| 1 | /* X86-64 specific support for 64-bit ELF |
| 2 | Copyright 2000, 2001, 2002 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 "bfdlink.h" |
| 24 | #include "libbfd.h" |
| 25 | #include "elf-bfd.h" |
| 26 | |
| 27 | #include "elf/x86-64.h" |
| 28 | |
| 29 | /* We use only the RELA entries. */ |
| 30 | #define USE_RELA 1 |
| 31 | |
| 32 | /* In case we're on a 32-bit machine, construct a 64-bit "-1" value. */ |
| 33 | #define MINUS_ONE (~ (bfd_vma) 0) |
| 34 | |
| 35 | /* The relocation "howto" table. Order of fields: |
| 36 | type, size, bitsize, pc_relative, complain_on_overflow, |
| 37 | special_function, name, partial_inplace, src_mask, dst_pack, pcrel_offset. */ |
| 38 | static reloc_howto_type x86_64_elf_howto_table[] = |
| 39 | { |
| 40 | HOWTO(R_X86_64_NONE, 0, 0, 0, false, 0, complain_overflow_dont, |
| 41 | bfd_elf_generic_reloc, "R_X86_64_NONE", false, 0x00000000, 0x00000000, |
| 42 | false), |
| 43 | HOWTO(R_X86_64_64, 0, 4, 64, false, 0, complain_overflow_bitfield, |
| 44 | bfd_elf_generic_reloc, "R_X86_64_64", false, MINUS_ONE, MINUS_ONE, |
| 45 | false), |
| 46 | HOWTO(R_X86_64_PC32, 0, 4, 32, true, 0, complain_overflow_signed, |
| 47 | bfd_elf_generic_reloc, "R_X86_64_PC32", false, 0xffffffff, 0xffffffff, |
| 48 | true), |
| 49 | HOWTO(R_X86_64_GOT32, 0, 4, 32, false, 0, complain_overflow_signed, |
| 50 | bfd_elf_generic_reloc, "R_X86_64_GOT32", false, 0xffffffff, 0xffffffff, |
| 51 | false), |
| 52 | HOWTO(R_X86_64_PLT32, 0, 4, 32, true, 0, complain_overflow_signed, |
| 53 | bfd_elf_generic_reloc, "R_X86_64_PLT32", false, 0xffffffff, 0xffffffff, |
| 54 | true), |
| 55 | HOWTO(R_X86_64_COPY, 0, 4, 32, false, 0, complain_overflow_bitfield, |
| 56 | bfd_elf_generic_reloc, "R_X86_64_COPY", false, 0xffffffff, 0xffffffff, |
| 57 | false), |
| 58 | HOWTO(R_X86_64_GLOB_DAT, 0, 4, 64, false, 0, complain_overflow_bitfield, |
| 59 | bfd_elf_generic_reloc, "R_X86_64_GLOB_DAT", false, MINUS_ONE, |
| 60 | MINUS_ONE, false), |
| 61 | HOWTO(R_X86_64_JUMP_SLOT, 0, 4, 64, false, 0, complain_overflow_bitfield, |
| 62 | bfd_elf_generic_reloc, "R_X86_64_JUMP_SLOT", false, MINUS_ONE, |
| 63 | MINUS_ONE, false), |
| 64 | HOWTO(R_X86_64_RELATIVE, 0, 4, 64, false, 0, complain_overflow_bitfield, |
| 65 | bfd_elf_generic_reloc, "R_X86_64_RELATIVE", false, MINUS_ONE, |
| 66 | MINUS_ONE, false), |
| 67 | HOWTO(R_X86_64_GOTPCREL, 0, 4, 32, true,0 , complain_overflow_signed, |
| 68 | bfd_elf_generic_reloc, "R_X86_64_GOTPCREL", false, 0xffffffff, |
| 69 | 0xffffffff, true), |
| 70 | HOWTO(R_X86_64_32, 0, 4, 32, false, 0, complain_overflow_unsigned, |
| 71 | bfd_elf_generic_reloc, "R_X86_64_32", false, 0xffffffff, 0xffffffff, |
| 72 | false), |
| 73 | HOWTO(R_X86_64_32S, 0, 4, 32, false, 0, complain_overflow_signed, |
| 74 | bfd_elf_generic_reloc, "R_X86_64_32S", false, 0xffffffff, 0xffffffff, |
| 75 | false), |
| 76 | HOWTO(R_X86_64_16, 0, 1, 16, false, 0, complain_overflow_bitfield, |
| 77 | bfd_elf_generic_reloc, "R_X86_64_16", false, 0xffff, 0xffff, false), |
| 78 | HOWTO(R_X86_64_PC16,0, 1, 16, true, 0, complain_overflow_bitfield, |
| 79 | bfd_elf_generic_reloc, "R_X86_64_PC16", false, 0xffff, 0xffff, true), |
| 80 | HOWTO(R_X86_64_8, 0, 0, 8, false, 0, complain_overflow_signed, |
| 81 | bfd_elf_generic_reloc, "R_X86_64_8", false, 0xff, 0xff, false), |
| 82 | HOWTO(R_X86_64_PC8, 0, 0, 8, true, 0, complain_overflow_signed, |
| 83 | bfd_elf_generic_reloc, "R_X86_64_PC8", false, 0xff, 0xff, true), |
| 84 | |
| 85 | /* GNU extension to record C++ vtable hierarchy. */ |
| 86 | HOWTO (R_X86_64_GNU_VTINHERIT, 0, 4, 0, false, 0, complain_overflow_dont, |
| 87 | NULL, "R_X86_64_GNU_VTINHERIT", false, 0, 0, false), |
| 88 | |
| 89 | /* GNU extension to record C++ vtable member usage. */ |
| 90 | HOWTO (R_X86_64_GNU_VTENTRY, 0, 4, 0, false, 0, complain_overflow_dont, |
| 91 | _bfd_elf_rel_vtable_reloc_fn, "R_X86_64_GNU_VTENTRY", false, 0, 0, |
| 92 | false) |
| 93 | }; |
| 94 | |
| 95 | /* Map BFD relocs to the x86_64 elf relocs. */ |
| 96 | struct elf_reloc_map |
| 97 | { |
| 98 | bfd_reloc_code_real_type bfd_reloc_val; |
| 99 | unsigned char elf_reloc_val; |
| 100 | }; |
| 101 | |
| 102 | static const struct elf_reloc_map x86_64_reloc_map[] = |
| 103 | { |
| 104 | { BFD_RELOC_NONE, R_X86_64_NONE, }, |
| 105 | { BFD_RELOC_64, R_X86_64_64, }, |
| 106 | { BFD_RELOC_32_PCREL, R_X86_64_PC32, }, |
| 107 | { BFD_RELOC_X86_64_GOT32, R_X86_64_GOT32,}, |
| 108 | { BFD_RELOC_X86_64_PLT32, R_X86_64_PLT32,}, |
| 109 | { BFD_RELOC_X86_64_COPY, R_X86_64_COPY, }, |
| 110 | { BFD_RELOC_X86_64_GLOB_DAT, R_X86_64_GLOB_DAT, }, |
| 111 | { BFD_RELOC_X86_64_JUMP_SLOT, R_X86_64_JUMP_SLOT, }, |
| 112 | { BFD_RELOC_X86_64_RELATIVE, R_X86_64_RELATIVE, }, |
| 113 | { BFD_RELOC_X86_64_GOTPCREL, R_X86_64_GOTPCREL, }, |
| 114 | { BFD_RELOC_32, R_X86_64_32, }, |
| 115 | { BFD_RELOC_X86_64_32S, R_X86_64_32S, }, |
| 116 | { BFD_RELOC_16, R_X86_64_16, }, |
| 117 | { BFD_RELOC_16_PCREL, R_X86_64_PC16, }, |
| 118 | { BFD_RELOC_8, R_X86_64_8, }, |
| 119 | { BFD_RELOC_8_PCREL, R_X86_64_PC8, }, |
| 120 | { BFD_RELOC_VTABLE_INHERIT, R_X86_64_GNU_VTINHERIT, }, |
| 121 | { BFD_RELOC_VTABLE_ENTRY, R_X86_64_GNU_VTENTRY, }, |
| 122 | }; |
| 123 | |
| 124 | static reloc_howto_type *elf64_x86_64_reloc_type_lookup |
| 125 | PARAMS ((bfd *, bfd_reloc_code_real_type)); |
| 126 | static void elf64_x86_64_info_to_howto |
| 127 | PARAMS ((bfd *, arelent *, Elf64_Internal_Rela *)); |
| 128 | static boolean elf64_x86_64_grok_prstatus |
| 129 | PARAMS ((bfd *, Elf_Internal_Note *)); |
| 130 | static boolean elf64_x86_64_grok_psinfo |
| 131 | PARAMS ((bfd *, Elf_Internal_Note *)); |
| 132 | static struct bfd_link_hash_table *elf64_x86_64_link_hash_table_create |
| 133 | PARAMS ((bfd *)); |
| 134 | static boolean elf64_x86_64_elf_object_p PARAMS ((bfd *abfd)); |
| 135 | static boolean create_got_section |
| 136 | PARAMS((bfd *, struct bfd_link_info *)); |
| 137 | static boolean elf64_x86_64_create_dynamic_sections |
| 138 | PARAMS((bfd *, struct bfd_link_info *)); |
| 139 | static void elf64_x86_64_copy_indirect_symbol |
| 140 | PARAMS ((struct elf_link_hash_entry *, struct elf_link_hash_entry *)); |
| 141 | static boolean elf64_x86_64_check_relocs |
| 142 | PARAMS ((bfd *, struct bfd_link_info *, asection *sec, |
| 143 | const Elf_Internal_Rela *)); |
| 144 | static asection *elf64_x86_64_gc_mark_hook |
| 145 | PARAMS ((asection *, struct bfd_link_info *, Elf_Internal_Rela *, |
| 146 | struct elf_link_hash_entry *, Elf_Internal_Sym *)); |
| 147 | |
| 148 | static boolean elf64_x86_64_gc_sweep_hook |
| 149 | PARAMS ((bfd *, struct bfd_link_info *, asection *, |
| 150 | const Elf_Internal_Rela *)); |
| 151 | |
| 152 | static struct bfd_hash_entry *link_hash_newfunc |
| 153 | PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *, const char *)); |
| 154 | static boolean elf64_x86_64_adjust_dynamic_symbol |
| 155 | PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *)); |
| 156 | |
| 157 | static boolean allocate_dynrelocs |
| 158 | PARAMS ((struct elf_link_hash_entry *, PTR)); |
| 159 | static boolean readonly_dynrelocs |
| 160 | PARAMS ((struct elf_link_hash_entry *, PTR)); |
| 161 | static boolean elf64_x86_64_size_dynamic_sections |
| 162 | PARAMS ((bfd *, struct bfd_link_info *)); |
| 163 | static boolean elf64_x86_64_relocate_section |
| 164 | PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *, |
| 165 | Elf_Internal_Rela *, Elf_Internal_Sym *, asection **)); |
| 166 | static boolean elf64_x86_64_finish_dynamic_symbol |
| 167 | PARAMS ((bfd *, struct bfd_link_info *, struct elf_link_hash_entry *, |
| 168 | Elf_Internal_Sym *sym)); |
| 169 | static boolean elf64_x86_64_finish_dynamic_sections |
| 170 | PARAMS ((bfd *, struct bfd_link_info *)); |
| 171 | static enum elf_reloc_type_class elf64_x86_64_reloc_type_class |
| 172 | PARAMS ((const Elf_Internal_Rela *)); |
| 173 | |
| 174 | /* Given a BFD reloc type, return a HOWTO structure. */ |
| 175 | static reloc_howto_type * |
| 176 | elf64_x86_64_reloc_type_lookup (abfd, code) |
| 177 | bfd *abfd ATTRIBUTE_UNUSED; |
| 178 | bfd_reloc_code_real_type code; |
| 179 | { |
| 180 | unsigned int i; |
| 181 | for (i = 0; i < sizeof (x86_64_reloc_map) / sizeof (struct elf_reloc_map); |
| 182 | i++) |
| 183 | { |
| 184 | if (x86_64_reloc_map[i].bfd_reloc_val == code) |
| 185 | return &x86_64_elf_howto_table[i]; |
| 186 | } |
| 187 | return 0; |
| 188 | } |
| 189 | |
| 190 | /* Given an x86_64 ELF reloc type, fill in an arelent structure. */ |
| 191 | |
| 192 | static void |
| 193 | elf64_x86_64_info_to_howto (abfd, cache_ptr, dst) |
| 194 | bfd *abfd ATTRIBUTE_UNUSED; |
| 195 | arelent *cache_ptr; |
| 196 | Elf64_Internal_Rela *dst; |
| 197 | { |
| 198 | unsigned r_type, i; |
| 199 | |
| 200 | r_type = ELF64_R_TYPE (dst->r_info); |
| 201 | if (r_type < (unsigned int) R_X86_64_GNU_VTINHERIT) |
| 202 | { |
| 203 | BFD_ASSERT (r_type <= (unsigned int) R_X86_64_PC8); |
| 204 | i = r_type; |
| 205 | } |
