| 1 | /* X86-64 specific support for 64-bit ELF |
| 2 | Copyright 2000, 2001 Free Software Foundation, Inc. |
| 3 | Contributed by Jan Hubicka <jh@suse.cz>. |
| 4 | |
| 5 | This file is part of BFD, the Binary File Descriptor library. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 20 | |
| 21 | #include "bfd.h" |
| 22 | #include "sysdep.h" |
| 23 | #include "libbfd.h" |
| 24 | #include "elf-bfd.h" |
| 25 | |
| 26 | #include "elf/x86-64.h" |
| 27 | |
| 28 | /* We use only the RELA entries. */ |
| 29 | #define USE_RELA |
| 30 | |
| 31 | /* In case we're on a 32-bit machine, construct a 64-bit "-1" value. */ |
| 32 | #define MINUS_ONE (~ (bfd_vma) 0) |
| 33 | |
| 34 | /* The relocation "howto" table. Order of fields: |
| 35 | type, size, bitsize, pc_relative, complain_on_overflow, |
| 36 | special_function, name, partial_inplace, src_mask, dst_pack, pcrel_offset. */ |
| 37 | static reloc_howto_type x86_64_elf_howto_table[] = |
| 38 | { |
| 39 | HOWTO(R_X86_64_NONE, 0, 0, 0, false, 0, complain_overflow_dont, |
| 40 | bfd_elf_generic_reloc, "R_X86_64_NONE", false, 0x00000000, 0x00000000, false), |
| 41 | HOWTO(R_X86_64_64, 0, 4, 64, false, 0, complain_overflow_bitfield, |
| 42 | bfd_elf_generic_reloc, "R_X86_64_64", false, MINUS_ONE, MINUS_ONE, false), |
| 43 | HOWTO(R_X86_64_PC32, 0, 4, 32, true, 0, complain_overflow_signed, |
| 44 | bfd_elf_generic_reloc, "R_X86_64_PC32", false, 0xffffffff, 0xffffffff, true), |
| 45 | HOWTO(R_X86_64_GOT32, 0, 4, 32, false, 0, complain_overflow_signed, |
| 46 | bfd_elf_generic_reloc, "R_X86_64_GOT32", false, 0xffffffff, 0xffffffff, false), |
| 47 | HOWTO(R_X86_64_PLT32, 0, 4, 32, true, 0, complain_overflow_signed, |
| 48 | bfd_elf_generic_reloc, "R_X86_64_PLT32", false, 0xffffffff, 0xffffffff, true), |
| 49 | HOWTO(R_X86_64_COPY, 0, 4, 32, false, 0, complain_overflow_bitfield, |
| 50 | bfd_elf_generic_reloc, "R_X86_64_COPY", false, 0xffffffff, 0xffffffff, false), |
| 51 | HOWTO(R_X86_64_GLOB_DAT, 0, 4, 64, false, 0, complain_overflow_bitfield, |
| 52 | bfd_elf_generic_reloc, "R_X86_64_GLOB_DAT", false, MINUS_ONE, MINUS_ONE, false), |
| 53 | HOWTO(R_X86_64_JUMP_SLOT, 0, 4, 64, false, 0, complain_overflow_bitfield, |
| 54 | bfd_elf_generic_reloc, "R_X86_64_JUMP_SLOT", false, MINUS_ONE, MINUS_ONE, false), |
| 55 | HOWTO(R_X86_64_RELATIVE, 0, 4, 64, false, 0, complain_overflow_bitfield, |
| 56 | bfd_elf_generic_reloc, "R_X86_64_RELATIVE", false, MINUS_ONE, MINUS_ONE, false), |
| 57 | HOWTO(R_X86_64_GOTPCREL, 0, 4, 32, true,0 , complain_overflow_signed, |
| 58 | bfd_elf_generic_reloc, "R_X86_64_GOTPCREL", false, 0xffffffff, 0xffffffff, true), |
| 59 | HOWTO(R_X86_64_32, 0, 4, 32, false, 0, complain_overflow_unsigned, |
| 60 | bfd_elf_generic_reloc, "R_X86_64_32", false, 0xffffffff, 0xffffffff, false), |
| 61 | HOWTO(R_X86_64_32S, 0, 4, 32, false, 0, complain_overflow_signed, |
| 62 | bfd_elf_generic_reloc, "R_X86_64_32S", false, 0xffffffff, 0xffffffff, false), |
| 63 | HOWTO(R_X86_64_16, 0, 1, 16, false, 0, complain_overflow_bitfield, |
| 64 | bfd_elf_generic_reloc, "R_X86_64_16", false, 0xffff, 0xffff, false), |
| 65 | HOWTO(R_X86_64_PC16,0, 1, 16, true, 0, complain_overflow_bitfield, |
| 66 | bfd_elf_generic_reloc, "R_X86_64_PC16", false, 0xffff, 0xffff, true), |
| 67 | HOWTO(R_X86_64_8, 0, 0, 8, false, 0, complain_overflow_signed, |
| 68 | bfd_elf_generic_reloc, "R_X86_64_8", false, 0xff, 0xff, false), |
| 69 | HOWTO(R_X86_64_PC8, 0, 0, 8, true, 0, complain_overflow_signed, |
| 70 | bfd_elf_generic_reloc, "R_X86_64_PC8", false, 0xff, 0xff, true) |
| 71 | }; |
| 72 | |
| 73 | /* Map BFD relocs to the x86_64 elf relocs. */ |
| 74 | struct elf_reloc_map |
| 75 | { |
| 76 | bfd_reloc_code_real_type bfd_reloc_val; |
| 77 | unsigned char elf_reloc_val; |
| 78 | }; |
| 79 | |
| 80 | static CONST struct elf_reloc_map x86_64_reloc_map[] = |
| 81 | { |
| 82 | { BFD_RELOC_NONE, R_X86_64_NONE, }, |
| 83 | { BFD_RELOC_64, R_X86_64_64, }, |
| 84 | { BFD_RELOC_32_PCREL, R_X86_64_PC32, }, |
| 85 | { BFD_RELOC_X86_64_GOT32, R_X86_64_GOT32,}, |
| 86 | { BFD_RELOC_X86_64_PLT32, R_X86_64_PLT32,}, |
| 87 | { BFD_RELOC_X86_64_COPY, R_X86_64_COPY, }, |
| 88 | { BFD_RELOC_X86_64_GLOB_DAT, R_X86_64_GLOB_DAT, }, |
| 89 | { BFD_RELOC_X86_64_JUMP_SLOT, R_X86_64_JUMP_SLOT, }, |
| 90 | { BFD_RELOC_X86_64_RELATIVE, R_X86_64_RELATIVE, }, |
| 91 | { BFD_RELOC_X86_64_GOTPCREL, R_X86_64_GOTPCREL, }, |
| 92 | { BFD_RELOC_32, R_X86_64_32, }, |
| 93 | { BFD_RELOC_X86_64_32S, R_X86_64_32S, }, |
| 94 | { BFD_RELOC_16, R_X86_64_16, }, |
| 95 | { BFD_RELOC_16_PCREL, R_X86_64_PC16, }, |
| 96 | { BFD_RELOC_8, R_X86_64_8, }, |
| 97 | { BFD_RELOC_8_PCREL, R_X86_64_PC8, }, |
| 98 | }; |
| 99 | |
| 100 | static reloc_howto_type *elf64_x86_64_reloc_type_lookup |
| 101 | PARAMS ((bfd *, bfd_reloc_code_real_type)); |
| 102 | static void elf64_x86_64_info_to_howto |
| 103 | PARAMS ((bfd *, arelent *, Elf64_Internal_Rela *)); |
| 104 | static struct bfd_link_hash_table *elf64_x86_64_link_hash_table_create |
| 105 | PARAMS ((bfd *)); |
| 106 | |
| 107 | static struct bfd_hash_entry *elf64_x86_64_link_hash_newfunc |
| 108 | PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *, const char *)); |
| 109 | static boolean elf64_x86_64_adjust_dynamic_symbol |
| 110 | PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *)); |
| 111 | |
| 112 | static boolean elf64_x86_64_size_dynamic_sections |
| 113 | PARAMS ((bfd *, struct bfd_link_info *)); |
| 114 | static boolean elf64_x86_64_relocate_section |
| 115 | PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *, |
| 116 | Elf_Internal_Rela *, Elf_Internal_Sym *, asection **)); |
| 117 | static boolean elf64_x86_64_finish_dynamic_symbol |
| 118 | PARAMS ((bfd *, struct bfd_link_info *, struct elf_link_hash_entry *, |
| 119 | Elf_Internal_Sym *sym)); |
| 120 | static boolean elf64_x86_64_finish_dynamic_sections |
| 121 | PARAMS ((bfd *, struct bfd_link_info *)); |
| 122 | |
| 123 | /* Given a BFD reloc type, return a HOWTO structure. */ |
| 124 | static reloc_howto_type * |
| 125 | elf64_x86_64_reloc_type_lookup (abfd, code) |
| 126 | bfd *abfd ATTRIBUTE_UNUSED; |
| 127 | bfd_reloc_code_real_type code; |
| 128 | { |
| 129 | unsigned int i; |
| 130 | for (i = 0; i < sizeof (x86_64_reloc_map) / sizeof (struct elf_reloc_map); |
| 131 | i++) |
| 132 | { |
| 133 | if (x86_64_reloc_map[i].bfd_reloc_val == code) |
| 134 | return &x86_64_elf_howto_table[(int) |
| 135 | x86_64_reloc_map[i].elf_reloc_val]; |
| 136 | } |
| 137 | return 0; |
| 138 | } |
| 139 | |
| 140 | /* Given an x86_64 ELF reloc type, fill in an arelent structure. */ |
| 141 | |
| 142 | static void |
| 143 | elf64_x86_64_info_to_howto (abfd, cache_ptr, dst) |
| 144 | bfd *abfd ATTRIBUTE_UNUSED; |
| 145 | arelent *cache_ptr; |
| 146 | Elf64_Internal_Rela *dst; |
| 147 | { |
| 148 | unsigned r_type; |
| 149 | |
| 150 | r_type = ELF64_R_TYPE (dst->r_info); |
| 151 | BFD_ASSERT (r_type < (unsigned int) R_X86_64_max); |
| 152 | cache_ptr->howto = &x86_64_elf_howto_table[r_type]; |
| 153 | BFD_ASSERT (r_type == cache_ptr->howto->type); |
| 154 | } |
| 155 | \f |
| 156 | /* Functions for the x86-64 ELF linker. */ |
| 157 | |
| 158 | /* The name of the dynamic interpreter. This is put in the .interp |
| 159 | section. */ |
| 160 | |
| 161 | #define ELF_DYNAMIC_INTERPRETER "/lib/ld64.so.1" |
| 162 | |
| 163 | /* The size in bytes of an entry in the global offset table. */ |
| 164 | |
| 165 | #define GOT_ENTRY_SIZE 8 |
| 166 | |
| 167 | /* The size in bytes of an entry in the procedure linkage table. */ |
| 168 | |
| 169 | #define PLT_ENTRY_SIZE 16 |
| 170 | |
| 171 | /* The first entry in a procedure linkage table looks like this. See the |
| 172 | SVR4 ABI i386 supplement and the x86-64 ABI to see how this works. */ |
| 173 | |
| 174 | static const bfd_byte elf64_x86_64_plt0_entry[PLT_ENTRY_SIZE] = |
| 175 | { |
| 176 | 0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */ |
| 177 | 0xff, 0x25, 16, 0, 0, 0, /* jmpq *GOT+16(%rip) */ |
| 178 | 0x90, 0x90, 0x90, 0x90 /* pad out to 16 bytes with nops. */ |
| 179 | }; |
| 180 | |
| 181 | /* Subsequent entries in a procedure linkage table look like this. */ |
| 182 | |
| 183 | static const bfd_byte elf64_x86_64_plt_entry[PLT_ENTRY_SIZE] = |
| 184 | { |
| 185 | 0xff, 0x25, /* jmpq *name@GOTPC(%rip) */ |
| 186 | 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */ |
| 187 | 0x68, /* pushq immediate */ |
| 188 | 0, 0, 0, 0, /* replaced with index into relocation table. */ |
| 189 | 0xe9, /* jmp relative */ |
| 190 | 0, 0, 0, 0 /* replaced with offset to start of .plt0. */ |
| 191 | }; |
| 192 | |
| 193 | /* The x86-64 linker needs to keep track of the number of relocs that |
| 194 | it decides to copy in check_relocs for each symbol. This is so |
| 195 | that it can discard PC relative relocs if it doesn't need them when |
| 196 | linking with -Bsymbolic. We store the information in a field |
| 197 | extending the regular ELF linker hash table. */ |
| 198 | |
| 199 | /* This structure keeps track of the number of PC relative relocs we |
| 200 | have copied for a given symbol. */ |
| 201 | |
| 202 | struct elf64_x86_64_pcrel_relocs_copied |
| 203 | { |
| 204 | /* Next section. */ |
