
1631
1632         return 0;
1633 }
1634
1635 static void kcore_copy__find_remaps(struct kcore_copy_info *kci)
1636 {
1637         struct phdr_data *p, *k = NULL;
1638         u64 kend;
1639
1640         if (!kci->stext)
1641                 return;
1642
1643         /* Find phdr that corresponds to the kernel map (contains stext) */
1644         kcore_copy__for_each_phdr(kci, p) {
1645                 u64 pend = p->addr + p->len - 1;
1646
1647                 if (p->addr <= kci->stext && pend >= kci->stext) {
1648                         k = p;
1649                         break;
1650                 }
1651         }
1652
1653         if (!k)
1654                 return;
1655
1656         kend = k->offset + k->len;
1657
1658         /* Find phdrs that remap the kernel */
1659         kcore_copy__for_each_phdr(kci, p) {
1660                 u64 pend = p->offset + p->len;
1661
1662                 if (p == k)
1663                         continue;
1664
1665                 if (p->offset >= k->offset && pend <= kend)
1666                         p->remaps = k;
1667         }
1668 }
1669
1670 static void kcore_copy__layout(struct kcore_copy_info *kci)
1671 {
1672         struct phdr_data *p;
1673         off_t rel = 0;
1674
1675         kcore_copy__find_remaps(kci);
1676
1677         kcore_copy__for_each_phdr(kci, p) {
1678                 if (!p->remaps) {
1679                         p->rel = rel;
1680                         rel += p->len;
1681                 }
1682                 kci->phnum += 1;
1683         }
1684
1685         kcore_copy__for_each_phdr(kci, p) {
1686                 struct phdr_data *k = p->remaps;
1687
1688                 if (k)
1689                         p->rel = p->offset - k->offset + k->rel;
1690         }
1691 }
1692
1693 static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
1694                                  Elf *elf)
1695 {
1696         if (kcore_copy__parse_kallsyms(kci, dir))
1697                 return -1;
1698
1699         if (kcore_copy__parse_modules(kci, dir))
1700                 return -1;
1701
1702         if (kci->stext)
1703                 kci->stext = round_down(kci->stext, page_size);
1704         else
1705                 kci->stext = round_down(kci->first_symbol, page_size);
1706
1707         if (kci->etext) {
1708                 kci->etext = round_up(kci->etext, page_size);
1709         } else if (kci->last_symbol) {
1710                 kci->etext = round_up(kci->last_symbol, page_size);
1711                 kci->etext += page_size;
1712         }
1713
1714         kci->first_module = round_down(kci->first_module, page_size);
1715
1716         if (kci->last_module_symbol) {
1717                 kci->last_module_symbol = round_up(kci->last_module_symbol,
1718                                                    page_size);
1719                 kci->last_module_symbol += page_size;
1720         }
1721
1722         if (!kci->stext || !kci->etext)
1723                 return -1;
1724
1725         if (kci->first_module && !kci->last_module_symbol)
1726                 return -1;
1727
1728         if (kcore_copy__read_maps(kci, elf))
1729                 return -1;
1730
1731         kcore_copy__layout(kci);
1732
1733         return 0;
1734 }
1735
1736 static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
1737                                  const char *name)
1738 {
1739         char from_filename[PATH_MAX];
1740         char to_filename[PATH_MAX];
1741
1742         scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1743         scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1744
1745         return copyfile_mode(from_filename, to_filename, 0400);
1746 }
1747
1748 static int kcore_copy__unlink(const char *dir, const char *name)
1749 {
1750         char filename[PATH_MAX];
1751
1752         scnprintf(filename, PATH_MAX, "%s/%s", dir, name);
1753
1754         return unlink(filename);
1755 }
1756
1757 static int kcore_copy__compare_fds(int from, int to)
1758 {
1759         char *buf_from;
1760         char *buf_to;
1761         ssize_t ret;
1762         size_t len;
1763         int err = -1;
1764
1765         buf_from = malloc(page_size);
1766         buf_to = malloc(page_size);
1767         if (!buf_from || !buf_to)
1768                 goto out;
1769
1770         while (1) {
1771                 /* Use read because mmap won't work on proc files */
1772                 ret = read(from, buf_from, page_size);
1773                 if (ret < 0)
1774                         goto out;