| 206 | else |
| 207 | { |
| 208 | BFD_ASSERT (r_type < (unsigned int) R_X86_64_max); |
| 209 | i = r_type - ((unsigned int) R_X86_64_GNU_VTINHERIT - R_X86_64_PC8 - 1); |
| 210 | } |
| 211 | cache_ptr->howto = &x86_64_elf_howto_table[i]; |
| 212 | BFD_ASSERT (r_type == cache_ptr->howto->type); |
| 213 | } |
| 214 | \f |
| 215 | /* Support for core dump NOTE sections. */ |
| 216 | static boolean |
| 217 | elf64_x86_64_grok_prstatus (abfd, note) |
| 218 | bfd *abfd; |
| 219 | Elf_Internal_Note *note; |
| 220 | { |
| 221 | int offset; |
| 222 | size_t raw_size; |
| 223 | |
| 224 | switch (note->descsz) |
| 225 | { |
| 226 | default: |
| 227 | return false; |
| 228 | |
| 229 | case 336: /* sizeof(istruct elf_prstatus) on Linux/x86_64 */ |
| 230 | /* pr_cursig */ |
| 231 | elf_tdata (abfd)->core_signal |
| 232 | = bfd_get_16 (abfd, note->descdata + 12); |
| 233 | |
| 234 | /* pr_pid */ |
| 235 | elf_tdata (abfd)->core_pid |
| 236 | = bfd_get_32 (abfd, note->descdata + 32); |
| 237 | |
| 238 | /* pr_reg */ |
| 239 | offset = 112; |
| 240 | raw_size = 216; |
| 241 | |
| 242 | break; |
| 243 | } |
| 244 | |
| 245 | /* Make a ".reg/999" section. */ |
| 246 | return _bfd_elfcore_make_pseudosection (abfd, ".reg", |
| 247 | raw_size, note->descpos + offset); |
| 248 | } |
| 249 | |
| 250 | static boolean |
| 251 | elf64_x86_64_grok_psinfo (abfd, note) |
| 252 | bfd *abfd; |
| 253 | Elf_Internal_Note *note; |
| 254 | { |
| 255 | switch (note->descsz) |
| 256 | { |
| 257 | default: |
| 258 | return false; |
| 259 | |
| 260 | case 136: /* sizeof(struct elf_prpsinfo) on Linux/x86_64 */ |
| 261 | elf_tdata (abfd)->core_program |
| 262 | = _bfd_elfcore_strndup (abfd, note->descdata + 40, 16); |
| 263 | elf_tdata (abfd)->core_command |
| 264 | = _bfd_elfcore_strndup (abfd, note->descdata + 56, 80); |
| 265 | } |
| 266 | |
| 267 | /* Note that for some reason, a spurious space is tacked |
| 268 | onto the end of the args in some (at least one anyway) |
| 269 | implementations, so strip it off if it exists. */ |
| 270 | |
| 271 | { |
| 272 | char *command = elf_tdata (abfd)->core_command; |
| 273 | int n = strlen (command); |
| 274 | |
| 275 | if (0 < n && command[n - 1] == ' ') |
| 276 | command[n - 1] = '\0'; |
| 277 | } |
| 278 | |
| 279 | return true; |
| 280 | } |
| 281 | \f |
| 282 | /* Functions for the x86-64 ELF linker. */ |
| 283 | |
| 284 | /* The name of the dynamic interpreter. This is put in the .interp |
| 285 | section. */ |
| 286 | |
| 287 | #define ELF_DYNAMIC_INTERPRETER "/lib/ld64.so.1" |
| 288 | |
| 289 | /* The size in bytes of an entry in the global offset table. */ |
| 290 | |
| 291 | #define GOT_ENTRY_SIZE 8 |
| 292 | |
| 293 | /* The size in bytes of an entry in the procedure linkage table. */ |
| 294 | |
| 295 | #define PLT_ENTRY_SIZE 16 |
| 296 | |
| 297 | /* The first entry in a procedure linkage table looks like this. See the |
| 298 | SVR4 ABI i386 supplement and the x86-64 ABI to see how this works. */ |
| 299 | |
| 300 | static const bfd_byte elf64_x86_64_plt0_entry[PLT_ENTRY_SIZE] = |
| 301 | { |
| 302 | 0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */ |
| 303 | 0xff, 0x25, 16, 0, 0, 0, /* jmpq *GOT+16(%rip) */ |
| 304 | 0x90, 0x90, 0x90, 0x90 /* pad out to 16 bytes with nops. */ |
| 305 | }; |
| 306 | |
| 307 | /* Subsequent entries in a procedure linkage table look like this. */ |
| 308 | |
| 309 | static const bfd_byte elf64_x86_64_plt_entry[PLT_ENTRY_SIZE] = |
| 310 | { |
| 311 | 0xff, 0x25, /* jmpq *name@GOTPC(%rip) */ |
| 312 | 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */ |
| 313 | 0x68, /* pushq immediate */ |
| 314 | 0, 0, 0, 0, /* replaced with index into relocation table. */ |
| 315 | 0xe9, /* jmp relative */ |
| 316 | 0, 0, 0, 0 /* replaced with offset to start of .plt0. */ |
| 317 | }; |
| 318 | |
| 319 | /* The x86-64 linker needs to keep track of the number of relocs that |
| 320 | it decides to copy as dynamic relocs in check_relocs for each symbol. |
| 321 | This is so that it can later discard them if they are found to be |
| 322 | unnecessary. We store the information in a field extending the |
| 323 | regular ELF linker hash table. */ |
| 324 | |
| 325 | struct elf64_x86_64_dyn_relocs |
| 326 | { |
| 327 | /* Next section. */ |
| 328 | struct elf64_x86_64_dyn_relocs *next; |
| 329 | |
| 330 | /* The input section of the reloc. */ |
| 331 | asection *sec; |
| 332 | |
| 333 | /* Total number of relocs copied for the input section. */ |
| 334 | bfd_size_type count; |
| 335 | |
| 336 | /* Number of pc-relative relocs copied for the input section. */ |
| 337 | bfd_size_type pc_count; |
| 338 | }; |
| 339 | |
| 340 | /* x86-64 ELF linker hash entry. */ |
| 341 | |
| 342 | struct elf64_x86_64_link_hash_entry |
| 343 | { |
| 344 | struct elf_link_hash_entry elf; |
| 345 | |
| 346 | /* Track dynamic relocs copied for this symbol. */ |
| 347 | struct elf64_x86_64_dyn_relocs *dyn_relocs; |
| 348 | }; |
| 349 | |
| 350 | /* x86-64 ELF linker hash table. */ |
| 351 | |
| 352 | struct elf64_x86_64_link_hash_table |
| 353 | { |
| 354 | struct elf_link_hash_table elf; |
| 355 | |
| 356 | /* Short-cuts to get to dynamic linker sections. */ |
| 357 | asection *sgot; |
| 358 | asection *sgotplt; |
| 359 | asection *srelgot; |
| 360 | asection *splt; |
| 361 | asection *srelplt; |
| 362 | asection *sdynbss; |
| 363 | asection *srelbss; |
| 364 | |
| 365 | /* Small local sym to section mapping cache. */ |
| 366 | struct sym_sec_cache sym_sec; |
| 367 | }; |
| 368 | |
| 369 | /* Get the x86-64 ELF linker hash table from a link_info structure. */ |
| 370 | |
| 371 | #define elf64_x86_64_hash_table(p) \ |
| 372 | ((struct elf64_x86_64_link_hash_table *) ((p)->hash)) |
| 373 | |
| 374 | /* Create an entry in an x86-64 ELF linker hash table. */ |
| 375 | |
| 376 | static struct bfd_hash_entry * |
| 377 | link_hash_newfunc (entry, table, string) |
| 378 | struct bfd_hash_entry *entry; |
| 379 | struct bfd_hash_table *table; |
| 380 | const char *string; |
| 381 | { |
| 382 | /* Allocate the structure if it has not already been allocated by a |
| 383 | subclass. */ |
| 384 | if (entry == NULL) |
| 385 | { |
| 386 | entry = bfd_hash_allocate (table, |
| 387 | sizeof (struct elf64_x86_64_link_hash_entry)); |
| 388 | if (entry == NULL) |
| 389 | return entry; |
| 390 | } |
| 391 | |
| 392 | /* Call the allocation method of the superclass. */ |
| 393 | entry = _bfd_elf_link_hash_newfunc (entry, table, string); |
| 394 | if (entry != NULL) |
| 395 | { |
| 396 | struct elf64_x86_64_link_hash_entry *eh; |
| 397 | |
| 398 | eh = (struct elf64_x86_64_link_hash_entry *) entry; |
| 399 | eh->dyn_relocs = NULL; |
| 400 | } |
| 401 | |
| 402 | return entry; |
| 403 | } |
| 404 | |
| 405 | /* Create an X86-64 ELF linker hash table. */ |
| 406 | |
| 407 | static struct bfd_link_hash_table * |
| 408 | elf64_x86_64_link_hash_table_create (abfd) |
| 409 | bfd *abfd; |
| 410 | { |
| 411 | struct elf64_x86_64_link_hash_table *ret; |
| 412 | bfd_size_type amt = sizeof (struct elf64_x86_64_link_hash_table); |
| 413 | |
| 414 | ret = (struct elf64_x86_64_link_hash_table *) bfd_malloc (amt); |
| 415 | if (ret == NULL) |
| 416 | return NULL; |
| 417 | |
| 418 | if (! _bfd_elf_link_hash_table_init (&ret->elf, abfd, link_hash_newfunc)) |
| 419 | { |
| 420 | free (ret); |
| 421 | return NULL; |
| 422 | } |
| 423 | |
| 424 | ret->sgot = NULL; |
| 425 | ret->sgotplt = NULL; |
| 426 | ret->srelgot = NULL; |
| 427 | ret->splt = NULL; |
| 428 | ret->srelplt = NULL; |
| 429 | ret->sdynbss = NULL; |
| 430 | ret->srelbss = NULL; |
| 431 | ret->sym_sec.abfd = NULL; |
| 432 | |
| 433 | return &ret->elf.root; |
| 434 | } |
| 435 | |
| 436 | /* Create .got, .gotplt, and .rela.got sections in DYNOBJ, and set up |
| 437 | shortcuts to them in our hash table. */ |
| 438 | |
| 439 | static boolean |
| 440 | create_got_section (dynobj, info) |
| 441 | bfd *dynobj; |
| 442 | struct bfd_link_info *info; |
| 443 | { |
| 444 | struct elf64_x86_64_link_hash_table *htab; |
| 445 | |
| 446 | if (! _bfd_elf_create_got_section (dynobj, info)) |
| 447 | return false; |
| 448 | |
| 449 | htab = elf64_x86_64_hash_table (info); |
| 450 | htab->sgot = bfd_get_section_by_name (dynobj, ".got"); |
| 451 | htab->sgotplt = bfd_get_section_by_name (dynobj, ".got.plt"); |
| 452 | if (!htab->sgot || !htab->sgotplt) |
| 453 | abort (); |
| 454 | |
| 455 | htab->srelgot = bfd_make_section (dynobj, ".rela.got"); |
| 456 | if (htab->srelgot == NULL |
| 457 | || ! bfd_set_section_flags (dynobj, htab->srelgot, |
| 458 | (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS |
| 459 | | SEC_IN_MEMORY | SEC_LINKER_CREATED |
| 460 | | SEC_READONLY)) |
| 461 | || ! bfd_set_section_alignment (dynobj, htab->srelgot, 3)) |
| 462 | return false; |
| 463 | return true; |
| 464 | } |
| 465 | |
| 466 | /* Create .plt, .rela.plt, .got, .got.plt, .rela.got, .dynbss, and |
| 467 | .rela.bss sections in DYNOBJ, and set up shortcuts to them in our |