| 205 | struct elf64_x86_64_pcrel_relocs_copied *next; |
| 206 | /* A section in dynobj. */ |
| 207 | asection *section; |
| 208 | /* Number of relocs copied in this section. */ |
| 209 | bfd_size_type count; |
| 210 | }; |
| 211 | |
| 212 | /* x86-64 ELF linker hash entry. */ |
| 213 | |
| 214 | struct elf64_x86_64_link_hash_entry |
| 215 | { |
| 216 | struct elf_link_hash_entry root; |
| 217 | |
| 218 | /* Number of PC relative relocs copied for this symbol. */ |
| 219 | struct elf64_x86_64_pcrel_relocs_copied *pcrel_relocs_copied; |
| 220 | }; |
| 221 | |
| 222 | /* x86-64 ELF linker hash table. */ |
| 223 | |
| 224 | struct elf64_x86_64_link_hash_table |
| 225 | { |
| 226 | struct elf_link_hash_table root; |
| 227 | }; |
| 228 | |
| 229 | /* Declare this now that the above structures are defined. */ |
| 230 | |
| 231 | static boolean elf64_x86_64_discard_copies |
| 232 | PARAMS ((struct elf64_x86_64_link_hash_entry *, PTR)); |
| 233 | |
| 234 | /* Traverse an x86-64 ELF linker hash table. */ |
| 235 | |
| 236 | #define elf64_x86_64_link_hash_traverse(table, func, info) \ |
| 237 | (elf_link_hash_traverse \ |
| 238 | (&(table)->root, \ |
| 239 | (boolean (*) PARAMS ((struct elf_link_hash_entry *, PTR))) (func), \ |
| 240 | (info))) |
| 241 | |
| 242 | /* Get the x86-64 ELF linker hash table from a link_info structure. */ |
| 243 | |
| 244 | #define elf64_x86_64_hash_table(p) \ |
| 245 | ((struct elf64_x86_64_link_hash_table *) ((p)->hash)) |
| 246 | |
| 247 | /* Create an entry in an x86-64 ELF linker hash table. */ |
| 248 | |
| 249 | static struct bfd_hash_entry * |
| 250 | elf64_x86_64_link_hash_newfunc (entry, table, string) |
| 251 | struct bfd_hash_entry *entry; |
| 252 | struct bfd_hash_table *table; |
| 253 | const char *string; |
| 254 | { |
| 255 | struct elf64_x86_64_link_hash_entry *ret = |
| 256 | (struct elf64_x86_64_link_hash_entry *) entry; |
| 257 | |
| 258 | /* Allocate the structure if it has not already been allocated by a |
| 259 | subclass. */ |
| 260 | if (ret == (struct elf64_x86_64_link_hash_entry *) NULL) |
| 261 | ret = ((struct elf64_x86_64_link_hash_entry *) |
| 262 | bfd_hash_allocate (table, |
| 263 | sizeof (struct elf64_x86_64_link_hash_entry))); |
| 264 | if (ret == (struct elf64_x86_64_link_hash_entry *) NULL) |
| 265 | return (struct bfd_hash_entry *) ret; |
| 266 | |
| 267 | /* Call the allocation method of the superclass. */ |
| 268 | ret = ((struct elf64_x86_64_link_hash_entry *) |
| 269 | _bfd_elf_link_hash_newfunc ((struct bfd_hash_entry *) ret, |
| 270 | table, string)); |
| 271 | if (ret != (struct elf64_x86_64_link_hash_entry *) NULL) |
| 272 | { |
| 273 | ret->pcrel_relocs_copied = NULL; |
| 274 | } |
| 275 | |
| 276 | return (struct bfd_hash_entry *) ret; |
| 277 | } |
| 278 | |
| 279 | /* Create an X86-64 ELF linker hash table. */ |
| 280 | |
| 281 | static struct bfd_link_hash_table * |
| 282 | elf64_x86_64_link_hash_table_create (abfd) |
| 283 | bfd *abfd; |
| 284 | { |
| 285 | struct elf64_x86_64_link_hash_table *ret; |
| 286 | |
| 287 | ret = ((struct elf64_x86_64_link_hash_table *) |
| 288 | bfd_alloc (abfd, sizeof (struct elf64_x86_64_link_hash_table))); |
| 289 | if (ret == (struct elf64_x86_64_link_hash_table *) NULL) |
| 290 | return NULL; |
| 291 | |
| 292 | if (! _bfd_elf_link_hash_table_init (&ret->root, abfd, |
| 293 | elf64_x86_64_link_hash_newfunc)) |
| 294 | { |
| 295 | bfd_release (abfd, ret); |
| 296 | return NULL; |
| 297 | } |
| 298 | |
| 299 | return &ret->root.root; |
| 300 | } |
| 301 | |
| 302 | boolean |
| 303 | elf64_x86_64_elf_object_p (abfd) |
| 304 | bfd *abfd; |
| 305 | { |
| 306 | /* Set the right machine number for an x86-64 elf64 file. */ |
| 307 | bfd_default_set_arch_mach (abfd, bfd_arch_i386, bfd_mach_x86_64); |
| 308 | return true; |
| 309 | } |
| 310 | |
| 311 | /* Look through the relocs for a section during the first phase, and |
| 312 | allocate space in the global offset table or procedure linkage |
| 313 | table. */ |
| 314 | |
| 315 | static boolean |
| 316 | elf64_x86_64_check_relocs (abfd, info, sec, relocs) |
| 317 | bfd *abfd; |
| 318 | struct bfd_link_info *info; |
| 319 | asection *sec; |
| 320 | const Elf_Internal_Rela *relocs; |
| 321 | { |
| 322 | bfd *dynobj; |
| 323 | Elf_Internal_Shdr *symtab_hdr; |
| 324 | struct elf_link_hash_entry **sym_hashes; |
| 325 | bfd_signed_vma *local_got_refcounts; |
| 326 | const Elf_Internal_Rela *rel; |
| 327 | const Elf_Internal_Rela *rel_end; |
| 328 | asection *sgot; |
| 329 | asection *srelgot; |
| 330 | asection *sreloc; |
| 331 | |
| 332 | if (info->relocateable) |
| 333 | return true; |
| 334 | |
| 335 | dynobj = elf_hash_table (info)->dynobj; |
| 336 | symtab_hdr = &elf_tdata (abfd)->symtab_hdr; |
| 337 | sym_hashes = elf_sym_hashes (abfd); |
| 338 | local_got_refcounts = elf_local_got_refcounts (abfd); |
| 339 | |
| 340 | sgot = srelgot = sreloc = NULL; |
| 341 | rel_end = relocs + sec->reloc_count; |
| 342 | for (rel = relocs; rel < rel_end; rel++) |
| 343 | { |
| 344 | unsigned long r_symndx; |
| 345 | struct elf_link_hash_entry *h; |
| 346 | |
| 347 | r_symndx = ELF64_R_SYM (rel->r_info); |
| 348 | if (r_symndx < symtab_hdr->sh_info) |
| 349 | h = NULL; |
| 350 | else |
| 351 | h = sym_hashes[r_symndx - symtab_hdr->sh_info]; |
| 352 | |
| 353 | /* Some relocs require a global offset table. */ |
| 354 | if (dynobj == NULL) |
| 355 | { |
| 356 | switch (ELF64_R_TYPE (rel->r_info)) |
| 357 | { |
| 358 | case R_X86_64_GOT32: |
| 359 | case R_X86_64_GOTPCREL: |
| 360 | elf_hash_table (info)->dynobj = dynobj = abfd; |
| 361 | if (! _bfd_elf_create_got_section (dynobj, info)) |
| 362 | return false; |
| 363 | break; |
| 364 | } |
| 365 | } |
| 366 | |
| 367 | switch (ELF64_R_TYPE (rel->r_info)) |
| 368 | { |
| 369 | case R_X86_64_GOTPCREL: |
| 370 | case R_X86_64_GOT32: |
| 371 | /* This symbol requires a global offset table entry. */ |
| 372 | |
| 373 | if (sgot == NULL) |
| 374 | { |
| 375 | sgot = bfd_get_section_by_name (dynobj, ".got"); |
| 376 | BFD_ASSERT (sgot != NULL); |
| 377 | } |
| 378 | |
| 379 | if (srelgot == NULL && (h != NULL || info->shared)) |
| 380 | { |
| 381 | srelgot = bfd_get_section_by_name (dynobj, ".rela.got"); |
| 382 | if (srelgot == NULL) |
| 383 | { |
| 384 | srelgot = bfd_make_section (dynobj, ".rela.got"); |
| 385 | if (srelgot == NULL |
| 386 | || ! bfd_set_section_flags (dynobj, srelgot, |
| 387 | (SEC_ALLOC |
| 388 | | SEC_LOAD |
| 389 | | SEC_HAS_CONTENTS |
| 390 | | SEC_IN_MEMORY |
| 391 | | SEC_LINKER_CREATED |
| 392 | | SEC_READONLY)) |
| 393 | || ! bfd_set_section_alignment (dynobj, srelgot, 3)) |
| 394 | return false; |
| 395 | } |
| 396 | } |
| 397 | |
| 398 | if (h != NULL) |
| 399 | { |
| 400 | if (h->got.refcount == -1) |
| 401 | { |
| 402 | h->got.refcount = 1; |
| 403 | |
| 404 | /* Make sure this symbol is output as a dynamic symbol. */ |
| 405 | if (h->dynindx == -1) |
| 406 | { |
| 407 | if (! bfd_elf64_link_record_dynamic_symbol (info, h)) |
| 408 | return false; |
| 409 | } |
| 410 | |
| 411 | sgot->_raw_size += GOT_ENTRY_SIZE; |
| 412 | srelgot->_raw_size += sizeof (Elf64_External_Rela); |
| 413 | } |
| 414 | else |
| 415 | h->got.refcount += 1; |
| 416 | } |
| 417 | else |
| 418 | { |
| 419 | /* This is a global offset table entry for a local symbol. */ |
| 420 | if (local_got_refcounts == NULL) |
| 421 | { |
| 422 | size_t size; |
| 423 | |
| 424 | size = symtab_hdr->sh_info * sizeof (bfd_signed_vma); |
| 425 | local_got_refcounts = ((bfd_signed_vma *) |
| 426 | bfd_alloc (abfd, size)); |
| 427 | if (local_got_refcounts == NULL) |
| 428 | return false; |
| 429 | elf_local_got_refcounts (abfd) = local_got_refcounts; |
| 430 | memset (local_got_refcounts, -1, size); |
| 431 | } |
| 432 | if (local_got_refcounts[r_symndx] == -1) |
| 433 | { |
| 434 | local_got_refcounts[r_symndx] = 1; |
| 435 | |
| 436 | sgot->_raw_size += GOT_ENTRY_SIZE; |
| 437 | if (info->shared) |
| 438 | { |
| 439 | /* If we are generating a shared object, we need to |
| 440 | output a R_X86_64_RELATIVE reloc so that the dynamic |
| 441 | linker can adjust this GOT entry. */ |
| 442 | srelgot->_raw_size += sizeof (Elf64_External_Rela); |
| 443 | } |
| 444 | } |
| 445 | else |
| 446 | local_got_refcounts[r_symndx] += 1; |
| 447 | } |
| 448 | break; |
| 449 | |
| 450 | case R_X86_64_PLT32: |
| 451 | /* This symbol requires a procedure linkage table entry. We |
| 452 | actually build the entry in adjust_dynamic_symbol, |
| 453 | because this might be a case of linking PIC code which is |
| 454 | never referenced by a dynamic object, in which case we |
| 455 | don't need to generate a procedure linkage table entry |
| 456 | after all. */ |
| 457 | |
| 458 | /* If this is a local symbol, we resolve it directly without |
| 459 | creating a procedure linkage table entry. */ |
| 460 | if (h == NULL) |
| 461 | continue; |
| 462 | |
| 463 | if (h->plt.refcount == -1) |
| 464 | { |
| 465 | h->plt.refcount = 1; |
| 466 | h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_PLT; |
| 467 | } |
| 468 | else |
| 469 | h->plt.refcount += 1; |
| 470 | break; |
| 471 | |
| 472 | case R_X86_64_32: |
| 473 | case R_X86_64_32S: |
| 474 | case R_X86_64_PC32: |
