arch/x86/boot/compressed/relocs.c

   1 #include <stdio.h>
   2 #include <stdarg.h>
   3 #include <stdlib.h>
   4 #include <stdint.h>
   5 #include <string.h>
   6 #include <errno.h>
   7 #include <unistd.h>
   8 #include <elf.h>
   9 #include <byteswap.h>
  10 #define USE_BSD
  11 #include <endian.h>
  12
  13 #define MAX_SHDRS 100
  14 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
  15 static Elf32_Ehdr ehdr;
  16 static Elf32_Shdr shdr[MAX_SHDRS];
  17 static Elf32_Sym  *symtab[MAX_SHDRS];
  18 static Elf32_Rel  *reltab[MAX_SHDRS];
  19 static char *strtab[MAX_SHDRS];
  20 static unsigned long reloc_count, reloc_idx;
  21 static unsigned long *relocs;
  22
  23 /*
  24  * Following symbols have been audited. There values are constant and do
  25  * not change if bzImage is loaded at a different physical address than
  26  * the address for which it has been compiled. Don't warn user about
  27  * absolute relocations present w.r.t these symbols.
  28  */
  29 static const char* safe_abs_relocs[] = {
  30                 "__kernel_vsyscall",
  31                 "__kernel_rt_sigreturn",
  32                 "__kernel_sigreturn",
  33                 "SYSENTER_RETURN",
  34                 "VDSO_NOTE_MASK",
  35                 "xen_irq_disable_direct_reloc",
  36                 "xen_save_fl_direct_reloc",
  37 };
  38
  39 static int is_safe_abs_reloc(const char* sym_name)
  40 {
  41         int i;
  42
  43         for(i = 0; i < ARRAY_SIZE(safe_abs_relocs); i++) {
  44                 if (!strcmp(sym_name, safe_abs_relocs[i]))
  45                         /* Match found */
  46                         return 1;
  47         }
  48         if (strncmp(sym_name, "__crc_", 6) == 0)
  49                 return 1;
  50         return 0;
  51 }
  52
  53 static void die(char *fmt, ...)
  54 {
  55         va_list ap;
  56         va_start(ap, fmt);
  57         vfprintf(stderr, fmt, ap);
  58         va_end(ap);
  59         exit(1);
  60 }
  61
  62 static const char *sym_type(unsigned type)
  63 {
  64         static const char *type_name[] = {
  65 #define SYM_TYPE(X) [X] = #X
  66                 SYM_TYPE(STT_NOTYPE),
  67                 SYM_TYPE(STT_OBJECT),
  68                 SYM_TYPE(STT_FUNC),
  69                 SYM_TYPE(STT_SECTION),
  70                 SYM_TYPE(STT_FILE),
  71                 SYM_TYPE(STT_COMMON),
  72                 SYM_TYPE(STT_TLS),
  73 #undef SYM_TYPE
  74         };
  75         const char *name = "unknown sym type name";
  76         if (type < ARRAY_SIZE(type_name)) {
  77                 name = type_name[type];
  78         }
  79         return name;
  80 }
  81
  82 static const char *sym_bind(unsigned bind)
  83 {
  84         static const char *bind_name[] = {
  85 #define SYM_BIND(X) [X] = #X
  86                 SYM_BIND(STB_LOCAL),
  87                 SYM_BIND(STB_GLOBAL),
  88                 SYM_BIND(STB_WEAK),
  89 #undef SYM_BIND
  90         };
  91         const char *name = "unknown sym bind name";
  92         if (bind < ARRAY_SIZE(bind_name)) {
  93                 name = bind_name[bind];
  94         }
  95         return name;
  96 }
  97
  98 static const char *sym_visibility(unsigned visibility)
  99 {
 100         static const char *visibility_name[] = {
 101 #define SYM_VISIBILITY(X) [X] = #X
 102                 SYM_VISIBILITY(STV_DEFAULT),
 103                 SYM_VISIBILITY(STV_INTERNAL),
 104                 SYM_VISIBILITY(STV_HIDDEN),
 105                 SYM_VISIBILITY(STV_PROTECTED),
 106 #undef SYM_VISIBILITY
 107         };
 108         const char *name = "unknown sym visibility name";
 109         if (visibility < ARRAY_SIZE(visibility_name)) {
 110                 name = visibility_name[visibility];
 111         }
 112         return name;
 113 }
 114
 115 static const char *rel_type(unsigned type)
 116 {
 117         static const char *type_name[] = {
 118 #define REL_TYPE(X) [X] = #X
 119                 REL_TYPE(R_386_NONE),
 120                 REL_TYPE(R_386_32),
 121                 REL_TYPE(R_386_PC32),
 122                 REL_TYPE(R_386_GOT32),
 123                 REL_TYPE(R_386_PLT32),
 124                 REL_TYPE(R_386_COPY),
 125                 REL_TYPE(R_386_GLOB_DAT),
 126                 REL_TYPE(R_386_JMP_SLOT),
 127                 REL_TYPE(R_386_RELATIVE),
 128                 REL_TYPE(R_386_GOTOFF),
