Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 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 | |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 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 | } |
Al Viro | 2a3d4f1 | 2007-02-01 13:52:23 +0000 | [diff] [blame] | 46 | if (strncmp(sym_name, "__crc_", 6) == 0) |
| 47 | return 1; |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 48 | return 0; |
| 49 | } |
| 50 | |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 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 | { |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 391 | int i, printed = 0; |
| 392 | |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 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 | } |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 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 | |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 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 | } |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 451 | |
| 452 | if (printed) |
| 453 | printf("\n"); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 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 | { |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 566 | die("relocs [--abs-syms |--abs-relocs | --text] vmlinux\n"); |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 567 | } |
| 568 | |
| 569 | int main(int argc, char **argv) |
| 570 | { |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 571 | int show_absolute_syms, show_absolute_relocs; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 572 | int as_text; |
| 573 | const char *fname; |
| 574 | FILE *fp; |
| 575 | int i; |
| 576 | |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 577 | show_absolute_syms = 0; |
| 578 | show_absolute_relocs = 0; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 579 | as_text = 0; |
| 580 | fname = NULL; |
| 581 | for(i = 1; i < argc; i++) { |
| 582 | char *arg = argv[i]; |
| 583 | if (*arg == '-') { |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 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; |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 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); |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 617 | if (show_absolute_syms) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 618 | print_absolute_symbols(); |
Vivek Goyal | 6a044b3 | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 619 | return 0; |
| 620 | } |
| 621 | if (show_absolute_relocs) { |
Eric W. Biederman | 968de4f | 2006-12-07 02:14:04 +0100 | [diff] [blame] | 622 | print_absolute_relocs(); |
| 623 | return 0; |
| 624 | } |
| 625 | emit_relocs(as_text); |
| 626 | return 0; |
| 627 | } |