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