| 468 | hash table. */ |
| 469 | |
| 470 | static boolean |
| 471 | elf64_x86_64_create_dynamic_sections (dynobj, info) |
| 472 | bfd *dynobj; |
| 473 | struct bfd_link_info *info; |
| 474 | { |
| 475 | struct elf64_x86_64_link_hash_table *htab; |
| 476 | |
| 477 | htab = elf64_x86_64_hash_table (info); |
| 478 | if (!htab->sgot && !create_got_section (dynobj, info)) |
| 479 | return false; |
| 480 | |
| 481 | if (!_bfd_elf_create_dynamic_sections (dynobj, info)) |
| 482 | return false; |
| 483 | |
| 484 | htab->splt = bfd_get_section_by_name (dynobj, ".plt"); |
| 485 | htab->srelplt = bfd_get_section_by_name (dynobj, ".rela.plt"); |
| 486 | htab->sdynbss = bfd_get_section_by_name (dynobj, ".dynbss"); |
| 487 | if (!info->shared) |
| 488 | htab->srelbss = bfd_get_section_by_name (dynobj, ".rela.bss"); |
| 489 | |
| 490 | if (!htab->splt || !htab->srelplt || !htab->sdynbss |
| 491 | || (!info->shared && !htab->srelbss)) |
| 492 | abort (); |
| 493 | |
| 494 | return true; |
| 495 | } |
| 496 | |
| 497 | /* Copy the extra info we tack onto an elf_link_hash_entry. */ |
| 498 | |
| 499 | static void |
| 500 | elf64_x86_64_copy_indirect_symbol (dir, ind) |
| 501 | struct elf_link_hash_entry *dir, *ind; |
| 502 | { |
| 503 | struct elf64_x86_64_link_hash_entry *edir, *eind; |
| 504 | |
| 505 | edir = (struct elf64_x86_64_link_hash_entry *) dir; |
| 506 | eind = (struct elf64_x86_64_link_hash_entry *) ind; |
| 507 | |
| 508 | if (eind->dyn_relocs != NULL) |
| 509 | { |
| 510 | if (edir->dyn_relocs != NULL) |
| 511 | { |
| 512 | struct elf64_x86_64_dyn_relocs **pp; |
| 513 | struct elf64_x86_64_dyn_relocs *p; |
| 514 | |
| 515 | if (ind->root.type == bfd_link_hash_indirect) |
| 516 | abort (); |
| 517 | |
| 518 | /* Add reloc counts against the weak sym to the strong sym |
| 519 | list. Merge any entries against the same section. */ |
| 520 | for (pp = &eind->dyn_relocs; (p = *pp) != NULL; ) |
| 521 | { |
| 522 | struct elf64_x86_64_dyn_relocs *q; |
| 523 | |
| 524 | for (q = edir->dyn_relocs; q != NULL; q = q->next) |
| 525 | if (q->sec == p->sec) |
| 526 | { |
| 527 | q->pc_count += p->pc_count; |
| 528 | q->count += p->count; |
| 529 | *pp = p->next; |
| 530 | break; |
| 531 | } |
| 532 | if (q == NULL) |
| 533 | pp = &p->next; |
| 534 | } |
| 535 | *pp = edir->dyn_relocs; |
| 536 | } |
| 537 | |
| 538 | edir->dyn_relocs = eind->dyn_relocs; |
| 539 | eind->dyn_relocs = NULL; |
| 540 | } |
| 541 | |
| 542 | _bfd_elf_link_hash_copy_indirect (dir, ind); |
| 543 | } |
| 544 | |
| 545 | static boolean |
| 546 | elf64_x86_64_elf_object_p (abfd) |
| 547 | bfd *abfd; |
| 548 | { |
| 549 | /* Set the right machine number for an x86-64 elf64 file. */ |
| 550 | bfd_default_set_arch_mach (abfd, bfd_arch_i386, bfd_mach_x86_64); |
| 551 | return true; |
| 552 | } |
| 553 | |
| 554 | /* Look through the relocs for a section during the first phase, and |
| 555 | calculate needed space in the global offset table, procedure |
| 556 | linkage table, and dynamic reloc sections. */ |
| 557 | |
| 558 | static boolean |
| 559 | elf64_x86_64_check_relocs (abfd, info, sec, relocs) |
| 560 | bfd *abfd; |
| 561 | struct bfd_link_info *info; |
| 562 | asection *sec; |
| 563 | const Elf_Internal_Rela *relocs; |
| 564 | { |
| 565 | struct elf64_x86_64_link_hash_table *htab; |
| 566 | Elf_Internal_Shdr *symtab_hdr; |
| 567 | struct elf_link_hash_entry **sym_hashes; |
| 568 | const Elf_Internal_Rela *rel; |
| 569 | const Elf_Internal_Rela *rel_end; |
| 570 | asection *sreloc; |
| 571 | |
| 572 | if (info->relocateable) |
| 573 | return true; |
| 574 | |
| 575 | htab = elf64_x86_64_hash_table (info); |
| 576 | symtab_hdr = &elf_tdata (abfd)->symtab_hdr; |
| 577 | sym_hashes = elf_sym_hashes (abfd); |
| 578 | |
| 579 | sreloc = NULL; |
| 580 | |
| 581 | rel_end = relocs + sec->reloc_count; |
| 582 | for (rel = relocs; rel < rel_end; rel++) |
| 583 | { |
| 584 | unsigned long r_symndx; |
| 585 | struct elf_link_hash_entry *h; |
| 586 | |
| 587 | r_symndx = ELF64_R_SYM (rel->r_info); |
| 588 | |
| 589 | if (r_symndx >= NUM_SHDR_ENTRIES (symtab_hdr)) |
| 590 | { |
| 591 | (*_bfd_error_handler) (_("%s: bad symbol index: %d"), |
| 592 | bfd_archive_filename (abfd), |
| 593 | r_symndx); |
| 594 | return false; |
| 595 | } |
| 596 | |
| 597 | if (r_symndx < symtab_hdr->sh_info) |
| 598 | h = NULL; |
| 599 | else |
| 600 | h = sym_hashes[r_symndx - symtab_hdr->sh_info]; |
| 601 | |
| 602 | switch (ELF64_R_TYPE (rel->r_info)) |
| 603 | { |
| 604 | case R_X86_64_GOT32: |
| 605 | case R_X86_64_GOTPCREL: |
| 606 | /* This symbol requires a global offset table entry. */ |
| 607 | if (h != NULL) |
| 608 | { |
| 609 | h->got.refcount += 1; |
| 610 | } |
| 611 | else |
| 612 | { |
| 613 | bfd_signed_vma *local_got_refcounts; |
| 614 | |
| 615 | /* This is a global offset table entry for a local symbol. */ |
| 616 | local_got_refcounts = elf_local_got_refcounts (abfd); |
| 617 | if (local_got_refcounts == NULL) |
| 618 | { |
| 619 | bfd_size_type size; |
| 620 | |
| 621 | size = symtab_hdr->sh_info; |
| 622 | size *= sizeof (bfd_signed_vma); |
| 623 | local_got_refcounts = ((bfd_signed_vma *) |
| 624 | bfd_zalloc (abfd, size)); |
| 625 | if (local_got_refcounts == NULL) |
| 626 | return false; |
| 627 | elf_local_got_refcounts (abfd) = local_got_refcounts; |
| 628 | } |
| 629 | local_got_refcounts[r_symndx] += 1; |
| 630 | } |
| 631 | /* Fall through */ |
| 632 | |
| 633 | //case R_X86_64_GOTPCREL: |
| 634 | if (htab->sgot == NULL) |
| 635 | { |
| 636 | if (htab->elf.dynobj == NULL) |
| 637 | htab->elf.dynobj = abfd; |
| 638 | if (!create_got_section (htab->elf.dynobj, info)) |
| 639 | return false; |
| 640 | } |
| 641 | break; |
| 642 | |
| 643 | case R_X86_64_PLT32: |
| 644 | /* This symbol requires a procedure linkage table entry. We |
| 645 | actually build the entry in adjust_dynamic_symbol, |
| 646 | because this might be a case of linking PIC code which is |
| 647 | never referenced by a dynamic object, in which case we |
| 648 | don't need to generate a procedure linkage table entry |
| 649 | after all. */ |
| 650 | |
| 651 | /* If this is a local symbol, we resolve it directly without |
| 652 | creating a procedure linkage table entry. */ |
| 653 | if (h == NULL) |
| 654 | continue; |
| 655 | |
| 656 | h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_PLT; |
| 657 | h->plt.refcount += 1; |
| 658 | break; |
| 659 | |
| 660 | case R_X86_64_8: |
| 661 | case R_X86_64_16: |
| 662 | case R_X86_64_32: |
| 663 | case R_X86_64_32S: |
| 664 | /* Let's help debug shared library creation. These relocs |
| 665 | cannot be used in shared libs. Don't error out for |
| 666 | sections we don't care about, such as debug sections or |
| 667 | non-constant sections. */ |
| 668 | if (info->shared |
| 669 | && (sec->flags & SEC_ALLOC) != 0 |
| 670 | && (sec->flags & SEC_READONLY) != 0) |
| 671 | { |
| 672 | (*_bfd_error_handler) |
| 673 | (_("%s: relocation %s can not be used when making a shared object; recompile with -fPIC"), |
| 674 | bfd_archive_filename (abfd), |
| 675 | x86_64_elf_howto_table[ELF64_R_TYPE (rel->r_info)].name); |
| 676 | bfd_set_error (bfd_error_bad_value); |
| 677 | return false; |
| 678 | } |
| 679 | /* Fall through. */ |
| 680 | |
| 681 | case R_X86_64_PC8: |
| 682 | case R_X86_64_PC16: |
| 683 | case R_X86_64_PC32: |
| 684 | case R_X86_64_64: |
| 685 | if (h != NULL && !info->shared) |
| 686 | { |
| 687 | /* If this reloc is in a read-only section, we might |
| 688 | need a copy reloc. We can't check reliably at this |
| 689 | stage whether the section is read-only, as input |
| 690 | sections have not yet been mapped to output sections. |
| 691 | Tentatively set the flag for now, and correct in |
| 692 | adjust_dynamic_symbol. */ |
| 693 | h->elf_link_hash_flags |= ELF_LINK_NON_GOT_REF; |
| 694 | |
| 695 | /* We may need a .plt entry if the function this reloc |
| 696 | refers to is in a shared lib. */ |
| 697 | h->plt.refcount += 1; |
| 698 | } |
| 699 | |
| 700 | /* If we are creating a shared library, and this is a reloc |
| 701 | against a global symbol, or a non PC relative reloc |
| 702 | against a local symbol, then we need to copy the reloc |
| 703 | into the shared library. However, if we are linking with |
| 704 | -Bsymbolic, we do not need to copy a reloc against a |
| 705 | global symbol which is defined in an object we are |
| 706 | including in the link (i.e., DEF_REGULAR is set). At |
| 707 | this point we have not seen all the input files, so it is |
| 708 | possible that DEF_REGULAR is not set now but will be set |
| 709 | later (it is never cleared). In case of a weak definition, |
| 710 | DEF_REGULAR may be cleared later by a strong definition in |
| 711 | a shared library. We account for that possibility below by |
| 712 | storing information in the relocs_copied field of the hash |
| 713 | table entry. A similar situation occurs when creating |
