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 ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
  14 static Elf32_Ehdr ehdr;
  15 static unsigned long reloc_count, reloc_idx;
  16 static unsigned long *relocs;
  17
  18 struct section {
  19         Elf32_Shdr     shdr;
  20         struct section *link;
  21         Elf32_Sym      *symtab;
  22         Elf32_Rel      *reltab;
  23         char           *strtab;
  24 };
  25 static struct section *secs;
  26
  27 /*
  28  * Following symbols have been audited. There values are constant and do
  29  * not change if bzImage is loaded at a different physical address than
  30  * the address for which it has been compiled. Don't warn user about
  31  * absolute relocations present w.r.t these symbols.
  32  */
  33 static const char* safe_abs_relocs[] = {
  34                 "xen_irq_disable_direct_reloc",
  35                 "xen_save_fl_direct_reloc",
  36 };
  37
  38 static int is_safe_abs_reloc(const char* sym_name)
  39 {
  40         int i;
  41
  42         for (i = 0; i < ARRAY_SIZE(safe_abs_relocs); i++) {
  43                 if (!strcmp(sym_name, safe_abs_relocs[i]))
  44                         /* Match found */
  45                         return 1;
  46         }
  47         if (strncmp(sym_name, "VDSO", 4) == 0)
  48                 return 1;
  49         if (strncmp(sym_name, "__crc_", 6) == 0)
  50                 return 1;
  51         return 0;
  52 }
  53
  54 static void die(char *fmt, ...)
  55 {
  56         va_list ap;
  57         va_start(ap, fmt);
  58         vfprintf(stderr, fmt, ap);
  59         va_end(ap);
  60         exit(1);
  61 }
  62
  63 static const char *sym_type(unsigned type)
  64 {
  65         static const char *type_name[] = {
  66 #define SYM_TYPE(X) [X] = #X
  67                 SYM_TYPE(STT_NOTYPE),
  68                 SYM_TYPE(STT_OBJECT),
  69                 SYM_TYPE(STT_FUNC),
  70                 SYM_TYPE(STT_SECTION),
  71                 SYM_TYPE(STT_FILE),
  72                 SYM_TYPE(STT_COMMON),
  73                 SYM_TYPE(STT_TLS),
  74 #undef SYM_TYPE
  75         };
  76         const char *name = "unknown sym type name";
  77         if (type < ARRAY_SIZE(type_name)) {
  78                 name = type_name[type];
  79         }
  80         return name;
  81 }
  82
  83 static const char *sym_bind(unsigned bind)
  84 {
  85         static const char *bind_name[] = {
  86 #define SYM_BIND(X) [X] = #X
  87                 SYM_BIND(STB_LOCAL),
  88                 SYM_BIND(STB_GLOBAL),
  89                 SYM_BIND(STB_WEAK),
  90 #undef SYM_BIND
  91         };
  92         const char *name = "unknown sym bind name";
  93         if (bind < ARRAY_SIZE(bind_name)) {
  94                 name = bind_name[bind];
  95         }
  96         return name;
  97 }
  98
  99 static const char *sym_visibility(unsigned visibility)
 100 {
 101         static const char *visibility_name[] = {
 102 #define SYM_VISIBILITY(X) [X] = #X
 103                 SYM_VISIBILITY(STV_DEFAULT),
 104                 SYM_VISIBILITY(STV_INTERNAL),
 105                 SYM_VISIBILITY(STV_HIDDEN),
 106                 SYM_VISIBILITY(STV_PROTECTED),
 107 #undef SYM_VISIBILITY
 108         };
 109         const char *name = "unknown sym visibility name";
 110         if (visibility < ARRAY_SIZE(visibility_name)) {
 111                 name = visibility_name[visibility];
 112         }
 113         return name;
 114 }
 115
 116 static const char *rel_type(unsigned type)
 117 {
 118         static const char *type_name[] = {
 119 #define REL_TYPE(X) [X] = #X
 120                 REL_TYPE(R_386_NONE),
 121                 REL_TYPE(R_386_32),
 122                 REL_TYPE(R_386_PC32),
 123                 REL_TYPE(R_386_GOT32),
 124                 REL_TYPE(R_386_PLT32),
 125                 REL_TYPE(R_386_COPY),
 126                 REL_TYPE(R_386_GLOB_DAT),
 127                 REL_TYPE(R_386_JMP_SLOT),
 128                 REL_TYPE(R_386_RELATIVE),
 129                 REL_TYPE(R_386_GOTOFF),
 130                 REL_TYPE(R_386_GOTPC),
 131 #undef REL_TYPE
 132         };
 133         const char *name = "unknown type rel type name";
 134         if (type < ARRAY_SIZE(type_name)) {
 135                 name = type_name[type];
 136         }
 137         return name;