1775
1776                 if (!ret)
1777                         break;
1778
1779                 len = ret;
1780
1781                 if (readn(to, buf_to, len) != (int)len)
1782                         goto out;
1783
1784                 if (memcmp(buf_from, buf_to, len))
1785                         goto out;
1786         }
1787
1788         err = 0;
1789 out:
1790         free(buf_to);
1791         free(buf_from);
1792         return err;
1793 }
1794
1795 static int kcore_copy__compare_files(const char *from_filename,
1796                                      const char *to_filename)
1797 {
1798         int from, to, err = -1;
1799
1800         from = open(from_filename, O_RDONLY);
1801         if (from < 0)
1802                 return -1;
1803
1804         to = open(to_filename, O_RDONLY);
1805         if (to < 0)
1806                 goto out_close_from;
1807
1808         err = kcore_copy__compare_fds(from, to);
1809
1810         close(to);
1811 out_close_from:
1812         close(from);
1813         return err;
1814 }
1815
1816 static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
1817                                     const char *name)
1818 {
1819         char from_filename[PATH_MAX];
1820         char to_filename[PATH_MAX];
1821
1822         scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1823         scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1824
1825         return kcore_copy__compare_files(from_filename, to_filename);
1826 }
1827
1828 /**
1829  * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
1830  * @from_dir: from directory
1831  * @to_dir: to directory
1832  *
1833  * This function copies kallsyms, modules and kcore files from one directory to
1834  * another.  kallsyms and modules are copied entirely.  Only code segments are
1835  * copied from kcore.  It is assumed that two segments suffice: one for the
1836  * kernel proper and one for all the modules.  The code segments are determined
1837  * from kallsyms and modules files.  The kernel map starts at _stext or the
1838  * lowest function symbol, and ends at _etext or the highest function symbol.
1839  * The module map starts at the lowest module address and ends at the highest
1840  * module symbol.  Start addresses are rounded down to the nearest page.  End
1841  * addresses are rounded up to the nearest page.  An extra page is added to the
1842  * highest kernel symbol and highest module symbol to, hopefully, encompass that
1843  * symbol too.  Because it contains only code sections, the resulting kcore is
1844  * unusual.  One significant peculiarity is that the mapping (start -> pgoff)
1845  * is not the same for the kernel map and the modules map.  That happens because
1846  * the data is copied adjacently whereas the original kcore has gaps.  Finally,
1847  * kallsyms and modules files are compared with their copies to check that
1848  * modules have not been loaded or unloaded while the copies were taking place.
1849  *
1850  * Return: %0 on success, %-1 on failure.
1851  */
1852 int kcore_copy(const char *from_dir, const char *to_dir)
1853 {
1854         struct kcore kcore;
1855         struct kcore extract;
1856         int idx = 0, err = -1;
1857         off_t offset, sz;
1858         struct kcore_copy_info kci = { .stext = 0, };
1859         char kcore_filename[PATH_MAX];
1860         char extract_filename[PATH_MAX];
1861         struct phdr_data *p;
1862
1863         INIT_LIST_HEAD(&kci.phdrs);
1864         INIT_LIST_HEAD(&kci.syms);
1865
1866         if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
1867                 return -1;
1868
1869         if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
1870                 goto out_unlink_kallsyms;
1871
1872         scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
1873         scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);
1874
1875         if (kcore__open(&kcore, kcore_filename))
1876                 goto out_unlink_modules;
1877
1878         if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
1879                 goto out_kcore_close;
1880
1881         if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
1882                 goto out_kcore_close;
1883
1884         if (kcore__copy_hdr(&kcore, &extract, kci.phnum))
1885                 goto out_extract_close;
1886
1887         offset = gelf_fsize(extract.elf, ELF_T_EHDR, 1, EV_CURRENT) +
1888                  gelf_fsize(extract.elf, ELF_T_PHDR, kci.phnum, EV_CURRENT);
1889         offset = round_up(offset, page_size);
