arch/i386/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 };
  35
  36 static int is_safe_abs_reloc(const char* sym_name)
  37 {
  38         int i, array_size;
  39
  40         array_size = sizeof(safe_abs_relocs)/sizeof(char*);
  41
  42         for(i = 0; i < array_size; i++) {
  43                 if (!strcmp(sym_name, safe_abs_relocs[i]))
  44                         /* Match found */
  45                         return 1;
  46         }
  47         if (strncmp(sym_name, "__crc_", 6) == 0)
  48                 return 1;
  49         return 0;
  50 }
  51
  52 static void die(char *fmt, ...)
  53 {
  54         va_list ap;
  55         va_start(ap, fmt);
  56         vfprintf(stderr, fmt, ap);
  57         va_end(ap);
  58         exit(1);
  59 }
  60
  61 static const char *sym_type(unsigned type)
  62 {
  63         static const char *type_name[] = {
  64 #define SYM_TYPE(X) [X] = #X
  65                 SYM_TYPE(STT_NOTYPE),
  66                 SYM_TYPE(STT_OBJECT),
  67                 SYM_TYPE(STT_FUNC),
  68                 SYM_TYPE(STT_SECTION),
  69                 SYM_TYPE(STT_FILE),
  70                 SYM_TYPE(STT_COMMON),
  71                 SYM_TYPE(STT_TLS),
  72 #undef SYM_TYPE
  73         };
  74         const char *name = "unknown sym type name";
  75         if (type < ARRAY_SIZE(type_name)) {
  76                 name = type_name[type];
  77         }
  78         return name;
  79 }
  80
  81 static const char *sym_bind(unsigned bind)
  82 {
  83         static const char *bind_name[] = {
  84 #define SYM_BIND(X) [X] = #X
  85                 SYM_BIND(STB_LOCAL),
  86                 SYM_BIND(STB_GLOBAL),
  87                 SYM_BIND(STB_WEAK),
  88 #undef SYM_BIND
  89         };
  90         const char *name = "unknown sym bind name";
  91         if (bind < ARRAY_SIZE(bind_name)) {
  92                 name = bind_name[bind];
  93         }
  94         return name;
  95 }
  96
  97 static const char *sym_visibility(unsigned visibility)
  98 {
  99         static const char *visibility_name[] = {
 100 #define SYM_VISIBILITY(X) [X] = #X
 101                 SYM_VISIBILITY(STV_DEFAULT),
 102                 SYM_VISIBILITY(STV_INTERNAL),
 103                 SYM_VISIBILITY(STV_HIDDEN),
 104                 SYM_VISIBILITY(STV_PROTECTED),
 105 #undef SYM_VISIBILITY
 106         };
 107         const char *name = "unknown sym visibility name";
 108         if (visibility < ARRAY_SIZE(visibility_name)) {
 109                 name = visibility_name[visibility];
 110         }
 111         return name;
 112 }
 113
 114 static const char *rel_type(unsigned type)
 115 {
 116         static const char *type_name[] = {
 117 #define REL_TYPE(X) [X] = #X
 118                 REL_TYPE(R_386_NONE),
 119                 REL_TYPE(R_386_32),
 120                 REL_TYPE(R_386_PC32),
 121                 REL_TYPE(R_386_GOT32),
 122                 REL_TYPE(R_386_PLT32),
 123                 REL_TYPE(R_386_COPY),
 124                 REL_TYPE(R_386_GLOB_DAT),
 125                 REL_TYPE(R_386_JMP_SLOT),
 126                 REL_TYPE(R_386_RELATIVE),
 127                 REL_TYPE(R_386_GOTOFF),
 128                 REL_TYPE(R_386_GOTPC),
 129 #undef REL_TYPE
 130         };
 131         const char *name = "unknown type rel type name";
 132         if (type < ARRAY_SIZE(type_name)) {
 133                 name = type_name[type];
 134         }
 135         return name;
 136 }
 137
 138 static const char *sec_name(unsigned shndx)
 139 {
 140         const char *sec_strtab;
 141         const char *name;
 142         sec_strtab = strtab[ehdr.e_shstrndx];
 143         name = "<noname>";
 144         if (shndx < ehdr.e_shnum) {
 145                 name = sec_strtab + shdr[shndx].sh_name;
 146         }
 147         else if (shndx == SHN_ABS) {
 148                 name = "ABSOLUTE";
 149         }
 150         else if (shndx == SHN_COMMON) {