 138 }
 139
 140 static const char *sec_name(unsigned shndx)
 141 {
 142         const char *sec_strtab;
 143         const char *name;
 144         sec_strtab = secs[ehdr.e_shstrndx].strtab;
 145         name = "<noname>";
 146         if (shndx < ehdr.e_shnum) {
 147                 name = sec_strtab + secs[shndx].shdr.sh_name;
 148         }
 149         else if (shndx == SHN_ABS) {
 150                 name = "ABSOLUTE";
 151         }
 152         else if (shndx == SHN_COMMON) {
 153                 name = "COMMON";
 154         }
 155         return name;
 156 }
 157
 158 static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym)
 159 {
 160         const char *name;
 161         name = "<noname>";
 162         if (sym->st_name) {
 163                 name = sym_strtab + sym->st_name;
 164         }
 165         else {
 166                 name = sec_name(secs[sym->st_shndx].shdr.sh_name);
 167         }
 168         return name;
 169 }
 170
 171
 172
 173 #if BYTE_ORDER == LITTLE_ENDIAN
 174 #define le16_to_cpu(val) (val)
 175 #define le32_to_cpu(val) (val)
 176 #endif
 177 #if BYTE_ORDER == BIG_ENDIAN
 178 #define le16_to_cpu(val) bswap_16(val)
 179 #define le32_to_cpu(val) bswap_32(val)
 180 #endif
 181
 182 static uint16_t elf16_to_cpu(uint16_t val)
 183 {
 184         return le16_to_cpu(val);
 185 }
 186
 187 static uint32_t elf32_to_cpu(uint32_t val)
 188 {
 189         return le32_to_cpu(val);
 190 }
 191
 192 static void read_ehdr(FILE *fp)
 193 {
 194         if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) {
 195                 die("Cannot read ELF header: %s\n",
 196                         strerror(errno));
 197         }
 198         if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0) {
 199                 die("No ELF magic\n");
 200         }
 201         if (ehdr.e_ident[EI_CLASS] != ELFCLASS32) {
 202                 die("Not a 32 bit executable\n");
 203         }
 204         if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) {
 205                 die("Not a LSB ELF executable\n");
 206         }
 207         if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) {
 208                 die("Unknown ELF version\n");
 209         }
 210         /* Convert the fields to native endian */
 211         ehdr.e_type      = elf16_to_cpu(ehdr.e_type);
 212         ehdr.e_machine   = elf16_to_cpu(ehdr.e_machine);
 213         ehdr.e_version   = elf32_to_cpu(ehdr.e_version);
 214         ehdr.e_entry     = elf32_to_cpu(ehdr.e_entry);
 215         ehdr.e_phoff     = elf32_to_cpu(ehdr.e_phoff);
 216         ehdr.e_shoff     = elf32_to_cpu(ehdr.e_shoff);
 217         ehdr.e_flags     = elf32_to_cpu(ehdr.e_flags);
 218         ehdr.e_ehsize    = elf16_to_cpu(ehdr.e_ehsize);
 219         ehdr.e_phentsize = elf16_to_cpu(ehdr.e_phentsize);
 220         ehdr.e_phnum     = elf16_to_cpu(ehdr.e_phnum);
 221         ehdr.e_shentsize = elf16_to_cpu(ehdr.e_shentsize);
 222         ehdr.e_shnum     = elf16_to_cpu(ehdr.e_shnum);
 223         ehdr.e_shstrndx  = elf16_to_cpu(ehdr.e_shstrndx);
 224
 225         if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) {
 226                 die("Unsupported ELF header type\n");
 227         }
 228         if (ehdr.e_machine != EM_386) {
 229                 die("Not for x86\n");
 230         }
 231         if (ehdr.e_version != EV_CURRENT) {
 232                 die("Unknown ELF version\n");
 233         }
 234         if (ehdr.e_ehsize != sizeof(Elf32_Ehdr)) {
 235                 die("Bad Elf header size\n");
 236         }
 237         if (ehdr.e_phentsize != sizeof(Elf32_Phdr)) {
 238                 die("Bad program header entry\n");
 239         }
 240         if (ehdr.e_shentsize != sizeof(Elf32_Shdr)) {
 241                 die("Bad section header entry\n");
 242         }
 243         if (ehdr.e_shstrndx >= ehdr.e_shnum) {
 244                 die("String table index out of bounds\n");
 245         }
 246 }
 247
 248 static void read_shdrs(FILE *fp)
 249 {
 250         int i;
 251         Elf32_Shdr shdr;
 252
 253         secs = calloc(ehdr.e_shnum, sizeof(struct section));
 254         if (!secs) {
 255                 die("Unable to allocate %d section headers\n",
 256                     ehdr.e_shnum);
 257         }
 258         if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) {