| 475 | if (h != NULL) |
| 476 | h->elf_link_hash_flags |= ELF_LINK_NON_GOT_REF; |
| 477 | |
| 478 | /* If we are creating a shared library, and this is a reloc |
| 479 | against a global symbol, or a non PC relative reloc |
| 480 | against a local symbol, then we need to copy the reloc |
| 481 | into the shared library. However, if we are linking with |
| 482 | -Bsymbolic, we do not need to copy a reloc against a |
| 483 | global symbol which is defined in an object we are |
| 484 | including in the link (i.e., DEF_REGULAR is set). At |
| 485 | this point we have not seen all the input files, so it is |
| 486 | possible that DEF_REGULAR is not set now but will be set |
| 487 | later (it is never cleared). We account for that |
| 488 | possibility below by storing information in the |
| 489 | pcrel_relocs_copied field of the hash table entry. |
| 490 | A similar situation occurs when creating shared libraries |
| 491 | and symbol visibility changes render the symbol local. */ |
| 492 | if (info->shared |
| 493 | && (sec->flags & SEC_ALLOC) != 0 |
| 494 | && (ELF64_R_TYPE (rel->r_info) != R_X86_64_PC32 |
| 495 | || (h != NULL |
| 496 | && (! info->symbolic |
| 497 | || (h->elf_link_hash_flags |
| 498 | & ELF_LINK_HASH_DEF_REGULAR) == 0)))) |
| 499 | { |
| 500 | /* When creating a shared object, we must copy these |
| 501 | reloc types into the output file. We create a reloc |
| 502 | section in dynobj and make room for this reloc. */ |
| 503 | if (sreloc == NULL) |
| 504 | { |
| 505 | const char *name; |
| 506 | |
| 507 | name = (bfd_elf_string_from_elf_section |
| 508 | (abfd, |
| 509 | elf_elfheader (abfd)->e_shstrndx, |
| 510 | elf_section_data (sec)->rel_hdr.sh_name)); |
| 511 | if (name == NULL) |
| 512 | return false; |
| 513 | |
| 514 | BFD_ASSERT (strncmp (name, ".rela", 5) == 0 |
| 515 | && strcmp (bfd_get_section_name (abfd, sec), |
| 516 | name + 5) == 0); |
| 517 | |
| 518 | sreloc = bfd_get_section_by_name (dynobj, name); |
| 519 | if (sreloc == NULL) |
| 520 | { |
| 521 | flagword flags; |
| 522 | |
| 523 | sreloc = bfd_make_section (dynobj, name); |
| 524 | flags = (SEC_HAS_CONTENTS | SEC_READONLY |
| 525 | | SEC_IN_MEMORY | SEC_LINKER_CREATED); |
| 526 | if ((sec->flags & SEC_ALLOC) != 0) |
| 527 | flags |= SEC_ALLOC | SEC_LOAD; |
| 528 | if (sreloc == NULL |
| 529 | || ! bfd_set_section_flags (dynobj, sreloc, flags) |
| 530 | || ! bfd_set_section_alignment (dynobj, sreloc, 2)) |
| 531 | return false; |
| 532 | } |
| 533 | } |
| 534 | |
| 535 | sreloc->_raw_size += sizeof (Elf64_External_Rela); |
| 536 | |
| 537 | /* If this is a global symbol, we count the number of PC |
| 538 | relative relocations we have entered for this symbol, |
| 539 | so that we can discard them later as necessary. Note |
| 540 | that this function is only called if we are using an |
| 541 | elf64_x86_64 linker hash table, which means that h is |
| 542 | really a pointer to an elf64_x86_64_link_hash_entry. */ |
| 543 | if (h != NULL |
| 544 | && ELF64_R_TYPE (rel->r_info) == R_X86_64_PC32) |
| 545 | { |
| 546 | struct elf64_x86_64_link_hash_entry *eh; |
| 547 | struct elf64_x86_64_pcrel_relocs_copied *p; |
| 548 | |
| 549 | eh = (struct elf64_x86_64_link_hash_entry *) h; |
| 550 | |
| 551 | for (p = eh->pcrel_relocs_copied; p != NULL; p = p->next) |
| 552 | if (p->section == sreloc) |
| 553 | break; |
| 554 | |
| 555 | if (p == NULL) |
| 556 | { |
| 557 | p = ((struct elf64_x86_64_pcrel_relocs_copied *) |
| 558 | bfd_alloc (dynobj, sizeof *p)); |
| 559 | if (p == NULL) |
| 560 | return false; |
| 561 | p->next = eh->pcrel_relocs_copied; |
| 562 | eh->pcrel_relocs_copied = p; |
| 563 | p->section = sreloc; |
| 564 | p->count = 0; |
| 565 | } |
| 566 | |
| 567 | ++p->count; |
| 568 | } |
| 569 | } |
| 570 | break; |
| 571 | } |
| 572 | } |
| 573 | |
| 574 | return true; |
| 575 | } |
| 576 | |
| 577 | /* Return the section that should be marked against GC for a given |
| 578 | relocation. */ |
| 579 | |
| 580 | static asection * |
| 581 | elf64_x86_64_gc_mark_hook (abfd, info, rel, h, sym) |
| 582 | bfd *abfd; |
| 583 | struct bfd_link_info *info ATTRIBUTE_UNUSED; |
| 584 | Elf_Internal_Rela *rel ATTRIBUTE_UNUSED; |
| 585 | struct elf_link_hash_entry *h; |
| 586 | Elf_Internal_Sym *sym; |
| 587 | { |
| 588 | if (h != NULL) |
| 589 | { |
| 590 | switch (h->root.type) |
| 591 | { |
| 592 | case bfd_link_hash_defined: |
| 593 | case bfd_link_hash_defweak: |
| 594 | return h->root.u.def.section; |
| 595 | |
| 596 | case bfd_link_hash_common: |
| 597 | return h->root.u.c.p->section; |
| 598 | |
| 599 | default: |
| 600 | break; |
| 601 | } |
| 602 | } |
| 603 | else |
| 604 | { |
| 605 | if (!(elf_bad_symtab (abfd) |
| 606 | && ELF_ST_BIND (sym->st_info) != STB_LOCAL) |
| 607 | && ! ((sym->st_shndx <= 0 || sym->st_shndx >= SHN_LORESERVE) |
| 608 | && sym->st_shndx != SHN_COMMON)) |
| 609 | { |
| 610 | return bfd_section_from_elf_index (abfd, sym->st_shndx); |
| 611 | } |
| 612 | } |
| 613 | |
| 614 | return NULL; |
| 615 | } |
| 616 | |
| 617 | /* Update the got entry reference counts for the section being removed. */ |
| 618 | |
| 619 | static boolean |
| 620 | elf64_x86_64_gc_sweep_hook (abfd, info, sec, relocs) |
| 621 | bfd *abfd; |
| 622 | struct bfd_link_info *info ATTRIBUTE_UNUSED; |
| 623 | asection *sec; |
| 624 | const Elf_Internal_Rela *relocs; |
| 625 | { |
| 626 | Elf_Internal_Shdr *symtab_hdr; |
| 627 | struct elf_link_hash_entry **sym_hashes; |
| 628 | bfd_signed_vma *local_got_refcounts; |
| 629 | const Elf_Internal_Rela *rel, *relend; |
| 630 | unsigned long r_symndx; |
| 631 | struct elf_link_hash_entry *h; |
| 632 | bfd *dynobj; |
| 633 | asection *sgot; |
| 634 | asection *srelgot; |
| 635 | |
| 636 | symtab_hdr = &elf_tdata (abfd)->symtab_hdr; |
| 637 | sym_hashes = elf_sym_hashes (abfd); |
| 638 | local_got_refcounts = elf_local_got_refcounts (abfd); |
| 639 | |
| 640 | dynobj = elf_hash_table (info)->dynobj; |
| 641 | if (dynobj == NULL) |
| 642 | return true; |
| 643 | |
| 644 | sgot = bfd_get_section_by_name (dynobj, ".got"); |
| 645 | srelgot = bfd_get_section_by_name (dynobj, ".rela.got"); |
| 646 | |
| 647 | relend = relocs + sec->reloc_count; |
| 648 | for (rel = relocs; rel < relend; rel++) |
| 649 | switch (ELF64_R_TYPE (rel->r_info)) |
| 650 | { |
| 651 | case R_X86_64_GOT32: |
| 652 | case R_X86_64_GOTPCREL: |
| 653 | r_symndx = ELF64_R_SYM (rel->r_info); |
| 654 | if (r_symndx >= symtab_hdr->sh_info) |
| 655 | { |
| 656 | h = sym_hashes[r_symndx - symtab_hdr->sh_info]; |
| 657 | if (h->got.refcount > 0) |
| 658 | { |
| 659 | h->got.refcount -= 1; |
| 660 | if (h->got.refcount == 0) |
| 661 | { |
| 662 | sgot->_raw_size -= GOT_ENTRY_SIZE; |
| 663 | srelgot->_raw_size -= sizeof (Elf64_External_Rela); |
| 664 | } |
| 665 | } |
| 666 | } |
| 667 | else if (local_got_refcounts != NULL) |
| 668 | { |
| 669 | if (local_got_refcounts[r_symndx] > 0) |
| 670 | { |
| 671 | local_got_refcounts[r_symndx] -= 1; |
| 672 | if (local_got_refcounts[r_symndx] == 0) |
| 673 | { |
| 674 | sgot->_raw_size -= GOT_ENTRY_SIZE; |
| 675 | if (info->shared) |
| 676 | srelgot->_raw_size -= sizeof (Elf64_External_Rela); |
| 677 | } |
| 678 | } |
| 679 | } |
| 680 | break; |
| 681 | |
| 682 | case R_X86_64_PLT32: |
| 683 | r_symndx = ELF64_R_SYM (rel->r_info); |
| 684 | if (r_symndx >= symtab_hdr->sh_info) |
| 685 | { |
| 686 | h = sym_hashes[r_symndx - symtab_hdr->sh_info]; |
| 687 | if (h->plt.refcount > 0) |
| 688 | h->plt.refcount -= 1; |
| 689 | } |
| 690 | break; |
| 691 | |
| 692 | default: |
| 693 | break; |
| 694 | } |
| 695 | |
| 696 | return true; |
| 697 | } |
| 698 | |
| 699 | /* Adjust a symbol defined by a dynamic object and referenced by a |
| 700 | regular object. The current definition is in some section of the |
| 701 | dynamic object, but we're not including those sections. We have to |
| 702 | change the definition to something the rest of the link can |
| 703 | understand. */ |
| 704 | |
| 705 | static boolean |
| 706 | elf64_x86_64_adjust_dynamic_symbol (info, h) |
| 707 | struct bfd_link_info *info; |
| 708 | struct elf_link_hash_entry *h; |
| 709 | { |
| 710 | bfd *dynobj; |
| 711 | asection *s; |
| 712 | unsigned int power_of_two; |
| 713 | |
| 714 | dynobj = elf_hash_table (info)->dynobj; |
| 715 | |
| 716 | /* Make sure we know what is going on here. */ |
| 717 | BFD_ASSERT (dynobj != NULL |
| 718 | && ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) |
| 719 | || h->weakdef != NULL |
| 720 | || ((h->elf_link_hash_flags |
| 721 | & ELF_LINK_HASH_DEF_DYNAMIC) != 0 |
| 722 | && (h->elf_link_hash_flags |
| 723 | & ELF_LINK_HASH_REF_REGULAR) != 0 |
| 724 | && (h->elf_link_hash_flags |
| 725 | & ELF_LINK_HASH_DEF_REGULAR) == 0))); |
| 726 | |
| 727 | /* If this is a function, put it in the procedure linkage table. We |
| 728 | will fill in the contents of the procedure linkage table later, |
| 729 | when we know the address of the .got section. */ |
| 730 | if (h->type == STT_FUNC |
| 731 | || (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0) |
| 732 | { |
| 733 | if ((! info->shared |
| 734 | && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0 |
