| 1 | /* Intel 80386/80486-specific support for 32-bit ELF |
| 2 | Copyright 1993, 1994, 1995 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of BFD, the Binary File Descriptor library. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 2 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; if not, write to the Free Software |
| 18 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 19 | |
| 20 | #include "bfd.h" |
| 21 | #include "sysdep.h" |
| 22 | #include "bfdlink.h" |
| 23 | #include "libbfd.h" |
| 24 | #include "libelf.h" |
| 25 | |
| 26 | static reloc_howto_type *elf_i386_reloc_type_lookup |
| 27 | PARAMS ((bfd *, bfd_reloc_code_real_type)); |
| 28 | static void elf_i386_info_to_howto |
| 29 | PARAMS ((bfd *, arelent *, Elf32_Internal_Rela *)); |
| 30 | static void elf_i386_info_to_howto_rel |
| 31 | PARAMS ((bfd *, arelent *, Elf32_Internal_Rel *)); |
| 32 | static boolean elf_i386_check_relocs |
| 33 | PARAMS ((bfd *, struct bfd_link_info *, asection *, |
| 34 | const Elf_Internal_Rela *)); |
| 35 | static boolean elf_i386_adjust_dynamic_symbol |
| 36 | PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *)); |
| 37 | static boolean elf_i386_size_dynamic_sections |
| 38 | PARAMS ((bfd *, struct bfd_link_info *)); |
| 39 | static boolean elf_i386_relocate_section |
| 40 | PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *, |
| 41 | Elf_Internal_Rela *, Elf_Internal_Sym *, asection **)); |
| 42 | static boolean elf_i386_finish_dynamic_symbol |
| 43 | PARAMS ((bfd *, struct bfd_link_info *, struct elf_link_hash_entry *, |
| 44 | Elf_Internal_Sym *)); |
| 45 | static boolean elf_i386_finish_dynamic_sections |
| 46 | PARAMS ((bfd *, struct bfd_link_info *)); |
| 47 | |
| 48 | #define USE_REL 1 /* 386 uses REL relocations instead of RELA */ |
| 49 | |
| 50 | enum reloc_type |
| 51 | { |
| 52 | R_386_NONE = 0, |
| 53 | R_386_32, |
| 54 | R_386_PC32, |
| 55 | R_386_GOT32, |
| 56 | R_386_PLT32, |
| 57 | R_386_COPY, |
| 58 | R_386_GLOB_DAT, |
| 59 | R_386_JUMP_SLOT, |
| 60 | R_386_RELATIVE, |
| 61 | R_386_GOTOFF, |
| 62 | R_386_GOTPC, |
| 63 | R_386_max |
| 64 | }; |
| 65 | |
| 66 | #if 0 |
| 67 | static CONST char *CONST reloc_type_names[] = |
| 68 | { |
| 69 | "R_386_NONE", |
| 70 | "R_386_32", |
| 71 | "R_386_PC32", |
| 72 | "R_386_GOT32", |
| 73 | "R_386_PLT32", |
| 74 | "R_386_COPY", |
| 75 | "R_386_GLOB_DAT", |
| 76 | "R_386_JUMP_SLOT", |
| 77 | "R_386_RELATIVE", |
| 78 | "R_386_GOTOFF", |
| 79 | "R_386_GOTPC", |
| 80 | }; |
| 81 | #endif |
| 82 | |
| 83 | static reloc_howto_type elf_howto_table[]= |
| 84 | { |
| 85 | HOWTO(R_386_NONE, 0,0, 0,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_NONE", true,0x00000000,0x00000000,false), |
| 86 | HOWTO(R_386_32, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_32", true,0xffffffff,0xffffffff,false), |
| 87 | HOWTO(R_386_PC32, 0,2,32,true, 0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_PC32", true,0xffffffff,0xffffffff,true), |
| 88 | HOWTO(R_386_GOT32, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_GOT32", true,0xffffffff,0xffffffff,false), |
| 89 | HOWTO(R_386_PLT32, 0,2,32,true,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_PLT32", true,0xffffffff,0xffffffff,true), |
| 90 | HOWTO(R_386_COPY, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_COPY", true,0xffffffff,0xffffffff,false), |
| 91 | HOWTO(R_386_GLOB_DAT, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_GLOB_DAT", true,0xffffffff,0xffffffff,false), |
| 92 | HOWTO(R_386_JUMP_SLOT, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_JUMP_SLOT",true,0xffffffff,0xffffffff,false), |
| 93 | HOWTO(R_386_RELATIVE, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_RELATIVE", true,0xffffffff,0xffffffff,false), |
| 94 | HOWTO(R_386_GOTOFF, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_GOTOFF", true,0xffffffff,0xffffffff,false), |
| 95 | HOWTO(R_386_GOTPC, 0,2,32,true,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_GOTPC", true,0xffffffff,0xffffffff,true), |
| 96 | }; |
| 97 | |
| 98 | #ifdef DEBUG_GEN_RELOC |
| 99 | #define TRACE(str) fprintf (stderr, "i386 bfd reloc lookup %d (%s)\n", code, str) |
| 100 | #else |
| 101 | #define TRACE(str) |
| 102 | #endif |
| 103 | |
| 104 | static reloc_howto_type * |
| 105 | elf_i386_reloc_type_lookup (abfd, code) |
| 106 | bfd *abfd; |
| 107 | bfd_reloc_code_real_type code; |
| 108 | { |
| 109 | switch (code) |
| 110 | { |
| 111 | case BFD_RELOC_NONE: |
| 112 | TRACE ("BFD_RELOC_NONE"); |
| 113 | return &elf_howto_table[ (int)R_386_NONE ]; |
| 114 | |
| 115 | case BFD_RELOC_32: |
| 116 | TRACE ("BFD_RELOC_32"); |
| 117 | return &elf_howto_table[ (int)R_386_32 ]; |
| 118 | |
| 119 | case BFD_RELOC_32_PCREL: |
| 120 | TRACE ("BFD_RELOC_PC32"); |
| 121 | return &elf_howto_table[ (int)R_386_PC32 ]; |
| 122 | |
| 123 | case BFD_RELOC_386_GOT32: |
| 124 | TRACE ("BFD_RELOC_386_GOT32"); |
| 125 | return &elf_howto_table[ (int)R_386_GOT32 ]; |
| 126 | |
| 127 | case BFD_RELOC_386_PLT32: |
| 128 | TRACE ("BFD_RELOC_386_PLT32"); |
| 129 | return &elf_howto_table[ (int)R_386_PLT32 ]; |
| 130 | |
| 131 | case BFD_RELOC_386_COPY: |
| 132 | TRACE ("BFD_RELOC_386_COPY"); |
| 133 | return &elf_howto_table[ (int)R_386_COPY ]; |
| 134 | |
| 135 | case BFD_RELOC_386_GLOB_DAT: |
| 136 | TRACE ("BFD_RELOC_386_GLOB_DAT"); |
| 137 | return &elf_howto_table[ (int)R_386_GLOB_DAT ]; |
| 138 | |
| 139 | case BFD_RELOC_386_JUMP_SLOT: |
| 140 | TRACE ("BFD_RELOC_386_JUMP_SLOT"); |
| 141 | return &elf_howto_table[ (int)R_386_JUMP_SLOT ]; |
| 142 | |
| 143 | case BFD_RELOC_386_RELATIVE: |
| 144 | TRACE ("BFD_RELOC_386_RELATIVE"); |
| 145 | return &elf_howto_table[ (int)R_386_RELATIVE ]; |
| 146 | |
| 147 | case BFD_RELOC_386_GOTOFF: |
| 148 | TRACE ("BFD_RELOC_386_GOTOFF"); |
| 149 | return &elf_howto_table[ (int)R_386_GOTOFF ]; |
| 150 | |
| 151 | case BFD_RELOC_386_GOTPC: |
| 152 | TRACE ("BFD_RELOC_386_GOTPC"); |
| 153 | return &elf_howto_table[ (int)R_386_GOTPC ]; |
| 154 | |
| 155 | default: |
| 156 | break; |
| 157 | } |
| 158 | |
| 159 | TRACE ("Unknown"); |
| 160 | return 0; |
| 161 | } |
| 162 | |
| 163 | static void |
| 164 | elf_i386_info_to_howto (abfd, cache_ptr, dst) |
| 165 | bfd *abfd; |
| 166 | arelent *cache_ptr; |
| 167 | Elf32_Internal_Rela *dst; |
| 168 | { |
| 169 | BFD_ASSERT (ELF32_R_TYPE(dst->r_info) < (unsigned int) R_386_max); |
| 170 | |
| 171 | cache_ptr->howto = &elf_howto_table[ELF32_R_TYPE(dst->r_info)]; |
| 172 | } |
| 173 | |
| 174 | static void |
| 175 | elf_i386_info_to_howto_rel (abfd, cache_ptr, dst) |
| 176 | bfd *abfd; |
| 177 | arelent *cache_ptr; |
| 178 | Elf32_Internal_Rel *dst; |