 259                 die("Seek to %d failed: %s\n",
 260                         ehdr.e_shoff, strerror(errno));
 261         }
 262         for (i = 0; i < ehdr.e_shnum; i++) {
 263                 struct section *sec = &secs[i];
 264                 if (fread(&shdr, sizeof shdr, 1, fp) != 1)
 265                         die("Cannot read ELF section headers %d/%d: %s\n",
 266                             i, ehdr.e_shnum, strerror(errno));
 267                 sec->shdr.sh_name      = elf32_to_cpu(shdr.sh_name);
 268                 sec->shdr.sh_type      = elf32_to_cpu(shdr.sh_type);
 269                 sec->shdr.sh_flags     = elf32_to_cpu(shdr.sh_flags);
 270                 sec->shdr.sh_addr      = elf32_to_cpu(shdr.sh_addr);
 271                 sec->shdr.sh_offset    = elf32_to_cpu(shdr.sh_offset);
 272                 sec->shdr.sh_size      = elf32_to_cpu(shdr.sh_size);
 273                 sec->shdr.sh_link      = elf32_to_cpu(shdr.sh_link);
 274                 sec->shdr.sh_info      = elf32_to_cpu(shdr.sh_info);
 275                 sec->shdr.sh_addralign = elf32_to_cpu(shdr.sh_addralign);
 276                 sec->shdr.sh_entsize   = elf32_to_cpu(shdr.sh_entsize);
 277                 if (sec->shdr.sh_link < ehdr.e_shnum)
 278                         sec->link = &secs[sec->shdr.sh_link];
 279         }
 280
 281 }
 282
 283 static void read_strtabs(FILE *fp)
 284 {
 285         int i;
 286         for (i = 0; i < ehdr.e_shnum; i++) {
 287                 struct section *sec = &secs[i];
 288                 if (sec->shdr.sh_type != SHT_STRTAB) {
 289                         continue;
 290                 }
 291                 sec->strtab = malloc(sec->shdr.sh_size);
 292                 if (!sec->strtab) {
 293                         die("malloc of %d bytes for strtab failed\n",
 294                                 sec->shdr.sh_size);
 295                 }
 296                 if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
 297                         die("Seek to %d failed: %s\n",
 298                                 sec->shdr.sh_offset, strerror(errno));
 299                 }
 300                 if (fread(sec->strtab, 1, sec->shdr.sh_size, fp)
 301                     != sec->shdr.sh_size) {
 302                         die("Cannot read symbol table: %s\n",
 303                                 strerror(errno));
 304                 }
 305         }
 306 }
 307
 308 static void read_symtabs(FILE *fp)
 309 {
 310         int i,j;
 311         for (i = 0; i < ehdr.e_shnum; i++) {
 312                 struct section *sec = &secs[i];
 313                 if (sec->shdr.sh_type != SHT_SYMTAB) {
 314                         continue;
 315                 }
 316                 sec->symtab = malloc(sec->shdr.sh_size);
 317                 if (!sec->symtab) {
 318                         die("malloc of %d bytes for symtab failed\n",
 319                                 sec->shdr.sh_size);
 320                 }
 321                 if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
 322                         die("Seek to %d failed: %s\n",
 323                                 sec->shdr.sh_offset, strerror(errno));
 324                 }
 325                 if (fread(sec->symtab, 1, sec->shdr.sh_size, fp)
 326                     != sec->shdr.sh_size) {
 327                         die("Cannot read symbol table: %s\n",
 328                                 strerror(errno));
 329                 }
 330                 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Sym); j++) {
 331                         Elf32_Sym *sym = &sec->symtab[j];
 332                         sym->st_name  = elf32_to_cpu(sym->st_name);
 333                         sym->st_value = elf32_to_cpu(sym->st_value);
 334                         sym->st_size  = elf32_to_cpu(sym->st_size);
 335                         sym->st_shndx = elf16_to_cpu(sym->st_shndx);
 336                 }
 337         }
 338 }
 339
 340
 341 static void read_relocs(FILE *fp)
 342 {
 343         int i,j;
 344         for (i = 0; i < ehdr.e_shnum; i++) {
 345                 struct section *sec = &secs[i];
 346                 if (sec->shdr.sh_type != SHT_REL) {
 347                         continue;
 348                 }
 349                 sec->reltab = malloc(sec->shdr.sh_size);