| 735 | && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) == 0) |
| 736 | || (info->shared && h->plt.refcount <= 0)) |
| 737 | { |
| 738 | /* This case can occur if we saw a PLT32 reloc in an input |
| 739 | file, but the symbol was never referred to by a dynamic |
| 740 | object, or if all references were garbage collected. In |
| 741 | such a case, we don't actually need to build a procedure |
| 742 | linkage table, and we can just do a PC32 reloc instead. */ |
| 743 | h->plt.offset = (bfd_vma) -1; |
| 744 | h->elf_link_hash_flags &= ~ELF_LINK_HASH_NEEDS_PLT; |
| 745 | return true; |
| 746 | } |
| 747 | |
| 748 | /* Make sure this symbol is output as a dynamic symbol. */ |
| 749 | if (h->dynindx == -1) |
| 750 | { |
| 751 | if (! bfd_elf64_link_record_dynamic_symbol (info, h)) |
| 752 | return false; |
| 753 | } |
| 754 | |
| 755 | s = bfd_get_section_by_name (dynobj, ".plt"); |
| 756 | BFD_ASSERT (s != NULL); |
| 757 | |
| 758 | /* If this is the first .plt entry, make room for the special |
| 759 | first entry. */ |
| 760 | if (s->_raw_size == 0) |
| 761 | s->_raw_size = PLT_ENTRY_SIZE; |
| 762 | |
| 763 | /* If this symbol is not defined in a regular file, and we are |
| 764 | not generating a shared library, then set the symbol to this |
| 765 | location in the .plt. This is required to make function |
| 766 | pointers compare as equal between the normal executable and |
| 767 | the shared library. */ |
| 768 | if (! info->shared |
| 769 | && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) |
| 770 | { |
| 771 | h->root.u.def.section = s; |
| 772 | h->root.u.def.value = s->_raw_size; |
| 773 | } |
| 774 | |
| 775 | h->plt.offset = s->_raw_size; |
| 776 | |
| 777 | /* Make room for this entry. */ |
| 778 | s->_raw_size += PLT_ENTRY_SIZE; |
| 779 | |
| 780 | /* We also need to make an entry in the .got.plt section, which |
| 781 | will be placed in the .got section by the linker script. */ |
| 782 | s = bfd_get_section_by_name (dynobj, ".got.plt"); |
| 783 | BFD_ASSERT (s != NULL); |
| 784 | s->_raw_size += GOT_ENTRY_SIZE; |
| 785 | |
| 786 | /* We also need to make an entry in the .rela.plt section. */ |
| 787 | s = bfd_get_section_by_name (dynobj, ".rela.plt"); |
| 788 | BFD_ASSERT (s != NULL); |
| 789 | s->_raw_size += sizeof (Elf64_External_Rela); |
| 790 | |
| 791 | return true; |
| 792 | } |
| 793 | |
| 794 | /* If this is a weak symbol, and there is a real definition, the |
| 795 | processor independent code will have arranged for us to see the |
| 796 | real definition first, and we can just use the same value. */ |
| 797 | if (h->weakdef != NULL) |
| 798 | { |
| 799 | BFD_ASSERT (h->weakdef->root.type == bfd_link_hash_defined |
| 800 | || h->weakdef->root.type == bfd_link_hash_defweak); |
| 801 | h->root.u.def.section = h->weakdef->root.u.def.section; |
| 802 | h->root.u.def.value = h->weakdef->root.u.def.value; |
| 803 | return true; |
| 804 | } |
| 805 | |
| 806 | /* This is a reference to a symbol defined by a dynamic object which |
| 807 | is not a function. */ |
| 808 | |
| 809 | /* If we are creating a shared library, we must presume that the |
| 810 | only references to the symbol are via the global offset table. |
| 811 | For such cases we need not do anything here; the relocations will |
| 812 | be handled correctly by relocate_section. */ |
| 813 | if (info->shared) |
| 814 | return true; |
| 815 | |
| 816 | /* If there are no references to this symbol that do not use the |
| 817 | GOT, we don't need to generate a copy reloc. */ |
| 818 | if ((h->elf_link_hash_flags & ELF_LINK_NON_GOT_REF) == 0) |
| 819 | return true; |
| 820 | |
| 821 | /* We must allocate the symbol in our .dynbss section, which will |
| 822 | become part of the .bss section of the executable. There will be |
| 823 | an entry for this symbol in the .dynsym section. The dynamic |
| 824 | object will contain position independent code, so all references |
| 825 | from the dynamic object to this symbol will go through the global |
| 826 | offset table. The dynamic linker will use the .dynsym entry to |
| 827 | determine the address it must put in the global offset table, so |
| 828 | both the dynamic object and the regular object will refer to the |
| 829 | same memory location for the variable. */ |
| 830 | |
| 831 | s = bfd_get_section_by_name (dynobj, ".dynbss"); |
| 832 | BFD_ASSERT (s != NULL); |
| 833 | |
| 834 | /* We must generate a R_X86_64_COPY reloc to tell the dynamic linker |
| 835 | to copy the initial value out of the dynamic object and into the |
| 836 | runtime process image. We need to remember the offset into the |
| 837 | .rela.bss section we are going to use. */ |
| 838 | if ((h->root.u.def.section->flags & SEC_ALLOC) != 0) |
| 839 | { |
| 840 | asection *srel; |
| 841 | |
| 842 | srel = bfd_get_section_by_name (dynobj, ".rela.bss"); |
| 843 | BFD_ASSERT (srel != NULL); |
| 844 | srel->_raw_size += sizeof (Elf64_External_Rela); |
| 845 | h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_COPY; |
| 846 | } |
| 847 | |
| 848 | /* We need to figure out the alignment required for this symbol. I |
| 849 | have no idea how ELF linkers handle this. 16-bytes is the size |
| 850 | of the largest type that requires hard alignment -- long double. */ |
| 851 | /* FIXME: This is VERY ugly. Should be fixed for all architectures using |
| 852 | this construct. */ |
| 853 | power_of_two = bfd_log2 (h->size); |
| 854 | if (power_of_two > 4) |
| 855 | power_of_two = 4; |
| 856 | |
| 857 | /* Apply the required alignment. */ |
| 858 | s->_raw_size = BFD_ALIGN (s->_raw_size, (bfd_size_type) (1 << power_of_two)); |
| 859 | if (power_of_two > bfd_get_section_alignment (dynobj, s)) |
| 860 | { |
| 861 | if (! bfd_set_section_alignment (dynobj, s, power_of_two)) |
| 862 | return false; |
| 863 | } |
| 864 | |
| 865 | /* Define the symbol as being at this point in the section. */ |
| 866 | h->root.u.def.section = s; |
| 867 | h->root.u.def.value = s->_raw_size; |
| 868 | |
| 869 | /* Increment the section size to make room for the symbol. */ |
| 870 | s->_raw_size += h->size; |
| 871 | |
| 872 | return true; |
| 873 | } |
| 874 | |
| 875 | /* Set the sizes of the dynamic sections. */ |
| 876 | |
| 877 | static boolean |
| 878 | elf64_x86_64_size_dynamic_sections (output_bfd, info) |
| 879 | bfd *output_bfd; |
| 880 | struct bfd_link_info *info; |
| 881 | { |
| 882 | bfd *dynobj; |
| 883 | asection *s; |
| 884 | boolean plt; |
| 885 | boolean relocs; |
| 886 | boolean reltext; |
| 887 | |
| 888 | dynobj = elf_hash_table (info)->dynobj; |
| 889 | BFD_ASSERT (dynobj != NULL); |
| 890 | |
| 891 | if (elf_hash_table (info)->dynamic_sections_created) |
| 892 | { |
| 893 | /* Set the contents of the .interp section to the interpreter. */ |
| 894 | if (! info->shared) |
| 895 | { |
| 896 | s = bfd_get_section_by_name (dynobj, ".interp"); |
| 897 | BFD_ASSERT (s != NULL); |
| 898 | s->_raw_size = sizeof ELF_DYNAMIC_INTERPRETER; |
| 899 | s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER; |
| 900 | } |
| 901 | } |
| 902 | else |
| 903 | { |
| 904 | /* We may have created entries in the .rela.got section. |
| 905 | However, if we are not creating the dynamic sections, we will |
| 906 | not actually use these entries. Reset the size of .rela.got, |
| 907 | which will cause it to get stripped from the output file |
| 908 | below. */ |
| 909 | s = bfd_get_section_by_name (dynobj, ".rela.got"); |
| 910 | if (s != NULL) |
| 911 | s->_raw_size = 0; |
| 912 | } |
| 913 | |
| 914 | /* If this is a -Bsymbolic shared link, then we need to discard all |
| 915 | PC relative relocs against symbols defined in a regular object. |
| 916 | We allocated space for them in the check_relocs routine, but we |
| 917 | will not fill them in in the relocate_section routine. */ |
| 918 | if (info->shared) |
| 919 | elf64_x86_64_link_hash_traverse (elf64_x86_64_hash_table (info), |
| 920 | elf64_x86_64_discard_copies, |
| 921 | (PTR) info); |
| 922 | |
| 923 | /* The check_relocs and adjust_dynamic_symbol entry points have |
| 924 | determined the sizes of the various dynamic sections. Allocate |
| 925 | memory for them. */ |
| 926 | plt = relocs = reltext = false; |
| 927 | for (s = dynobj->sections; s != NULL; s = s->next) |
| 928 | { |
| 929 | const char *name; |
| 930 | boolean strip; |
| 931 | |
| 932 | if ((s->flags & SEC_LINKER_CREATED) == 0) |
| 933 | continue; |
| 934 | |
| 935 | /* It's OK to base decisions on the section name, because none |
| 936 | of the dynobj section names depend upon the input files. */ |
| 937 | name = bfd_get_section_name (dynobj, s); |
| 938 | |
| 939 | strip = false; |
| 940 | if (strcmp (name, ".plt") == 0) |
| 941 | { |
| 942 | if (s->_raw_size == 0) |
| 943 | { |
| 944 | /* Strip this section if we don't need it; see the |
| 945 | comment below. */ |
| 946 | strip = true; |
| 947 | } |
| 948 | else |
| 949 | { |
| 950 | /* Remember whether there is a PLT. */ |
| 951 | plt = true; |
| 952 | } |
| 953 | } |
| 954 | else if (strncmp (name, ".rela", 5) == 0) |
| 955 | { |
| 956 | if (s->_raw_size == 0) |
| 957 | { |
| 958 | /* If we don't need this section, strip it from the |
| 959 | output file. This is mostly to handle .rela.bss and |
