Matt Redfearn | 766c580 | 2016-03-31 10:05:32 +0100 | [diff] [blame] | 1 | /* This is included from relocs_32/64.c */ |
| 2 | |
| 3 | #define ElfW(type) _ElfW(ELF_BITS, type) |
| 4 | #define _ElfW(bits, type) __ElfW(bits, type) |
| 5 | #define __ElfW(bits, type) Elf##bits##_##type |
| 6 | |
| 7 | #define Elf_Addr ElfW(Addr) |
| 8 | #define Elf_Ehdr ElfW(Ehdr) |
| 9 | #define Elf_Phdr ElfW(Phdr) |
| 10 | #define Elf_Shdr ElfW(Shdr) |
| 11 | #define Elf_Sym ElfW(Sym) |
| 12 | |
| 13 | static Elf_Ehdr ehdr; |
| 14 | |
| 15 | struct relocs { |
| 16 | uint32_t *offset; |
| 17 | unsigned long count; |
| 18 | unsigned long size; |
| 19 | }; |
| 20 | |
| 21 | static struct relocs relocs; |
| 22 | |
| 23 | struct section { |
| 24 | Elf_Shdr shdr; |
| 25 | struct section *link; |
| 26 | Elf_Sym *symtab; |
| 27 | Elf_Rel *reltab; |
| 28 | char *strtab; |
| 29 | long shdr_offset; |
| 30 | }; |
| 31 | static struct section *secs; |
| 32 | |
| 33 | static const char * const regex_sym_kernel = { |
| 34 | /* Symbols matching these regex's should never be relocated */ |
| 35 | "^(__crc_)", |
| 36 | }; |
| 37 | |
| 38 | static regex_t sym_regex_c; |
| 39 | |
| 40 | static int regex_skip_reloc(const char *sym_name) |
| 41 | { |
| 42 | return !regexec(&sym_regex_c, sym_name, 0, NULL, 0); |
| 43 | } |
| 44 | |
| 45 | static void regex_init(void) |
| 46 | { |
| 47 | char errbuf[128]; |
| 48 | int err; |
| 49 | |
| 50 | err = regcomp(&sym_regex_c, regex_sym_kernel, |
| 51 | REG_EXTENDED|REG_NOSUB); |
| 52 | |
| 53 | if (err) { |
| 54 | regerror(err, &sym_regex_c, errbuf, sizeof(errbuf)); |
| 55 | die("%s", errbuf); |
| 56 | } |
| 57 | } |
| 58 | |
| 59 | static const char *rel_type(unsigned type) |
| 60 | { |
| 61 | static const char * const type_name[] = { |
| 62 | #define REL_TYPE(X)[X] = #X |
| 63 | REL_TYPE(R_MIPS_NONE), |
| 64 | REL_TYPE(R_MIPS_16), |
| 65 | REL_TYPE(R_MIPS_32), |
| 66 | REL_TYPE(R_MIPS_REL32), |
| 67 | REL_TYPE(R_MIPS_26), |
| 68 | REL_TYPE(R_MIPS_HI16), |
| 69 | REL_TYPE(R_MIPS_LO16), |
| 70 | REL_TYPE(R_MIPS_GPREL16), |
| 71 | REL_TYPE(R_MIPS_LITERAL), |
| 72 | REL_TYPE(R_MIPS_GOT16), |
| 73 | REL_TYPE(R_MIPS_PC16), |
| 74 | REL_TYPE(R_MIPS_CALL16), |
| 75 | REL_TYPE(R_MIPS_GPREL32), |
| 76 | REL_TYPE(R_MIPS_64), |
| 77 | REL_TYPE(R_MIPS_HIGHER), |
| 78 | REL_TYPE(R_MIPS_HIGHEST), |
| 79 | REL_TYPE(R_MIPS_PC21_S2), |
| 80 | REL_TYPE(R_MIPS_PC26_S2), |
| 81 | #undef REL_TYPE |
| 82 | }; |
| 83 | const char *name = "unknown type rel type name"; |
| 84 | |
| 85 | if (type < ARRAY_SIZE(type_name) && type_name[type]) |
| 86 | name = type_name[type]; |
| 87 | return name; |
| 88 | } |
| 89 | |
| 90 | static const char *sec_name(unsigned shndx) |
| 91 | { |
| 92 | const char *sec_strtab; |
| 93 | const char *name; |
| 94 | |
| 95 | sec_strtab = secs[ehdr.e_shstrndx].strtab; |
| 96 | if (shndx < ehdr.e_shnum) |