| 714 | shared libraries and symbol visibility changes render the |
| 715 | symbol local. |
| 716 | |
| 717 | If on the other hand, we are creating an executable, we |
| 718 | may need to keep relocations for symbols satisfied by a |
| 719 | dynamic library if we manage to avoid copy relocs for the |
| 720 | symbol. */ |
| 721 | if ((info->shared |
| 722 | && (sec->flags & SEC_ALLOC) != 0 |
| 723 | && (((ELF64_R_TYPE (rel->r_info) != R_X86_64_PC8) |
| 724 | && (ELF64_R_TYPE (rel->r_info) != R_X86_64_PC16) |
| 725 | && (ELF64_R_TYPE (rel->r_info) != R_X86_64_PC32)) |
| 726 | || (h != NULL |
| 727 | && (! info->symbolic |
| 728 | || h->root.type == bfd_link_hash_defweak |
| 729 | || (h->elf_link_hash_flags |
| 730 | & ELF_LINK_HASH_DEF_REGULAR) == 0)))) |
| 731 | || (!info->shared |
| 732 | && (sec->flags & SEC_ALLOC) != 0 |
| 733 | && h != NULL |
| 734 | && (h->root.type == bfd_link_hash_defweak |
| 735 | || (h->elf_link_hash_flags |
| 736 | & ELF_LINK_HASH_DEF_REGULAR) == 0))) |
| 737 | { |
| 738 | struct elf64_x86_64_dyn_relocs *p; |
| 739 | struct elf64_x86_64_dyn_relocs **head; |
| 740 | |
| 741 | /* We must copy these reloc types into the output file. |
| 742 | Create a reloc section in dynobj and make room for |
| 743 | this reloc. */ |
| 744 | if (sreloc == NULL) |
| 745 | { |
| 746 | const char *name; |
| 747 | bfd *dynobj; |
| 748 | |
| 749 | name = (bfd_elf_string_from_elf_section |
| 750 | (abfd, |
| 751 | elf_elfheader (abfd)->e_shstrndx, |
| 752 | elf_section_data (sec)->rel_hdr.sh_name)); |
| 753 | if (name == NULL) |
| 754 | return false; |
| 755 | |
| 756 | if (strncmp (name, ".rela", 5) != 0 |
| 757 | || strcmp (bfd_get_section_name (abfd, sec), |
| 758 | name + 5) != 0) |
| 759 | { |
| 760 | (*_bfd_error_handler) |
| 761 | (_("%s: bad relocation section name `%s\'"), |
| 762 | bfd_archive_filename (abfd), name); |
| 763 | } |
| 764 | |
| 765 | if (htab->elf.dynobj == NULL) |
| 766 | htab->elf.dynobj = abfd; |
| 767 | |
| 768 | dynobj = htab->elf.dynobj; |
| 769 | |
| 770 | sreloc = bfd_get_section_by_name (dynobj, name); |
| 771 | if (sreloc == NULL) |
| 772 | { |
| 773 | flagword flags; |
| 774 | |
| 775 | sreloc = bfd_make_section (dynobj, name); |
| 776 | flags = (SEC_HAS_CONTENTS | SEC_READONLY |
| 777 | | SEC_IN_MEMORY | SEC_LINKER_CREATED); |
| 778 | if ((sec->flags & SEC_ALLOC) != 0) |
| 779 | flags |= SEC_ALLOC | SEC_LOAD; |
| 780 | if (sreloc == NULL |
| 781 | || ! bfd_set_section_flags (dynobj, sreloc, flags) |
| 782 | || ! bfd_set_section_alignment (dynobj, sreloc, 3)) |
| 783 | return false; |
| 784 | } |
| 785 | elf_section_data (sec)->sreloc = sreloc; |
| 786 | } |
| 787 | |
| 788 | /* If this is a global symbol, we count the number of |
| 789 | relocations we need for this symbol. */ |
| 790 | if (h != NULL) |
| 791 | { |
| 792 | head = &((struct elf64_x86_64_link_hash_entry *) h)->dyn_relocs; |
| 793 | } |
| 794 | else |
| 795 | { |
| 796 | /* Track dynamic relocs needed for local syms too. |
| 797 | We really need local syms available to do this |
| 798 | easily. Oh well. */ |
| 799 | |
| 800 | asection *s; |
| 801 | s = bfd_section_from_r_symndx (abfd, &htab->sym_sec, |
| 802 | sec, r_symndx); |
| 803 | if (s == NULL) |
| 804 | return false; |
| 805 | |
| 806 | head = ((struct elf64_x86_64_dyn_relocs **) |
| 807 | &elf_section_data (s)->local_dynrel); |
| 808 | } |
| 809 | |
| 810 | p = *head; |
| 811 | if (p == NULL || p->sec != sec) |
| 812 | { |
| 813 | bfd_size_type amt = sizeof *p; |
| 814 | p = ((struct elf64_x86_64_dyn_relocs *) |
| 815 | bfd_alloc (htab->elf.dynobj, amt)); |
| 816 | if (p == NULL) |
| 817 | return false; |
| 818 | p->next = *head; |
| 819 | *head = p; |
| 820 | p->sec = sec; |
| 821 | p->count = 0; |
| 822 | p->pc_count = 0; |
| 823 | } |
| 824 | |
| 825 | p->count += 1; |
| 826 | if (ELF64_R_TYPE (rel->r_info) == R_X86_64_PC8 |
| 827 | || ELF64_R_TYPE (rel->r_info) == R_X86_64_PC16 |
| 828 | || ELF64_R_TYPE (rel->r_info) == R_X86_64_PC32) |
| 829 | p->pc_count += 1; |
| 830 | } |
| 831 | break; |
| 832 | |
| 833 | /* This relocation describes the C++ object vtable hierarchy. |
| 834 | Reconstruct it for later use during GC. */ |
| 835 | case R_X86_64_GNU_VTINHERIT: |
| 836 | if (!_bfd_elf64_gc_record_vtinherit (abfd, sec, h, rel->r_offset)) |
| 837 | return false; |
| 838 | break; |
| 839 | |
| 840 | /* This relocation describes which C++ vtable entries are actually |
| 841 | used. Record for later use during GC. */ |
| 842 | case R_X86_64_GNU_VTENTRY: |
| 843 | if (!_bfd_elf64_gc_record_vtentry (abfd, sec, h, rel->r_addend)) |
| 844 | return false; |
| 845 | break; |
| 846 | |
| 847 | default: |
| 848 | break; |
| 849 | } |
| 850 | } |
| 851 | |
| 852 | return true; |
| 853 | } |
| 854 | |
| 855 | /* Return the section that should be marked against GC for a given |
| 856 | relocation. */ |
| 857 | |
| 858 | static asection * |
| 859 | elf64_x86_64_gc_mark_hook (sec, info, rel, h, sym) |
| 860 | asection *sec; |
| 861 | struct bfd_link_info *info ATTRIBUTE_UNUSED; |
| 862 | Elf_Internal_Rela *rel; |
| 863 | struct elf_link_hash_entry *h; |
| 864 | Elf_Internal_Sym *sym; |
| 865 | { |
| 866 | if (h != NULL) |
| 867 | { |
| 868 | switch (ELF64_R_TYPE (rel->r_info)) |
| 869 | { |
| 870 | case R_X86_64_GNU_VTINHERIT: |
| 871 | case R_X86_64_GNU_VTENTRY: |
| 872 | break; |
| 873 | |
| 874 | default: |
| 875 | switch (h->root.type) |
| 876 | { |
| 877 | case bfd_link_hash_defined: |
| 878 | case bfd_link_hash_defweak: |
| 879 | return h->root.u.def.section; |
| 880 | |
| 881 | case bfd_link_hash_common: |
| 882 | return h->root.u.c.p->section; |
| 883 | |
| 884 | default: |
| 885 | break; |
| 886 | } |
| 887 | } |
| 888 | } |
| 889 | else |
| 890 | return bfd_section_from_elf_index (sec->owner, sym->st_shndx); |
| 891 | |
| 892 | return NULL; |
| 893 | } |
| 894 | |
| 895 | /* Update the got entry reference counts for the section being removed. */ |
| 896 | |
| 897 | static boolean |
| 898 | elf64_x86_64_gc_sweep_hook (abfd, info, sec, relocs) |
| 899 | bfd *abfd; |
| 900 | struct bfd_link_info *info; |
| 901 | asection *sec; |
| 902 | const Elf_Internal_Rela *relocs; |
| 903 | { |
| 904 | Elf_Internal_Shdr *symtab_hdr; |
| 905 | struct elf_link_hash_entry **sym_hashes; |
| 906 | bfd_signed_vma *local_got_refcounts; |
| 907 | const Elf_Internal_Rela *rel, *relend; |
| 908 | unsigned long r_symndx; |
| 909 | struct elf_link_hash_entry *h; |
| 910 | |
| 911 | elf_section_data (sec)->local_dynrel = NULL; |
| 912 | |
| 913 | symtab_hdr = &elf_tdata (abfd)->symtab_hdr; |
| 914 | sym_hashes = elf_sym_hashes (abfd); |
| 915 | local_got_refcounts = elf_local_got_refcounts (abfd); |
| 916 | |
| 917 | relend = relocs + sec->reloc_count; |
| 918 | for (rel = relocs; rel < relend; rel++) |
| 919 | switch (ELF64_R_TYPE (rel->r_info)) |
| 920 | { |
| 921 | case R_X86_64_GOT32: |
| 922 | case R_X86_64_GOTPCREL: |
| 923 | r_symndx = ELF64_R_SYM (rel->r_info); |
| 924 | if (r_symndx >= symtab_hdr->sh_info) |
| 925 | { |
| 926 | h = sym_hashes[r_symndx - symtab_hdr->sh_info]; |
| 927 | if (h->got.refcount > 0) |
| 928 | h->got.refcount -= 1; |
| 929 | } |
| 930 | else if (local_got_refcounts != NULL) |
| 931 | { |
| 932 | if (local_got_refcounts[r_symndx] > 0) |
| 933 | local_got_refcounts[r_symndx] -= 1; |
| 934 | } |
| 935 | break; |
| 936 | |
| 937 | case R_X86_64_8: |
| 938 | case R_X86_64_16: |
| 939 | case R_X86_64_32: |
| 940 | case R_X86_64_64: |
| 941 | case R_X86_64_32S: |
| 942 | case R_X86_64_PC8: |
| 943 | case R_X86_64_PC16: |
| 944 | case R_X86_64_PC32: |
| 945 | r_symndx = ELF64_R_SYM (rel->r_info); |
| 946 | if (r_symndx >= symtab_hdr->sh_info) |
| 947 | { |
| 948 | struct elf64_x86_64_link_hash_entry *eh; |
| 949 | struct elf64_x86_64_dyn_relocs **pp; |
| 950 | struct elf64_x86_64_dyn_relocs *p; |
| 951 | |
| 952 | h = sym_hashes[r_symndx - symtab_hdr->sh_info]; |
| 953 | |
| 954 | if (!info->shared && h->plt.refcount > 0) |
| 955 | h->plt.refcount -= 1; |
| 956 | |
| 957 | eh = (struct elf64_x86_64_link_hash_entry *) h; |
| 958 | |
| 959 | for (pp = &eh->dyn_relocs; (p = *pp) != NULL; pp = &p->next) |
| 960 | if (p->sec == sec) |
| 961 | { |
| 962 | if (ELF64_R_TYPE (rel->r_info) == R_X86_64_PC8 |
| 963 | || ELF64_R_TYPE (rel->r_info) == R_X86_64_PC16 |
| 964 | || ELF64_R_TYPE (rel->r_info) == R_X86_64_PC32) |
| 965 | p->pc_count -= 1; |
| 966 | p->count -= 1; |
| 967 | if (p->count == 0) |
| 968 | *pp = p->next; |
| 969 | break; |
| 970 | } |
| 971 | } |
| 972 | break; |
| 973 | |
| 974 | |
| 975 | case R_X86_64_PLT32: |
| 976 | r_symndx = ELF64_R_SYM (rel->r_info); |
| 977 | if (r_symndx >= symtab_hdr->sh_info) |
| 978 | { |
| 979 | h = sym_hashes[r_symndx - symtab_hdr->sh_info]; |
| 980 | if (h->plt.refcount > 0) |
| 981 | h->plt.refcount -= 1; |
| 982 | } |
| 983 | break; |
| 984 | |
| 985 | default: |
| 986 | break; |
| 987 | } |
| 988 | |
| 989 | return true; |
| 990 | } |
| 991 | |
| 992 | /* Adjust a symbol defined by a dynamic object and referenced by a |