 151                 name = "COMMON";
 152         }
 153         return name;
 154 }
 155
 156 static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym)
 157 {
 158         const char *name;
 159         name = "<noname>";
 160         if (sym->st_name) {
 161                 name = sym_strtab + sym->st_name;
 162         }
 163         else {
 164                 name = sec_name(shdr[sym->st_shndx].sh_name);
 165         }
 166         return name;
 167 }
 168
 169
 170
 171 #if BYTE_ORDER == LITTLE_ENDIAN
 172 #define le16_to_cpu(val) (val)
 173 #define le32_to_cpu(val) (val)
 174 #endif
 175 #if BYTE_ORDER == BIG_ENDIAN
 176 #define le16_to_cpu(val) bswap_16(val)
 177 #define le32_to_cpu(val) bswap_32(val)
 178 #endif
 179
 180 static uint16_t elf16_to_cpu(uint16_t val)
 181 {
 182         return le16_to_cpu(val);
 183 }
 184
 185 static uint32_t elf32_to_cpu(uint32_t val)
 186 {
 187         return le32_to_cpu(val);
 188 }
 189
 190 static void read_ehdr(FILE *fp)
 191 {
 192         if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) {
 193                 die("Cannot read ELF header: %s\n",
 194                         strerror(errno));
 195         }
 196         if (memcmp(ehdr.e_ident, ELFMAG, 4) != 0) {
 197                 die("No ELF magic\n");
 198         }
 199         if (ehdr.e_ident[EI_CLASS] != ELFCLASS32) {
 200                 die("Not a 32 bit executable\n");
 201         }
 202         if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) {
 203                 die("Not a LSB ELF executable\n");
 204         }
 205         if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) {
 206                 die("Unknown ELF version\n");
 207         }
 208         /* Convert the fields to native endian */
 209         ehdr.e_type      = elf16_to_cpu(ehdr.e_type);
 210         ehdr.e_machine   = elf16_to_cpu(ehdr.e_machine);
 211         ehdr.e_version   = elf32_to_cpu(ehdr.e_version);
 212         ehdr.e_entry     = elf32_to_cpu(ehdr.e_entry);
 213         ehdr.e_phoff     = elf32_to_cpu(ehdr.e_phoff);
 214         ehdr.e_shoff     = elf32_to_cpu(ehdr.e_shoff);
 215         ehdr.e_flags     = elf32_to_cpu(ehdr.e_flags);
 216         ehdr.e_ehsize    = elf16_to_cpu(ehdr.e_ehsize);
 217         ehdr.e_phentsize = elf16_to_cpu(ehdr.e_phentsize);
 218         ehdr.e_phnum     = elf16_to_cpu(ehdr.e_phnum);
 219         ehdr.e_shentsize = elf16_to_cpu(ehdr.e_shentsize);
 220         ehdr.e_shnum     = elf16_to_cpu(ehdr.e_shnum);
 221         ehdr.e_shstrndx  = elf16_to_cpu(ehdr.e_shstrndx);
 222
 223         if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) {
 224                 die("Unsupported ELF header type\n");
 225         }
 226         if (ehdr.e_machine != EM_386) {
 227                 die("Not for x86\n");
 228         }
 229         if (ehdr.e_version != EV_CURRENT) {
 230                 die("Unknown ELF version\n");
 231         }
 232         if (ehdr.e_ehsize != sizeof(Elf32_Ehdr)) {
 233                 die("Bad Elf header size\n");
 234         }
 235         if (ehdr.e_phentsize != sizeof(Elf32_Phdr)) {
 236                 die("Bad program header entry\n");
 237         }
 238         if (ehdr.e_shentsize != sizeof(Elf32_Shdr)) {
 239                 die("Bad section header entry\n");
 240         }
 241         if (ehdr.e_shstrndx >= ehdr.e_shnum) {
 242                 die("String table index out of bounds\n");
 243         }
 244 }
 245
 246 static void read_shdrs(FILE *fp)
 247 {
 248         int i;
 249         if (ehdr.e_shnum > MAX_SHDRS) {
 250                 die("%d section headers supported: %d\n",
 251                         ehdr.e_shnum, MAX_SHDRS);
 252         }
 253         if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) {
 254                 die("Seek to %d failed: %s\n",
 255                         ehdr.e_shoff, strerror(errno));
 256         }