| 179 | { |
| 180 | BFD_ASSERT (ELF32_R_TYPE(dst->r_info) < (unsigned int) R_386_max); |
| 181 | |
| 182 | cache_ptr->howto = &elf_howto_table[ELF32_R_TYPE(dst->r_info)]; |
| 183 | } |
| 184 | \f |
| 185 | /* Functions for the i386 ELF linker. */ |
| 186 | |
| 187 | /* The name of the dynamic interpreter. This is put in the .interp |
| 188 | section. */ |
| 189 | |
| 190 | #define ELF_DYNAMIC_INTERPRETER "/usr/lib/libc.so.1" |
| 191 | |
| 192 | /* The size in bytes of an entry in the procedure linkage table. */ |
| 193 | |
| 194 | #define PLT_ENTRY_SIZE 16 |
| 195 | |
| 196 | /* The first entry in an absolute procedure linkage table looks like |
| 197 | this. See the SVR4 ABI i386 supplement to see how this works. */ |
| 198 | |
| 199 | static const bfd_byte elf_i386_plt0_entry[PLT_ENTRY_SIZE] = |
| 200 | { |
| 201 | 0xff, 0x35, /* pushl contents of address */ |
| 202 | 0, 0, 0, 0, /* replaced with address of .got + 4. */ |
| 203 | 0xff, 0x25, /* jmp indirect */ |
| 204 | 0, 0, 0, 0, /* replaced with address of .got + 8. */ |
| 205 | 0, 0, 0, 0 /* pad out to 16 bytes. */ |
| 206 | }; |
| 207 | |
| 208 | /* Subsequent entries in an absolute procedure linkage table look like |
| 209 | this. */ |
| 210 | |
| 211 | static const bfd_byte elf_i386_plt_entry[PLT_ENTRY_SIZE] = |
| 212 | { |
| 213 | 0xff, 0x25, /* jmp indirect */ |
| 214 | 0, 0, 0, 0, /* replaced with address of this symbol in .got. */ |
| 215 | 0x68, /* pushl immediate */ |
| 216 | 0, 0, 0, 0, /* replaced with offset into relocation table. */ |
| 217 | 0xe9, /* jmp relative */ |
| 218 | 0, 0, 0, 0 /* replaced with offset to start of .plt. */ |
| 219 | }; |
| 220 | |
| 221 | /* The first entry in a PIC procedure linkage table look like this. */ |
| 222 | |
| 223 | static const bfd_byte elf_i386_pic_plt0_entry[PLT_ENTRY_SIZE] = |
| 224 | { |
| 225 | 0xff, 0xb3, 4, 0, 0, 0, /* pushl 4(%ebx) */ |
| 226 | 0xff, 0xa3, 8, 0, 0, 0, /* jmp *8(%ebx) */ |
| 227 | 0, 0, 0, 0 /* pad out to 16 bytes. */ |
| 228 | }; |
| 229 | |
| 230 | /* Subsequent entries in a PIC procedure linkage table look like this. */ |
| 231 | |
| 232 | static const bfd_byte elf_i386_pic_plt_entry[PLT_ENTRY_SIZE] = |
| 233 | { |
| 234 | 0xff, 0xa3, /* jmp *offset(%ebx) */ |
| 235 | 0, 0, 0, 0, /* replaced with offset of this symbol in .got. */ |
| 236 | 0x68, /* pushl immediate */ |
| 237 | 0, 0, 0, 0, /* replaced with offset into relocation table. */ |
| 238 | 0xe9, /* jmp relative */ |
| 239 | 0, 0, 0, 0 /* replaced with offset to start of .plt. */ |
| 240 | }; |
| 241 | |
| 242 | /* Look through the relocs for a section during the first phase, and |
| 243 | allocate space in the global offset table or procedure linkage |
| 244 | table. */ |
| 245 | |
| 246 | static boolean |
| 247 | elf_i386_check_relocs (abfd, info, sec, relocs) |
| 248 | bfd *abfd; |
| 249 | struct bfd_link_info *info; |
| 250 | asection *sec; |
| 251 | const Elf_Internal_Rela *relocs; |
| 252 | { |
| 253 | bfd *dynobj; |
| 254 | Elf_Internal_Shdr *symtab_hdr; |
| 255 | struct elf_link_hash_entry **sym_hashes; |
| 256 | bfd_vma *local_got_offsets; |
| 257 | const Elf_Internal_Rela *rel; |
| 258 | const Elf_Internal_Rela *rel_end; |
| 259 | asection *sgot; |
| 260 | asection *srelgot; |
| 261 | asection *sreloc; |
| 262 | |
| 263 | if (info->relocateable) |
| 264 | return true; |
| 265 | |
| 266 | dynobj = elf_hash_table (info)->dynobj; |
| 267 | symtab_hdr = &elf_tdata (abfd)->symtab_hdr; |
| 268 | sym_hashes = elf_sym_hashes (abfd); |
| 269 | local_got_offsets = elf_local_got_offsets (abfd); |
| 270 | |
| 271 | sgot = NULL; |
| 272 | srelgot = NULL; |
| 273 | sreloc = NULL; |
| 274 | |
| 275 | rel_end = relocs + sec->reloc_count; |
| 276 | for (rel = relocs; rel < rel_end; rel++) |
| 277 | { |
| 278 | long r_symndx; |
| 279 | struct elf_link_hash_entry *h; |
| 280 | |
| 281 | r_symndx = ELF32_R_SYM (rel->r_info); |
| 282 | |
| 283 | if (r_symndx < symtab_hdr->sh_info) |
| 284 | h = NULL; |
| 285 | else |
| 286 | h = sym_hashes[r_symndx - symtab_hdr->sh_info]; |
| 287 | |
| 288 | /* Some relocs require a global offset table. */ |
| 289 | if (dynobj == NULL) |
| 290 | { |
| 291 | switch (ELF32_R_TYPE (rel->r_info)) |
| 292 | { |
| 293 | case R_386_GOT32: |
| 294 | case R_386_GOTOFF: |
| 295 | case R_386_GOTPC: |
| 296 | elf_hash_table (info)->dynobj = dynobj = abfd; |
| 297 | if (! _bfd_elf_create_got_section (dynobj, info)) |
| 298 | return false; |
| 299 | break; |
| 300 | |
| 301 | default: |
| 302 | break; |
| 303 | } |
| 304 | } |
| 305 | |
| 306 | switch (ELF32_R_TYPE (rel->r_info)) |
| 307 | { |
| 308 | case R_386_GOT32: |
| 309 | /* This symbol requires a global offset table entry. */ |
| 310 | |
| 311 | if (sgot == NULL) |
| 312 | { |
| 313 | sgot = bfd_get_section_by_name (dynobj, ".got"); |
| 314 | BFD_ASSERT (sgot != NULL); |
| 315 | } |
| 316 | |
| 317 | if (srelgot == NULL |
| 318 | && (h != NULL || info->shared)) |
| 319 | { |
| 320 | srelgot = bfd_get_section_by_name (dynobj, ".rel.got"); |
| 321 | if (srelgot == NULL) |
| 322 | { |
| 323 | srelgot = bfd_make_section (dynobj, ".rel.got"); |
| 324 | if (srelgot == NULL |
| 325 | || ! bfd_set_section_flags (dynobj, srelgot, |
| 326 | (SEC_ALLOC |
| 327 | | SEC_LOAD |
| 328 | | SEC_HAS_CONTENTS |
| 329 | | SEC_IN_MEMORY |
| 330 | | SEC_READONLY)) |
| 331 | || ! bfd_set_section_alignment (dynobj, srelgot, 2)) |
| 332 | return false; |
| 333 | } |
| 334 | } |
| 335 | |
| 336 | if (h != NULL) |
| 337 | { |
| 338 | if (h->got_offset != (bfd_vma) -1) |
| 339 | { |
| 340 | /* We have already allocated space in the .got. */ |
| 341 | break; |
| 342 | } |
| 343 | h->got_offset = sgot->_raw_size; |
| 344 | |
| 345 | /* Make sure this symbol is output as a dynamic symbol. */ |
| 346 | if (h->dynindx == -1) |
| 347 | { |
| 348 | if (! bfd_elf32_link_record_dynamic_symbol (info, h)) |
| 349 | return false; |
| 350 | } |
| 351 | |
| 352 | srelgot->_raw_size += sizeof (Elf32_External_Rel); |
| 353 | } |
| 354 | else |
| 355 | { |
| 356 | /* This is a global offset table entry for a local |
| 357 | symbol. */ |
| 358 | if (local_got_offsets == NULL) |
| 359 | { |
| 360 | size_t size; |
| 361 | register int i; |
| 362 | |
| 363 | size = symtab_hdr->sh_info * sizeof (bfd_vma); |
| 364 | local_got_offsets = (bfd_vma *) bfd_alloc (abfd, size); |
| 365 | if (local_got_offsets == NULL) |
| 366 | { |
| 367 | bfd_set_error (bfd_error_no_memory); |
| 368 | return false; |
| 369 | } |
| 370 | elf_local_got_offsets (abfd) = local_got_offsets; |
| 371 | for (i = 0; i < symtab_hdr->sh_info; i++) |
| 372 | local_got_offsets[i] = (bfd_vma) -1; |
| 373 | } |