| 993 | regular object. The current definition is in some section of the |
| 994 | dynamic object, but we're not including those sections. We have to |
| 995 | change the definition to something the rest of the link can |
| 996 | understand. */ |
| 997 | |
| 998 | static boolean |
| 999 | elf64_x86_64_adjust_dynamic_symbol (info, h) |
| 1000 | struct bfd_link_info *info; |
| 1001 | struct elf_link_hash_entry *h; |
| 1002 | { |
| 1003 | struct elf64_x86_64_link_hash_table *htab; |
| 1004 | struct elf64_x86_64_link_hash_entry * eh; |
| 1005 | struct elf64_x86_64_dyn_relocs *p; |
| 1006 | asection *s; |
| 1007 | unsigned int power_of_two; |
| 1008 | |
| 1009 | /* If this is a function, put it in the procedure linkage table. We |
| 1010 | will fill in the contents of the procedure linkage table later, |
| 1011 | when we know the address of the .got section. */ |
| 1012 | if (h->type == STT_FUNC |
| 1013 | || (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0) |
| 1014 | { |
| 1015 | if (h->plt.refcount <= 0 |
| 1016 | || (! info->shared |
| 1017 | && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0 |
| 1018 | && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) == 0 |
| 1019 | && h->root.type != bfd_link_hash_undefweak |
| 1020 | && h->root.type != bfd_link_hash_undefined)) |
| 1021 | { |
| 1022 | /* This case can occur if we saw a PLT32 reloc in an input |
| 1023 | file, but the symbol was never referred to by a dynamic |
| 1024 | object, or if all references were garbage collected. In |
| 1025 | such a case, we don't actually need to build a procedure |
| 1026 | linkage table, and we can just do a PC32 reloc instead. */ |
| 1027 | h->plt.offset = (bfd_vma) -1; |
| 1028 | h->elf_link_hash_flags &= ~ELF_LINK_HASH_NEEDS_PLT; |
| 1029 | } |
| 1030 | |
| 1031 | return true; |
| 1032 | } |
| 1033 | else |
| 1034 | /* It's possible that we incorrectly decided a .plt reloc was |
| 1035 | needed for an R_X86_64_PC32 reloc to a non-function sym in |
| 1036 | check_relocs. We can't decide accurately between function and |
| 1037 | non-function syms in check-relocs; Objects loaded later in |
| 1038 | the link may change h->type. So fix it now. */ |
| 1039 | h->plt.offset = (bfd_vma) -1; |
| 1040 | |
| 1041 | /* If this is a weak symbol, and there is a real definition, the |
| 1042 | processor independent code will have arranged for us to see the |
| 1043 | real definition first, and we can just use the same value. */ |
| 1044 | if (h->weakdef != NULL) |
| 1045 | { |
| 1046 | BFD_ASSERT (h->weakdef->root.type == bfd_link_hash_defined |
| 1047 | || h->weakdef->root.type == bfd_link_hash_defweak); |
| 1048 | h->root.u.def.section = h->weakdef->root.u.def.section; |
| 1049 | h->root.u.def.value = h->weakdef->root.u.def.value; |
| 1050 | return true; |
| 1051 | } |
| 1052 | |
| 1053 | /* This is a reference to a symbol defined by a dynamic object which |
| 1054 | is not a function. */ |
| 1055 | |
| 1056 | /* If we are creating a shared library, we must presume that the |
| 1057 | only references to the symbol are via the global offset table. |
| 1058 | For such cases we need not do anything here; the relocations will |
| 1059 | be handled correctly by relocate_section. */ |
| 1060 | if (info->shared) |
| 1061 | return true; |
| 1062 | |
| 1063 | /* If there are no references to this symbol that do not use the |
| 1064 | GOT, we don't need to generate a copy reloc. */ |
| 1065 | if ((h->elf_link_hash_flags & ELF_LINK_NON_GOT_REF) == 0) |
| 1066 | return true; |
| 1067 | |
| 1068 | /* If -z nocopyreloc was given, we won't generate them either. */ |
| 1069 | if (info->nocopyreloc) |
| 1070 | { |
| 1071 | h->elf_link_hash_flags &= ~ELF_LINK_NON_GOT_REF; |
| 1072 | return true; |
| 1073 | } |
| 1074 | |
| 1075 | eh = (struct elf64_x86_64_link_hash_entry *) h; |
| 1076 | for (p = eh->dyn_relocs; p != NULL; p = p->next) |
| 1077 | { |
| 1078 | s = p->sec->output_section; |
| 1079 | if (s != NULL && (s->flags & SEC_READONLY) != 0) |
| 1080 | break; |
| 1081 | } |
| 1082 | |
| 1083 | /* If we didn't find any dynamic relocs in read-only sections, then |
| 1084 | we'll be keeping the dynamic relocs and avoiding the copy reloc. */ |
| 1085 | if (p == NULL) |
| 1086 | { |
| 1087 | h->elf_link_hash_flags &= ~ELF_LINK_NON_GOT_REF; |
| 1088 | return true; |
| 1089 | } |
| 1090 | |
| 1091 | /* We must allocate the symbol in our .dynbss section, which will |
| 1092 | become part of the .bss section of the executable. There will be |
| 1093 | an entry for this symbol in the .dynsym section. The dynamic |
| 1094 | object will contain position independent code, so all references |
| 1095 | from the dynamic object to this symbol will go through the global |
| 1096 | offset table. The dynamic linker will use the .dynsym entry to |
| 1097 | determine the address it must put in the global offset table, so |
| 1098 | both the dynamic object and the regular object will refer to the |
| 1099 | same memory location for the variable. */ |
| 1100 | |
| 1101 | htab = elf64_x86_64_hash_table (info); |
| 1102 | |
| 1103 | /* We must generate a R_X86_64_COPY reloc to tell the dynamic linker |
| 1104 | to copy the initial value out of the dynamic object and into the |
| 1105 | runtime process image. */ |
| 1106 | if ((h->root.u.def.section->flags & SEC_ALLOC) != 0) |
| 1107 | { |
| 1108 | htab->srelbss->_raw_size += sizeof (Elf64_External_Rela); |
| 1109 | h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_COPY; |
| 1110 | } |
| 1111 | |
| 1112 | /* We need to figure out the alignment required for this symbol. I |
| 1113 | have no idea how ELF linkers handle this. 16-bytes is the size |
| 1114 | of the largest type that requires hard alignment -- long double. */ |
| 1115 | /* FIXME: This is VERY ugly. Should be fixed for all architectures using |
| 1116 | this construct. */ |
| 1117 | power_of_two = bfd_log2 (h->size); |
| 1118 | if (power_of_two > 4) |
| 1119 | power_of_two = 4; |
| 1120 | |
| 1121 | /* Apply the required alignment. */ |
| 1122 | s = htab->sdynbss; |
| 1123 | s->_raw_size = BFD_ALIGN (s->_raw_size, (bfd_size_type) (1 << power_of_two)); |
| 1124 | if (power_of_two > bfd_get_section_alignment (htab->elf.dynobj, s)) |
| 1125 | { |
| 1126 | if (! bfd_set_section_alignment (htab->elf.dynobj, s, power_of_two)) |
| 1127 | return false; |
| 1128 | } |
| 1129 | |
| 1130 | /* Define the symbol as being at this point in the section. */ |
| 1131 | h->root.u.def.section = s; |
| 1132 | h->root.u.def.value = s->_raw_size; |
| 1133 | |
| 1134 | /* Increment the section size to make room for the symbol. */ |
| 1135 | s->_raw_size += h->size; |
| 1136 | |
| 1137 | return true; |
| 1138 | } |
| 1139 | |
| 1140 | /* This is the condition under which elf64_x86_64_finish_dynamic_symbol |
| 1141 | will be called from elflink.h. If elflink.h doesn't call our |
| 1142 | finish_dynamic_symbol routine, we'll need to do something about |
| 1143 | initializing any .plt and .got entries in elf64_x86_64_relocate_section. */ |
| 1144 | #define WILL_CALL_FINISH_DYNAMIC_SYMBOL(DYN, INFO, H) \ |
| 1145 | ((DYN) \ |
| 1146 | && ((INFO)->shared \ |
| 1147 | || ((H)->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0) \ |
| 1148 | && ((H)->dynindx != -1 \ |
| 1149 | || ((H)->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)) |
| 1150 | |
| 1151 | /* Allocate space in .plt, .got and associated reloc sections for |
| 1152 | dynamic relocs. */ |
| 1153 | |
| 1154 | static boolean |
| 1155 | allocate_dynrelocs (h, inf) |
| 1156 | struct elf_link_hash_entry *h; |
| 1157 | PTR inf; |
| 1158 | { |
| 1159 | struct bfd_link_info *info; |
| 1160 | struct elf64_x86_64_link_hash_table *htab; |
| 1161 | struct elf64_x86_64_link_hash_entry *eh; |
| 1162 | struct elf64_x86_64_dyn_relocs *p; |
| 1163 | |
| 1164 | if (h->root.type == bfd_link_hash_indirect) |
| 1165 | return true; |
| 1166 | |
| 1167 | if (h->root.type == bfd_link_hash_warning) |
| 1168 | h = (struct elf_link_hash_entry *) h->root.u.i.link; |
| 1169 | |
| 1170 | info = (struct bfd_link_info *) inf; |
| 1171 | htab = elf64_x86_64_hash_table (info); |
| 1172 | |
| 1173 | if (htab->elf.dynamic_sections_created |
| 1174 | && h->plt.refcount > 0) |
| 1175 | { |
| 1176 | /* Make sure this symbol is output as a dynamic symbol. |
| 1177 | Undefined weak syms won't yet be marked as dynamic. */ |
| 1178 | if (h->dynindx == -1 |
| 1179 | && (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0) |
| 1180 | { |
| 1181 | if (! bfd_elf64_link_record_dynamic_symbol (info, h)) |
| 1182 | return false; |
| 1183 | } |
| 1184 | |
| 1185 | if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, info, h)) |
| 1186 | { |
| 1187 | asection *s = htab->splt; |
| 1188 | |
| 1189 | /* If this is the first .plt entry, make room for the special |
| 1190 | first entry. */ |
| 1191 | if (s->_raw_size == 0) |
| 1192 | s->_raw_size += PLT_ENTRY_SIZE; |
| 1193 | |
| 1194 | h->plt.offset = s->_raw_size; |