| 97 | name = sec_strtab + secs[shndx].shdr.sh_name; |
| 98 | else if (shndx == SHN_ABS) |
| 99 | name = "ABSOLUTE"; |
| 100 | else if (shndx == SHN_COMMON) |
| 101 | name = "COMMON"; |
| 102 | else |
| 103 | name = "<noname>"; |
| 104 | return name; |
| 105 | } |
| 106 | |
| 107 | static struct section *sec_lookup(const char *secname) |
| 108 | { |
| 109 | int i; |
| 110 | |
| 111 | for (i = 0; i < ehdr.e_shnum; i++) |
| 112 | if (strcmp(secname, sec_name(i)) == 0) |
| 113 | return &secs[i]; |
| 114 | |
| 115 | return NULL; |
| 116 | } |
| 117 | |
| 118 | static const char *sym_name(const char *sym_strtab, Elf_Sym *sym) |
| 119 | { |
| 120 | const char *name; |
| 121 | |
| 122 | if (sym->st_name) |
| 123 | name = sym_strtab + sym->st_name; |
| 124 | else |
| 125 | name = sec_name(sym->st_shndx); |
| 126 | return name; |
| 127 | } |
| 128 | |
| 129 | #if BYTE_ORDER == LITTLE_ENDIAN |
| 130 | #define le16_to_cpu(val) (val) |
| 131 | #define le32_to_cpu(val) (val) |
| 132 | #define le64_to_cpu(val) (val) |
| 133 | #define be16_to_cpu(val) bswap_16(val) |
| 134 | #define be32_to_cpu(val) bswap_32(val) |
| 135 | #define be64_to_cpu(val) bswap_64(val) |
| 136 | |
| 137 | #define cpu_to_le16(val) (val) |
| 138 | #define cpu_to_le32(val) (val) |
| 139 | #define cpu_to_le64(val) (val) |
| 140 | #define cpu_to_be16(val) bswap_16(val) |
| 141 | #define cpu_to_be32(val) bswap_32(val) |
| 142 | #define cpu_to_be64(val) bswap_64(val) |
| 143 | #endif |
| 144 | #if BYTE_ORDER == BIG_ENDIAN |
| 145 | #define le16_to_cpu(val) bswap_16(val) |
| 146 | #define le32_to_cpu(val) bswap_32(val) |
| 147 | #define le64_to_cpu(val) bswap_64(val) |
| 148 | #define be16_to_cpu(val) (val) |
| 149 | #define be32_to_cpu(val) (val) |
| 150 | #define be64_to_cpu(val) (val) |
| 151 | |
| 152 | #define cpu_to_le16(val) bswap_16(val) |
| 153 | #define cpu_to_le32(val) bswap_32(val) |
| 154 | #define cpu_to_le64(val) bswap_64(val) |
| 155 | #define cpu_to_be16(val) (val) |
| 156 | #define cpu_to_be32(val) (val) |
| 157 | #define cpu_to_be64(val) (val) |
| 158 | #endif |
| 159 | |
| 160 | static uint16_t elf16_to_cpu(uint16_t val) |
| 161 | { |
| 162 | if (ehdr.e_ident[EI_DATA] == ELFDATA2LSB) |
| 163 | return le16_to_cpu(val); |
| 164 | else |
| 165 | return be16_to_cpu(val); |
| 166 | } |
| 167 | |
| 168 | static uint32_t elf32_to_cpu(uint32_t val) |
| 169 | { |
| 170 | if (ehdr.e_ident[EI_DATA] == ELFDATA2LSB) |
| 171 | return le32_to_cpu(val); |
| 172 | else |
| 173 | return be32_to_cpu(val); |
| 174 | } |
| 175 | |
| 176 | static uint32_t cpu_to_elf32(uint32_t val) |
| 177 | { |
| 178 | if (ehdr.e_ident[EI_DATA] == ELFDATA2LSB) |
| 179 | return cpu_to_le32(val); |
| 180 | else |
| 181 | return cpu_to_be32(val); |
| 182 | } |
| 183 | |
| 184 | #define elf_half_to_cpu(x) elf16_to_cpu(x) |
| 185 | #define elf_word_to_cpu(x) elf32_to_cpu(x) |