| 960 | .rela.plt. We must create both sections in |
| 961 | create_dynamic_sections, because they must be created |
| 962 | before the linker maps input sections to output |
| 963 | sections. The linker does that before |
| 964 | adjust_dynamic_symbol is called, and it is that |
| 965 | function which decides whether anything needs to go |
| 966 | into these sections. */ |
| 967 | strip = true; |
| 968 | } |
| 969 | else |
| 970 | { |
| 971 | asection *target; |
| 972 | |
| 973 | /* Remember whether there are any reloc sections other |
| 974 | than .rela.plt. */ |
| 975 | if (strcmp (name, ".rela.plt") != 0) |
| 976 | { |
| 977 | const char *outname; |
| 978 | |
| 979 | relocs = true; |
| 980 | |
| 981 | /* If this relocation section applies to a read only |
| 982 | section, then we probably need a DT_TEXTREL |
| 983 | entry. The entries in the .rela.plt section |
| 984 | really apply to the .got section, which we |
| 985 | created ourselves and so know is not readonly. */ |
| 986 | outname = bfd_get_section_name (output_bfd, |
| 987 | s->output_section); |
| 988 | target = bfd_get_section_by_name (output_bfd, outname + 5); |
| 989 | if (target != NULL |
| 990 | && (target->flags & SEC_READONLY) != 0 |
| 991 | && (target->flags & SEC_ALLOC) != 0) |
| 992 | reltext = true; |
| 993 | } |
| 994 | |
| 995 | /* We use the reloc_count field as a counter if we need |
| 996 | to copy relocs into the output file. */ |
| 997 | s->reloc_count = 0; |
| 998 | } |
| 999 | } |
| 1000 | else if (strncmp (name, ".got", 4) != 0) |
| 1001 | { |
| 1002 | /* It's not one of our sections, so don't allocate space. */ |
| 1003 | continue; |
| 1004 | } |
| 1005 | |
| 1006 | if (strip) |
| 1007 | { |
| 1008 | _bfd_strip_section_from_output (info, s); |
| 1009 | continue; |
| 1010 | } |
| 1011 | |
| 1012 | /* Allocate memory for the section contents. We use bfd_zalloc |
| 1013 | here in case unused entries are not reclaimed before the |
| 1014 | section's contents are written out. This should not happen, |
| 1015 | but this way if it does, we get a R_X86_64_NONE reloc instead |
| 1016 | of garbage. */ |
| 1017 | s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->_raw_size); |
| 1018 | if (s->contents == NULL && s->_raw_size != 0) |
| 1019 | return false; |
| 1020 | } |
| 1021 | |
| 1022 | if (elf_hash_table (info)->dynamic_sections_created) |
| 1023 | { |
| 1024 | /* Add some entries to the .dynamic section. We fill in the |
| 1025 | values later, in elf64_x86_64_finish_dynamic_sections, but we |
| 1026 | must add the entries now so that we get the correct size for |
| 1027 | the .dynamic section. The DT_DEBUG entry is filled in by the |
| 1028 | dynamic linker and used by the debugger. */ |
| 1029 | if (! info->shared) |
| 1030 | { |
| 1031 | if (! bfd_elf64_add_dynamic_entry (info, DT_DEBUG, 0)) |
| 1032 | return false; |
| 1033 | } |
| 1034 | |
| 1035 | if (plt) |
| 1036 | { |
| 1037 | if (! bfd_elf64_add_dynamic_entry (info, DT_PLTGOT, 0) |
| 1038 | || ! bfd_elf64_add_dynamic_entry (info, DT_PLTRELSZ, 0) |
| 1039 | || ! bfd_elf64_add_dynamic_entry (info, DT_PLTREL, DT_RELA) |
| 1040 | || ! bfd_elf64_add_dynamic_entry (info, DT_JMPREL, 0)) |
| 1041 | return false; |
| 1042 | } |
| 1043 | |
| 1044 | if (relocs) |
| 1045 | { |
| 1046 | if (! bfd_elf64_add_dynamic_entry (info, DT_RELA, 0) |
| 1047 | || ! bfd_elf64_add_dynamic_entry (info, DT_RELASZ, 0) |
| 1048 | || ! bfd_elf64_add_dynamic_entry (info, DT_RELAENT, |
| 1049 | sizeof (Elf64_External_Rela))) |
| 1050 | return false; |
| 1051 | } |
| 1052 | |
| 1053 | if (reltext) |
| 1054 | { |
| 1055 | if (! bfd_elf64_add_dynamic_entry (info, DT_TEXTREL, 0)) |
| 1056 | return false; |
| 1057 | info->flags |= DF_TEXTREL; |
| 1058 | } |
| 1059 | } |
| 1060 | |
| 1061 | return true; |
| 1062 | } |
| 1063 | |
| 1064 | /* This function is called via elf64_x86_64_link_hash_traverse if we are |
| 1065 | creating a shared object. In the -Bsymbolic case, it discards the |
| 1066 | space allocated to copy PC relative relocs against symbols which |
| 1067 | are defined in regular objects. For the normal non-symbolic case, |
| 1068 | we also discard space for relocs that have become local due to |
| 1069 | symbol visibility changes. We allocated space for them in the |
| 1070 | check_relocs routine, but we won't fill them in in the |
| 1071 | relocate_section routine. */ |
| 1072 | |
| 1073 | static boolean |
| 1074 | elf64_x86_64_discard_copies (h, inf) |
| 1075 | struct elf64_x86_64_link_hash_entry *h; |
| 1076 | PTR inf; |
| 1077 | { |
| 1078 | struct elf64_x86_64_pcrel_relocs_copied *s; |
| 1079 | struct bfd_link_info *info = (struct bfd_link_info *) inf; |
| 1080 | |
| 1081 | /* If a symbol has been forced local or we have found a regular |
| 1082 | definition for the symbolic link case, then we won't be needing |
| 1083 | any relocs. */ |
| 1084 | if ((h->root.elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0 |
| 1085 | && ((h->root.elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0 |
| 1086 | || info->symbolic)) |
| 1087 | { |
| 1088 | for (s = h->pcrel_relocs_copied; s != NULL; s = s->next) |
| 1089 | s->section->_raw_size -= s->count * sizeof (Elf64_External_Rela); |
| 1090 | } |
| 1091 | |
| 1092 | return true; |
| 1093 | } |
| 1094 | |
| 1095 | /* Relocate an x86_64 ELF section. */ |
| 1096 | |
| 1097 | static boolean |
| 1098 | elf64_x86_64_relocate_section (output_bfd, info, input_bfd, input_section, |
| 1099 | contents, relocs, local_syms, local_sections) |
| 1100 | bfd *output_bfd; |
| 1101 | struct bfd_link_info *info; |
| 1102 | bfd *input_bfd; |
| 1103 | asection *input_section; |
| 1104 | bfd_byte *contents; |
| 1105 | Elf_Internal_Rela *relocs; |
| 1106 | Elf_Internal_Sym *local_syms; |
| 1107 | asection **local_sections; |
| 1108 | { |
| 1109 | bfd *dynobj; |
| 1110 | Elf_Internal_Shdr *symtab_hdr; |
| 1111 | struct elf_link_hash_entry **sym_hashes; |
| 1112 | bfd_vma *local_got_offsets; |
| 1113 | asection *sgot; |
| 1114 | asection *splt; |
| 1115 | asection *sreloc; |
| 1116 | Elf_Internal_Rela *rela; |
| 1117 | Elf_Internal_Rela *relend; |
| 1118 | |
| 1119 | dynobj = elf_hash_table (info)->dynobj; |
| 1120 | symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr; |
| 1121 | sym_hashes = elf_sym_hashes (input_bfd); |
| 1122 | local_got_offsets = elf_local_got_offsets (input_bfd); |
| 1123 | |
| 1124 | sreloc = splt = sgot = NULL; |
| 1125 | if (dynobj != NULL) |
| 1126 | { |
| 1127 | splt = bfd_get_section_by_name (dynobj, ".plt"); |
| 1128 | sgot = bfd_get_section_by_name (dynobj, ".got"); |
| 1129 | } |
| 1130 | |
| 1131 | rela = relocs; |
| 1132 | relend = relocs + input_section->reloc_count; |
| 1133 | for (; rela < relend; rela++) |
| 1134 | { |
| 1135 | int r_type; |
| 1136 | reloc_howto_type *howto; |
| 1137 | unsigned long r_symndx; |
| 1138 | struct elf_link_hash_entry *h; |
| 1139 | Elf_Internal_Sym *sym; |
| 1140 | asection *sec; |
| 1141 | bfd_vma relocation; |
| 1142 | bfd_reloc_status_type r; |
| 1143 | unsigned int indx; |
| 1144 | |
| 1145 | r_type = ELF64_R_TYPE (rela->r_info); |
| 1146 | |
| 1147 | if ((indx = (unsigned) r_type) >= R_X86_64_max) |
| 1148 | { |
| 1149 | bfd_set_error (bfd_error_bad_value); |
| 1150 | return false; |
| 1151 | } |
| 1152 | howto = x86_64_elf_howto_table + indx; |
| 1153 | |
| 1154 | r_symndx = ELF64_R_SYM (rela->r_info); |
| 1155 | |
| 1156 | if (info->relocateable) |
| 1157 | { |
| 1158 | /* This is a relocateable link. We don't have to change |
| 1159 | anything, unless the reloc is against a section symbol, |
| 1160 | in which case we have to adjust according to where the |
| 1161 | section symbol winds up in the output section. */ |
| 1162 | if (r_symndx < symtab_hdr->sh_info) |
| 1163 | { |
| 1164 | sym = local_syms + r_symndx; |
| 1165 | if (ELF_ST_TYPE (sym->st_info) == STT_SECTION) |
| 1166 | { |
| 1167 | sec = local_sections[r_symndx]; |
| 1168 | rela->r_addend += sec->output_offset + sym->st_value; |
| 1169 | } |
| 1170 | } |
| 1171 | |
| 1172 | continue; |
| 1173 | } |
| 1174 | |
| 1175 | /* This is a final link. */ |
| 1176 | h = NULL; |
| 1177 | sym = NULL; |
| 1178 | sec = NULL; |
| 1179 | if (r_symndx < symtab_hdr->sh_info) |
| 1180 | { |
| 1181 | sym = local_syms + r_symndx; |
| 1182 | sec = local_sections[r_symndx]; |
| 1183 | relocation = (sec->output_section->vma |
| 1184 | + sec->output_offset |
| 1185 | + sym->st_value); |
| 1186 | } |
| 1187 | else |
| 1188 | { |
| 1189 | h = sym_hashes[r_symndx - symtab_hdr->sh_info]; |
| 1190 | while (h->root.type == bfd_link_hash_indirect |
| 1191 | || h->root.type == bfd_link_hash_warning) |
| 1192 | h = (struct elf_link_hash_entry *) h->root.u.i.link; |
| 1193 | if (h->root.type == bfd_link_hash_defined |
| 1194 | || h->root.type == bfd_link_hash_defweak) |
| 1195 | { |
| 1196 | sec = h->root.u.def.section; |
| 1197 | if (r_type == R_X86_64_GOTPCREL |
| 1198 | || (r_type = R_X86_64_PLT32 |
| 1199 | && splt != NULL |
| 1200 | && h->plt.offset != (bfd_vma) -1) |
| 1201 | || (r_type = R_X86_64_GOT32 |
| 1202 | && elf_hash_table (info)->dynamic_sections_created |
| 1203 | && (!info->shared |
| 1204 | || (! info->symbolic && h->dynindx != -1) |