| 1195 | |
| 1196 | /* If this symbol is not defined in a regular file, and we are |
| 1197 | not generating a shared library, then set the symbol to this |
| 1198 | location in the .plt. This is required to make function |
| 1199 | pointers compare as equal between the normal executable and |
| 1200 | the shared library. */ |
| 1201 | if (! info->shared |
| 1202 | && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) |
| 1203 | { |
| 1204 | h->root.u.def.section = s; |
| 1205 | h->root.u.def.value = h->plt.offset; |
| 1206 | } |
| 1207 | |
| 1208 | /* Make room for this entry. */ |
| 1209 | s->_raw_size += PLT_ENTRY_SIZE; |
| 1210 | |
| 1211 | /* We also need to make an entry in the .got.plt section, which |
| 1212 | will be placed in the .got section by the linker script. */ |
| 1213 | htab->sgotplt->_raw_size += GOT_ENTRY_SIZE; |
| 1214 | |
| 1215 | /* We also need to make an entry in the .rela.plt section. */ |
| 1216 | htab->srelplt->_raw_size += sizeof (Elf64_External_Rela); |
| 1217 | } |
| 1218 | else |
| 1219 | { |
| 1220 | h->plt.offset = (bfd_vma) -1; |
| 1221 | h->elf_link_hash_flags &= ~ELF_LINK_HASH_NEEDS_PLT; |
| 1222 | } |
| 1223 | } |
| 1224 | else |
| 1225 | { |
| 1226 | h->plt.offset = (bfd_vma) -1; |
| 1227 | h->elf_link_hash_flags &= ~ELF_LINK_HASH_NEEDS_PLT; |
| 1228 | } |
| 1229 | |
| 1230 | if (h->got.refcount > 0) |
| 1231 | { |
| 1232 | asection *s; |
| 1233 | boolean dyn; |
| 1234 | |
| 1235 | /* Make sure this symbol is output as a dynamic symbol. |
| 1236 | Undefined weak syms won't yet be marked as dynamic. */ |
| 1237 | if (h->dynindx == -1 |
| 1238 | && (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0) |
| 1239 | { |
| 1240 | if (! bfd_elf64_link_record_dynamic_symbol (info, h)) |
| 1241 | return false; |
| 1242 | } |
| 1243 | |
| 1244 | s = htab->sgot; |
| 1245 | h->got.offset = s->_raw_size; |
| 1246 | s->_raw_size += GOT_ENTRY_SIZE; |
| 1247 | dyn = htab->elf.dynamic_sections_created; |
| 1248 | if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info, h)) |
| 1249 | htab->srelgot->_raw_size += sizeof (Elf64_External_Rela); |
| 1250 | } |
| 1251 | else |
| 1252 | h->got.offset = (bfd_vma) -1; |
| 1253 | |
| 1254 | eh = (struct elf64_x86_64_link_hash_entry *) h; |
| 1255 | if (eh->dyn_relocs == NULL) |
| 1256 | return true; |
| 1257 | |
| 1258 | /* In the shared -Bsymbolic case, discard space allocated for |
| 1259 | dynamic pc-relative relocs against symbols which turn out to be |
| 1260 | defined in regular objects. For the normal shared case, discard |
| 1261 | space for pc-relative relocs that have become local due to symbol |
| 1262 | visibility changes. */ |
| 1263 | |
| 1264 | if (info->shared) |
| 1265 | { |
| 1266 | if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0 |
| 1267 | && ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0 |
| 1268 | || info->symbolic)) |
| 1269 | { |
| 1270 | struct elf64_x86_64_dyn_relocs **pp; |
| 1271 | |
| 1272 | for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) |
| 1273 | { |
| 1274 | p->count -= p->pc_count; |
| 1275 | p->pc_count = 0; |
| 1276 | if (p->count == 0) |
| 1277 | *pp = p->next; |
| 1278 | else |
| 1279 | pp = &p->next; |
| 1280 | } |
| 1281 | } |
| 1282 | } |
| 1283 | else |
| 1284 | { |
| 1285 | /* For the non-shared case, discard space for relocs against |
| 1286 | symbols which turn out to need copy relocs or are not |
| 1287 | dynamic. */ |
| 1288 | |
| 1289 | if ((h->elf_link_hash_flags & ELF_LINK_NON_GOT_REF) == 0 |
| 1290 | && (((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 |
| 1291 | && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) |
| 1292 | || (htab->elf.dynamic_sections_created |
| 1293 | && (h->root.type == bfd_link_hash_undefweak |
| 1294 | || h->root.type == bfd_link_hash_undefined)))) |
| 1295 | { |
| 1296 | /* Make sure this symbol is output as a dynamic symbol. |
| 1297 | Undefined weak syms won't yet be marked as dynamic. */ |
| 1298 | if (h->dynindx == -1 |
| 1299 | && (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0) |
| 1300 | { |
| 1301 | if (! bfd_elf64_link_record_dynamic_symbol (info, h)) |
| 1302 | return false; |
| 1303 | } |
| 1304 | |
| 1305 | /* If that succeeded, we know we'll be keeping all the |
| 1306 | relocs. */ |
| 1307 | if (h->dynindx != -1) |
| 1308 | goto keep; |
| 1309 | } |
| 1310 | |
| 1311 | eh->dyn_relocs = NULL; |
| 1312 | |
| 1313 | keep: ; |
| 1314 | } |
| 1315 | |
| 1316 | /* Finally, allocate space. */ |
| 1317 | for (p = eh->dyn_relocs; p != NULL; p = p->next) |
| 1318 | { |
| 1319 | asection *sreloc = elf_section_data (p->sec)->sreloc; |
| 1320 | sreloc->_raw_size += p->count * sizeof (Elf64_External_Rela); |
| 1321 | } |
| 1322 | |
| 1323 | return true; |
| 1324 | } |
| 1325 | |
| 1326 | /* Find any dynamic relocs that apply to read-only sections. */ |
| 1327 | |
| 1328 | static boolean |
| 1329 | readonly_dynrelocs (h, inf) |
| 1330 | struct elf_link_hash_entry *h; |
| 1331 | PTR inf; |
| 1332 | { |
| 1333 | struct elf64_x86_64_link_hash_entry *eh; |
| 1334 | struct elf64_x86_64_dyn_relocs *p; |
| 1335 | |
| 1336 | if (h->root.type == bfd_link_hash_warning) |
| 1337 | h = (struct elf_link_hash_entry *) h->root.u.i.link; |
| 1338 | |
| 1339 | eh = (struct elf64_x86_64_link_hash_entry *) h; |
| 1340 | for (p = eh->dyn_relocs; p != NULL; p = p->next) |
| 1341 | { |
| 1342 | asection *s = p->sec->output_section; |
| 1343 | |
| 1344 | if (s != NULL && (s->flags & SEC_READONLY) != 0) |
| 1345 | { |
| 1346 | struct bfd_link_info *info = (struct bfd_link_info *) inf; |
| 1347 | |
| 1348 | info->flags |= DF_TEXTREL; |
| 1349 | |
| 1350 | /* Not an error, just cut short the traversal. */ |
| 1351 | return false; |
| 1352 | } |
| 1353 | } |
| 1354 | return true; |
| 1355 | } |
| 1356 | |
| 1357 | /* Set the sizes of the dynamic sections. */ |
| 1358 | |
| 1359 | static boolean |
| 1360 | elf64_x86_64_size_dynamic_sections (output_bfd, info) |
| 1361 | bfd *output_bfd ATTRIBUTE_UNUSED; |
| 1362 | struct bfd_link_info *info; |
| 1363 | { |
| 1364 | struct elf64_x86_64_link_hash_table *htab; |
| 1365 | bfd *dynobj; |
| 1366 | asection *s; |
| 1367 | boolean relocs; |
| 1368 | bfd *ibfd; |
| 1369 | |
| 1370 | htab = elf64_x86_64_hash_table (info); |
| 1371 | dynobj = htab->elf.dynobj; |
| 1372 | if (dynobj == NULL) |
| 1373 | abort (); |
| 1374 | |
| 1375 | if (htab->elf.dynamic_sections_created) |
| 1376 | { |
| 1377 | /* Set the contents of the .interp section to the interpreter. */ |
| 1378 | if (! info->shared) |
| 1379 | { |
| 1380 | s = bfd_get_section_by_name (dynobj, ".interp"); |
| 1381 | if (s == NULL) |
| 1382 | abort (); |
| 1383 | s->_raw_size = sizeof ELF_DYNAMIC_INTERPRETER; |
| 1384 | s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER; |
| 1385 | } |
| 1386 | } |
| 1387 | |
| 1388 | /* Set up .got offsets for local syms, and space for local dynamic |
| 1389 | relocs. */ |
| 1390 | for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next) |
| 1391 | { |
| 1392 | bfd_signed_vma *local_got; |
| 1393 | bfd_signed_vma *end_local_got; |
| 1394 | bfd_size_type locsymcount; |
| 1395 | Elf_Internal_Shdr *symtab_hdr; |
| 1396 | asection *srel; |
| 1397 | |
| 1398 | if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour) |
| 1399 | continue; |
| 1400 | |
| 1401 | for (s = ibfd->sections; s != NULL; s = s->next) |
| 1402 | { |
| 1403 | struct elf64_x86_64_dyn_relocs *p; |
| 1404 | |
| 1405 | for (p = *((struct elf64_x86_64_dyn_relocs **) |
| 1406 | &elf_section_data (s)->local_dynrel); |
| 1407 | p != NULL; |
| 1408 | p = p->next) |
| 1409 | { |
| 1410 | if (!bfd_is_abs_section (p->sec) |
| 1411 | && bfd_is_abs_section (p->sec->output_section)) |
| 1412 | { |
| 1413 | /* Input section has been discarded, either because |
| 1414 | it is a copy of a linkonce section or due to |
| 1415 | linker script /DISCARD/, so we'll be discarding |
| 1416 | the relocs too. */ |
| 1417 | } |
| 1418 | else if (p->count != 0) |
| 1419 | { |
| 1420 | srel = elf_section_data (p->sec)->sreloc; |
| 1421 | srel->_raw_size += p->count * sizeof (Elf64_External_Rela); |
| 1422 | if ((p->sec->output_section->flags & SEC_READONLY) != 0) |
| 1423 | info->flags |= DF_TEXTREL; |
| 1424 | |
| 1425 | } |
| 1426 | } |
| 1427 | } |
| 1428 | |
| 1429 | local_got = elf_local_got_refcounts (ibfd); |
| 1430 | if (!local_got) |
| 1431 | continue; |
| 1432 | |
| 1433 | symtab_hdr = &elf_tdata (ibfd)->symtab_hdr; |
| 1434 | locsymcount = symtab_hdr->sh_info; |
| 1435 | end_local_got = local_got + locsymcount; |
| 1436 | s = htab->sgot; |
| 1437 | srel = htab->srelgot; |
| 1438 | for (; local_got < end_local_got; ++local_got) |
| 1439 | { |
| 1440 | if (*local_got > 0) |
| 1441 | { |
| 1442 | *local_got = s->_raw_size; |
| 1443 | s->_raw_size += GOT_ENTRY_SIZE; |
| 1444 | if (info->shared) |
| 1445 | srel->_raw_size += sizeof (Elf64_External_Rela); |
| 1446 | } |
| 1447 | else |
| 1448 | *local_got = (bfd_vma) -1; |