| 186 | |
| 187 | #if ELF_BITS == 64 |
| 188 | static uint64_t elf64_to_cpu(uint64_t val) |
| 189 | { |
| 190 | if (ehdr.e_ident[EI_DATA] == ELFDATA2LSB) |
| 191 | return le64_to_cpu(val); |
| 192 | else |
| 193 | return be64_to_cpu(val); |
| 194 | } |
| 195 | #define elf_addr_to_cpu(x) elf64_to_cpu(x) |
| 196 | #define elf_off_to_cpu(x) elf64_to_cpu(x) |
| 197 | #define elf_xword_to_cpu(x) elf64_to_cpu(x) |
| 198 | #else |
| 199 | #define elf_addr_to_cpu(x) elf32_to_cpu(x) |
| 200 | #define elf_off_to_cpu(x) elf32_to_cpu(x) |
| 201 | #define elf_xword_to_cpu(x) elf32_to_cpu(x) |
| 202 | #endif |
| 203 | |
| 204 | static void read_ehdr(FILE *fp) |
| 205 | { |
| 206 | if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) |
| 207 | die("Cannot read ELF header: %s\n", strerror(errno)); |
| 208 | |
| 209 | if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0) |
| 210 | die("No ELF magic\n"); |
| 211 | |
| 212 | if (ehdr.e_ident[EI_CLASS] != ELF_CLASS) |
| 213 | die("Not a %d bit executable\n", ELF_BITS); |
| 214 | |
| 215 | if ((ehdr.e_ident[EI_DATA] != ELFDATA2LSB) && |
| 216 | (ehdr.e_ident[EI_DATA] != ELFDATA2MSB)) |
| 217 | die("Unknown ELF Endianness\n"); |
| 218 | |
| 219 | if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) |
| 220 | die("Unknown ELF version\n"); |
| 221 | |
| 222 | /* Convert the fields to native endian */ |
| 223 | ehdr.e_type = elf_half_to_cpu(ehdr.e_type); |
| 224 | ehdr.e_machine = elf_half_to_cpu(ehdr.e_machine); |
| 225 | ehdr.e_version = elf_word_to_cpu(ehdr.e_version); |
| 226 | ehdr.e_entry = elf_addr_to_cpu(ehdr.e_entry); |
| 227 | ehdr.e_phoff = elf_off_to_cpu(ehdr.e_phoff); |
| 228 | ehdr.e_shoff = elf_off_to_cpu(ehdr.e_shoff); |
| 229 | ehdr.e_flags = elf_word_to_cpu(ehdr.e_flags); |
| 230 | ehdr.e_ehsize = elf_half_to_cpu(ehdr.e_ehsize); |
| 231 | ehdr.e_phentsize = elf_half_to_cpu(ehdr.e_phentsize); |
| 232 | ehdr.e_phnum = elf_half_to_cpu(ehdr.e_phnum); |
| 233 | ehdr.e_shentsize = elf_half_to_cpu(ehdr.e_shentsize); |
| 234 | ehdr.e_shnum = elf_half_to_cpu(ehdr.e_shnum); |
| 235 | ehdr.e_shstrndx = elf_half_to_cpu(ehdr.e_shstrndx); |
| 236 | |
| 237 | if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) |
| 238 | die("Unsupported ELF header type\n"); |
| 239 | |
| 240 | if (ehdr.e_machine != ELF_MACHINE) |
| 241 | die("Not for %s\n", ELF_MACHINE_NAME); |
| 242 | |
| 243 | if (ehdr.e_version != EV_CURRENT) |
| 244 | die("Unknown ELF version\n"); |
| 245 | |
| 246 | if (ehdr.e_ehsize != sizeof(Elf_Ehdr)) |
| 247 | die("Bad Elf header size\n"); |
| 248 | |
| 249 | if (ehdr.e_phentsize != sizeof(Elf_Phdr)) |
| 250 | die("Bad program header entry\n"); |
| 251 | |
| 252 | if (ehdr.e_shentsize != sizeof(Elf_Shdr)) |
| 253 | die("Bad section header entry\n"); |
| 254 | |
| 255 | if (ehdr.e_shstrndx >= ehdr.e_shnum) |