1890
1891         kcore_copy__for_each_phdr(&kci, p) {
1892                 off_t offs = p->rel + offset;
1893
1894                 if (kcore__add_phdr(&extract, idx++, offs, p->addr, p->len))
1895                         goto out_extract_close;
1896         }
1897
1898         sz = kcore__write(&extract);
1899         if (sz < 0 || sz > offset)
1900                 goto out_extract_close;
1901
1902         kcore_copy__for_each_phdr(&kci, p) {
1903                 off_t offs = p->rel + offset;
1904
1905                 if (p->remaps)
1906                         continue;
1907                 if (copy_bytes(kcore.fd, p->offset, extract.fd, offs, p->len))
1908                         goto out_extract_close;
1909         }
1910
1911         if (kcore_copy__compare_file(from_dir, to_dir, "modules"))
1912                 goto out_extract_close;
1913
1914         if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
1915                 goto out_extract_close;
1916
1917         err = 0;
1918
1919 out_extract_close:
1920         kcore__close(&extract);
1921         if (err)
1922                 unlink(extract_filename);
1923 out_kcore_close:
1924         kcore__close(&kcore);
1925 out_unlink_modules:
1926         if (err)
1927                 kcore_copy__unlink(to_dir, "modules");
1928 out_unlink_kallsyms:
1929         if (err)
1930                 kcore_copy__unlink(to_dir, "kallsyms");
1931
1932         kcore_copy__free_phdrs(&kci);
1933         kcore_copy__free_syms(&kci);
1934
1935         return err;
1936 }
1937
1938 int kcore_extract__create(struct kcore_extract *kce)
1939 {
1940         struct kcore kcore;
1941         struct kcore extract;
1942         size_t count = 1;
1943         int idx = 0, err = -1;
1944         off_t offset = page_size, sz;
1945
1946         if (kcore__open(&kcore, kce->kcore_filename))
1947                 return -1;
1948
1949         strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
1950         if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
1951                 goto out_kcore_close;
1952
1953         if (kcore__copy_hdr(&kcore, &extract, count))
1954                 goto out_extract_close;
1955
1956         if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
1957                 goto out_extract_close;
1958
1959         sz = kcore__write(&extract);
1960         if (sz < 0 || sz > offset)
1961                 goto out_extract_close;
1962
1963         if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
1964                 goto out_extract_close;
1965
1966         err = 0;
1967
1968 out_extract_close:
1969         kcore__close(&extract);
1970         if (err)
1971                 unlink(kce->extract_filename);
1972 out_kcore_close:
1973         kcore__close(&kcore);
1974
1975         return err;
1976 }
1977
1978 void kcore_extract__delete(struct kcore_extract *kce)
1979 {
1980         unlink(kce->extract_filename);
1981 }
1982
1983 #ifdef HAVE_GELF_GETNOTE_SUPPORT
1984
1985 static void sdt_adjust_loc(struct sdt_note *tmp, GElf_Addr base_off)
1986 {
1987         if (!base_off)
1988                 return;
1989
1990         if (tmp->bit32)
1991                 tmp->addr.a32[SDT_NOTE_IDX_LOC] =
1992                         tmp->addr.a32[SDT_NOTE_IDX_LOC] + base_off -
1993                         tmp->addr.a32[SDT_NOTE_IDX_BASE];
1994         else
1995                 tmp->addr.a64[SDT_NOTE_IDX_LOC] =
1996                         tmp->addr.a64[SDT_NOTE_IDX_LOC] + base_off -
1997                         tmp->addr.a64[SDT_NOTE_IDX_BASE];
1998 }
1999
2000 static void sdt_adjust_refctr(struct sdt_note *tmp, GElf_Addr base_addr,
2001                               GElf_Addr base_off)
2002 {
2003         if (!base_off)
2004                 return;
2005
2006         if (tmp->bit32 && tmp->addr.a32[SDT_NOTE_IDX_REFCTR])
2007                 tmp->addr.a32[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
2008         else if (tmp->addr.a64[SDT_NOTE_IDX_REFCTR])
2009                 tmp->addr.a64[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
2010 }
2011
2012 /**
2013  * populate_sdt_note : Parse raw data and identify SDT note
2014  * @elf: elf of the opened file
2015  * @data: raw data of a section with description offset applied
2016  * @len: note description size
2017  * @type: type of the note
2018  * @sdt_notes: List to add the SDT note
2019  *
2020  * Responsible for parsing the @data in section .note.stapsdt in @elf and
2021  * if its an SDT note, it appends to @sdt_notes list.