| 1449 | } |
| 1450 | } |
| 1451 | |
| 1452 | /* Allocate global sym .plt and .got entries, and space for global |
| 1453 | sym dynamic relocs. */ |
| 1454 | elf_link_hash_traverse (&htab->elf, allocate_dynrelocs, (PTR) info); |
| 1455 | |
| 1456 | /* We now have determined the sizes of the various dynamic sections. |
| 1457 | Allocate memory for them. */ |
| 1458 | relocs = false; |
| 1459 | for (s = dynobj->sections; s != NULL; s = s->next) |
| 1460 | { |
| 1461 | if ((s->flags & SEC_LINKER_CREATED) == 0) |
| 1462 | continue; |
| 1463 | |
| 1464 | if (s == htab->splt |
| 1465 | || s == htab->sgot |
| 1466 | || s == htab->sgotplt) |
| 1467 | { |
| 1468 | /* Strip this section if we don't need it; see the |
| 1469 | comment below. */ |
| 1470 | } |
| 1471 | else if (strncmp (bfd_get_section_name (dynobj, s), ".rela", 5) == 0) |
| 1472 | { |
| 1473 | if (s->_raw_size != 0 && s != htab->srelplt) |
| 1474 | relocs = true; |
| 1475 | |
| 1476 | /* We use the reloc_count field as a counter if we need |
| 1477 | to copy relocs into the output file. */ |
| 1478 | s->reloc_count = 0; |
| 1479 | } |
| 1480 | else |
| 1481 | { |
| 1482 | /* It's not one of our sections, so don't allocate space. */ |
| 1483 | continue; |
| 1484 | } |
| 1485 | |
| 1486 | if (s->_raw_size == 0) |
| 1487 | { |
| 1488 | /* If we don't need this section, strip it from the |
| 1489 | output file. This is mostly to handle .rela.bss and |
| 1490 | .rela.plt. We must create both sections in |
| 1491 | create_dynamic_sections, because they must be created |
| 1492 | before the linker maps input sections to output |
| 1493 | sections. The linker does that before |
| 1494 | adjust_dynamic_symbol is called, and it is that |
| 1495 | function which decides whether anything needs to go |
| 1496 | into these sections. */ |
| 1497 | |
| 1498 | _bfd_strip_section_from_output (info, s); |
| 1499 | continue; |
| 1500 | } |
| 1501 | |
| 1502 | /* Allocate memory for the section contents. We use bfd_zalloc |
| 1503 | here in case unused entries are not reclaimed before the |
| 1504 | section's contents are written out. This should not happen, |
| 1505 | but this way if it does, we get a R_X86_64_NONE reloc instead |
| 1506 | of garbage. */ |
| 1507 | s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->_raw_size); |
| 1508 | if (s->contents == NULL) |
| 1509 | return false; |
| 1510 | } |
| 1511 | |
| 1512 | if (htab->elf.dynamic_sections_created) |
| 1513 | { |
| 1514 | /* Add some entries to the .dynamic section. We fill in the |
| 1515 | values later, in elf64_x86_64_finish_dynamic_sections, but we |
| 1516 | must add the entries now so that we get the correct size for |
| 1517 | the .dynamic section. The DT_DEBUG entry is filled in by the |
| 1518 | dynamic linker and used by the debugger. */ |
| 1519 | #define add_dynamic_entry(TAG, VAL) \ |
| 1520 | bfd_elf64_add_dynamic_entry (info, (bfd_vma) (TAG), (bfd_vma) (VAL)) |
| 1521 | |
| 1522 | if (! info->shared) |
| 1523 | { |
| 1524 | if (!add_dynamic_entry (DT_DEBUG, 0)) |
| 1525 | return false; |
| 1526 | } |
| 1527 | |
| 1528 | if (htab->splt->_raw_size != 0) |
| 1529 | { |
| 1530 | if (!add_dynamic_entry (DT_PLTGOT, 0) |
| 1531 | || !add_dynamic_entry (DT_PLTRELSZ, 0) |
| 1532 | || !add_dynamic_entry (DT_PLTREL, DT_RELA) |
| 1533 | || !add_dynamic_entry (DT_JMPREL, 0)) |
| 1534 | return false; |
| 1535 | } |
| 1536 | |
| 1537 | if (relocs) |
| 1538 | { |
| 1539 | if (!add_dynamic_entry (DT_RELA, 0) |
| 1540 | || !add_dynamic_entry (DT_RELASZ, 0) |
| 1541 | || !add_dynamic_entry (DT_RELAENT, sizeof (Elf64_External_Rela))) |
| 1542 | return false; |
| 1543 | |
| 1544 | /* If any dynamic relocs apply to a read-only section, |
| 1545 | then we need a DT_TEXTREL entry. */ |
| 1546 | if ((info->flags & DF_TEXTREL) == 0) |
| 1547 | elf_link_hash_traverse (&htab->elf, readonly_dynrelocs, |
| 1548 | (PTR) info); |
| 1549 | |
| 1550 | if ((info->flags & DF_TEXTREL) != 0) |
| 1551 | { |
| 1552 | if (!add_dynamic_entry (DT_TEXTREL, 0)) |
| 1553 | return false; |
| 1554 | } |
| 1555 | } |
| 1556 | } |
| 1557 | #undef add_dynamic_entry |
| 1558 | |
| 1559 | return true; |
| 1560 | } |
| 1561 | |
| 1562 | /* Relocate an x86_64 ELF section. */ |
| 1563 | |
| 1564 | static boolean |
| 1565 | elf64_x86_64_relocate_section (output_bfd, info, input_bfd, input_section, |
| 1566 | contents, relocs, local_syms, local_sections) |
| 1567 | bfd *output_bfd; |
| 1568 | struct bfd_link_info *info; |
| 1569 | bfd *input_bfd; |
| 1570 | asection *input_section; |
| 1571 | bfd_byte *contents; |
| 1572 | Elf_Internal_Rela *relocs; |
| 1573 | Elf_Internal_Sym *local_syms; |
| 1574 | asection **local_sections; |
| 1575 | { |
| 1576 | struct elf64_x86_64_link_hash_table *htab; |
| 1577 | Elf_Internal_Shdr *symtab_hdr; |
| 1578 | struct elf_link_hash_entry **sym_hashes; |
| 1579 | bfd_vma *local_got_offsets; |
| 1580 | Elf_Internal_Rela *rel; |
| 1581 | Elf_Internal_Rela *relend; |
| 1582 | |
| 1583 | if (info->relocateable) |
| 1584 | return true; |
| 1585 | |
| 1586 | htab = elf64_x86_64_hash_table (info); |
| 1587 | symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr; |
| 1588 | sym_hashes = elf_sym_hashes (input_bfd); |
| 1589 | local_got_offsets = elf_local_got_offsets (input_bfd); |
| 1590 | |
| 1591 | rel = relocs; |
| 1592 | relend = relocs + input_section->reloc_count; |
| 1593 | for (; rel < relend; rel++) |
| 1594 | { |
| 1595 | int r_type; |
| 1596 | reloc_howto_type *howto; |
| 1597 | unsigned long r_symndx; |
| 1598 | struct elf_link_hash_entry *h; |
| 1599 | Elf_Internal_Sym *sym; |
| 1600 | asection *sec; |
| 1601 | bfd_vma off; |
| 1602 | bfd_vma relocation; |
| 1603 | boolean unresolved_reloc; |
| 1604 | bfd_reloc_status_type r; |
| 1605 | |
| 1606 | r_type = ELF64_R_TYPE (rel->r_info); |
| 1607 | if (r_type == (int) R_X86_64_GNU_VTINHERIT |
| 1608 | || r_type == (int) R_X86_64_GNU_VTENTRY) |
| 1609 | continue; |
| 1610 | |
| 1611 | if (r_type < 0 || r_type >= R_X86_64_max) |
| 1612 | { |
| 1613 | bfd_set_error (bfd_error_bad_value); |
| 1614 | return false; |
| 1615 | } |
| 1616 | |
| 1617 | howto = x86_64_elf_howto_table + r_type; |
| 1618 | r_symndx = ELF64_R_SYM (rel->r_info); |
| 1619 | h = NULL; |
| 1620 | sym = NULL; |
| 1621 | sec = NULL; |
| 1622 | unresolved_reloc = false; |
| 1623 | if (r_symndx < symtab_hdr->sh_info) |
| 1624 | { |
| 1625 | sym = local_syms + r_symndx; |
| 1626 | sec = local_sections[r_symndx]; |
| 1627 | |
| 1628 | relocation = _bfd_elf_rela_local_sym (output_bfd, sym, sec, rel); |
| 1629 | } |
| 1630 | else |
| 1631 | { |
| 1632 | h = sym_hashes[r_symndx - symtab_hdr->sh_info]; |
| 1633 | while (h->root.type == bfd_link_hash_indirect |
| 1634 | || h->root.type == bfd_link_hash_warning) |
| 1635 | h = (struct elf_link_hash_entry *) h->root.u.i.link; |
| 1636 | |
| 1637 | if (h->root.type == bfd_link_hash_defined |
| 1638 | || h->root.type == bfd_link_hash_defweak) |
| 1639 | { |
| 1640 | sec = h->root.u.def.section; |
| 1641 | if (sec->output_section == NULL) |
| 1642 | { |
| 1643 | /* Set a flag that will be cleared later if we find a |
| 1644 | relocation value for this symbol. output_section |
| 1645 | is typically NULL for symbols satisfied by a shared |
| 1646 | library. */ |
| 1647 | unresolved_reloc = true; |
| 1648 | relocation = 0; |
| 1649 | } |
| 1650 | else |
| 1651 | relocation = (h->root.u.def.value |
| 1652 | + sec->output_section->vma |
| 1653 | + sec->output_offset); |
| 1654 | } |
| 1655 | else if (h->root.type == bfd_link_hash_undefweak) |
| 1656 | relocation = 0; |
| 1657 | else if (info->shared |
| 1658 | && (!info->symbolic || info->allow_shlib_undefined) |
| 1659 | && !info->no_undefined |
| 1660 | && ELF_ST_VISIBILITY (h->other) == STV_DEFAULT) |
| 1661 | relocation = 0; |
| 1662 | else |
| 1663 | { |
| 1664 | if (! ((*info->callbacks->undefined_symbol) |
| 1665 | (info, h->root.root.string, input_bfd, |
| 1666 | input_section, rel->r_offset, |
| 1667 | (!info->shared || info->no_undefined |
| 1668 | || ELF_ST_VISIBILITY (h->other))))) |
| 1669 | return false; |
| 1670 | relocation = 0; |
| 1671 | } |
| 1672 | } |
| 1673 | /* When generating a shared object, the relocations handled here are |
| 1674 | copied into the output file to be resolved at run time. */ |
| 1675 | switch (r_type) |
| 1676 | { |
| 1677 | case R_X86_64_GOT32: |
| 1678 | /* Relocation is to the entry for this symbol in the global |
| 1679 | offset table. */ |
| 1680 | case R_X86_64_GOTPCREL: |
| 1681 | /* Use global offset table as symbol value. */ |
| 1682 | if (htab->sgot == NULL) |
| 1683 | abort (); |
| 1684 | |
| 1685 | if (h != NULL) |
| 1686 | { |
| 1687 | boolean dyn; |
| 1688 | |
| 1689 | off = h->got.offset; |
| 1690 | dyn = htab->elf.dynamic_sections_created; |
| 1691 | |
| 1692 | if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info, h) |
| 1693 | || (info->shared |
| 1694 | && (info->symbolic |
| 1695 | || h->dynindx == -1 |