| 374 | if (local_got_offsets[r_symndx] != (bfd_vma) -1) |
| 375 | { |
| 376 | /* We have already allocated space in the .got. */ |
| 377 | break; |
| 378 | } |
| 379 | local_got_offsets[r_symndx] = sgot->_raw_size; |
| 380 | |
| 381 | if (info->shared) |
| 382 | { |
| 383 | /* If we are generating a shared object, we need to |
| 384 | output a R_386_RELATIVE reloc so that the dynamic |
| 385 | linker can adjust this GOT entry. */ |
| 386 | srelgot->_raw_size += sizeof (Elf32_External_Rel); |
| 387 | } |
| 388 | } |
| 389 | |
| 390 | sgot->_raw_size += 4; |
| 391 | |
| 392 | break; |
| 393 | |
| 394 | case R_386_PLT32: |
| 395 | /* This symbol requires a procedure linkage table entry. We |
| 396 | actually build the entry in adjust_dynamic_symbol, |
| 397 | because this might be a case of linking PIC code without |
| 398 | linking in any dynamic objects, in which case we don't |
| 399 | need to generate a procedure linkage table after all. */ |
| 400 | |
| 401 | /* If this is a local symbol, we resolve it directly without |
| 402 | creating a procedure linkage table entry. */ |
| 403 | if (h == NULL) |
| 404 | continue; |
| 405 | |
| 406 | /* Make sure this symbol is output as a dynamic symbol. */ |
| 407 | if (h->dynindx == -1) |
| 408 | { |
| 409 | if (! bfd_elf32_link_record_dynamic_symbol (info, h)) |
| 410 | return false; |
| 411 | } |
| 412 | |
| 413 | h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_PLT; |
| 414 | |
| 415 | break; |
| 416 | |
| 417 | case R_386_32: |
| 418 | case R_386_PC32: |
| 419 | if (info->shared |
| 420 | && (sec->flags & SEC_ALLOC) != 0) |
| 421 | { |
| 422 | /* When creating a shared object, we must copy these |
| 423 | reloc types into the output file. We create a reloc |
| 424 | section in dynobj and make room for this reloc. */ |
| 425 | if (sreloc == NULL) |
| 426 | { |
| 427 | const char *name; |
| 428 | |
| 429 | name = (bfd_elf_string_from_elf_section |
| 430 | (abfd, |
| 431 | elf_elfheader (abfd)->e_shstrndx, |
| 432 | elf_section_data (sec)->rel_hdr.sh_name)); |
| 433 | if (name == NULL) |
| 434 | return false; |
| 435 | |
| 436 | BFD_ASSERT (strncmp (name, ".rel", 4) == 0 |
| 437 | && strcmp (bfd_get_section_name (abfd, sec), |
| 438 | name + 4) == 0); |
| 439 | |
| 440 | sreloc = bfd_get_section_by_name (dynobj, name); |
| 441 | if (sreloc == NULL) |
| 442 | { |
| 443 | sreloc = bfd_make_section (dynobj, name); |
| 444 | if (sreloc == NULL |
| 445 | || ! bfd_set_section_flags (dynobj, sreloc, |
| 446 | (SEC_ALLOC |
| 447 | | SEC_LOAD |
| 448 | | SEC_HAS_CONTENTS |
| 449 | | SEC_IN_MEMORY |
| 450 | | SEC_READONLY)) |
| 451 | || ! bfd_set_section_alignment (dynobj, sreloc, 2)) |
| 452 | return false; |
| 453 | } |
| 454 | } |
| 455 | |
| 456 | sreloc->_raw_size += sizeof (Elf32_External_Rel); |
| 457 | } |
| 458 | |
| 459 | break; |
| 460 | |
| 461 | default: |
| 462 | break; |
| 463 | } |
| 464 | } |
| 465 | |
| 466 | return true; |
| 467 | } |
| 468 | |
| 469 | /* Adjust a symbol defined by a dynamic object and referenced by a |
| 470 | regular object. The current definition is in some section of the |
| 471 | dynamic object, but we're not including those sections. We have to |
| 472 | change the definition to something the rest of the link can |
| 473 | understand. */ |
| 474 | |
| 475 | static boolean |
| 476 | elf_i386_adjust_dynamic_symbol (info, h) |
| 477 | struct bfd_link_info *info; |
| 478 | struct elf_link_hash_entry *h; |
| 479 | { |
| 480 | bfd *dynobj; |
| 481 | asection *s; |
| 482 | unsigned int power_of_two; |
| 483 | |
| 484 | dynobj = elf_hash_table (info)->dynobj; |
| 485 | |
| 486 | /* Make sure we know what is going on here. */ |
| 487 | BFD_ASSERT (dynobj != NULL |
| 488 | && ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) |
| 489 | || ((h->elf_link_hash_flags |
| 490 | & ELF_LINK_HASH_DEF_DYNAMIC) != 0 |
| 491 | && (h->elf_link_hash_flags |
| 492 | & ELF_LINK_HASH_REF_REGULAR) != 0 |
| 493 | && (h->elf_link_hash_flags |
| 494 | & ELF_LINK_HASH_DEF_REGULAR) == 0))); |
| 495 | |
| 496 | /* If this is a function, put it in the procedure linkage table. We |
| 497 | will fill in the contents of the procedure linkage table later, |
| 498 | when we know the address of the .got section. */ |
| 499 | if (h->type == STT_FUNC |
| 500 | || (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0) |
| 501 | { |
| 502 | if (! elf_hash_table (info)->dynamic_sections_created) |
| 503 | { |
| 504 | /* This case can occur if we saw a PLT32 reloc in an input |
| 505 | file, but none of the input files were dynamic objects. |
| 506 | In such a case, we don't actually need to build a |
| 507 | procedure linkage table, and we can just do a PC32 reloc |
| 508 | instead. */ |
| 509 | BFD_ASSERT ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0); |
| 510 | return true; |
| 511 | } |
| 512 | |
| 513 | s = bfd_get_section_by_name (dynobj, ".plt"); |
| 514 | BFD_ASSERT (s != NULL); |
| 515 | |
| 516 | /* If this is the first .plt entry, make room for the special |
| 517 | first entry. */ |
| 518 | if (s->_raw_size == 0) |
| 519 | s->_raw_size += PLT_ENTRY_SIZE; |
| 520 | |
| 521 | /* If this symbol is not defined in a regular file, and we are |
| 522 | not generating a shared library, then set the symbol to this |
| 523 | location in the .plt. This is required to make function |
| 524 | pointers compare as equal between the normal executable and |
| 525 | the shared library. */ |
| 526 | if (! info->shared |
| 527 | && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) |
| 528 | { |
| 529 | h->root.u.def.section = s; |
| 530 | h->root.u.def.value = s->_raw_size; |
| 531 | } |
| 532 | |
| 533 | h->plt_offset = s->_raw_size; |
| 534 | |
| 535 | /* Make room for this entry. */ |
| 536 | s->_raw_size += PLT_ENTRY_SIZE; |
| 537 | |
| 538 | /* We also need to make an entry in the .got.plt section, which |
| 539 | will be placed in the .got section by the linker script. */ |
| 540 | |
| 541 | s = bfd_get_section_by_name (dynobj, ".got.plt"); |
| 542 | BFD_ASSERT (s != NULL); |
| 543 | s->_raw_size += 4; |
| 544 | |
| 545 | /* We also need to make an entry in the .rel.plt section. */ |
| 546 | |
| 547 | s = bfd_get_section_by_name (dynobj, ".rel.plt"); |
| 548 | BFD_ASSERT (s != NULL); |
| 549 | s->_raw_size += sizeof (Elf32_External_Rel); |
| 550 | |
| 551 | return true; |
| 552 | } |
| 553 | |
| 554 | /* If this is a weak symbol, and there is a real definition, the |
| 555 | processor independent code will have arranged for us to see the |
| 556 | real definition first, and we can just use the same value. */ |
| 557 | if (h->weakdef != NULL) |
| 558 | { |