2022  */
2023 static int populate_sdt_note(Elf **elf, const char *data, size_t len,
2024                              struct list_head *sdt_notes)
2025 {
2026         const char *provider, *name, *args;
2027         struct sdt_note *tmp = NULL;
2028         GElf_Ehdr ehdr;
2029         GElf_Shdr shdr;
2030         int ret = -EINVAL;
2031
2032         union {
2033                 Elf64_Addr a64[NR_ADDR];
2034                 Elf32_Addr a32[NR_ADDR];
2035         } buf;
2036
2037         Elf_Data dst = {
2038                 .d_buf = &buf, .d_type = ELF_T_ADDR, .d_version = EV_CURRENT,
2039                 .d_size = gelf_fsize((*elf), ELF_T_ADDR, NR_ADDR, EV_CURRENT),
2040                 .d_off = 0, .d_align = 0
2041         };
2042         Elf_Data src = {
2043                 .d_buf = (void *) data, .d_type = ELF_T_ADDR,
2044                 .d_version = EV_CURRENT, .d_size = dst.d_size, .d_off = 0,
2045                 .d_align = 0
2046         };
2047
2048         tmp = (struct sdt_note *)calloc(1, sizeof(struct sdt_note));
2049         if (!tmp) {
2050                 ret = -ENOMEM;
2051                 goto out_err;
2052         }
2053
2054         INIT_LIST_HEAD(&tmp->note_list);
2055
2056         if (len < dst.d_size + 3)
2057                 goto out_free_note;
2058
2059         /* Translation from file representation to memory representation */
2060         if (gelf_xlatetom(*elf, &dst, &src,
2061                           elf_getident(*elf, NULL)[EI_DATA]) == NULL) {
2062                 pr_err("gelf_xlatetom : %s\n", elf_errmsg(-1));
2063                 goto out_free_note;
2064         }
2065
2066         /* Populate the fields of sdt_note */
2067         provider = data + dst.d_size;
2068
2069         name = (const char *)memchr(provider, '\0', data + len - provider);
2070         if (name++ == NULL)
2071                 goto out_free_note;
2072
2073         tmp->provider = strdup(provider);
2074         if (!tmp->provider) {
2075                 ret = -ENOMEM;
2076                 goto out_free_note;
2077         }
2078         tmp->name = strdup(name);
2079         if (!tmp->name) {
2080                 ret = -ENOMEM;
2081                 goto out_free_prov;
2082         }
2083
2084         args = memchr(name, '\0', data + len - name);
2085
2086         /*
2087          * There is no argument if:
2088          * - We reached the end of the note;
2089          * - There is not enough room to hold a potential string;
2090          * - The argument string is empty or just contains ':'.
2091          */
2092         if (args == NULL || data + len - args < 2 ||
2093                 args[1] == ':' || args[1] == '\0')
2094                 tmp->args = NULL;
2095         else {
2096                 tmp->args = strdup(++args);
2097                 if (!tmp->args) {
2098                         ret = -ENOMEM;
2099                         goto out_free_name;
2100                 }
2101         }
2102
2103         if (gelf_getclass(*elf) == ELFCLASS32) {
2104                 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr));
2105                 tmp->bit32 = true;
2106         } else {
2107                 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf64_Addr));
2108                 tmp->bit32 = false;
2109         }
2110
2111         if (!gelf_getehdr(*elf, &ehdr)) {
2112                 pr_debug("%s : cannot get elf header.\n", __func__);
2113                 ret = -EBADF;
2114                 goto out_free_args;
2115         }
2116
2117         /* Adjust the prelink effect :
2118          * Find out the .stapsdt.base section.
2119          * This scn will help us to handle prelinking (if present).
2120          * Compare the retrieved file offset of the base section with the
2121          * base address in the description of the SDT note. If its different,
2122          * then accordingly, adjust the note location.
2123          */
2124         if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL))
2125                 sdt_adjust_loc(tmp, shdr.sh_offset);
2126
2127         /* Adjust reference counter offset */
2128         if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_PROBES_SCN, NULL))
2129                 sdt_adjust_refctr(tmp, shdr.sh_addr, shdr.sh_offset);
2130
2131         list_add_tail(&tmp->note_list, sdt_notes);
2132         return 0;
2133
2134 out_free_args:
2135         free(tmp->args);
2136 out_free_name:
2137         free(tmp->name);
2138 out_free_prov:
2139         free(tmp->provider);
2140 out_free_note:
2141         free(tmp);
2142 out_err:
2143         return ret;
2144 }
2145
2146 /**
2147  * construct_sdt_notes_list : constructs a list of SDT notes
2148  * @elf : elf to look into
2149  * @sdt_notes : empty list_head
2150  *
2151  * Scans the sections in 'elf' for the section
2152  * .note.stapsdt. It, then calls populate_sdt_note to find
2153  * out the SDT events and populates the 'sdt_notes'.