 257         if (fread(&shdr, sizeof(shdr[0]), ehdr.e_shnum, fp) != ehdr.e_shnum) {
 258                 die("Cannot read ELF section headers: %s\n",
 259                         strerror(errno));
 260         }
 261         for(i = 0; i < ehdr.e_shnum; i++) {
 262                 shdr[i].sh_name      = elf32_to_cpu(shdr[i].sh_name);
 263                 shdr[i].sh_type      = elf32_to_cpu(shdr[i].sh_type);
 264                 shdr[i].sh_flags     = elf32_to_cpu(shdr[i].sh_flags);
 265                 shdr[i].sh_addr      = elf32_to_cpu(shdr[i].sh_addr);
 266                 shdr[i].sh_offset    = elf32_to_cpu(shdr[i].sh_offset);
 267                 shdr[i].sh_size      = elf32_to_cpu(shdr[i].sh_size);
 268                 shdr[i].sh_link      = elf32_to_cpu(shdr[i].sh_link);
 269                 shdr[i].sh_info      = elf32_to_cpu(shdr[i].sh_info);
 270                 shdr[i].sh_addralign = elf32_to_cpu(shdr[i].sh_addralign);
 271                 shdr[i].sh_entsize   = elf32_to_cpu(shdr[i].sh_entsize);
 272         }
 273
 274 }
 275
 276 static void read_strtabs(FILE *fp)
 277 {
 278         int i;
 279         for(i = 0; i < ehdr.e_shnum; i++) {
 280                 if (shdr[i].sh_type != SHT_STRTAB) {
 281                         continue;
 282                 }
 283                 strtab[i] = malloc(shdr[i].sh_size);
 284                 if (!strtab[i]) {
 285                         die("malloc of %d bytes for strtab failed\n",
 286                                 shdr[i].sh_size);
 287                 }
 288                 if (fseek(fp, shdr[i].sh_offset, SEEK_SET) < 0) {
 289                         die("Seek to %d failed: %s\n",
 290                                 shdr[i].sh_offset, strerror(errno));
 291                 }
 292                 if (fread(strtab[i], 1, shdr[i].sh_size, fp) != shdr[i].sh_size) {
 293                         die("Cannot read symbol table: %s\n",
 294                                 strerror(errno));
 295                 }
 296         }
 297 }
 298
 299 static void read_symtabs(FILE *fp)
 300 {
 301         int i,j;
 302         for(i = 0; i < ehdr.e_shnum; i++) {
 303                 if (shdr[i].sh_type != SHT_SYMTAB) {
 304                         continue;
 305                 }
 306                 symtab[i] = malloc(shdr[i].sh_size);
 307                 if (!symtab[i]) {
 308                         die("malloc of %d bytes for symtab failed\n",
 309                                 shdr[i].sh_size);
 310                 }
 311                 if (fseek(fp, shdr[i].sh_offset, SEEK_SET) < 0) {
 312                         die("Seek to %d failed: %s\n",
 313                                 shdr[i].sh_offset, strerror(errno));
 314                 }
 315                 if (fread(symtab[i], 1, shdr[i].sh_size, fp) != shdr[i].sh_size) {
 316                         die("Cannot read symbol table: %s\n",
 317                                 strerror(errno));
 318                 }
 319                 for(j = 0; j < shdr[i].sh_size/sizeof(symtab[i][0]); j++) {
 320                         symtab[i][j].st_name  = elf32_to_cpu(symtab[i][j].st_name);
 321                         symtab[i][j].st_value = elf32_to_cpu(symtab[i][j].st_value);
 322                         symtab[i][j].st_size  = elf32_to_cpu(symtab[i][j].st_size);
 323                         symtab[i][j].st_shndx = elf16_to_cpu(symtab[i][j].st_shndx);
 324                 }
 325         }
 326 }
 327
 328
 329 static void read_relocs(FILE *fp)
 330 {
 331         int i,j;
 332         for(i = 0; i < ehdr.e_shnum; i++) {
 333                 if (shdr[i].sh_type != SHT_REL) {
 334                         continue;
 335                 }
 336                 reltab[i] = malloc(shdr[i].sh_size);
 337                 if (!reltab[i]) {
 338                         die("malloc of %d bytes for relocs failed\n",
 339                                 shdr[i].sh_size);
 340                 }