 129                 REL_TYPE(R_386_GOTPC),
 130 #undef REL_TYPE
 131         };
 132         const char *name = "unknown type rel type name";
 133         if (type < ARRAY_SIZE(type_name)) {
 134                 name = type_name[type];
 135         }
 136         return name;
 137 }
 138
 139 static const char *sec_name(unsigned shndx)
 140 {
 141         const char *sec_strtab;
 142         const char *name;
 143         sec_strtab = strtab[ehdr.e_shstrndx];
 144         name = "<noname>";
 145         if (shndx < ehdr.e_shnum) {
 146                 name = sec_strtab + shdr[shndx].sh_name;
 147         }
 148         else if (shndx == SHN_ABS) {
 149                 name = "ABSOLUTE";
 150         }
 151         else if (shndx == SHN_COMMON) {
 152                 name = "COMMON";
 153         }
 154         return name;
 155 }
 156
 157 static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym)
 158 {
 159         const char *name;
 160         name = "<noname>";
 161         if (sym->st_name) {
 162                 name = sym_strtab + sym->st_name;
 163         }
 164         else {
 165                 name = sec_name(shdr[sym->st_shndx].sh_name);
 166         }
 167         return name;
 168 }
 169
 170
 171
 172 #if BYTE_ORDER == LITTLE_ENDIAN
 173 #define le16_to_cpu(val) (val)
 174 #define le32_to_cpu(val) (val)
 175 #endif
 176 #if BYTE_ORDER == BIG_ENDIAN
 177 #define le16_to_cpu(val) bswap_16(val)
 178 #define le32_to_cpu(val) bswap_32(val)
 179 #endif
 180
 181 static uint16_t elf16_to_cpu(uint16_t val)
 182 {
 183         return le16_to_cpu(val);
 184 }
 185
 186 static uint32_t elf32_to_cpu(uint32_t val)
 187 {
 188         return le32_to_cpu(val);
 189 }
 190
 191 static void read_ehdr(FILE *fp)
 192 {
 193         if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) {
 194                 die("Cannot read ELF header: %s\n",
 195                         strerror(errno));
 196         }
 197         if (memcmp(ehdr.e_ident, ELFMAG, 4) != 0) {
 198                 die("No ELF magic\n");
 199         }
 200         if (ehdr.e_ident[EI_CLASS] != ELFCLASS32) {
 201                 die("Not a 32 bit executable\n");
 202         }
 203         if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) {
 204                 die("Not a LSB ELF executable\n");
 205         }
 206         if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) {
 207                 die("Unknown ELF version\n");
 208         }
 209         /* Convert the fields to native endian */
 210         ehdr.e_type      = elf16_to_cpu(ehdr.e_type);
 211         ehdr.e_machine   = elf16_to_cpu(ehdr.e_machine);
 212         ehdr.e_version   = elf32_to_cpu(ehdr.e_version);
 213         ehdr.e_entry     = elf32_to_cpu(ehdr.e_entry);
 214         ehdr.e_phoff     = elf32_to_cpu(ehdr.e_phoff);
 215         ehdr.e_shoff     = elf32_to_cpu(ehdr.e_shoff);
 216         ehdr.e_flags     = elf32_to_cpu(ehdr.e_flags);
 217         ehdr.e_ehsize    = elf16_to_cpu(ehdr.e_ehsize);
 218         ehdr.e_phentsize = elf16_to_cpu(ehdr.e_phentsize);
 219         ehdr.e_phnum     = elf16_to_cpu(ehdr.e_phnum);
 220         ehdr.e_shentsize = elf16_to_cpu(ehdr.e_shentsize);
 221         ehdr.e_shnum     = elf16_to_cpu(ehdr.e_shnum);
 222         ehdr.e_shstrndx  = elf16_to_cpu(ehdr.e_shstrndx);
 223
 224         if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) {
 225                 die("Unsupported ELF header type\n");
 226         }
 227         if (ehdr.e_machine != EM_386) {
 228                 die("Not for x86\n");
 229         }
 230         if (ehdr.e_version != EV_CURRENT) {
 231                 die("Unknown ELF version\n");
 232         }
 233         if (ehdr.e_ehsize != sizeof(Elf32_Ehdr)) {
 234                 die("Bad Elf header size\n");
 235         }
 236         if (ehdr.e_phentsize != sizeof(Elf32_Phdr)) {
 237                 die("Bad program header entry\n");
 238         }
 239         if (ehdr.e_shentsize != sizeof(Elf32_Shdr)) {
 240                 die("Bad section header entry\n");
 241         }
 242         if (ehdr.e_shstrndx >= ehdr.e_shnum) {
 243                 die("String table index out of bounds\n");
 244         }
 245 }
 246
 247 static void read_shdrs(FILE *fp)
 248 {
 249         int i;
 250         if (ehdr.e_shnum > MAX_SHDRS) {
 251                 die("%d section headers supported: %d\n",