| 1205 | || (h->elf_link_hash_flags |
| 1206 | & ELF_LINK_HASH_DEF_REGULAR) == 0)) |
| 1207 | || (info->shared |
| 1208 | && ((! info->symbolic && h->dynindx != -1) |
| 1209 | || (h->elf_link_hash_flags |
| 1210 | & ELF_LINK_HASH_DEF_REGULAR) == 0) |
| 1211 | && ( r_type == R_X86_64_8 || |
| 1212 | r_type == R_X86_64_16 || |
| 1213 | r_type == R_X86_64_32 || |
| 1214 | r_type == R_X86_64_64 || |
| 1215 | r_type == R_X86_64_PC16 || |
| 1216 | r_type == R_X86_64_PC32) |
| 1217 | && ((input_section->flags & SEC_ALLOC) != 0 |
| 1218 | /* DWARF will emit R_X86_64_32 relocations in its |
| 1219 | sections against symbols defined externally |
| 1220 | in shared libraries. We can't do anything |
| 1221 | with them here. */ |
| 1222 | || ((input_section->flags & SEC_DEBUGGING) != 0 |
| 1223 | && (h->elf_link_hash_flags |
| 1224 | & ELF_LINK_HASH_DEF_DYNAMIC) != 0)))) |
| 1225 | { |
| 1226 | /* In these cases, we don't need the relocation |
| 1227 | value. We check specially because in some |
| 1228 | obscure cases sec->output_section will be NULL. */ |
| 1229 | relocation = 0; |
| 1230 | } |
| 1231 | else if (sec->output_section == NULL) |
| 1232 | { |
| 1233 | (*_bfd_error_handler) |
| 1234 | (_("%s: warning: unresolvable relocation against symbol `%s' from %s section"), |
| 1235 | bfd_get_filename (input_bfd), h->root.root.string, |
| 1236 | bfd_get_section_name (input_bfd, input_section)); |
| 1237 | relocation = 0; |
| 1238 | } |
| 1239 | else |
| 1240 | relocation = (h->root.u.def.value |
| 1241 | + sec->output_section->vma |
| 1242 | + sec->output_offset); |
| 1243 | } |
| 1244 | else if (h->root.type == bfd_link_hash_undefweak) |
| 1245 | relocation = 0; |
| 1246 | else if (info->shared && !info->symbolic && !info->no_undefined |
| 1247 | && ELF_ST_VISIBILITY (h->other) == STV_DEFAULT) |
| 1248 | relocation = 0; |
| 1249 | else |
| 1250 | { |
| 1251 | if (! ((*info->callbacks->undefined_symbol) |
| 1252 | (info, h->root.root.string, input_bfd, |
| 1253 | input_section, rela->r_offset, |
| 1254 | (!info->shared || info->no_undefined |
| 1255 | || ELF_ST_VISIBILITY (h->other))))) |
| 1256 | return false; |
| 1257 | relocation = 0; |
| 1258 | } |
| 1259 | } |
| 1260 | |
| 1261 | /* When generating a shared object, the relocations handled here are |
| 1262 | copied into the output file to be resolved at run time. */ |
| 1263 | switch (r_type) |
| 1264 | { |
| 1265 | case R_X86_64_GOT32: |
| 1266 | /* Relocation is to the entry for this symbol in the global |
| 1267 | offset table. */ |
| 1268 | BFD_ASSERT (sgot != NULL); |
| 1269 | |
| 1270 | if (h != NULL) |
| 1271 | { |
| 1272 | bfd_vma off = h->got.offset; |
| 1273 | BFD_ASSERT (off != (bfd_vma) -1); |
| 1274 | |
| 1275 | if (! elf_hash_table (info)->dynamic_sections_created |
| 1276 | || (info->shared |
| 1277 | && (info->symbolic || h->dynindx == -1) |
| 1278 | && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))) |
| 1279 | { |
| 1280 | /* This is actually a static link, or it is a -Bsymbolic |
| 1281 | link and the symbol is defined locally, or the symbol |
| 1282 | was forced to be local because of a version file. We |
| 1283 | must initialize this entry in the global offset table. |
| 1284 | Since the offset must always be a multiple of 8, we |
| 1285 | use the least significant bit to record whether we |
| 1286 | have initialized it already. |
| 1287 | |
| 1288 | When doing a dynamic link, we create a .rela.got |
| 1289 | relocation entry to initialize the value. This is |
| 1290 | done in the finish_dynamic_symbol routine. */ |
| 1291 | if ((off & 1) != 0) |
| 1292 | off &= ~1; |
| 1293 | else |
| 1294 | { |
| 1295 | bfd_put_64 (output_bfd, relocation, |
| 1296 | sgot->contents + off); |
| 1297 | h->got.offset |= 1; |
| 1298 | } |
| 1299 | } |
| 1300 | relocation = sgot->output_offset + off; |
| 1301 | } |
| 1302 | else |
| 1303 | { |
| 1304 | bfd_vma off; |
| 1305 | |
| 1306 | BFD_ASSERT (local_got_offsets != NULL |
| 1307 | && local_got_offsets[r_symndx] != (bfd_vma) -1); |
| 1308 | |
| 1309 | off = local_got_offsets[r_symndx]; |
| 1310 | |
| 1311 | /* The offset must always be a multiple of 8. We use |
| 1312 | the least significant bit to record whether we have |
| 1313 | already generated the necessary reloc. */ |
| 1314 | if ((off & 1) != 0) |
| 1315 | off &= ~1; |
| 1316 | else |
| 1317 | { |
| 1318 | bfd_put_64 (output_bfd, relocation, sgot->contents + off); |
| 1319 | |
| 1320 | if (info->shared) |
| 1321 | { |
| 1322 | asection *srelgot; |
| 1323 | Elf_Internal_Rela outrel; |
| 1324 | |
| 1325 | /* We need to generate a R_X86_64_RELATIVE reloc |
| 1326 | for the dynamic linker. */ |
| 1327 | srelgot = bfd_get_section_by_name (dynobj, ".rela.got"); |
| 1328 | BFD_ASSERT (srelgot != NULL); |
| 1329 | |
| 1330 | outrel.r_offset = (sgot->output_section->vma |
| 1331 | + sgot->output_offset |
| 1332 | + off); |
| 1333 | outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE); |
| 1334 | outrel.r_addend = relocation; |
| 1335 | bfd_elf64_swap_reloca_out (output_bfd, &outrel, |
| 1336 | (((Elf64_External_Rela *) |
| 1337 | srelgot->contents) |
| 1338 | + srelgot->reloc_count)); |
| 1339 | ++srelgot->reloc_count; |
| 1340 | } |
| 1341 | |
| 1342 | local_got_offsets[r_symndx] |= 1; |
| 1343 | } |
| 1344 | |
| 1345 | relocation = sgot->output_offset + off; |
| 1346 | } |
| 1347 | |
| 1348 | break; |
| 1349 | |
| 1350 | case R_X86_64_GOTPCREL: |
| 1351 | /* Use global offset table as symbol value. */ |
| 1352 | |
| 1353 | BFD_ASSERT (sgot != NULL); |
| 1354 | if (h != NULL) |
| 1355 | { |
| 1356 | bfd_vma off = h->got.offset; |
| 1357 | BFD_ASSERT (off != (bfd_vma) -1); |
| 1358 | |
| 1359 | if (! elf_hash_table (info)->dynamic_sections_created |
| 1360 | || (info->shared |
| 1361 | && (info->symbolic || h->dynindx == -1) |
| 1362 | && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))) |
| 1363 | { |
| 1364 | /* This is actually a static link, or it is a -Bsymbolic |
| 1365 | link and the symbol is defined locally, or the symbol |
| 1366 | was forced to be local because of a version file. We |
| 1367 | must initialize this entry in the global offset table. |
| 1368 | Since the offset must always be a multiple of 8, we |
| 1369 | use the least significant bit to record whether we |
| 1370 | have initialized it already. |
| 1371 | |
| 1372 | When doing a dynamic link, we create a .rela.got |
| 1373 | relocation entry to initialize the value. This is |
| 1374 | done in the finish_dynamic_symbol routine. */ |
| 1375 | if ((off & 1) != 0) |
| 1376 | off &= ~1; |
| 1377 | else |
| 1378 | { |
| 1379 | bfd_put_64 (output_bfd, relocation, |
| 1380 | sgot->contents + off); |
| 1381 | h->got.offset |= 1; |
| 1382 | } |
| 1383 | } |
| 1384 | relocation = sgot->output_offset + off; |
| 1385 | } |
| 1386 | else |
| 1387 | { |
| 1388 | bfd_vma off; |
| 1389 | |
| 1390 | BFD_ASSERT (local_got_offsets != NULL |
| 1391 | && local_got_offsets[r_symndx] != (bfd_vma) -1); |
| 1392 | |
| 1393 | off = local_got_offsets[r_symndx]; |
| 1394 | |
| 1395 | /* The offset must always be a multiple of 8. We use |
| 1396 | the least significant bit to record whether we have |
| 1397 | already generated the necessary reloc. */ |
| 1398 | if ((off & 1) != 0) |
| 1399 | off &= ~1; |
| 1400 | else |
| 1401 | { |
| 1402 | bfd_put_64 (output_bfd, relocation, sgot->contents + off); |
| 1403 | |
| 1404 | if (info->shared) |
| 1405 | { |
| 1406 | asection *srelgot; |
| 1407 | Elf_Internal_Rela outrel; |
| 1408 | |
| 1409 | /* We need to generate a R_X86_64_RELATIVE reloc |
| 1410 | for the dynamic linker. */ |
| 1411 | srelgot = bfd_get_section_by_name (dynobj, ".rela.got"); |
| 1412 | BFD_ASSERT (srelgot != NULL); |
| 1413 | |
| 1414 | outrel.r_offset = (sgot->output_section->vma |
| 1415 | + sgot->output_offset |
| 1416 | + off); |
| 1417 | outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE); |
| 1418 | outrel.r_addend = relocation; |
| 1419 | bfd_elf64_swap_reloca_out (output_bfd, &outrel, |
| 1420 | (((Elf64_External_Rela *) |
| 1421 | srelgot->contents) |
| 1422 | + srelgot->reloc_count)); |
| 1423 | ++srelgot->reloc_count; |
| 1424 | } |
| 1425 | |
| 1426 | local_got_offsets[r_symndx] |= 1; |
| 1427 | } |
| 1428 | |
| 1429 | relocation = sgot->output_section->vma + off; |
| 1430 | } |
| 1431 | break; |
| 1432 | |
| 1433 | case R_X86_64_PLT32: |
| 1434 | /* Relocation is to the entry for this symbol in the |
| 1435 | procedure linkage table. */ |
| 1436 | |
| 1437 | /* Resolve a PLT32 reloc against a local symbol directly, |
| 1438 | without using the procedure linkage table. */ |
| 1439 | if (h == NULL) |
| 1440 | break; |
| 1441 | |
| 1442 | if (h->plt.offset == (bfd_vma) -1 || splt == NULL) |
| 1443 | { |
| 1444 | /* We didn't make a PLT entry for this symbol. This |
| 1445 | happens when statically linking PIC code, or when |
| 1446 | using -Bsymbolic. */ |
| 1447 | break; |
| 1448 | } |
| 1449 | |
| 1450 | relocation = (splt->output_section->vma |
| 1451 | + splt->output_offset |
| 1452 | + h->plt.offset); |
| 1453 | break; |
| 1454 | |
| 1455 | case R_X86_64_8: |
| 1456 | case R_X86_64_16: |
| 1457 | case R_X86_64_32: |
| 1458 | case R_X86_64_PC8: |
