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