 252                         ehdr.e_shnum, MAX_SHDRS);
 253         }
 254         if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) {
 255                 die("Seek to %d failed: %s\n",
 256                         ehdr.e_shoff, strerror(errno));
 257         }
 258         if (fread(&shdr, sizeof(shdr[0]), ehdr.e_shnum, fp) != ehdr.e_shnum) {
 259                 die("Cannot read ELF section headers: %s\n",
 260                         strerror(errno));
 261         }
 262         for(i = 0; i < ehdr.e_shnum; i++) {
 263                 shdr[i].sh_name      = elf32_to_cpu(shdr[i].sh_name);
 264                 shdr[i].sh_type      = elf32_to_cpu(shdr[i].sh_type);
 265                 shdr[i].sh_flags     = elf32_to_cpu(shdr[i].sh_flags);
 266                 shdr[i].sh_addr      = elf32_to_cpu(shdr[i].sh_addr);
 267                 shdr[i].sh_offset    = elf32_to_cpu(shdr[i].sh_offset);
 268                 shdr[i].sh_size      = elf32_to_cpu(shdr[i].sh_size);
 269                 shdr[i].sh_link      = elf32_to_cpu(shdr[i].sh_link);
 270                 shdr[i].sh_info      = elf32_to_cpu(shdr[i].sh_info);
 271                 shdr[i].sh_addralign = elf32_to_cpu(shdr[i].sh_addralign);
 272                 shdr[i].sh_entsize   = elf32_to_cpu(shdr[i].sh_entsize);
 273         }
 274
 275 }
 276
 277 static void read_strtabs(FILE *fp)
 278 {
 279         int i;
 280         for(i = 0; i < ehdr.e_shnum; i++) {
 281                 if (shdr[i].sh_type != SHT_STRTAB) {
 282                         continue;
 283                 }
 284                 strtab[i] = malloc(shdr[i].sh_size);
 285                 if (!strtab[i]) {
 286                         die("malloc of %d bytes for strtab failed\n",
 287                                 shdr[i].sh_size);
 288                 }
 289                 if (fseek(fp, shdr[i].sh_offset, SEEK_SET) < 0) {
 290                         die("Seek to %d failed: %s\n",
 291                                 shdr[i].sh_offset, strerror(errno));
 292                 }
 293                 if (fread(strtab[i], 1, shdr[i].sh_size, fp) != shdr[i].sh_size) {
 294                         die("Cannot read symbol table: %s\n",
 295                                 strerror(errno));
 296                 }
 297         }
 298 }
 299
 300 static void read_symtabs(FILE *fp)
 301 {
 302         int i,j;
 303         for(i = 0; i < ehdr.e_shnum; i++) {
 304                 if (shdr[i].sh_type != SHT_SYMTAB) {
 305                         continue;
 306                 }
 307                 symtab[i] = malloc(shdr[i].sh_size);
 308                 if (!symtab[i]) {
 309                         die("malloc of %d bytes for symtab failed\n",
 310                                 shdr[i].sh_size);
 311                 }
 312                 if (fseek(fp, shdr[i].sh_offset, SEEK_SET) < 0) {
 313                         die("Seek to %d failed: %s\n",
 314                                 shdr[i].sh_offset, strerror(errno));
 315                 }
 316                 if (fread(symtab[i], 1, shdr[i].sh_size, fp) != shdr[i].sh_size) {
 317                         die("Cannot read symbol table: %s\n",
 318                                 strerror(errno));
 319                 }
 320                 for(j = 0; j < shdr[i].sh_size/sizeof(symtab[i][0]); j++) {
 321                         symtab[i][j].st_name  = elf32_to_cpu(symtab[i][j].st_name);
 322                         symtab[i][j].st_value = elf32_to_cpu(symtab[i][j].st_value);
 323                         symtab[i][j].st_size  = elf32_to_cpu(symtab[i][j].st_size);
 324                         symtab[i][j].st_shndx = elf16_to_cpu(symtab[i][j].st_shndx);
 325                 }
 326         }
 327 }
 328
 329
 330 static void read_relocs(FILE *fp)
 331 {
 332         int i,j;
 333         for(i = 0; i < ehdr.e_shnum; i++) {
 334                 if (shdr[i].sh_type != SHT_REL) {
 335                         continue;
 336                 }
 337                 reltab[i] = malloc(shdr[i].sh_size);
 338                 if (!reltab[i]) {
 339                         die("malloc of %d bytes for relocs failed\n",
 340                                 shdr[i].sh_size);
 341                 }
 342                 if (fseek(fp, shdr[i].sh_offset, SEEK_SET) < 0) {
 343                         die("Seek to %d failed: %s\n",