| 1459 | case R_X86_64_PC16: |
| 1460 | case R_X86_64_PC32: |
| 1461 | /* FIXME: The abi says the linker should make sure the value is |
| 1462 | the same when it's zeroextended to 64 bit. */ |
| 1463 | if (info->shared |
| 1464 | && (input_section->flags & SEC_ALLOC) != 0 |
| 1465 | && ((r_type != R_X86_64_PC8 && r_type != R_X86_64_PC16 |
| 1466 | && r_type != R_X86_64_PC32) |
| 1467 | || (h != NULL |
| 1468 | && h->dynindx != -1 |
| 1469 | && (! info->symbolic |
| 1470 | || (h->elf_link_hash_flags |
| 1471 | & ELF_LINK_HASH_DEF_REGULAR) == 0)))) |
| 1472 | { |
| 1473 | Elf_Internal_Rela outrel; |
| 1474 | boolean skip, relocate; |
| 1475 | |
| 1476 | /* When generating a shared object, these relocations |
| 1477 | are copied into the output file to be resolved at run |
| 1478 | time. */ |
| 1479 | |
| 1480 | if (sreloc == NULL) |
| 1481 | { |
| 1482 | const char *name; |
| 1483 | |
| 1484 | name = (bfd_elf_string_from_elf_section |
| 1485 | (input_bfd, |
| 1486 | elf_elfheader (input_bfd)->e_shstrndx, |
| 1487 | elf_section_data (input_section)->rel_hdr.sh_name)); |
| 1488 | if (name == NULL) |
| 1489 | return false; |
| 1490 | |
| 1491 | BFD_ASSERT (strncmp (name, ".rela", 5) == 0 |
| 1492 | && strcmp (bfd_get_section_name (input_bfd, |
| 1493 | input_section), |
| 1494 | name + 5) == 0); |
| 1495 | |
| 1496 | sreloc = bfd_get_section_by_name (dynobj, name); |
| 1497 | BFD_ASSERT (sreloc != NULL); |
| 1498 | } |
| 1499 | |
| 1500 | skip = false; |
| 1501 | |
| 1502 | if (elf_section_data (input_section)->stab_info == NULL) |
| 1503 | outrel.r_offset = rela->r_offset; |
| 1504 | else |
| 1505 | { |
| 1506 | bfd_vma off; |
| 1507 | |
| 1508 | off = (_bfd_stab_section_offset |
| 1509 | (output_bfd, &elf_hash_table (info)->stab_info, |
| 1510 | input_section, |
| 1511 | &elf_section_data (input_section)->stab_info, |
| 1512 | rela->r_offset)); |
| 1513 | if (off == (bfd_vma) -1) |
| 1514 | skip = true; |
| 1515 | outrel.r_offset = off; |
| 1516 | } |
| 1517 | |
| 1518 | outrel.r_offset += (input_section->output_section->vma |
| 1519 | + input_section->output_offset); |
| 1520 | |
| 1521 | if (skip) |
| 1522 | { |
| 1523 | memset (&outrel, 0, sizeof outrel); |
| 1524 | relocate = false; |
| 1525 | } |
| 1526 | else if ((r_type == R_X86_64_PC8) || (r_type == R_X86_64_PC16) |
| 1527 | || (r_type == R_X86_64_PC32)) |
| 1528 | { |
| 1529 | BFD_ASSERT (h != NULL && h->dynindx != -1); |
| 1530 | relocate = false; |
| 1531 | outrel.r_info = ELF64_R_INFO (h->dynindx, r_type); |
| 1532 | outrel.r_addend = relocation + rela->r_addend; |
| 1533 | } |
| 1534 | else |
| 1535 | { |
| 1536 | /* h->dynindx may be -1 if this symbol was marked to |
| 1537 | become local. */ |
| 1538 | if (h == NULL |
| 1539 | || ((info->symbolic || h->dynindx == -1) |
| 1540 | && (h->elf_link_hash_flags |
| 1541 | & ELF_LINK_HASH_DEF_REGULAR) != 0)) |
| 1542 | { |
| 1543 | relocate = true; |
| 1544 | outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE); |
| 1545 | outrel.r_addend = relocation + rela->r_addend; |
| 1546 | } |
| 1547 | else |
| 1548 | { |
| 1549 | BFD_ASSERT (h->dynindx != -1); |
| 1550 | relocate = false; |
| 1551 | outrel.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_32); |
| 1552 | outrel.r_addend = relocation + rela->r_addend; |
| 1553 | } |
| 1554 | } |
| 1555 | |
| 1556 | bfd_elf64_swap_reloca_out (output_bfd, &outrel, |
| 1557 | (((Elf64_External_Rela *) |
| 1558 | sreloc->contents) |
| 1559 | + sreloc->reloc_count)); |
| 1560 | ++sreloc->reloc_count; |
| 1561 | |
| 1562 | /* If this reloc is against an external symbol, we do |
| 1563 | not want to fiddle with the addend. Otherwise, we |
| 1564 | need to include the symbol value so that it becomes |
| 1565 | an addend for the dynamic reloc. */ |
| 1566 | if (! relocate) |
| 1567 | continue; |
| 1568 | } |
| 1569 | |
| 1570 | break; |
| 1571 | |
| 1572 | default: |
| 1573 | break; |
| 1574 | } |
| 1575 | |
| 1576 | r = _bfd_final_link_relocate (howto, input_bfd, input_section, |
| 1577 | contents, rela->r_offset, |
| 1578 | relocation, rela->r_addend); |
| 1579 | |
| 1580 | if (r != bfd_reloc_ok) |
| 1581 | { |
| 1582 | switch (r) |
| 1583 | { |
| 1584 | default: |
| 1585 | case bfd_reloc_outofrange: |
| 1586 | abort (); |
| 1587 | case bfd_reloc_overflow: |
| 1588 | { |
| 1589 | const char *name; |
| 1590 | |
| 1591 | if (h != NULL) |
| 1592 | name = h->root.root.string; |
| 1593 | else |
| 1594 | { |
| 1595 | name = bfd_elf_string_from_elf_section (input_bfd, |
| 1596 | symtab_hdr->sh_link, |
| 1597 | sym->st_name); |
| 1598 | if (name == NULL) |
| 1599 | return false; |
| 1600 | if (*name == '\0') |
| 1601 | name = bfd_section_name (input_bfd, sec); |
| 1602 | } |
| 1603 | if (! ((*info->callbacks->reloc_overflow) |
| 1604 | (info, name, howto->name, (bfd_vma) 0, |
| 1605 | input_bfd, input_section, rela->r_offset))) |
| 1606 | return false; |
| 1607 | } |
| 1608 | break; |
| 1609 | } |
| 1610 | } |
| 1611 | } |
| 1612 | |
| 1613 | return true; |
| 1614 | } |
| 1615 | |
| 1616 | /* Finish up dynamic symbol handling. We set the contents of various |
| 1617 | dynamic sections here. */ |
| 1618 | |
| 1619 | static boolean |
| 1620 | elf64_x86_64_finish_dynamic_symbol (output_bfd, info, h, sym) |
| 1621 | bfd *output_bfd; |
| 1622 | struct bfd_link_info *info; |
| 1623 | struct elf_link_hash_entry *h; |
| 1624 | Elf_Internal_Sym *sym; |
| 1625 | { |
| 1626 | bfd *dynobj; |
| 1627 | |
| 1628 | dynobj = elf_hash_table (info)->dynobj; |
| 1629 | |
| 1630 | if (h->plt.offset != (bfd_vma) -1) |
| 1631 | { |
| 1632 | asection *splt; |
| 1633 | asection *sgot; |
| 1634 | asection *srela; |
| 1635 | bfd_vma plt_index; |
| 1636 | bfd_vma got_offset; |
| 1637 | Elf_Internal_Rela rela; |
| 1638 | |
| 1639 | /* This symbol has an entry in the procedure linkage table. Set |
| 1640 | it up. */ |
| 1641 | |
| 1642 | BFD_ASSERT (h->dynindx != -1); |
| 1643 | |
| 1644 | splt = bfd_get_section_by_name (dynobj, ".plt"); |
| 1645 | sgot = bfd_get_section_by_name (dynobj, ".got.plt"); |
| 1646 | srela = bfd_get_section_by_name (dynobj, ".rela.plt"); |
| 1647 | BFD_ASSERT (splt != NULL && sgot != NULL && srela != NULL); |
| 1648 | |
| 1649 | /* Get the index in the procedure linkage table which |
| 1650 | corresponds to this symbol. This is the index of this symbol |
| 1651 | in all the symbols for which we are making plt entries. The |
| 1652 | first entry in the procedure linkage table is reserved. */ |
| 1653 | plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1; |
| 1654 | |
| 1655 | /* Get the offset into the .got table of the entry that |
| 1656 | corresponds to this function. Each .got entry is GOT_ENTRY_SIZE |
| 1657 | bytes. The first three are reserved. */ |
| 1658 | got_offset = (plt_index + 3) * GOT_ENTRY_SIZE; |
| 1659 | |
| 1660 | /* Fill in the entry in the procedure linkage table. */ |
| 1661 | memcpy (splt->contents + h->plt.offset, elf64_x86_64_plt_entry, |
| 1662 | PLT_ENTRY_SIZE); |
| 1663 | |
| 1664 | /* Insert the relocation positions of the plt section. The magic |
| 1665 | numbers at the end of the statements are the positions of the |
| 1666 | relocations in the plt section. */ |
| 1667 | /* Put offset for jmp *name@GOTPCREL(%rip), since the |
| 1668 | instruction uses 6 bytes, subtract this value. */ |
| 1669 | bfd_put_32 (output_bfd, |
| 1670 | (sgot->output_section->vma |
| 1671 | + sgot->output_offset |
| 1672 | + got_offset |
| 1673 | - splt->output_section->vma |
| 1674 | - splt->output_offset |
| 1675 | - h->plt.offset |
| 1676 | - 6), |
| 1677 | splt->contents + h->plt.offset + 2); |
| 1678 | /* Put relocation index. */ |
| 1679 | bfd_put_32 (output_bfd, plt_index, |
| 1680 | splt->contents + h->plt.offset + 7); |
| 1681 | /* Put offset for jmp .PLT0. */ |
| 1682 | bfd_put_32 (output_bfd, - (h->plt.offset + PLT_ENTRY_SIZE), |
| 1683 | splt->contents + h->plt.offset + 12); |
| 1684 | |
| 1685 | /* Fill in the entry in the global offset table, initially this |
| 1686 | points to the pushq instruction in the PLT which is at offset 6. */ |
| 1687 | bfd_put_64 (output_bfd, (splt->output_section->vma + splt->output_offset |
| 1688 | + h->plt.offset + 6), |
| 1689 | sgot->contents + got_offset); |
| 1690 | |
| 1691 | /* Fill in the entry in the .rela.plt section. */ |
| 1692 | rela.r_offset = (sgot->output_section->vma |
| 1693 | + sgot->output_offset |
| 1694 | + got_offset); |
| 1695 | rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_JUMP_SLOT); |
| 1696 | rela.r_addend = 0; |
| 1697 | bfd_elf64_swap_reloca_out (output_bfd, &rela, |
| 1698 | ((Elf64_External_Rela *) srela->contents |
| 1699 | + plt_index)); |
| 1700 | |
| 1701 | if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) |
| 1702 | { |
| 1703 | /* Mark the symbol as undefined, rather than as defined in |
| 1704 | the .plt section. Leave the value alone. */ |
| 1705 | sym->st_shndx = SHN_UNDEF; |
| 1706 | /* If the symbol is weak, we do need to clear the value. |
| 1707 | Otherwise, the PLT entry would provide a definition for |
| 1708 | the symbol even if the symbol wasn't defined anywhere, |
| 1709 | and so the symbol would never be NULL. */ |