| 256 | die("String table index out of bounds\n"); |
| 257 | } |
| 258 | |
| 259 | static void read_shdrs(FILE *fp) |
| 260 | { |
| 261 | int i; |
| 262 | Elf_Shdr shdr; |
| 263 | |
| 264 | secs = calloc(ehdr.e_shnum, sizeof(struct section)); |
| 265 | if (!secs) |
| 266 | die("Unable to allocate %d section headers\n", ehdr.e_shnum); |
| 267 | |
| 268 | if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) |
| 269 | die("Seek to %d failed: %s\n", ehdr.e_shoff, strerror(errno)); |
| 270 | |
| 271 | for (i = 0; i < ehdr.e_shnum; i++) { |
| 272 | struct section *sec = &secs[i]; |
| 273 | |
| 274 | sec->shdr_offset = ftell(fp); |
| 275 | if (fread(&shdr, sizeof(shdr), 1, fp) != 1) |
| 276 | die("Cannot read ELF section headers %d/%d: %s\n", |
| 277 | i, ehdr.e_shnum, strerror(errno)); |
| 278 | sec->shdr.sh_name = elf_word_to_cpu(shdr.sh_name); |
| 279 | sec->shdr.sh_type = elf_word_to_cpu(shdr.sh_type); |
| 280 | sec->shdr.sh_flags = elf_xword_to_cpu(shdr.sh_flags); |
| 281 | sec->shdr.sh_addr = elf_addr_to_cpu(shdr.sh_addr); |
| 282 | sec->shdr.sh_offset = elf_off_to_cpu(shdr.sh_offset); |
| 283 | sec->shdr.sh_size = elf_xword_to_cpu(shdr.sh_size); |
| 284 | sec->shdr.sh_link = elf_word_to_cpu(shdr.sh_link); |
| 285 | sec->shdr.sh_info = elf_word_to_cpu(shdr.sh_info); |
| 286 | sec->shdr.sh_addralign = elf_xword_to_cpu(shdr.sh_addralign); |
| 287 | sec->shdr.sh_entsize = elf_xword_to_cpu(shdr.sh_entsize); |
| 288 | if (sec->shdr.sh_link < ehdr.e_shnum) |
| 289 | sec->link = &secs[sec->shdr.sh_link]; |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | static void read_strtabs(FILE *fp) |
| 294 | { |
| 295 | int i; |
| 296 | |
| 297 | for (i = 0; i < ehdr.e_shnum; i++) { |
| 298 | struct section *sec = &secs[i]; |
| 299 | |
| 300 | if (sec->shdr.sh_type != SHT_STRTAB) |
| 301 | continue; |
| 302 | |
| 303 | sec->strtab = malloc(sec->shdr.sh_size); |
| 304 | if (!sec->strtab) |
| 305 | die("malloc of %d bytes for strtab failed\n", |
| 306 | sec->shdr.sh_size); |
| 307 | |
| 308 | if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) |
| 309 | die("Seek to %d failed: %s\n", |
| 310 | sec->shdr.sh_offset, strerror(errno)); |
| 311 | |
| 312 | if (fread(sec->strtab, 1, sec->shdr.sh_size, fp) != |
| 313 | sec->shdr.sh_size) |
| 314 | die("Cannot read symbol table: %s\n", strerror(errno)); |
| 315 | } |
| 316 | } |
| 317 | |
| 318 | static void read_symtabs(FILE *fp) |
| 319 | { |
| 320 | int i, j; |
| 321 | |
| 322 | for (i = 0; i < ehdr.e_shnum; i++) { |
| 323 | struct section *sec = &secs[i]; |
| 324 | if (sec->shdr.sh_type != SHT_SYMTAB) |
| 325 | continue; |
| 326 | |
| 327 | sec->symtab = malloc(sec->shdr.sh_size); |
| 328 | if (!sec->symtab) |
| 329 | die("malloc of %d bytes for symtab failed\n", |
| 330 | sec->shdr.sh_size); |
| 331 | |
| 332 | if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) |