| 559 | BFD_ASSERT (h->weakdef->root.type == bfd_link_hash_defined |
| 560 | || h->weakdef->root.type == bfd_link_hash_defweak); |
| 561 | h->root.u.def.section = h->weakdef->root.u.def.section; |
| 562 | h->root.u.def.value = h->weakdef->root.u.def.value; |
| 563 | return true; |
| 564 | } |
| 565 | |
| 566 | /* This is a reference to a symbol defined by a dynamic object which |
| 567 | is not a function. */ |
| 568 | |
| 569 | /* If we are creating a shared library, we must presume that the |
| 570 | only references to the symbol are via the global offset table. |
| 571 | For such cases we need not do anything here; the relocations will |
| 572 | be handled correctly by relocate_section. */ |
| 573 | if (info->shared) |
| 574 | return true; |
| 575 | |
| 576 | /* We must allocate the symbol in our .dynbss section, which will |
| 577 | become part of the .bss section of the executable. There will be |
| 578 | an entry for this symbol in the .dynsym section. The dynamic |
| 579 | object will contain position independent code, so all references |
| 580 | from the dynamic object to this symbol will go through the global |
| 581 | offset table. The dynamic linker will use the .dynsym entry to |
| 582 | determine the address it must put in the global offset table, so |
| 583 | both the dynamic object and the regular object will refer to the |
| 584 | same memory location for the variable. */ |
| 585 | |
| 586 | s = bfd_get_section_by_name (dynobj, ".dynbss"); |
| 587 | BFD_ASSERT (s != NULL); |
| 588 | |
| 589 | /* If the symbol is currently defined in the .bss section of the |
| 590 | dynamic object, then it is OK to simply initialize it to zero. |
| 591 | If the symbol is in some other section, we must generate a |
| 592 | R_386_COPY reloc to tell the dynamic linker to copy the initial |
| 593 | value out of the dynamic object and into the runtime process |
| 594 | image. We need to remember the offset into the .rel.bss section |
| 595 | we are going to use. */ |
| 596 | if ((h->root.u.def.section->flags & SEC_LOAD) != 0) |
| 597 | { |
| 598 | asection *srel; |
| 599 | |
| 600 | srel = bfd_get_section_by_name (dynobj, ".rel.bss"); |
| 601 | BFD_ASSERT (srel != NULL); |
| 602 | srel->_raw_size += sizeof (Elf32_External_Rel); |
| 603 | h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_COPY; |
| 604 | } |
| 605 | |
| 606 | /* We need to figure out the alignment required for this symbol. I |
| 607 | have no idea how ELF linkers handle this. */ |
| 608 | power_of_two = bfd_log2 (h->size); |
| 609 | if (power_of_two > 3) |
| 610 | power_of_two = 3; |
| 611 | |
| 612 | /* Apply the required alignment. */ |
| 613 | s->_raw_size = BFD_ALIGN (s->_raw_size, |
| 614 | (bfd_size_type) (1 << power_of_two)); |
| 615 | if (power_of_two > bfd_get_section_alignment (dynobj, s)) |
| 616 | { |
| 617 | if (! bfd_set_section_alignment (dynobj, s, power_of_two)) |
| 618 | return false; |
| 619 | } |
| 620 | |
| 621 | /* Define the symbol as being at this point in the section. */ |
| 622 | h->root.u.def.section = s; |
| 623 | h->root.u.def.value = s->_raw_size; |
| 624 | |
| 625 | /* Increment the section size to make room for the symbol. */ |
| 626 | s->_raw_size += h->size; |
| 627 | |
| 628 | return true; |
| 629 | } |
| 630 | |
| 631 | /* Set the sizes of the dynamic sections. */ |
| 632 | |
| 633 | static boolean |
| 634 | elf_i386_size_dynamic_sections (output_bfd, info) |
| 635 | bfd *output_bfd; |
| 636 | struct bfd_link_info *info; |
| 637 | { |
| 638 | bfd *dynobj; |
| 639 | asection *s; |
| 640 | boolean plt; |
| 641 | boolean relocs; |
| 642 | boolean reltext; |
| 643 | |
| 644 | dynobj = elf_hash_table (info)->dynobj; |
| 645 | BFD_ASSERT (dynobj != NULL); |
| 646 | |
| 647 | if (elf_hash_table (info)->dynamic_sections_created) |
| 648 | { |
| 649 | /* Set the contents of the .interp section to the interpreter. */ |
| 650 | if (! info->shared) |
| 651 | { |
| 652 | s = bfd_get_section_by_name (dynobj, ".interp"); |
| 653 | BFD_ASSERT (s != NULL); |
| 654 | s->_raw_size = sizeof ELF_DYNAMIC_INTERPRETER; |
| 655 | s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER; |
| 656 | } |
| 657 | } |
| 658 | else |
| 659 | { |
| 660 | /* We may have created entries in the .rel.got section. |
| 661 | However, if we are not creating the dynamic sections, we will |
| 662 | not actually use these entries. Reset the size of .rel.got, |
| 663 | which will cause it to get stripped from the output file |
| 664 | below. */ |
| 665 | s = bfd_get_section_by_name (dynobj, ".rel.got"); |
| 666 | if (s != NULL) |
| 667 | s->_raw_size = 0; |
| 668 | } |
| 669 | |
| 670 | /* The check_relocs and adjust_dynamic_symbol entry points have |
| 671 | determined the sizes of the various dynamic sections. Allocate |
| 672 | memory for them. */ |
| 673 | plt = false; |
| 674 | relocs = false; |
| 675 | reltext = false; |
| 676 | for (s = dynobj->sections; s != NULL; s = s->next) |
| 677 | { |
| 678 | const char *name; |
| 679 | boolean strip; |
| 680 | |
| 681 | if ((s->flags & SEC_IN_MEMORY) == 0) |
| 682 | continue; |
| 683 | |
| 684 | /* It's OK to base decisions on the section name, because none |
| 685 | of the dynobj section names depend upon the input files. */ |
| 686 | name = bfd_get_section_name (dynobj, s); |
| 687 | |
| 688 | strip = false; |
| 689 | |
| 690 | if (strcmp (name, ".plt") == 0) |
| 691 | { |
| 692 | if (s->_raw_size == 0) |
| 693 | { |
| 694 | /* Strip this section if we don't need it; see the |
| 695 | comment below. */ |
| 696 | strip = true; |
| 697 | } |
| 698 | else |
| 699 | { |
| 700 | /* Remember whether there is a PLT. */ |
| 701 | plt = true; |
| 702 | } |
| 703 | } |
| 704 | else if (strncmp (name, ".rel", 4) == 0) |
| 705 | { |
| 706 | if (s->_raw_size == 0) |
| 707 | { |
| 708 | /* If we don't need this section, strip it from the |
| 709 | output file. This is mostly to handle .rel.bss and |
| 710 | .rel.plt. We must create both sections in |
| 711 | create_dynamic_sections, because they must be created |
| 712 | before the linker maps input sections to output |
| 713 | sections. The linker does that before |
| 714 | adjust_dynamic_symbol is called, and it is that |
| 715 | function which decides whether anything needs to go |
| 716 | into these sections. */ |
| 717 | strip = true; |
| 718 | } |
| 719 | else |
| 720 | { |
| 721 | asection *target; |
| 722 | |
| 723 | /* Remember whether there are any reloc sections other |
| 724 | than .rel.plt. */ |
| 725 | if (strcmp (name, ".rel.plt") != 0) |
| 726 | relocs = true; |
| 727 | |
| 728 | /* If this relocation section applies to a read only |