 341                 if (fseek(fp, shdr[i].sh_offset, SEEK_SET) < 0) {
 342                         die("Seek to %d failed: %s\n",
 343                                 shdr[i].sh_offset, strerror(errno));
 344                 }
 345                 if (fread(reltab[i], 1, shdr[i].sh_size, fp) != shdr[i].sh_size) {
 346                         die("Cannot read symbol table: %s\n",
 347                                 strerror(errno));
 348                 }
 349                 for(j = 0; j < shdr[i].sh_size/sizeof(reltab[0][0]); j++) {
 350                         reltab[i][j].r_offset = elf32_to_cpu(reltab[i][j].r_offset);
 351                         reltab[i][j].r_info   = elf32_to_cpu(reltab[i][j].r_info);
 352                 }
 353         }
 354 }
 355
 356
 357 static void print_absolute_symbols(void)
 358 {
 359         int i;
 360         printf("Absolute symbols\n");
 361         printf(" Num:    Value Size  Type       Bind        Visibility  Name\n");
 362         for(i = 0; i < ehdr.e_shnum; i++) {
 363                 char *sym_strtab;
 364                 Elf32_Sym *sh_symtab;
 365                 int j;
 366                 if (shdr[i].sh_type != SHT_SYMTAB) {
 367                         continue;
 368                 }
 369                 sh_symtab = symtab[i];
 370                 sym_strtab = strtab[shdr[i].sh_link];
 371                 for(j = 0; j < shdr[i].sh_size/sizeof(symtab[0][0]); j++) {
 372                         Elf32_Sym *sym;
 373                         const char *name;
 374                         sym = &symtab[i][j];
 375                         name = sym_name(sym_strtab, sym);
 376                         if (sym->st_shndx != SHN_ABS) {
 377                                 continue;
 378                         }
 379                         printf("%5d %08x %5d %10s %10s %12s %s\n",
 380                                 j, sym->st_value, sym->st_size,
 381                                 sym_type(ELF32_ST_TYPE(sym->st_info)),
 382                                 sym_bind(ELF32_ST_BIND(sym->st_info)),
 383                                 sym_visibility(ELF32_ST_VISIBILITY(sym->st_other)),
 384                                 name);
 385                 }
 386         }
 387         printf("\n");
 388 }
 389
 390 static void print_absolute_relocs(void)
 391 {
 392         int i, printed = 0;
 393
 394         for(i = 0; i < ehdr.e_shnum; i++) {
 395                 char *sym_strtab;
 396                 Elf32_Sym *sh_symtab;
 397                 unsigned sec_applies, sec_symtab;
 398                 int j;
 399                 if (shdr[i].sh_type != SHT_REL) {
 400                         continue;
 401                 }
 402                 sec_symtab  = shdr[i].sh_link;
 403                 sec_applies = shdr[i].sh_info;
 404                 if (!(shdr[sec_applies].sh_flags & SHF_ALLOC)) {
 405                         continue;
 406                 }
 407                 sh_symtab = symtab[sec_symtab];
 408                 sym_strtab = strtab[shdr[sec_symtab].sh_link];
 409                 for(j = 0; j < shdr[i].sh_size/sizeof(reltab[0][0]); j++) {
 410                         Elf32_Rel *rel;
 411                         Elf32_Sym *sym;
 412                         const char *name;
 413                         rel = &reltab[i][j];
 414                         sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
 415                         name = sym_name(sym_strtab, sym);
 416                         if (sym->st_shndx != SHN_ABS) {
 417                                 continue;
 418                         }
 419
 420                         /* Absolute symbols are not relocated if bzImage is
 421                          * loaded at a non-compiled address. Display a warning
 422                          * to user at compile time about the absolute
 423                          * relocations present.