| 333 | die("Seek to %d failed: %s\n", |
| 334 | sec->shdr.sh_offset, strerror(errno)); |
| 335 | |
| 336 | if (fread(sec->symtab, 1, sec->shdr.sh_size, fp) != |
| 337 | sec->shdr.sh_size) |
| 338 | die("Cannot read symbol table: %s\n", strerror(errno)); |
| 339 | |
| 340 | for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Sym); j++) { |
| 341 | Elf_Sym *sym = &sec->symtab[j]; |
| 342 | |
| 343 | sym->st_name = elf_word_to_cpu(sym->st_name); |
| 344 | sym->st_value = elf_addr_to_cpu(sym->st_value); |
| 345 | sym->st_size = elf_xword_to_cpu(sym->st_size); |
| 346 | sym->st_shndx = elf_half_to_cpu(sym->st_shndx); |
| 347 | } |
| 348 | } |
| 349 | } |
| 350 | |
| 351 | static void read_relocs(FILE *fp) |
| 352 | { |
| 353 | static unsigned long base = 0; |
| 354 | int i, j; |
| 355 | |
| 356 | if (!base) { |
| 357 | struct section *sec = sec_lookup(".text"); |
| 358 | |
| 359 | if (!sec) |
| 360 | die("Could not find .text section\n"); |
| 361 | |
| 362 | base = sec->shdr.sh_addr; |
| 363 | } |
| 364 | |
| 365 | for (i = 0; i < ehdr.e_shnum; i++) { |
| 366 | struct section *sec = &secs[i]; |
| 367 | |
| 368 | if (sec->shdr.sh_type != SHT_REL_TYPE) |
| 369 | continue; |
| 370 | |
| 371 | sec->reltab = malloc(sec->shdr.sh_size); |
| 372 | if (!sec->reltab) |
| 373 | die("malloc of %d bytes for relocs failed\n", |
| 374 | sec->shdr.sh_size); |
| 375 | |
| 376 | if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) |
| 377 | die("Seek to %d failed: %s\n", |
| 378 | sec->shdr.sh_offset, strerror(errno)); |
| 379 | |
| 380 | if (fread(sec->reltab, 1, sec->shdr.sh_size, fp) != |
| 381 | sec->shdr.sh_size) |
| 382 | die("Cannot read symbol table: %s\n", strerror(errno)); |
| 383 | |
| 384 | for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) { |
| 385 | Elf_Rel *rel = &sec->reltab[j]; |
| 386 | |
| 387 | rel->r_offset = elf_addr_to_cpu(rel->r_offset); |
| 388 | /* Set offset into kernel image */ |
| 389 | rel->r_offset -= base; |
| 390 | #if (ELF_BITS == 32) |
| 391 | rel->r_info = elf_xword_to_cpu(rel->r_info); |
| 392 | #else |
| 393 | /* Convert MIPS64 RELA format - only the symbol |
| 394 | * index needs converting to native endianness |
| 395 | */ |
| 396 | rel->r_info = rel->r_info; |
| 397 | ELF_R_SYM(rel->r_info) = elf32_to_cpu(ELF_R_SYM(rel->r_info)); |
| 398 | #endif |
| 399 | #if (SHT_REL_TYPE == SHT_RELA) |
| 400 | rel->r_addend = elf_xword_to_cpu(rel->r_addend); |
| 401 | #endif |
| 402 | } |
| 403 | } |
| 404 | } |
| 405 | |
| 406 | static void remove_relocs(FILE *fp) |
| 407 | { |
| 408 | int i; |
| 409 | Elf_Shdr shdr; |
| 410 | |
| 411 | for (i = 0; i < ehdr.e_shnum; i++) { |
| 412 | struct section *sec = &secs[i]; |
| 413 | |
| 414 | if (sec->shdr.sh_type != SHT_REL_TYPE) |
| 415 | continue; |
| 416 | |
| 417 | if (fseek(fp, sec->shdr_offset, SEEK_SET) < 0) |
| 418 | die("Seek to %d failed: %s\n", |