| 729 | section, then we probably need a DT_TEXTREL entry. */ |
| 730 | target = bfd_get_section_by_name (output_bfd, name + 4); |
| 731 | if (target != NULL |
| 732 | && (target->flags & SEC_READONLY) != 0) |
| 733 | reltext = true; |
| 734 | |
| 735 | /* We use the reloc_count field as a counter if we need |
| 736 | to copy relocs into the output file. */ |
| 737 | s->reloc_count = 0; |
| 738 | } |
| 739 | } |
| 740 | else if (strncmp (name, ".got", 4) != 0) |
| 741 | { |
| 742 | /* It's not one of our sections, so don't allocate space. */ |
| 743 | continue; |
| 744 | } |
| 745 | |
| 746 | if (strip) |
| 747 | { |
| 748 | asection **spp; |
| 749 | |
| 750 | for (spp = &s->output_section->owner->sections; |
| 751 | *spp != s->output_section; |
| 752 | spp = &(*spp)->next) |
| 753 | ; |
| 754 | *spp = s->output_section->next; |
| 755 | --s->output_section->owner->section_count; |
| 756 | |
| 757 | continue; |
| 758 | } |
| 759 | |
| 760 | /* Allocate memory for the section contents. */ |
| 761 | s->contents = (bfd_byte *) bfd_alloc (dynobj, s->_raw_size); |
| 762 | if (s->contents == NULL && s->_raw_size != 0) |
| 763 | { |
| 764 | bfd_set_error (bfd_error_no_memory); |
| 765 | return false; |
| 766 | } |
| 767 | } |
| 768 | |
| 769 | if (elf_hash_table (info)->dynamic_sections_created) |
| 770 | { |
| 771 | /* Add some entries to the .dynamic section. We fill in the |
| 772 | values later, in elf_i386_finish_dynamic_sections, but we |
| 773 | must add the entries now so that we get the correct size for |
| 774 | the .dynamic section. The DT_DEBUG entry is filled in by the |
| 775 | dynamic linker and used by the debugger. */ |
| 776 | if (! info->shared) |
| 777 | { |
| 778 | if (! bfd_elf32_add_dynamic_entry (info, DT_DEBUG, 0)) |
| 779 | return false; |
| 780 | } |
| 781 | |
| 782 | if (plt) |
| 783 | { |
| 784 | if (! bfd_elf32_add_dynamic_entry (info, DT_PLTGOT, 0) |
| 785 | || ! bfd_elf32_add_dynamic_entry (info, DT_PLTRELSZ, 0) |
| 786 | || ! bfd_elf32_add_dynamic_entry (info, DT_PLTREL, DT_REL) |
| 787 | || ! bfd_elf32_add_dynamic_entry (info, DT_JMPREL, 0)) |
| 788 | return false; |
| 789 | } |
| 790 | |
| 791 | if (relocs) |
| 792 | { |
| 793 | if (! bfd_elf32_add_dynamic_entry (info, DT_REL, 0) |
| 794 | || ! bfd_elf32_add_dynamic_entry (info, DT_RELSZ, 0) |
| 795 | || ! bfd_elf32_add_dynamic_entry (info, DT_RELENT, |
| 796 | sizeof (Elf32_External_Rel))) |
| 797 | return false; |
| 798 | } |
| 799 | |
| 800 | if (reltext) |
| 801 | { |
| 802 | if (! bfd_elf32_add_dynamic_entry (info, DT_TEXTREL, 0)) |
| 803 | return false; |
| 804 | } |
| 805 | } |
| 806 | |
| 807 | return true; |
| 808 | } |
| 809 | |
| 810 | /* Relocate an i386 ELF section. */ |
| 811 | |
| 812 | static boolean |
| 813 | elf_i386_relocate_section (output_bfd, info, input_bfd, input_section, |
| 814 | contents, relocs, local_syms, local_sections) |
| 815 | bfd *output_bfd; |
| 816 | struct bfd_link_info *info; |
| 817 | bfd *input_bfd; |
| 818 | asection *input_section; |
| 819 | bfd_byte *contents; |
| 820 | Elf_Internal_Rela *relocs; |
| 821 | Elf_Internal_Sym *local_syms; |
| 822 | asection **local_sections; |
| 823 | { |
| 824 | bfd *dynobj; |
| 825 | Elf_Internal_Shdr *symtab_hdr; |
| 826 | struct elf_link_hash_entry **sym_hashes; |
| 827 | bfd_vma *local_got_offsets; |
| 828 | asection *sgot; |
| 829 | asection *splt; |
| 830 | asection *sreloc; |
| 831 | Elf_Internal_Rela *rel; |
| 832 | Elf_Internal_Rela *relend; |
| 833 | |
| 834 | dynobj = elf_hash_table (info)->dynobj; |
| 835 | symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr; |
| 836 | sym_hashes = elf_sym_hashes (input_bfd); |
| 837 | local_got_offsets = elf_local_got_offsets (input_bfd); |
| 838 | |
| 839 | sgot = NULL; |
| 840 | splt = NULL; |
| 841 | sreloc = NULL; |
| 842 | |
| 843 | rel = relocs; |
| 844 | relend = relocs + input_section->reloc_count; |
| 845 | for (; rel < relend; rel++) |
| 846 | { |
| 847 | int r_type; |
| 848 | reloc_howto_type *howto; |
| 849 | long r_symndx; |
| 850 | struct elf_link_hash_entry *h; |
| 851 | Elf_Internal_Sym *sym; |
| 852 | asection *sec; |
| 853 | bfd_vma relocation; |
| 854 | bfd_reloc_status_type r; |
| 855 | |
| 856 | r_type = ELF32_R_TYPE (rel->r_info); |
| 857 | if (r_type < 0 || r_type >= (int) R_386_max) |
| 858 | { |
| 859 | bfd_set_error (bfd_error_bad_value); |
| 860 | return false; |
| 861 | } |
| 862 | howto = elf_howto_table + r_type; |
| 863 | |
| 864 | r_symndx = ELF32_R_SYM (rel->r_info); |
| 865 | |
| 866 | if (info->relocateable) |
| 867 | { |
| 868 | /* This is a relocateable link. We don't have to change |
| 869 | anything, unless the reloc is against a section symbol, |
| 870 | in which case we have to adjust according to where the |
| 871 | section symbol winds up in the output section. */ |
| 872 | if (r_symndx < symtab_hdr->sh_info) |
| 873 | { |
| 874 | sym = local_syms + r_symndx; |
| 875 | if (ELF_ST_TYPE (sym->st_info) == STT_SECTION) |
| 876 | { |
| 877 | bfd_vma val; |
| 878 | |
| 879 | sec = local_sections[r_symndx]; |
| 880 | val = bfd_get_32 (input_bfd, contents + rel->r_offset); |
| 881 | val += sec->output_offset + sym->st_value; |
| 882 | bfd_put_32 (input_bfd, val, contents + rel->r_offset); |
| 883 | } |
| 884 | } |
| 885 | |
| 886 | continue; |
| 887 | } |
| 888 | |
| 889 | /* This is a final link. */ |
| 890 | h = NULL; |
| 891 | sym = NULL; |
| 892 | sec = NULL; |
| 893 | if (r_symndx < symtab_hdr->sh_info) |
| 894 | { |
| 895 | sym = local_syms + r_symndx; |
| 896 | sec = local_sections[r_symndx]; |
| 897 | relocation = (sec->output_section->vma |
| 898 | + sec->output_offset |
| 899 | + sym->st_value); |
| 900 | } |
| 901 | else |
| 902 | { |
| 903 | h = sym_hashes[r_symndx - symtab_hdr->sh_info]; |
| 904 | if (h->root.type == bfd_link_hash_defined |
| 905 | || h->root.type == bfd_link_hash_defweak) |
| 906 | { |
| 907 | sec = h->root.u.def.section; |
| 908 | if (r_type == R_386_GOTPC |
| 909 | || (r_type == R_386_PLT32 |
| 910 | && h->plt_offset != (bfd_vma) -1) |
| 911 | || (r_type == R_386_GOT32 |
| 912 | && elf_hash_table (info)->dynamic_sections_created) |
| 913 | || (info->shared |
| 914 | && (r_type == R_386_32 |
| 915 | || r_type == R_386_PC32) |
| 916 | && (input_section->flags & SEC_ALLOC) != 0)) |
| 917 | { |
| 918 | /* In these cases, we don't need the relocation |
| 919 | value. We check specially because in some |
| 920 | obscure cases sec->output_section will be NULL. */ |
| 921 | relocation = 0; |
| 922 | } |
| 923 | else |
| 924 | relocation = (h->root.u.def.value |
| 925 | + sec->output_section->vma |
| 926 | + sec->output_offset); |
| 927 | } |