 424                          *
 425                          * User need to audit the code to make sure
 426                          * some symbols which should have been section
 427                          * relative have not become absolute because of some
 428                          * linker optimization or wrong programming usage.
 429                          *
 430                          * Before warning check if this absolute symbol
 431                          * relocation is harmless.
 432                          */
 433                         if (is_safe_abs_reloc(name))
 434                                 continue;
 435
 436                         if (!printed) {
 437                                 printf("WARNING: Absolute relocations"
 438                                         " present\n");
 439                                 printf("Offset     Info     Type     Sym.Value "
 440                                         "Sym.Name\n");
 441                                 printed = 1;
 442                         }
 443
 444                         printf("%08x %08x %10s %08x  %s\n",
 445                                 rel->r_offset,
 446                                 rel->r_info,
 447                                 rel_type(ELF32_R_TYPE(rel->r_info)),
 448                                 sym->st_value,
 449                                 name);
 450                 }
 451         }
 452
 453         if (printed)
 454                 printf("\n");
 455 }
 456
 457 static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym))
 458 {
 459         int i;
 460         /* Walk through the relocations */
 461         for(i = 0; i < ehdr.e_shnum; i++) {
 462                 char *sym_strtab;
 463                 Elf32_Sym *sh_symtab;
 464                 unsigned sec_applies, sec_symtab;
 465                 int j;
 466                 if (shdr[i].sh_type != SHT_REL) {
 467                         continue;
 468                 }
 469                 sec_symtab  = shdr[i].sh_link;
 470                 sec_applies = shdr[i].sh_info;
 471                 if (!(shdr[sec_applies].sh_flags & SHF_ALLOC)) {
 472                         continue;
 473                 }
 474                 sh_symtab = symtab[sec_symtab];
 475                 sym_strtab = strtab[shdr[sec_symtab].sh_link];
 476                 for(j = 0; j < shdr[i].sh_size/sizeof(reltab[0][0]); j++) {
 477                         Elf32_Rel *rel;
 478                         Elf32_Sym *sym;
 479                         unsigned r_type;
 480                         rel = &reltab[i][j];
 481                         sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
 482                         r_type = ELF32_R_TYPE(rel->r_info);
 483                         /* Don't visit relocations to absolute symbols */
 484                         if (sym->st_shndx == SHN_ABS) {
 485                                 continue;
 486                         }
 487                         if (r_type == R_386_PC32) {
 488                                 /* PC relative relocations don't need to be adjusted */
 489                         }
 490                         else if (r_type == R_386_32) {
 491                                 /* Visit relocations that need to be adjusted */
 492                                 visit(rel, sym);
 493                         }
 494                         else {
 495                                 die("Unsupported relocation type: %d\n", r_type);
 496                         }
 497                 }
 498         }
 499 }
 500
 501 static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
 502 {
 503         reloc_count += 1;
 504 }
 505
 506 static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
 507 {
 508         /* Remember the address that needs to be adjusted. */
 509         relocs[reloc_idx++] = rel->r_offset;
 510 }
 511
 512 static int cmp_relocs(const void *va, const void *vb)
 513 {
 514         const unsigned long *a, *b;
 515         a = va; b = vb;
 516         return (*a == *b)? 0 : (*a > *b)? 1 : -1;
 517 }
 518
 519 static void emit_relocs(int as_text)
 520 {
 521         int i;
 522         /* Count how many relocations I have and allocate space for them. */
 523         reloc_count = 0;
 524         walk_relocs(count_reloc);
 525         relocs = malloc(reloc_count * sizeof(relocs[0]));
 526         if (!relocs) {
 527                 die("malloc of %d entries for relocs failed\n",
 528                         reloc_count);
 529         }
 530         /* Collect up the relocations */
 531         reloc_idx = 0;
 532         walk_relocs(collect_reloc);
 533
 534         /* Order the relocations for more efficient processing */
 535         qsort(relocs, reloc_count, sizeof(relocs[0]), cmp_relocs);
 536
 537         /* Print the relocations */
 538         if (as_text) {
 539                 /* Print the relocations in a form suitable that
 540                  * gas will like.