| 419 | sec->shdr_offset, strerror(errno)); |
| 420 | |
| 421 | if (fread(&shdr, sizeof(shdr), 1, fp) != 1) |
| 422 | die("Cannot read ELF section headers %d/%d: %s\n", |
| 423 | i, ehdr.e_shnum, strerror(errno)); |
| 424 | |
| 425 | /* Set relocation section size to 0, effectively removing it. |
| 426 | * This is necessary due to lack of support for relocations |
| 427 | * in objcopy when creating 32bit elf from 64bit elf. |
| 428 | */ |
| 429 | shdr.sh_size = 0; |
| 430 | |
| 431 | if (fseek(fp, sec->shdr_offset, SEEK_SET) < 0) |
| 432 | die("Seek to %d failed: %s\n", |
| 433 | sec->shdr_offset, strerror(errno)); |
| 434 | |
| 435 | if (fwrite(&shdr, sizeof(shdr), 1, fp) != 1) |
| 436 | die("Cannot write ELF section headers %d/%d: %s\n", |
| 437 | i, ehdr.e_shnum, strerror(errno)); |
| 438 | } |
| 439 | } |
| 440 | |
| 441 | static void add_reloc(struct relocs *r, uint32_t offset, unsigned type) |
| 442 | { |
| 443 | /* Relocation representation in binary table: |
| 444 | * |76543210|76543210|76543210|76543210| |
| 445 | * | Type | offset from _text >> 2 | |
| 446 | */ |
| 447 | offset >>= 2; |
| 448 | if (offset > 0x00FFFFFF) |
| 449 | die("Kernel image exceeds maximum size for relocation!\n"); |
| 450 | |
| 451 | offset = (offset & 0x00FFFFFF) | ((type & 0xFF) << 24); |
| 452 | |
| 453 | if (r->count == r->size) { |
| 454 | unsigned long newsize = r->size + 50000; |
| 455 | void *mem = realloc(r->offset, newsize * sizeof(r->offset[0])); |
| 456 | |
| 457 | if (!mem) |
| 458 | die("realloc failed\n"); |
| 459 | |
| 460 | r->offset = mem; |
| 461 | r->size = newsize; |
| 462 | } |
| 463 | r->offset[r->count++] = offset; |
| 464 | } |
| 465 | |
| 466 | static void walk_relocs(int (*process)(struct section *sec, Elf_Rel *rel, |
| 467 | Elf_Sym *sym, const char *symname)) |
| 468 | { |
| 469 | int i; |
| 470 | |
| 471 | /* Walk through the relocations */ |
| 472 | for (i = 0; i < ehdr.e_shnum; i++) { |
| 473 | char *sym_strtab; |
| 474 | Elf_Sym *sh_symtab; |
| 475 | struct section *sec_applies, *sec_symtab; |
| 476 | int j; |
| 477 | struct section *sec = &secs[i]; |
| 478 | |
| 479 | if (sec->shdr.sh_type != SHT_REL_TYPE) |
| 480 | continue; |
| 481 | |
| 482 | sec_symtab = sec->link; |
| 483 | sec_applies = &secs[sec->shdr.sh_info]; |
| 484 | if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) |
| 485 | continue; |
| 486 | |
| 487 | sh_symtab = sec_symtab->symtab; |
| 488 | sym_strtab = sec_symtab->link->strtab; |
| 489 | for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) { |
| 490 | Elf_Rel *rel = &sec->reltab[j]; |
| 491 | Elf_Sym *sym = &sh_symtab[ELF_R_SYM(rel->r_info)]; |
| 492 | const char *symname = sym_name(sym_strtab, sym); |
| 493 | |
| 494 | process(sec, rel, sym, symname); |
| 495 | } |
| 496 | } |
| 497 | } |
| 498 | |