| 1710 | if ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR_NONWEAK) |
| 1711 | == 0) |
| 1712 | sym->st_value = 0; |
| 1713 | } |
| 1714 | } |
| 1715 | |
| 1716 | if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_COPY) != 0) |
| 1717 | { |
| 1718 | asection *s; |
| 1719 | Elf_Internal_Rela rela; |
| 1720 | |
| 1721 | /* This symbol needs a copy reloc. Set it up. */ |
| 1722 | |
| 1723 | BFD_ASSERT (h->dynindx != -1 |
| 1724 | && (h->root.type == bfd_link_hash_defined |
| 1725 | || h->root.type == bfd_link_hash_defweak)); |
| 1726 | |
| 1727 | s = bfd_get_section_by_name (h->root.u.def.section->owner, |
| 1728 | ".rela.bss"); |
| 1729 | BFD_ASSERT (s != NULL); |
| 1730 | |
| 1731 | rela.r_offset = (h->root.u.def.value |
| 1732 | + h->root.u.def.section->output_section->vma |
| 1733 | + h->root.u.def.section->output_offset); |
| 1734 | rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_COPY); |
| 1735 | rela.r_addend = 0; |
| 1736 | bfd_elf64_swap_reloca_out (output_bfd, &rela, |
| 1737 | ((Elf64_External_Rela *) s->contents |
| 1738 | + s->reloc_count)); |
| 1739 | ++s->reloc_count; |
| 1740 | } |
| 1741 | |
| 1742 | /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */ |
| 1743 | if (strcmp (h->root.root.string, "_DYNAMIC") == 0 |
| 1744 | || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0) |
| 1745 | sym->st_shndx = SHN_ABS; |
| 1746 | |
| 1747 | return true; |
| 1748 | } |
| 1749 | |
| 1750 | /* Finish up the dynamic sections. */ |
| 1751 | |
| 1752 | static boolean |
| 1753 | elf64_x86_64_finish_dynamic_sections (output_bfd, info) |
| 1754 | bfd *output_bfd; |
| 1755 | struct bfd_link_info *info; |
| 1756 | { |
| 1757 | bfd *dynobj; |
| 1758 | asection *sdyn; |
| 1759 | asection *sgot; |
| 1760 | |
| 1761 | dynobj = elf_hash_table (info)->dynobj; |
| 1762 | |
| 1763 | sgot = bfd_get_section_by_name (dynobj, ".got.plt"); |
| 1764 | BFD_ASSERT (sgot != NULL); |
| 1765 | sdyn = bfd_get_section_by_name (dynobj, ".dynamic"); |
| 1766 | |
| 1767 | if (elf_hash_table (info)->dynamic_sections_created) |
| 1768 | { |
| 1769 | asection *splt; |
| 1770 | Elf64_External_Dyn *dyncon, *dynconend; |
| 1771 | |
| 1772 | BFD_ASSERT (sdyn != NULL); |
| 1773 | |
| 1774 | dyncon = (Elf64_External_Dyn *) sdyn->contents; |
| 1775 | dynconend = (Elf64_External_Dyn *) (sdyn->contents + sdyn->_raw_size); |
| 1776 | for (; dyncon < dynconend; dyncon++) |
| 1777 | { |
| 1778 | Elf_Internal_Dyn dyn; |
| 1779 | const char *name; |
| 1780 | asection *s; |
| 1781 | |
| 1782 | bfd_elf64_swap_dyn_in (dynobj, dyncon, &dyn); |
| 1783 | |
| 1784 | switch (dyn.d_tag) |
| 1785 | { |
| 1786 | default: |
| 1787 | break; |
| 1788 | |
| 1789 | case DT_PLTGOT: |
| 1790 | name = ".got"; |
| 1791 | goto get_vma; |
| 1792 | |
| 1793 | case DT_JMPREL: |
| 1794 | name = ".rela.plt"; |
| 1795 | |
| 1796 | get_vma: |
| 1797 | s = bfd_get_section_by_name (output_bfd, name); |
| 1798 | BFD_ASSERT (s != NULL); |
| 1799 | dyn.d_un.d_ptr = s->vma; |
| 1800 | break; |
| 1801 | |
| 1802 | case DT_RELASZ: |
| 1803 | /* FIXME: This comment and code is from elf64-alpha.c: */ |
| 1804 | /* My interpretation of the TIS v1.1 ELF document indicates |
| 1805 | that RELASZ should not include JMPREL. This is not what |
| 1806 | the rest of the BFD does. It is, however, what the |
| 1807 | glibc ld.so wants. Do this fixup here until we found |
| 1808 | out who is right. */ |
| 1809 | s = bfd_get_section_by_name (output_bfd, ".rela.plt"); |
| 1810 | if (s) |
| 1811 | { |
| 1812 | /* Subtract JMPREL size from RELASZ. */ |
| 1813 | dyn.d_un.d_val -= |
| 1814 | (s->_cooked_size ? s->_cooked_size : s->_raw_size); |
| 1815 | } |
| 1816 | break; |
| 1817 | |
| 1818 | case DT_PLTRELSZ: |
| 1819 | s = bfd_get_section_by_name (output_bfd, ".rela.plt"); |
| 1820 | BFD_ASSERT (s != NULL); |
| 1821 | dyn.d_un.d_val = |
| 1822 | (s->_cooked_size != 0 ? s->_cooked_size : s->_raw_size); |
| 1823 | break; |
| 1824 | } |
| 1825 | |
| 1826 | bfd_elf64_swap_dyn_out (output_bfd, &dyn, dyncon); |
| 1827 | } |
| 1828 | |
| 1829 | /* Initialize the contents of the .plt section. */ |
| 1830 | splt = bfd_get_section_by_name (dynobj, ".plt"); |
| 1831 | BFD_ASSERT (splt != NULL); |
| 1832 | if (splt->_raw_size > 0) |
| 1833 | { |
| 1834 | /* Fill in the first entry in the procedure linkage table. */ |
| 1835 | memcpy (splt->contents, elf64_x86_64_plt0_entry, PLT_ENTRY_SIZE); |
| 1836 | /* Add offset for pushq GOT+8(%rip), since the instruction |
| 1837 | uses 6 bytes subtract this value. */ |
| 1838 | bfd_put_32 (output_bfd, |
| 1839 | (sgot->output_section->vma |
| 1840 | + sgot->output_offset |
| 1841 | + 8 |
| 1842 | - splt->output_section->vma |
| 1843 | - splt->output_offset |
| 1844 | - 6), |
| 1845 | splt->contents + 2); |
| 1846 | /* Add offset for jmp *GOT+16(%rip). The 12 is the offset to |
| 1847 | the end of the instruction. */ |
| 1848 | bfd_put_32 (output_bfd, |
| 1849 | (sgot->output_section->vma |
| 1850 | + sgot->output_offset |
| 1851 | + 16 |
| 1852 | - splt->output_section->vma |
| 1853 | - splt->output_offset |
| 1854 | - 12), |
| 1855 | splt->contents + 8); |
| 1856 | |
| 1857 | } |
| 1858 | |
| 1859 | elf_section_data (splt->output_section)->this_hdr.sh_entsize = |
| 1860 | PLT_ENTRY_SIZE; |
| 1861 | } |
| 1862 | |
| 1863 | /* Set the first entry in the global offset table to the address of |
| 1864 | the dynamic section. */ |
| 1865 | if (sgot->_raw_size > 0) |
| 1866 | { |
| 1867 | if (sdyn == NULL) |
| 1868 | bfd_put_64 (output_bfd, (bfd_vma) 0, sgot->contents); |
| 1869 | else |
| 1870 | bfd_put_64 (output_bfd, |
| 1871 | sdyn->output_section->vma + sdyn->output_offset, |
| 1872 | sgot->contents); |
| 1873 | /* Write GOT[1] and GOT[2], needed for the dynamic linker. */ |
| 1874 | bfd_put_64 (output_bfd, (bfd_vma) 0, sgot->contents + GOT_ENTRY_SIZE); |
| 1875 | bfd_put_64 (output_bfd, (bfd_vma) 0, sgot->contents + GOT_ENTRY_SIZE*2); |
| 1876 | } |
| 1877 | |
| 1878 | elf_section_data (sgot->output_section)->this_hdr.sh_entsize = |
| 1879 | GOT_ENTRY_SIZE; |
| 1880 | |
| 1881 | return true; |
| 1882 | } |
| 1883 | |
| 1884 | /* |
| 1885 | * Why was the hash table entry size definition changed from |
| 1886 | * ARCH_SIZE/8 to 4? This breaks the 64 bit dynamic linker and |
| 1887 | * this is the only reason for the elf64_x86_64_size_info structure. |
| 1888 | */ |
| 1889 | |
| 1890 | const struct elf_size_info elf64_86_64_size_info = |
| 1891 | { |
| 1892 | sizeof (Elf64_External_Ehdr), |
| 1893 | sizeof (Elf64_External_Phdr), |
| 1894 | sizeof (Elf64_External_Shdr), |
| 1895 | sizeof (Elf64_External_Rel), |
| 1896 | sizeof (Elf64_External_Rela), |
| 1897 | sizeof (Elf64_External_Sym), |
| 1898 | sizeof (Elf64_External_Dyn), |
| 1899 | sizeof (Elf_External_Note), |
| 1900 | 8, /* hash-table entry size */ |
| 1901 | 1, /* internal relocations per external relocations */ |
| 1902 | 64, /* arch_size */ |
| 1903 | 8, /* file_align */ |
| 1904 | ELFCLASS64, EV_CURRENT, |
| 1905 | bfd_elf64_write_out_phdrs, |
| 1906 | bfd_elf64_write_shdrs_and_ehdr, |
| 1907 | bfd_elf64_write_relocs, |
| 1908 | bfd_elf64_swap_symbol_out, |
| 1909 | bfd_elf64_slurp_reloc_table, |
| 1910 | bfd_elf64_slurp_symbol_table, |
| 1911 | bfd_elf64_swap_dyn_in, |
| 1912 | bfd_elf64_swap_dyn_out, |
| 1913 | NULL, |
| 1914 | NULL, |
| 1915 | NULL, |
| 1916 | NULL |
| 1917 | }; |
| 1918 | |
| 1919 | #define TARGET_LITTLE_SYM bfd_elf64_x86_64_vec |
| 1920 | #define TARGET_LITTLE_NAME "elf64-x86-64" |
| 1921 | #define ELF_ARCH bfd_arch_i386 |
| 1922 | #define ELF_MACHINE_CODE EM_X86_64 |
| 1923 | #define ELF_MAXPAGESIZE 0x100000 |
| 1924 | |
| 1925 | #define elf_backend_size_info elf64_86_64_size_info |
| 1926 | |
| 1927 | #define elf_backend_can_gc_sections 1 |
| 1928 | #define elf_backend_want_got_plt 1 |
| 1929 | #define elf_backend_plt_readonly 1 |
| 1930 | #define elf_backend_want_plt_sym 0 |
| 1931 | #define elf_backend_got_header_size (GOT_ENTRY_SIZE*3) |
| 1932 | #define elf_backend_plt_header_size PLT_ENTRY_SIZE |
| 1933 | |
| 1934 | #define elf_info_to_howto elf64_x86_64_info_to_howto |
| 1935 | |
| 1936 | #define bfd_elf64_bfd_final_link _bfd_elf64_gc_common_final_link |
| 1937 | #define bfd_elf64_bfd_link_hash_table_create \ |
| 1938 | elf64_x86_64_link_hash_table_create |
| 1939 | #define bfd_elf64_bfd_reloc_type_lookup elf64_x86_64_reloc_type_lookup |
| 1940 | |
| 1941 | #define elf_backend_adjust_dynamic_symbol elf64_x86_64_adjust_dynamic_symbol |
| 1942 | #define elf_backend_check_relocs elf64_x86_64_check_relocs |
| 1943 | #define elf_backend_create_dynamic_sections _bfd_elf_create_dynamic_sections |
| 1944 | #define elf_backend_finish_dynamic_sections \ |
| 1945 | elf64_x86_64_finish_dynamic_sections |
| 1946 | #define elf_backend_finish_dynamic_symbol elf64_x86_64_finish_dynamic_symbol |
| 1947 | #define elf_backend_gc_mark_hook elf64_x86_64_gc_mark_hook |
| 1948 | #define elf_backend_gc_sweep_hook elf64_x86_64_gc_sweep_hook |
| 1949 | #define elf_backend_relocate_section elf64_x86_64_relocate_section |
| 1950 | #define elf_backend_size_dynamic_sections elf64_x86_64_size_dynamic_sections |
| 1951 | #define elf_backend_object_p elf64_x86_64_elf_object_p |
| 1952 | |
| 1953 | #include "elf64-target.h" |