| 928 | else if (h->root.type == bfd_link_hash_undefweak) |
| 929 | relocation = 0; |
| 930 | else if (info->shared) |
| 931 | relocation = 0; |
| 932 | else |
| 933 | { |
| 934 | if (! ((*info->callbacks->undefined_symbol) |
| 935 | (info, h->root.root.string, input_bfd, |
| 936 | input_section, rel->r_offset))) |
| 937 | return false; |
| 938 | relocation = 0; |
| 939 | } |
| 940 | } |
| 941 | |
| 942 | switch (r_type) |
| 943 | { |
| 944 | case R_386_GOT32: |
| 945 | /* Relocation is to the entry for this symbol in the global |
| 946 | offset table. */ |
| 947 | if (sgot == NULL) |
| 948 | { |
| 949 | sgot = bfd_get_section_by_name (dynobj, ".got"); |
| 950 | BFD_ASSERT (sgot != NULL); |
| 951 | } |
| 952 | |
| 953 | if (h != NULL) |
| 954 | { |
| 955 | bfd_vma off; |
| 956 | |
| 957 | off = h->got_offset; |
| 958 | BFD_ASSERT (off != (bfd_vma) -1); |
| 959 | |
| 960 | if (! elf_hash_table (info)->dynamic_sections_created) |
| 961 | { |
| 962 | /* This is actually a static link. We must |
| 963 | initialize this entry in the global offset table. |
| 964 | Since the offset must always be a multiple of 4, |
| 965 | we use the least significant bit to record |
| 966 | whether we have initialized it already. |
| 967 | |
| 968 | When doing a dynamic link, we create a .rel.got |
| 969 | relocation entry to initialize the value. This |
| 970 | is done in the finish_dynamic_symbol routine. */ |
| 971 | if ((off & 1) != 0) |
| 972 | off &= ~1; |
| 973 | else |
| 974 | { |
| 975 | bfd_put_32 (output_bfd, relocation, |
| 976 | sgot->contents + off); |
| 977 | h->got_offset |= 1; |
| 978 | } |
| 979 | } |
| 980 | |
| 981 | relocation = sgot->output_offset + off; |
| 982 | } |
| 983 | else |
| 984 | { |
| 985 | bfd_vma off; |
| 986 | |
| 987 | BFD_ASSERT (local_got_offsets != NULL |
| 988 | && local_got_offsets[r_symndx] != (bfd_vma) -1); |
| 989 | |
| 990 | off = local_got_offsets[r_symndx]; |
| 991 | |
| 992 | /* The offset must always be a multiple of 4. We use |
| 993 | the least significant bit to record whether we have |
| 994 | already generated the necessary reloc. */ |
| 995 | if ((off & 1) != 0) |
| 996 | off &= ~1; |
| 997 | else |
| 998 | { |
| 999 | bfd_put_32 (output_bfd, relocation, sgot->contents + off); |
| 1000 | |
| 1001 | if (info->shared) |
| 1002 | { |
| 1003 | asection *srelgot; |
| 1004 | Elf_Internal_Rel outrel; |
| 1005 | |
| 1006 | srelgot = bfd_get_section_by_name (dynobj, ".rel.got"); |
| 1007 | BFD_ASSERT (srelgot != NULL); |
| 1008 | |
| 1009 | outrel.r_offset = (sgot->output_section->vma |
| 1010 | + sgot->output_offset |
| 1011 | + off); |
| 1012 | outrel.r_info = ELF32_R_INFO (0, R_386_RELATIVE); |
| 1013 | bfd_elf32_swap_reloc_out (output_bfd, &outrel, |
| 1014 | (((Elf32_External_Rel *) |
| 1015 | srelgot->contents) |
| 1016 | + srelgot->reloc_count)); |
| 1017 | ++srelgot->reloc_count; |
| 1018 | } |
| 1019 | |
| 1020 | local_got_offsets[r_symndx] |= 1; |
| 1021 | } |
| 1022 | |
| 1023 | relocation = sgot->output_offset + off; |
| 1024 | } |
| 1025 | |
| 1026 | break; |
| 1027 | |
| 1028 | case R_386_GOTOFF: |
| 1029 | /* Relocation is relative to the start of the global offset |
| 1030 | table. */ |
| 1031 | |
| 1032 | if (sgot == NULL) |
| 1033 | { |
| 1034 | sgot = bfd_get_section_by_name (dynobj, ".got"); |
| 1035 | BFD_ASSERT (sgot != NULL); |
| 1036 | } |
| 1037 | |
| 1038 | /* Note that sgot->output_offset is not involved in this |
| 1039 | calculation. We always want the start of .got. If we |
| 1040 | defined _GLOBAL_OFFSET_TABLE in a different way, as is |
| 1041 | permitted by the ABI, we might have to change this |
| 1042 | calculation. */ |
| 1043 | relocation -= sgot->output_section->vma; |
| 1044 | |
| 1045 | break; |
| 1046 | |
| 1047 | case R_386_GOTPC: |
| 1048 | /* Use global offset table as symbol value. */ |
| 1049 | |
| 1050 | if (sgot == NULL) |
| 1051 | { |
| 1052 | sgot = bfd_get_section_by_name (dynobj, ".got"); |
| 1053 | BFD_ASSERT (sgot != NULL); |
| 1054 | } |
| 1055 | |
| 1056 | relocation = sgot->output_section->vma; |
| 1057 | |
| 1058 | break; |
| 1059 | |
| 1060 | case R_386_PLT32: |
| 1061 | /* Relocation is to the entry for this symbol in the |
| 1062 | procedure linkage table. */ |
| 1063 | |
| 1064 | /* Resolve a PLT32 reloc again a local symbol directly, |
| 1065 | without using the procedure linkage table. */ |
| 1066 | if (h == NULL) |
| 1067 | break; |
| 1068 | |
| 1069 | if (h->plt_offset == (bfd_vma) -1) |
| 1070 | { |
| 1071 | /* We didn't make a PLT entry for this symbol. This |
| 1072 | happens when statically linking PIC code. */ |
| 1073 | break; |
| 1074 | } |
| 1075 | |
| 1076 | if (splt == NULL) |
| 1077 | { |
| 1078 | splt = bfd_get_section_by_name (dynobj, ".plt"); |
| 1079 | BFD_ASSERT (splt != NULL); |
| 1080 | } |
| 1081 | |
| 1082 | relocation = (splt->output_section->vma |
| 1083 | + splt->output_offset |
| 1084 | + h->plt_offset); |
| 1085 | |
| 1086 | break; |
| 1087 | |
| 1088 | case R_386_32: |
| 1089 | case R_386_PC32: |
| 1090 | if (info->shared |
| 1091 | && (input_section->flags & SEC_ALLOC) != 0 |
| 1092 | && (r_type != R_386_PC32 || h != NULL)) |
| 1093 | { |
| 1094 | Elf_Internal_Rel outrel; |
| 1095 | |
| 1096 | /* When generating a shared object, these relocations |
| 1097 | are copied into the output file to be resolved at run |
| 1098 | time. */ |
| 1099 | |
| 1100 | if (sreloc == NULL) |
| 1101 | { |
| 1102 | const char *name; |
| 1103 | |
| 1104 | name = (bfd_elf_string_from_elf_section |
| 1105 | (input_bfd, |
| 1106 | elf_elfheader (input_bfd)->e_shstrndx, |
| 1107 | elf_section_data (input_section)->rel_hdr.sh_name)); |
| 1108 | if (name == NULL) |
| 1109 | return false; |
| 1110 | |
| 1111 | BFD_ASSERT (strncmp (name, ".rel", 4) == 0 |
| 1112 | && strcmp (bfd_get_section_name (input_bfd, |
| 1113 | input_section), |
| 1114 | name + 4) == 0); |
| 1115 | |
| 1116 | sreloc = bfd_get_section_by_name (dynobj, name); |
| 1117 | BFD_ASSERT (sreloc != NULL); |
| 1118 | } |
| 1119 | |
| 1120 | outrel.r_offset = (rel->r_offset |
| 1121 | + input_section->output_section->vma |
| 1122 | + input_section->output_offset); |
| 1123 | if (r_type == R_386_PC32) |
| 1124 | { |
| 1125 | BFD_ASSERT (h != NULL && h->dynindx != -1); |
| 1126 | outrel.r_info = ELF32_R_INFO (h->dynindx, R_386_PC32); |
| 1127 | } |
| 1128 | else |
| 1129 | { |
| 1130 | if (h == NULL) |
| 1131 | outrel.r_info = ELF32_R_INFO (0, R_386_RELATIVE); |
| 1132 | else |
| 1133 | { |
| 1134 | BFD_ASSERT (h->dynindx != (bfd_vma) -1); |
| 1135 | outrel.r_info = ELF32_R_INFO (h->dynindx, R_386_32); |
| 1136 | } |
| 1137 | } |
| 1138 | |