 541                  */
 542                 printf(".section \".data.reloc\",\"a\"\n");
 543                 printf(".balign 4\n");
 544                 for(i = 0; i < reloc_count; i++) {
 545                         printf("\t .long 0x%08lx\n", relocs[i]);
 546                 }
 547                 printf("\n");
 548         }
 549         else {
 550                 unsigned char buf[4];
 551                 buf[0] = buf[1] = buf[2] = buf[3] = 0;
 552                 /* Print a stop */
 553                 printf("%c%c%c%c", buf[0], buf[1], buf[2], buf[3]);
 554                 /* Now print each relocation */
 555                 for(i = 0; i < reloc_count; i++) {
 556                         buf[0] = (relocs[i] >>  0) & 0xff;
 557                         buf[1] = (relocs[i] >>  8) & 0xff;
 558                         buf[2] = (relocs[i] >> 16) & 0xff;
 559                         buf[3] = (relocs[i] >> 24) & 0xff;
 560                         printf("%c%c%c%c", buf[0], buf[1], buf[2], buf[3]);
 561                 }
 562         }
 563 }
 564
 565 static void usage(void)
 566 {
 567         die("relocs [--abs-syms |--abs-relocs | --text] vmlinux\n");
 568 }
 569
 570 int main(int argc, char **argv)
 571 {
 572         int show_absolute_syms, show_absolute_relocs;
 573         int as_text;
 574         const char *fname;
 575         FILE *fp;
 576         int i;
 577
 578         show_absolute_syms = 0;
 579         show_absolute_relocs = 0;
 580         as_text = 0;
 581         fname = NULL;
 582         for(i = 1; i < argc; i++) {
 583                 char *arg = argv[i];
 584                 if (*arg == '-') {
 585                         if (strcmp(argv[1], "--abs-syms") == 0) {
 586                                 show_absolute_syms = 1;
 587                                 continue;
 588                         }
 589
 590                         if (strcmp(argv[1], "--abs-relocs") == 0) {
 591                                 show_absolute_relocs = 1;
 592                                 continue;
 593                         }
 594                         else if (strcmp(argv[1], "--text") == 0) {
 595                                 as_text = 1;
 596                                 continue;
 597                         }
 598                 }
 599                 else if (!fname) {
 600                         fname = arg;
 601                         continue;
 602                 }
 603                 usage();
 604         }
 605         if (!fname) {
 606                 usage();
 607         }
 608         fp = fopen(fname, "r");
 609         if (!fp) {
 610                 die("Cannot open %s: %s\n",
 611                         fname, strerror(errno));
 612         }
 613         read_ehdr(fp);
 614         read_shdrs(fp);
 615         read_strtabs(fp);
 616         read_symtabs(fp);
 617         read_relocs(fp);
 618         if (show_absolute_syms) {
 619                 print_absolute_symbols();
 620                 return 0;
 621         }
 622         if (show_absolute_relocs) {
 623                 print_absolute_relocs();
 624                 return 0;
 625         }
 626         emit_relocs(as_text);
 627         return 0;
 628 }