| 499 | static int do_reloc(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, |
| 500 | const char *symname) |
| 501 | { |
| 502 | unsigned r_type = ELF_R_TYPE(rel->r_info); |
| 503 | unsigned bind = ELF_ST_BIND(sym->st_info); |
| 504 | |
| 505 | if ((bind == STB_WEAK) && (sym->st_value == 0)) { |
| 506 | /* Don't relocate weak symbols without a target */ |
| 507 | return 0; |
| 508 | } |
| 509 | |
| 510 | if (regex_skip_reloc(symname)) |
| 511 | return 0; |
| 512 | |
| 513 | switch (r_type) { |
| 514 | case R_MIPS_NONE: |
| 515 | case R_MIPS_REL32: |
| 516 | case R_MIPS_PC16: |
| 517 | case R_MIPS_PC21_S2: |
| 518 | case R_MIPS_PC26_S2: |
| 519 | /* |
| 520 | * NONE can be ignored and PC relative relocations don't |
| 521 | * need to be adjusted. |
| 522 | */ |
| 523 | case R_MIPS_HIGHEST: |
| 524 | case R_MIPS_HIGHER: |
| 525 | /* We support relocating within the same 4Gb segment only, |
| 526 | * thus leaving the top 32bits unchanged |
| 527 | */ |
| 528 | case R_MIPS_LO16: |
| 529 | /* We support relocating by 64k jumps only |
| 530 | * thus leaving the bottom 16bits unchanged |
| 531 | */ |
| 532 | break; |
| 533 | |
| 534 | case R_MIPS_64: |
| 535 | case R_MIPS_32: |
| 536 | case R_MIPS_26: |
| 537 | case R_MIPS_HI16: |
| 538 | add_reloc(&relocs, rel->r_offset, r_type); |
| 539 | break; |
| 540 | |
| 541 | default: |
| 542 | die("Unsupported relocation type: %s (%d)\n", |
| 543 | rel_type(r_type), r_type); |
| 544 | break; |
| 545 | } |
| 546 | |
| 547 | return 0; |
| 548 | } |
| 549 | |
| 550 | static int write_reloc_as_bin(uint32_t v, FILE *f) |
| 551 | { |
| 552 | unsigned char buf[4]; |
| 553 | |
| 554 | v = cpu_to_elf32(v); |
| 555 | |
| 556 | memcpy(buf, &v, sizeof(uint32_t)); |
| 557 | return fwrite(buf, 1, 4, f); |
| 558 | } |
| 559 | |
| 560 | static int write_reloc_as_text(uint32_t v, FILE *f) |
| 561 | { |
| 562 | int res; |
| 563 | |
| 564 | res = fprintf(f, "\t.long 0x%08"PRIx32"\n", v); |
| 565 | if (res < 0) |
| 566 | return res; |
| 567 | else |
| 568 | return sizeof(uint32_t); |
| 569 | } |
| 570 | |
| 571 | static void emit_relocs(int as_text, int as_bin, FILE *outf) |
| 572 | { |
| 573 | int i; |
| 574 | int (*write_reloc)(uint32_t, FILE *) = write_reloc_as_bin; |
| 575 | int size = 0; |
| 576 | int size_reserved; |
| 577 | struct section *sec_reloc; |
| 578 | |
| 579 | sec_reloc = sec_lookup(".data.reloc"); |
| 580 | if (!sec_reloc) |
| 581 | die("Could not find relocation section\n"); |
| 582 | |
| 583 | size_reserved = sec_reloc->shdr.sh_size; |
| 584 | |
| 585 | /* Collect up the relocations */ |
| 586 | walk_relocs(do_reloc); |
| 587 | |
| 588 | /* Print the relocations */ |
| 589 | if (as_text) { |
| 590 | /* Print the relocations in a form suitable that |
| 591 | * gas will like. |
| 592 | */ |
| 593 | printf(".section \".data.reloc\",\"a\"\n"); |
| 594 | printf(".balign 4\n"); |
| 595 | /* Output text to stdout */ |