 350                 if (!sec->reltab) {
 351                         die("malloc of %d bytes for relocs failed\n",
 352                                 sec->shdr.sh_size);
 353                 }
 354                 if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
 355                         die("Seek to %d failed: %s\n",
 356                                 sec->shdr.sh_offset, strerror(errno));
 357                 }
 358                 if (fread(sec->reltab, 1, sec->shdr.sh_size, fp)
 359                     != sec->shdr.sh_size) {
 360                         die("Cannot read symbol table: %s\n",
 361                                 strerror(errno));
 362                 }
 363                 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
 364                         Elf32_Rel *rel = &sec->reltab[j];
 365                         rel->r_offset = elf32_to_cpu(rel->r_offset);
 366                         rel->r_info   = elf32_to_cpu(rel->r_info);
 367                 }
 368         }
 369 }
 370
 371
 372 static void print_absolute_symbols(void)
 373 {
 374         int i;
 375         printf("Absolute symbols\n");
 376         printf(" Num:    Value Size  Type       Bind        Visibility  Name\n");
 377         for (i = 0; i < ehdr.e_shnum; i++) {
 378                 struct section *sec = &secs[i];
 379                 char *sym_strtab;
 380                 Elf32_Sym *sh_symtab;
 381                 int j;
 382
 383                 if (sec->shdr.sh_type != SHT_SYMTAB) {
 384                         continue;
 385                 }
 386                 sh_symtab = sec->symtab;
 387                 sym_strtab = sec->link->strtab;
 388                 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Sym); j++) {
 389                         Elf32_Sym *sym;
 390                         const char *name;
 391                         sym = &sec->symtab[j];
 392                         name = sym_name(sym_strtab, sym);
 393                         if (sym->st_shndx != SHN_ABS) {
 394                                 continue;
 395                         }
 396                         printf("%5d %08x %5d %10s %10s %12s %s\n",
 397                                 j, sym->st_value, sym->st_size,
 398                                 sym_type(ELF32_ST_TYPE(sym->st_info)),
 399                                 sym_bind(ELF32_ST_BIND(sym->st_info)),
 400                                 sym_visibility(ELF32_ST_VISIBILITY(sym->st_other)),
 401                                 name);
 402                 }
 403         }
 404         printf("\n");
 405 }
 406
 407 static void print_absolute_relocs(void)
 408 {
 409         int i, printed = 0;
 410
 411         for (i = 0; i < ehdr.e_shnum; i++) {
 412                 struct section *sec = &secs[i];
 413                 struct section *sec_applies, *sec_symtab;
 414                 char *sym_strtab;
 415                 Elf32_Sym *sh_symtab;
 416                 int j;
 417                 if (sec->shdr.sh_type != SHT_REL) {
 418                         continue;
 419                 }
 420                 sec_symtab  = sec->link;
 421                 sec_applies = &secs[sec->shdr.sh_info];
 422                 if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
 423                         continue;
 424                 }
 425                 sh_symtab  = sec_symtab->symtab;
 426                 sym_strtab = sec_symtab->link->strtab;
 427                 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
 428                         Elf32_Rel *rel;
 429                         Elf32_Sym *sym;
 430                         const char *name;
 431                         rel = &sec->reltab[j];
 432                         sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
 433                         name = sym_name(sym_strtab, sym);
 434                         if (sym->st_shndx != SHN_ABS) {
 435                                 continue;
 436                         }
 437
 438                         /* Absolute symbols are not relocated if bzImage is
 439                          * loaded at a non-compiled address. Display a warning
 440                          * to user at compile time about the absolute
 441                          * relocations present.