 344                                 shdr[i].sh_offset, strerror(errno));
 345                 }
 346                 if (fread(reltab[i], 1, shdr[i].sh_size, fp) != shdr[i].sh_size) {
 347                         die("Cannot read symbol table: %s\n",
 348                                 strerror(errno));
 349                 }
 350                 for(j = 0; j < shdr[i].sh_size/sizeof(reltab[0][0]); j++) {
 351                         reltab[i][j].r_offset = elf32_to_cpu(reltab[i][j].r_offset);
 352                         reltab[i][j].r_info   = elf32_to_cpu(reltab[i][j].r_info);
 353                 }
 354         }
 355 }
 356
 357
 358 static void print_absolute_symbols(void)
 359 {
 360         int i;
 361         printf("Absolute symbols\n");
 362         printf(" Num:    Value Size  Type       Bind        Visibility  Name\n");
 363         for(i = 0; i < ehdr.e_shnum; i++) {
 364                 char *sym_strtab;
 365                 Elf32_Sym *sh_symtab;
 366                 int j;
 367                 if (shdr[i].sh_type != SHT_SYMTAB) {
 368                         continue;
 369                 }
 370                 sh_symtab = symtab[i];
 371                 sym_strtab = strtab[shdr[i].sh_link];
 372                 for(j = 0; j < shdr[i].sh_size/sizeof(symtab[0][0]); j++) {
 373                         Elf32_Sym *sym;
 374                         const char *name;
 375                         sym = &symtab[i][j];
 376                         name = sym_name(sym_strtab, sym);
 377                         if (sym->st_shndx != SHN_ABS) {
 378                                 continue;
 379                         }
 380                         printf("%5d %08x %5d %10s %10s %12s %s\n",
 381                                 j, sym->st_value, sym->st_size,
 382                                 sym_type(ELF32_ST_TYPE(sym->st_info)),
 383                                 sym_bind(ELF32_ST_BIND(sym->st_info)),
 384                                 sym_visibility(ELF32_ST_VISIBILITY(sym->st_other)),
 385                                 name);
 386                 }
 387         }
 388         printf("\n");
 389 }
 390
 391 static void print_absolute_relocs(void)
 392 {
 393         int i, printed = 0;
 394
 395         for(i = 0; i < ehdr.e_shnum; i++) {
 396                 char *sym_strtab;
 397                 Elf32_Sym *sh_symtab;
 398                 unsigned sec_applies, sec_symtab;
 399                 int j;
 400                 if (shdr[i].sh_type != SHT_REL) {
 401                         continue;
 402                 }
 403                 sec_symtab  = shdr[i].sh_link;
 404                 sec_applies = shdr[i].sh_info;
 405                 if (!(shdr[sec_applies].sh_flags & SHF_ALLOC)) {
 406                         continue;
 407                 }
 408                 sh_symtab = symtab[sec_symtab];
 409                 sym_strtab = strtab[shdr[sec_symtab].sh_link];
 410                 for(j = 0; j < shdr[i].sh_size/sizeof(reltab[0][0]); j++) {
 411                         Elf32_Rel *rel;
 412                         Elf32_Sym *sym;
 413                         const char *name;
 414                         rel = &reltab[i][j];
 415                         sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
 416                         name = sym_name(sym_strtab, sym);
 417                         if (sym->st_shndx != SHN_ABS) {
 418                                 continue;
 419                         }
 420
 421                         /* Absolute symbols are not relocated if bzImage is
 422                          * loaded at a non-compiled address. Display a warning
 423                          * to user at compile time about the absolute
 424                          * relocations present.
 425                          *
 426                          * User need to audit the code to make sure
 427                          * some symbols which should have been section
 428                          * relative have not become absolute because of some
 429                          * linker optimization or wrong programming usage.
 430                          *
 431                          * Before warning check if this absolute symbol
 432                          * relocation is harmless.
 433                          */
 434                         if (is_safe_abs_reloc(name))