| 1139 | bfd_elf32_swap_reloc_out (output_bfd, &outrel, |
| 1140 | (((Elf32_External_Rel *) |
| 1141 | sreloc->contents) |
| 1142 | + sreloc->reloc_count)); |
| 1143 | ++sreloc->reloc_count; |
| 1144 | |
| 1145 | /* If this reloc is against an external symbol, we do |
| 1146 | not want to fiddle with the addend. Otherwise, we |
| 1147 | need to include the symbol value so that it becomes |
| 1148 | an addend for the dynamic reloc. */ |
| 1149 | if (h != NULL) |
| 1150 | continue; |
| 1151 | } |
| 1152 | |
| 1153 | break; |
| 1154 | |
| 1155 | default: |
| 1156 | break; |
| 1157 | } |
| 1158 | |
| 1159 | r = _bfd_final_link_relocate (howto, input_bfd, input_section, |
| 1160 | contents, rel->r_offset, |
| 1161 | relocation, (bfd_vma) 0); |
| 1162 | |
| 1163 | if (r != bfd_reloc_ok) |
| 1164 | { |
| 1165 | switch (r) |
| 1166 | { |
| 1167 | default: |
| 1168 | case bfd_reloc_outofrange: |
| 1169 | abort (); |
| 1170 | case bfd_reloc_overflow: |
| 1171 | { |
| 1172 | const char *name; |
| 1173 | |
| 1174 | if (h != NULL) |
| 1175 | name = h->root.root.string; |
| 1176 | else |
| 1177 | { |
| 1178 | name = bfd_elf_string_from_elf_section (input_bfd, |
| 1179 | symtab_hdr->sh_link, |
| 1180 | sym->st_name); |
| 1181 | if (name == NULL) |
| 1182 | return false; |
| 1183 | if (*name == '\0') |
| 1184 | name = bfd_section_name (input_bfd, sec); |
| 1185 | } |
| 1186 | if (! ((*info->callbacks->reloc_overflow) |
| 1187 | (info, name, howto->name, (bfd_vma) 0, |
| 1188 | input_bfd, input_section, rel->r_offset))) |
| 1189 | return false; |
| 1190 | } |
| 1191 | break; |
| 1192 | } |
| 1193 | } |
| 1194 | } |
| 1195 | |
| 1196 | return true; |
| 1197 | } |
| 1198 | |
| 1199 | /* Finish up dynamic symbol handling. We set the contents of various |
| 1200 | dynamic sections here. */ |
| 1201 | |
| 1202 | static boolean |
| 1203 | elf_i386_finish_dynamic_symbol (output_bfd, info, h, sym) |
| 1204 | bfd *output_bfd; |
| 1205 | struct bfd_link_info *info; |
| 1206 | struct elf_link_hash_entry *h; |
| 1207 | Elf_Internal_Sym *sym; |
| 1208 | { |
| 1209 | bfd *dynobj; |
| 1210 | |
| 1211 | dynobj = elf_hash_table (info)->dynobj; |
| 1212 | |
| 1213 | if (h->plt_offset != (bfd_vma) -1) |
| 1214 | { |
| 1215 | asection *splt; |
| 1216 | asection *sgot; |
| 1217 | asection *srel; |
| 1218 | bfd_vma plt_index; |
| 1219 | bfd_vma got_offset; |
| 1220 | Elf_Internal_Rel rel; |
| 1221 | |
| 1222 | /* This symbol has an entry in the procedure linkage table. Set |
| 1223 | it up. */ |
| 1224 | |
| 1225 | BFD_ASSERT (h->dynindx != -1); |
| 1226 | |
| 1227 | splt = bfd_get_section_by_name (dynobj, ".plt"); |
| 1228 | sgot = bfd_get_section_by_name (dynobj, ".got.plt"); |
| 1229 | srel = bfd_get_section_by_name (dynobj, ".rel.plt"); |
| 1230 | BFD_ASSERT (splt != NULL && sgot != NULL && srel != NULL); |
| 1231 | |
| 1232 | /* Get the index in the procedure linkage table which |
| 1233 | corresponds to this symbol. This is the index of this symbol |
| 1234 | in all the symbols for which we are making plt entries. The |
| 1235 | first entry in the procedure linkage table is reserved. */ |
| 1236 | plt_index = h->plt_offset / PLT_ENTRY_SIZE - 1; |
| 1237 | |
| 1238 | /* Get the offset into the .got table of the entry that |
| 1239 | corresponds to this function. Each .got entry is 4 bytes. |
| 1240 | The first three are reserved. */ |
| 1241 | got_offset = (plt_index + 3) * 4; |
| 1242 | |
| 1243 | /* Fill in the entry in the procedure linkage table. */ |
| 1244 | if (! info->shared) |
| 1245 | { |
| 1246 | memcpy (splt->contents + h->plt_offset, elf_i386_plt_entry, |
| 1247 | PLT_ENTRY_SIZE); |
| 1248 | bfd_put_32 (output_bfd, |
| 1249 | (sgot->output_section->vma |
| 1250 | + sgot->output_offset |
| 1251 | + got_offset), |
| 1252 | splt->contents + h->plt_offset + 2); |
| 1253 | } |
| 1254 | else |
| 1255 | { |
| 1256 | memcpy (splt->contents + h->plt_offset, elf_i386_pic_plt_entry, |
| 1257 | PLT_ENTRY_SIZE); |
| 1258 | bfd_put_32 (output_bfd, got_offset, |
| 1259 | splt->contents + h->plt_offset + 2); |
| 1260 | } |
| 1261 | |
| 1262 | bfd_put_32 (output_bfd, plt_index * sizeof (Elf32_External_Rel), |
| 1263 | splt->contents + h->plt_offset + 7); |
| 1264 | bfd_put_32 (output_bfd, - (h->plt_offset + PLT_ENTRY_SIZE), |
| 1265 | splt->contents + h->plt_offset + 12); |
| 1266 | |
| 1267 | /* Fill in the entry in the global offset table. */ |
| 1268 | bfd_put_32 (output_bfd, |
| 1269 | (splt->output_section->vma |
| 1270 | + splt->output_offset |
| 1271 | + h->plt_offset |
| 1272 | + 6), |
| 1273 | sgot->contents + got_offset); |
| 1274 | |
| 1275 | /* Fill in the entry in the .rel.plt section. */ |
| 1276 | rel.r_offset = (sgot->output_section->vma |
| 1277 | + sgot->output_offset |
| 1278 | + got_offset); |
| 1279 | rel.r_info = ELF32_R_INFO (h->dynindx, R_386_JUMP_SLOT); |
| 1280 | bfd_elf32_swap_reloc_out (output_bfd, &rel, |
| 1281 | ((Elf32_External_Rel *) srel->contents |
| 1282 | + plt_index)); |
| 1283 | |
| 1284 | if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) |
| 1285 | { |
| 1286 | /* Mark the symbol as undefined, rather than as defined in |
| 1287 | the .plt section. Leave the value alone. */ |
| 1288 | sym->st_shndx = SHN_UNDEF; |
| 1289 | } |
| 1290 | } |
| 1291 | |
| 1292 | if (h->got_offset != (bfd_vma) -1) |
| 1293 | { |
| 1294 | asection *sgot; |
| 1295 | asection *srel; |
| 1296 | Elf_Internal_Rel rel; |
| 1297 | |
| 1298 | /* This symbol has an entry in the global offset table. Set it |
| 1299 | up. */ |
| 1300 | |
| 1301 | BFD_ASSERT (h->dynindx != -1); |
| 1302 | |
| 1303 | sgot = bfd_get_section_by_name (dynobj, ".got"); |
| 1304 | srel = bfd_get_section_by_name (dynobj, ".rel.got"); |
| 1305 | BFD_ASSERT (sgot != NULL && srel != NULL); |
| 1306 | |
| 1307 | bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + h->got_offset); |
| 1308 | |
| 1309 | rel.r_offset = (sgot->output_section->vma |
| 1310 | + sgot->output_offset |
| 1311 | + h->got_offset); |
| 1312 | rel.r_info = ELF32_R_INFO (h->dynindx, R_386_GLOB_DAT); |
| 1313 | bfd_elf32_swap_reloc_out (output_bfd, &rel, |
| 1314 | ((Elf32_External_Rel *) srel->contents |
| 1315 | + srel->reloc_count)); |
| 1316 | ++srel->reloc_count; |
| 1317 | } |
| 1318 | |
| 1319 | if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_COPY) != 0) |
| 1320 | { |
| 1321 | asection *s; |
| 1322 | Elf_Internal_Rel rel; |
| 1323 | |
| 1324 | /* This symbol needs a copy reloc. Set it up. */ |
| 1325 | |
| 1326 | BFD_ASSERT (h->dynindx != -1 |
| 1327 | && (h->root.type == bfd_link_hash_defined |
| 1328 | || h->root.type == bfd_link_hash_defweak)); |
| 1329 | |