 442                          *
 443                          * User need to audit the code to make sure
 444                          * some symbols which should have been section
 445                          * relative have not become absolute because of some
 446                          * linker optimization or wrong programming usage.
 447                          *
 448                          * Before warning check if this absolute symbol
 449                          * relocation is harmless.
 450                          */
 451                         if (is_safe_abs_reloc(name))
 452                                 continue;
 453
 454                         if (!printed) {
 455                                 printf("WARNING: Absolute relocations"
 456                                         " present\n");
 457                                 printf("Offset     Info     Type     Sym.Value "
 458                                         "Sym.Name\n");
 459                                 printed = 1;
 460                         }
 461
 462                         printf("%08x %08x %10s %08x  %s\n",
 463                                 rel->r_offset,
 464                                 rel->r_info,
 465                                 rel_type(ELF32_R_TYPE(rel->r_info)),
 466                                 sym->st_value,
 467                                 name);
 468                 }
 469         }
 470
 471         if (printed)
 472                 printf("\n");
 473 }
 474
 475 static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym))
 476 {
 477         int i;
 478         /* Walk through the relocations */
 479         for (i = 0; i < ehdr.e_shnum; i++) {
 480                 char *sym_strtab;
 481                 Elf32_Sym *sh_symtab;
 482                 struct section *sec_applies, *sec_symtab;
 483                 int j;
 484                 struct section *sec = &secs[i];
 485
 486                 if (sec->shdr.sh_type != SHT_REL) {
 487                         continue;
 488                 }
 489                 sec_symtab  = sec->link;
 490                 sec_applies = &secs[sec->shdr.sh_info];
 491                 if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
 492                         continue;
 493                 }
 494                 sh_symtab = sec_symtab->symtab;
 495                 sym_strtab = sec_symtab->link->strtab;
 496                 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
 497                         Elf32_Rel *rel;
 498                         Elf32_Sym *sym;
 499                         unsigned r_type;
 500                         rel = &sec->reltab[j];
 501                         sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
 502                         r_type = ELF32_R_TYPE(rel->r_info);
 503                         /* Don't visit relocations to absolute symbols */
 504                         if (sym->st_shndx == SHN_ABS) {
 505                                 continue;
 506                         }
 507                         if (r_type == R_386_NONE || r_type == R_386_PC32) {
 508                                 /*
 509                                  * NONE can be ignored and and PC relative
 510                                  * relocations don't need to be adjusted.