 435                                 continue;
 436
 437                         if (!printed) {
 438                                 printf("WARNING: Absolute relocations"
 439                                         " present\n");
 440                                 printf("Offset     Info     Type     Sym.Value "
 441                                         "Sym.Name\n");
 442                                 printed = 1;
 443                         }
 444
 445                         printf("%08x %08x %10s %08x  %s\n",
 446                                 rel->r_offset,
 447                                 rel->r_info,
 448                                 rel_type(ELF32_R_TYPE(rel->r_info)),
 449                                 sym->st_value,
 450                                 name);
 451                 }
 452         }
 453
 454         if (printed)
 455                 printf("\n");
 456 }
 457
 458 static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym))
 459 {
 460         int i;
 461         /* Walk through the relocations */
 462         for(i = 0; i < ehdr.e_shnum; i++) {
 463                 char *sym_strtab;
 464                 Elf32_Sym *sh_symtab;
 465                 unsigned sec_applies, sec_symtab;
 466                 int j;
 467                 if (shdr[i].sh_type != SHT_REL) {
 468                         continue;
 469                 }
 470                 sec_symtab  = shdr[i].sh_link;
 471                 sec_applies = shdr[i].sh_info;
 472                 if (!(shdr[sec_applies].sh_flags & SHF_ALLOC)) {
 473                         continue;
 474                 }
 475                 sh_symtab = symtab[sec_symtab];
 476                 sym_strtab = strtab[shdr[sec_symtab].sh_link];
 477                 for(j = 0; j < shdr[i].sh_size/sizeof(reltab[0][0]); j++) {
 478                         Elf32_Rel *rel;
 479                         Elf32_Sym *sym;
 480                         unsigned r_type;
 481                         rel = &reltab[i][j];
 482                         sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
 483                         r_type = ELF32_R_TYPE(rel->r_info);
 484                         /* Don't visit relocations to absolute symbols */
 485                         if (sym->st_shndx == SHN_ABS) {
 486                                 continue;
 487                         }
 488                         if (r_type == R_386_PC32) {
 489                                 /* PC relative relocations don't need to be adjusted */
 490                         }
 491                         else if (r_type == R_386_32) {
 492                                 /* Visit relocations that need to be adjusted */
 493                                 visit(rel, sym);
 494                         }
 495                         else {
 496                                 die("Unsupported relocation type: %d\n", r_type);
 497                         }
 498                 }
 499         }
 500 }
 501
 502 static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
 503 {
 504         reloc_count += 1;
 505 }
 506
 507 static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
 508 {
 509         /* Remember the address that needs to be adjusted. */
 510         relocs[reloc_idx++] = rel->r_offset;
 511 }
 512
 513 static int cmp_relocs(const void *va, const void *vb)
 514 {
 515         const unsigned long *a, *b;
 516         a = va; b = vb;
 517         return (*a == *b)? 0 : (*a > *b)? 1 : -1;
 518 }
 519
 520 static void emit_relocs(int as_text)
 521 {
 522         int i;
 523         /* Count how many relocations I have and allocate space for them. */
 524         reloc_count = 0;
 525         walk_relocs(count_reloc);
 526         relocs = malloc(reloc_count * sizeof(relocs[0]));
 527         if (!relocs) {
 528                 die("malloc of %d entries for relocs failed\n",
 529                         reloc_count);
 530         }
 531         /* Collect up the relocations */
 532         reloc_idx = 0;
 533         walk_relocs(collect_reloc);
 534
 535         /* Order the relocations for more efficient processing */
 536         qsort(relocs, reloc_count, sizeof(relocs[0]), cmp_relocs);
 537
 538         /* Print the relocations */
 539         if (as_text) {
 540                 /* Print the relocations in a form suitable that
 541                  * gas will like.