| 1330 | s = bfd_get_section_by_name (h->root.u.def.section->owner, |
| 1331 | ".rel.bss"); |
| 1332 | BFD_ASSERT (s != NULL); |
| 1333 | |
| 1334 | rel.r_offset = (h->root.u.def.value |
| 1335 | + h->root.u.def.section->output_section->vma |
| 1336 | + h->root.u.def.section->output_offset); |
| 1337 | rel.r_info = ELF32_R_INFO (h->dynindx, R_386_COPY); |
| 1338 | bfd_elf32_swap_reloc_out (output_bfd, &rel, |
| 1339 | ((Elf32_External_Rel *) s->contents |
| 1340 | + s->reloc_count)); |
| 1341 | ++s->reloc_count; |
| 1342 | } |
| 1343 | |
| 1344 | /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */ |
| 1345 | if (strcmp (h->root.root.string, "_DYNAMIC") == 0 |
| 1346 | || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0) |
| 1347 | sym->st_shndx = SHN_ABS; |
| 1348 | |
| 1349 | return true; |
| 1350 | } |
| 1351 | |
| 1352 | /* Finish up the dynamic sections. */ |
| 1353 | |
| 1354 | static boolean |
| 1355 | elf_i386_finish_dynamic_sections (output_bfd, info) |
| 1356 | bfd *output_bfd; |
| 1357 | struct bfd_link_info *info; |
| 1358 | { |
| 1359 | bfd *dynobj; |
| 1360 | asection *sgot; |
| 1361 | asection *sdyn; |
| 1362 | |
| 1363 | dynobj = elf_hash_table (info)->dynobj; |
| 1364 | |
| 1365 | sgot = bfd_get_section_by_name (dynobj, ".got.plt"); |
| 1366 | BFD_ASSERT (sgot != NULL); |
| 1367 | sdyn = bfd_get_section_by_name (dynobj, ".dynamic"); |
| 1368 | |
| 1369 | if (elf_hash_table (info)->dynamic_sections_created) |
| 1370 | { |
| 1371 | asection *splt; |
| 1372 | Elf32_External_Dyn *dyncon, *dynconend; |
| 1373 | |
| 1374 | splt = bfd_get_section_by_name (dynobj, ".plt"); |
| 1375 | BFD_ASSERT (splt != NULL && sdyn != NULL); |
| 1376 | |
| 1377 | dyncon = (Elf32_External_Dyn *) sdyn->contents; |
| 1378 | dynconend = (Elf32_External_Dyn *) (sdyn->contents + sdyn->_raw_size); |
| 1379 | for (; dyncon < dynconend; dyncon++) |
| 1380 | { |
| 1381 | Elf_Internal_Dyn dyn; |
| 1382 | const char *name; |
| 1383 | asection *s; |
| 1384 | |
| 1385 | bfd_elf32_swap_dyn_in (dynobj, dyncon, &dyn); |
| 1386 | |
| 1387 | switch (dyn.d_tag) |
| 1388 | { |
| 1389 | default: |
| 1390 | break; |
| 1391 | |
| 1392 | case DT_PLTGOT: |
| 1393 | name = ".got"; |
| 1394 | goto get_vma; |
| 1395 | case DT_JMPREL: |
| 1396 | name = ".rel.plt"; |
| 1397 | get_vma: |
| 1398 | s = bfd_get_section_by_name (output_bfd, name); |
| 1399 | BFD_ASSERT (s != NULL); |
| 1400 | dyn.d_un.d_ptr = s->vma; |
| 1401 | bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon); |
| 1402 | break; |
| 1403 | |
| 1404 | case DT_PLTRELSZ: |
| 1405 | s = bfd_get_section_by_name (output_bfd, ".rel.plt"); |
| 1406 | BFD_ASSERT (s != NULL); |
| 1407 | if (s->_cooked_size != 0) |
| 1408 | dyn.d_un.d_val = s->_cooked_size; |
| 1409 | else |
| 1410 | dyn.d_un.d_val = s->_raw_size; |
| 1411 | bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon); |
| 1412 | break; |
| 1413 | |
| 1414 | case DT_RELSZ: |
| 1415 | /* My reading of the SVR4 ABI indicates that the |
| 1416 | procedure linkage table relocs (DT_JMPREL) should be |
| 1417 | included in the overall relocs (DT_REL). This is |
| 1418 | what Solaris does. However, UnixWare can not handle |
| 1419 | that case. Therefore, we override the DT_RELSZ entry |
| 1420 | here to make it not include the JMPREL relocs. Since |
| 1421 | the linker script arranges for .rel.plt to follow all |
| 1422 | other relocation sections, we don't have to worry |
| 1423 | about changing the DT_REL entry. */ |
| 1424 | s = bfd_get_section_by_name (output_bfd, ".rel.plt"); |
| 1425 | if (s != NULL) |
| 1426 | { |
| 1427 | if (s->_cooked_size != 0) |
| 1428 | dyn.d_un.d_val -= s->_cooked_size; |
| 1429 | else |
| 1430 | dyn.d_un.d_val -= s->_raw_size; |
| 1431 | } |
| 1432 | bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon); |
| 1433 | break; |
| 1434 | } |
| 1435 | } |
| 1436 | |
| 1437 | /* Fill in the first entry in the procedure linkage table. */ |
| 1438 | if (splt->_raw_size > 0) |
| 1439 | { |
| 1440 | if (info->shared) |
| 1441 | memcpy (splt->contents, elf_i386_pic_plt0_entry, PLT_ENTRY_SIZE); |
| 1442 | else |
| 1443 | { |
| 1444 | memcpy (splt->contents, elf_i386_plt0_entry, PLT_ENTRY_SIZE); |
| 1445 | bfd_put_32 (output_bfd, |
| 1446 | sgot->output_section->vma + sgot->output_offset + 4, |
| 1447 | splt->contents + 2); |
| 1448 | bfd_put_32 (output_bfd, |
| 1449 | sgot->output_section->vma + sgot->output_offset + 8, |
| 1450 | splt->contents + 8); |
| 1451 | } |
| 1452 | } |
| 1453 | |
| 1454 | /* UnixWare sets the entsize of .plt to 4, although that doesn't |
| 1455 | really seem like the right value. */ |
| 1456 | elf_section_data (splt->output_section)->this_hdr.sh_entsize = 4; |
| 1457 | } |
| 1458 | |
| 1459 | /* Fill in the first three entries in the global offset table. */ |
| 1460 | if (sgot->_raw_size > 0) |
| 1461 | { |
| 1462 | if (sdyn == NULL) |
| 1463 | bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents); |
| 1464 | else |
| 1465 | bfd_put_32 (output_bfd, |
| 1466 | sdyn->output_section->vma + sdyn->output_offset, |
| 1467 | sgot->contents); |
| 1468 | bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + 4); |
| 1469 | bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + 8); |
| 1470 | } |
| 1471 | |
| 1472 | elf_section_data (sgot->output_section)->this_hdr.sh_entsize = 4; |
| 1473 | |
| 1474 | return true; |
| 1475 | } |
| 1476 | |
| 1477 | #define TARGET_LITTLE_SYM bfd_elf32_i386_vec |
| 1478 | #define TARGET_LITTLE_NAME "elf32-i386" |
| 1479 | #define ELF_ARCH bfd_arch_i386 |
| 1480 | #define ELF_MACHINE_CODE EM_386 |
| 1481 | #define elf_info_to_howto elf_i386_info_to_howto |
| 1482 | #define elf_info_to_howto_rel elf_i386_info_to_howto_rel |
| 1483 | #define bfd_elf32_bfd_reloc_type_lookup elf_i386_reloc_type_lookup |
| 1484 | #define ELF_MAXPAGESIZE 0x1000 |
| 1485 | #define elf_backend_create_dynamic_sections \ |
| 1486 | _bfd_elf_create_dynamic_sections |
| 1487 | #define elf_backend_check_relocs elf_i386_check_relocs |
| 1488 | #define elf_backend_adjust_dynamic_symbol \ |
| 1489 | elf_i386_adjust_dynamic_symbol |
| 1490 | #define elf_backend_size_dynamic_sections \ |
| 1491 | elf_i386_size_dynamic_sections |
| 1492 | #define elf_backend_relocate_section elf_i386_relocate_section |
| 1493 | #define elf_backend_finish_dynamic_symbol \ |
| 1494 | elf_i386_finish_dynamic_symbol |
| 1495 | #define elf_backend_finish_dynamic_sections \ |
| 1496 | elf_i386_finish_dynamic_sections |
| 1497 | #define elf_backend_want_got_plt 1 |
| 1498 | #define elf_backend_plt_readonly 0 |
| 1499 | #define elf_backend_want_plt_sym 0 |
| 1500 | |
| 1501 | #include "elf32-target.h" |