 511                                  */
 512                         }
 513                         else if (r_type == R_386_32) {
 514                                 /* Visit relocations that need to be adjusted */
 515                                 visit(rel, sym);
 516                         }
 517                         else {
 518                                 die("Unsupported relocation type: %d\n", r_type);
 519                         }
 520                 }
 521         }
 522 }
 523
 524 static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
 525 {
 526         reloc_count += 1;
 527 }
 528
 529 static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
 530 {
 531         /* Remember the address that needs to be adjusted. */
 532         relocs[reloc_idx++] = rel->r_offset;
 533 }
 534
 535 static int cmp_relocs(const void *va, const void *vb)
 536 {
 537         const unsigned long *a, *b;
 538         a = va; b = vb;
 539         return (*a == *b)? 0 : (*a > *b)? 1 : -1;
 540 }
 541
 542 static void emit_relocs(int as_text)
 543 {
 544         int i;
 545         /* Count how many relocations I have and allocate space for them. */
 546         reloc_count = 0;
 547         walk_relocs(count_reloc);
 548         relocs = malloc(reloc_count * sizeof(relocs[0]));
 549         if (!relocs) {
 550                 die("malloc of %d entries for relocs failed\n",
 551                         reloc_count);
 552         }
 553         /* Collect up the relocations */
 554         reloc_idx = 0;
 555         walk_relocs(collect_reloc);
 556
 557         /* Order the relocations for more efficient processing */
 558         qsort(relocs, reloc_count, sizeof(relocs[0]), cmp_relocs);
 559
 560         /* Print the relocations */
 561         if (as_text) {
 562                 /* Print the relocations in a form suitable that
 563                  * gas will like.
 564                  */
 565                 printf(".section \".data.reloc\",\"a\"\n");
 566                 printf(".balign 4\n");
 567                 for (i = 0; i < reloc_count; i++) {
 568                         printf("\t .long 0x%08lx\n", relocs[i]);
 569                 }
 570                 printf("\n");
 571         }
 572         else {
 573                 unsigned char buf[4];
 574                 buf[0] = buf[1] = buf[2] = buf[3] = 0;
 575                 /* Print a stop */
 576                 printf("%c%c%c%c", buf[0], buf[1], buf[2], buf[3]);
 577                 /* Now print each relocation */
 578                 for (i = 0; i < reloc_count; i++) {
 579                         buf[0] = (relocs[i] >>  0) & 0xff;
 580                         buf[1] = (relocs[i] >>  8) & 0xff;
 581                         buf[2] = (relocs[i] >> 16) & 0xff;
 582                         buf[3] = (relocs[i] >> 24) & 0xff;
 583                         printf("%c%c%c%c", buf[0], buf[1], buf[2], buf[3]);
 584                 }
 585         }
 586 }
 587
 588 static void usage(void)
 589 {
 590         die("relocs [--abs-syms |--abs-relocs | --text] vmlinux\n");
 591 }
 592
 593 int main(int argc, char **argv)
 594 {
 595         int show_absolute_syms, show_absolute_relocs;
 596         int as_text;
 597         const char *fname;
 598         FILE *fp;
 599         int i;
 600
 601         show_absolute_syms = 0;
 602         show_absolute_relocs = 0;
 603         as_text = 0;
 604         fname = NULL;
 605         for (i = 1; i < argc; i++) {
 606                 char *arg = argv[i];
 607                 if (*arg == '-') {
 608                         if (strcmp(argv[1], "--abs-syms") == 0) {
 609                                 show_absolute_syms = 1;
 610                                 continue;
 611                         }
 612
 613                         if (strcmp(argv[1], "--abs-relocs") == 0) {
 614                                 show_absolute_relocs = 1;
 615                                 continue;
 616                         }
 617                         else if (strcmp(argv[1], "--text") == 0) {
 618                                 as_text = 1;
 619                                 continue;
 620                         }
 621                 }
 622                 else if (!fname) {
 623                         fname = arg;
 624                         continue;
 625                 }
 626                 usage();
 627         }
 628         if (!fname) {
 629                 usage();
 630         }
 631         fp = fopen(fname, "r");
 632         if (!fp) {
 633                 die("Cannot open %s: %s\n",
 634                         fname, strerror(errno));
 635         }
 636         read_ehdr(fp);
 637         read_shdrs(fp);
 638         read_strtabs(fp);
 639         read_symtabs(fp);
 640         read_relocs(fp);
 641         if (show_absolute_syms) {
 642                 print_absolute_symbols();
 643                 return 0;
 644         }
 645         if (show_absolute_relocs) {
 646                 print_absolute_relocs();
 647                 return 0;
 648         }
 649         emit_relocs(as_text);
 650         return 0;
 651 }