 542                  */
 543                 printf(".section \".data.reloc\",\"a\"\n");
 544                 printf(".balign 4\n");
 545                 for(i = 0; i < reloc_count; i++) {
 546                         printf("\t .long 0x%08lx\n", relocs[i]);
 547                 }
 548                 printf("\n");
 549         }
 550         else {
 551                 unsigned char buf[4];
 552                 buf[0] = buf[1] = buf[2] = buf[3] = 0;
 553                 /* Print a stop */
 554                 printf("%c%c%c%c", buf[0], buf[1], buf[2], buf[3]);
 555                 /* Now print each relocation */
 556                 for(i = 0; i < reloc_count; i++) {
 557                         buf[0] = (relocs[i] >>  0) & 0xff;
 558                         buf[1] = (relocs[i] >>  8) & 0xff;
 559                         buf[2] = (relocs[i] >> 16) & 0xff;
 560                         buf[3] = (relocs[i] >> 24) & 0xff;
 561                         printf("%c%c%c%c", buf[0], buf[1], buf[2], buf[3]);
 562                 }
 563         }
 564 }
 565
 566 static void usage(void)
 567 {
 568         die("relocs [--abs-syms |--abs-relocs | --text] vmlinux\n");
 569 }
 570
 571 int main(int argc, char **argv)
 572 {
 573         int show_absolute_syms, show_absolute_relocs;
 574         int as_text;
 575         const char *fname;
 576         FILE *fp;
 577         int i;
 578
 579         show_absolute_syms = 0;
 580         show_absolute_relocs = 0;
 581         as_text = 0;
 582         fname = NULL;
 583         for(i = 1; i < argc; i++) {
 584                 char *arg = argv[i];
 585                 if (*arg == '-') {
 586                         if (strcmp(argv[1], "--abs-syms") == 0) {
 587                                 show_absolute_syms = 1;
 588                                 continue;
 589                         }
 590
 591                         if (strcmp(argv[1], "--abs-relocs") == 0) {
 592                                 show_absolute_relocs = 1;
 593                                 continue;
 594                         }
 595                         else if (strcmp(argv[1], "--text") == 0) {
 596                                 as_text = 1;
 597                                 continue;
 598                         }
 599                 }
 600                 else if (!fname) {
 601                         fname = arg;
 602                         continue;
 603                 }
 604                 usage();
 605         }
 606         if (!fname) {
 607                 usage();
 608         }
 609         fp = fopen(fname, "r");
 610         if (!fp) {
 611                 die("Cannot open %s: %s\n",
 612                         fname, strerror(errno));
 613         }
 614         read_ehdr(fp);
 615         read_shdrs(fp);
 616         read_strtabs(fp);
 617         read_symtabs(fp);
 618         read_relocs(fp);
 619         if (show_absolute_syms) {
 620                 print_absolute_symbols();
 621                 return 0;
 622         }
 623         if (show_absolute_relocs) {
 624                 print_absolute_relocs();
 625                 return 0;
 626         }
 627         emit_relocs(as_text);
 628         return 0;
 629 }