| 596 | write_reloc = write_reloc_as_text; |
| 597 | outf = stdout; |
| 598 | } else if (as_bin) { |
| 599 | /* Output raw binary to stdout */ |
| 600 | outf = stdout; |
| 601 | } else { |
| 602 | /* Seek to offset of the relocation section. |
| 603 | * Each relocation is then written into the |
| 604 | * vmlinux kernel image. |
| 605 | */ |
| 606 | if (fseek(outf, sec_reloc->shdr.sh_offset, SEEK_SET) < 0) { |
| 607 | die("Seek to %d failed: %s\n", |
| 608 | sec_reloc->shdr.sh_offset, strerror(errno)); |
| 609 | } |
| 610 | } |
| 611 | |
| 612 | for (i = 0; i < relocs.count; i++) |
| 613 | size += write_reloc(relocs.offset[i], outf); |
| 614 | |
| 615 | /* Print a stop, but only if we've actually written some relocs */ |
| 616 | if (size) |
| 617 | size += write_reloc(0, outf); |
| 618 | |
| 619 | if (size > size_reserved) |
| 620 | /* Die, but suggest a value for CONFIG_RELOCATION_TABLE_SIZE |
| 621 | * which will fix this problem and allow a bit of headroom |
| 622 | * if more kernel features are enabled |
| 623 | */ |
| 624 | die("Relocations overflow available space!\n" \ |
| 625 | "Please adjust CONFIG_RELOCATION_TABLE_SIZE " \ |
| 626 | "to at least 0x%08x\n", (size + 0x1000) & ~0xFFF); |
| 627 | } |
| 628 | |
| 629 | /* |
| 630 | * As an aid to debugging problems with different linkers |
| 631 | * print summary information about the relocs. |
| 632 | * Since different linkers tend to emit the sections in |
| 633 | * different orders we use the section names in the output. |
| 634 | */ |
| 635 | static int do_reloc_info(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym, |
| 636 | const char *symname) |
| 637 | { |
| 638 | printf("%16s 0x%08x %16s %40s %16s\n", |
| 639 | sec_name(sec->shdr.sh_info), |
| 640 | (unsigned int)rel->r_offset, |
| 641 | rel_type(ELF_R_TYPE(rel->r_info)), |
| 642 | symname, |
| 643 | sec_name(sym->st_shndx)); |
| 644 | return 0; |
| 645 | } |
| 646 | |
| 647 | static void print_reloc_info(void) |
| 648 | { |
| 649 | printf("%16s %10s %16s %40s %16s\n", |
| 650 | "reloc section", |
| 651 | "offset", |
| 652 | "reloc type", |
| 653 | "symbol", |
| 654 | "symbol section"); |
| 655 | walk_relocs(do_reloc_info); |
| 656 | } |
| 657 | |
| 658 | #if ELF_BITS == 64 |
| 659 | # define process process_64 |
| 660 | #else |
| 661 | # define process process_32 |
| 662 | #endif |
| 663 | |
| 664 | void process(FILE *fp, int as_text, int as_bin, |
| 665 | int show_reloc_info, int keep_relocs) |
| 666 | { |
| 667 | regex_init(); |
| 668 | read_ehdr(fp); |
| 669 | read_shdrs(fp); |
| 670 | read_strtabs(fp); |
| 671 | read_symtabs(fp); |
| 672 | read_relocs(fp); |
| 673 | if (show_reloc_info) { |
| 674 | print_reloc_info(); |
| 675 | return; |
| 676 | } |
| 677 | emit_relocs(as_text, as_bin, fp); |
| 678 | if (!keep_relocs) |
| 679 | remove_relocs(fp); |
| 680 | } |