2154  */
2155 static int construct_sdt_notes_list(Elf *elf, struct list_head *sdt_notes)
2156 {
2157         GElf_Ehdr ehdr;
2158         Elf_Scn *scn = NULL;
2159         Elf_Data *data;
2160         GElf_Shdr shdr;
2161         size_t shstrndx, next;
2162         GElf_Nhdr nhdr;
2163         size_t name_off, desc_off, offset;
2164         int ret = 0;
2165
2166         if (gelf_getehdr(elf, &ehdr) == NULL) {
2167                 ret = -EBADF;
2168                 goto out_ret;
2169         }
2170         if (elf_getshdrstrndx(elf, &shstrndx) != 0) {
2171                 ret = -EBADF;
2172                 goto out_ret;
2173         }
2174
2175         /* Look for the required section */
2176         scn = elf_section_by_name(elf, &ehdr, &shdr, SDT_NOTE_SCN, NULL);
2177         if (!scn) {
2178                 ret = -ENOENT;
2179                 goto out_ret;
2180         }
2181
2182         if ((shdr.sh_type != SHT_NOTE) || (shdr.sh_flags & SHF_ALLOC)) {
2183                 ret = -ENOENT;
2184                 goto out_ret;
2185         }
2186
2187         data = elf_getdata(scn, NULL);
2188
2189         /* Get the SDT notes */
2190         for (offset = 0; (next = gelf_getnote(data, offset, &nhdr, &name_off,
2191                                               &desc_off)) > 0; offset = next) {
2192                 if (nhdr.n_namesz == sizeof(SDT_NOTE_NAME) &&
2193                     !memcmp(data->d_buf + name_off, SDT_NOTE_NAME,
2194                             sizeof(SDT_NOTE_NAME))) {
2195                         /* Check the type of the note */
2196                         if (nhdr.n_type != SDT_NOTE_TYPE)
2197                                 goto out_ret;
2198
2199                         ret = populate_sdt_note(&elf, ((data->d_buf) + desc_off),
2200                                                 nhdr.n_descsz, sdt_notes);
2201                         if (ret < 0)
2202                                 goto out_ret;
2203                 }
2204         }
2205         if (list_empty(sdt_notes))
2206                 ret = -ENOENT;
2207
2208 out_ret:
2209         return ret;
2210 }
2211
2212 /**
2213  * get_sdt_note_list : Wrapper to construct a list of sdt notes
2214  * @head : empty list_head
2215  * @target : file to find SDT notes from
2216  *
2217  * This opens the file, initializes
2218  * the ELF and then calls construct_sdt_notes_list.
2219  */
2220 int get_sdt_note_list(struct list_head *head, const char *target)
2221 {
2222         Elf *elf;
2223         int fd, ret;
2224
2225         fd = open(target, O_RDONLY);
2226         if (fd < 0)
2227                 return -EBADF;
2228
2229         elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
2230         if (!elf) {
2231                 ret = -EBADF;
2232                 goto out_close;
2233         }
2234         ret = construct_sdt_notes_list(elf, head);
2235         elf_end(elf);
2236 out_close:
2237         close(fd);
2238         return ret;
2239 }
2240
2241 /**
2242  * cleanup_sdt_note_list : free the sdt notes' list
2243  * @sdt_notes: sdt notes' list
2244  *
2245  * Free up the SDT notes in @sdt_notes.
2246  * Returns the number of SDT notes free'd.
2247  */
2248 int cleanup_sdt_note_list(struct list_head *sdt_notes)
2249 {
2250         struct sdt_note *tmp, *pos;
2251         int nr_free = 0;
2252
2253         list_for_each_entry_safe(pos, tmp, sdt_notes, note_list) {
2254                 list_del(&pos->note_list);
2255                 free(pos->name);
2256                 free(pos->provider);
2257                 free(pos);
2258                 nr_free++;
2259         }
2260         return nr_free;
2261 }
2262
2263 /**
2264  * sdt_notes__get_count: Counts the number of sdt events
2265  * @start: list_head to sdt_notes list
2266  *
2267  * Returns the number of SDT notes in a list
2268  */
2269 int sdt_notes__get_count(struct list_head *start)
2270 {
2271         struct sdt_note *sdt_ptr;
2272         int count = 0;
2273
2274         list_for_each_entry(sdt_ptr, start, note_list)
2275                 count++;
2276         return count;
2277 }
2278 #endif
2279
2280 void symbol__elf_init(void)
2281 {
2282         elf_version(EV_CURRENT);
2283 }