| 1696 | || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL)) |
| 1697 | && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))) |
| 1698 | { |
| 1699 | /* This is actually a static link, or it is a -Bsymbolic |
| 1700 | link and the symbol is defined locally, or the symbol |
| 1701 | was forced to be local because of a version file. We |
| 1702 | must initialize this entry in the global offset table. |
| 1703 | Since the offset must always be a multiple of 8, we |
| 1704 | use the least significant bit to record whether we |
| 1705 | have initialized it already. |
| 1706 | |
| 1707 | When doing a dynamic link, we create a .rela.got |
| 1708 | relocation entry to initialize the value. This is |
| 1709 | done in the finish_dynamic_symbol routine. */ |
| 1710 | if ((off & 1) != 0) |
| 1711 | off &= ~1; |
| 1712 | else |
| 1713 | { |
| 1714 | bfd_put_64 (output_bfd, relocation, |
| 1715 | htab->sgot->contents + off); |
| 1716 | h->got.offset |= 1; |
| 1717 | } |
| 1718 | } |
| 1719 | else |
| 1720 | unresolved_reloc = false; |
| 1721 | } |
| 1722 | else |
| 1723 | { |
| 1724 | if (local_got_offsets == NULL) |
| 1725 | abort (); |
| 1726 | |
| 1727 | off = local_got_offsets[r_symndx]; |
| 1728 | |
| 1729 | /* The offset must always be a multiple of 8. We use |
| 1730 | the least significant bit to record whether we have |
| 1731 | already generated the necessary reloc. */ |
| 1732 | if ((off & 1) != 0) |
| 1733 | off &= ~1; |
| 1734 | else |
| 1735 | { |
| 1736 | bfd_put_64 (output_bfd, relocation, |
| 1737 | htab->sgot->contents + off); |
| 1738 | |
| 1739 | if (info->shared) |
| 1740 | { |
| 1741 | asection *srelgot; |
| 1742 | Elf_Internal_Rela outrel; |
| 1743 | Elf64_External_Rela *loc; |
| 1744 | |
| 1745 | /* We need to generate a R_X86_64_RELATIVE reloc |
| 1746 | for the dynamic linker. */ |
| 1747 | srelgot = htab->srelgot; |
| 1748 | if (srelgot == NULL) |
| 1749 | abort (); |
| 1750 | |
| 1751 | outrel.r_offset = (htab->sgot->output_section->vma |
| 1752 | + htab->sgot->output_offset |
| 1753 | + off); |
| 1754 | outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE); |
| 1755 | outrel.r_addend = relocation; |
| 1756 | loc = (Elf64_External_Rela *) srelgot->contents; |
| 1757 | loc += srelgot->reloc_count++; |
| 1758 | bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc); |
| 1759 | } |
| 1760 | |
| 1761 | local_got_offsets[r_symndx] |= 1; |
| 1762 | } |
| 1763 | } |
| 1764 | |
| 1765 | if (off >= (bfd_vma) -2) |
| 1766 | abort (); |
| 1767 | |
| 1768 | relocation = htab->sgot->output_offset + off; |
| 1769 | if (r_type == R_X86_64_GOTPCREL) |
| 1770 | relocation += htab->sgot->output_section->vma; |
| 1771 | |
| 1772 | break; |
| 1773 | |
| 1774 | case R_X86_64_PLT32: |
| 1775 | /* Relocation is to the entry for this symbol in the |
| 1776 | procedure linkage table. */ |
| 1777 | |
| 1778 | /* Resolve a PLT32 reloc against a local symbol directly, |
| 1779 | without using the procedure linkage table. */ |
| 1780 | if (h == NULL) |
| 1781 | break; |
| 1782 | |
| 1783 | if (h->plt.offset == (bfd_vma) -1 |
| 1784 | || htab->splt == NULL) |
| 1785 | { |
| 1786 | /* We didn't make a PLT entry for this symbol. This |
| 1787 | happens when statically linking PIC code, or when |
| 1788 | using -Bsymbolic. */ |
| 1789 | break; |
| 1790 | } |
| 1791 | |
| 1792 | relocation = (htab->splt->output_section->vma |
| 1793 | + htab->splt->output_offset |
| 1794 | + h->plt.offset); |
| 1795 | unresolved_reloc = false; |
| 1796 | break; |
| 1797 | |
| 1798 | case R_X86_64_PC8: |
| 1799 | case R_X86_64_PC16: |
| 1800 | case R_X86_64_PC32: |
| 1801 | case R_X86_64_8: |
| 1802 | case R_X86_64_16: |
| 1803 | case R_X86_64_32: |
| 1804 | case R_X86_64_64: |
| 1805 | /* FIXME: The ABI says the linker should make sure the value is |
| 1806 | the same when it's zeroextended to 64 bit. */ |
| 1807 | |
| 1808 | /* r_symndx will be zero only for relocs against symbols |
| 1809 | from removed linkonce sections, or sections discarded by |
| 1810 | a linker script. */ |
| 1811 | if (r_symndx == 0 |
| 1812 | || (input_section->flags & SEC_ALLOC) == 0) |
| 1813 | break; |
| 1814 | |
| 1815 | if ((info->shared |
| 1816 | && ((r_type != R_X86_64_PC8 |
| 1817 | && r_type != R_X86_64_PC16 |
| 1818 | && r_type != R_X86_64_PC32) |
| 1819 | || (h != NULL |
| 1820 | && h->dynindx != -1 |
| 1821 | && (! info->symbolic |
| 1822 | || (h->elf_link_hash_flags |
| 1823 | & ELF_LINK_HASH_DEF_REGULAR) == 0)))) |
| 1824 | || (!info->shared |
| 1825 | && h != NULL |
| 1826 | && h->dynindx != -1 |
| 1827 | && (h->elf_link_hash_flags & ELF_LINK_NON_GOT_REF) == 0 |
| 1828 | && (((h->elf_link_hash_flags |
| 1829 | & ELF_LINK_HASH_DEF_DYNAMIC) != 0 |
| 1830 | && (h->elf_link_hash_flags |
| 1831 | & ELF_LINK_HASH_DEF_REGULAR) == 0) |
| 1832 | || h->root.type == bfd_link_hash_undefweak |
| 1833 | || h->root.type == bfd_link_hash_undefined))) |
| 1834 | { |
| 1835 | Elf_Internal_Rela outrel; |
| 1836 | boolean skip, relocate; |
| 1837 | asection *sreloc; |
| 1838 | Elf64_External_Rela *loc; |
| 1839 | |
| 1840 | /* When generating a shared object, these relocations |
| 1841 | are copied into the output file to be resolved at run |
| 1842 | time. */ |
| 1843 | |
| 1844 | skip = false; |
| 1845 | relocate = false; |
| 1846 | |
| 1847 | outrel.r_offset = |
| 1848 | _bfd_elf_section_offset (output_bfd, info, input_section, |
| 1849 | rel->r_offset); |
| 1850 | if (outrel.r_offset == (bfd_vma) -1) |
| 1851 | skip = true; |
| 1852 | else if (outrel.r_offset == (bfd_vma) -2) |
| 1853 | skip = true, relocate = true; |
| 1854 | |
| 1855 | outrel.r_offset += (input_section->output_section->vma |
| 1856 | + input_section->output_offset); |
| 1857 | |
| 1858 | if (skip) |
| 1859 | memset (&outrel, 0, sizeof outrel); |
| 1860 | |
| 1861 | /* h->dynindx may be -1 if this symbol was marked to |
| 1862 | become local. */ |
| 1863 | else if (h != NULL |
| 1864 | && h->dynindx != -1 |
| 1865 | && (r_type == R_X86_64_PC8 |
| 1866 | || r_type == R_X86_64_PC16 |
| 1867 | || r_type == R_X86_64_PC32 |
| 1868 | || !info->shared |
| 1869 | || !info->symbolic |
| 1870 | || (h->elf_link_hash_flags |
| 1871 | & ELF_LINK_HASH_DEF_REGULAR) == 0)) |
| 1872 | { |
| 1873 | outrel.r_info = ELF64_R_INFO (h->dynindx, r_type); |
| 1874 | outrel.r_addend = rel->r_addend; |
| 1875 | } |
| 1876 | else |
| 1877 | { |
| 1878 | /* This symbol is local, or marked to become local. */ |
| 1879 | relocate = true; |
| 1880 | outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE); |
| 1881 | outrel.r_addend = relocation + rel->r_addend; |
| 1882 | } |
| 1883 | |
| 1884 | sreloc = elf_section_data (input_section)->sreloc; |
| 1885 | if (sreloc == NULL) |
| 1886 | abort (); |
| 1887 | |
| 1888 | loc = (Elf64_External_Rela *) sreloc->contents; |
| 1889 | loc += sreloc->reloc_count++; |
| 1890 | bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc); |
| 1891 | |
| 1892 | /* If this reloc is against an external symbol, we do |
| 1893 | not want to fiddle with the addend. Otherwise, we |
| 1894 | need to include the symbol value so that it becomes |
| 1895 | an addend for the dynamic reloc. */ |
| 1896 | if (! relocate) |
| 1897 | continue; |
| 1898 | } |
| 1899 | |
| 1900 | break; |
| 1901 | |
| 1902 | default: |
| 1903 | break; |
| 1904 | } |
| 1905 | |
| 1906 | /* FIXME: Why do we allow debugging sections to escape this error? |
| 1907 | More importantly, why do we not emit dynamic relocs for |
| 1908 | R_386_32 above in debugging sections (which are ! SEC_ALLOC)? |
| 1909 | If we had emitted the dynamic reloc, we could remove the |
| 1910 | fudge here. */ |
| 1911 | if (unresolved_reloc |
| 1912 | && !(info->shared |
| 1913 | && (input_section->flags & SEC_DEBUGGING) != 0 |
| 1914 | && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0)) |
| 1915 | (*_bfd_error_handler) |
| 1916 | (_("%s(%s+0x%lx): unresolvable relocation against symbol `%s'"), |
| 1917 | bfd_archive_filename (input_bfd), |
| 1918 | bfd_get_section_name (input_bfd, input_section), |
| 1919 | (long) rel->r_offset, |
| 1920 | h->root.root.string); |
| 1921 | |
| 1922 | r = _bfd_final_link_relocate (howto, input_bfd, input_section, |
| 1923 | contents, rel->r_offset, |
| 1924 | relocation, rel->r_addend); |
| 1925 | |
| 1926 | if (r != bfd_reloc_ok) |
| 1927 | { |
| 1928 | const char *name; |
| 1929 | |
| 1930 | if (h != NULL) |
| 1931 | name = h->root.root.string; |
| 1932 | else |
| 1933 | { |
| 1934 | name = bfd_elf_string_from_elf_section (input_bfd, |
| 1935 | symtab_hdr->sh_link, |
| 1936 | sym->st_name); |
| 1937 | if (name == NULL) |
| 1938 | return false; |
| 1939 | if (*name == '\0') |
| 1940 | name = bfd_section_name (input_bfd, sec); |
| 1941 | } |
| 1942 | |
| 1943 | if (r == bfd_reloc_overflow) |
| 1944 | { |
| 1945 | |
| 1946 | if (! ((*info->callbacks->reloc_overflow) |
| 1947 | (info, name, howto->name, (bfd_vma) 0, |
| 1948 | input_bfd, input_section, rel->r_offset))) |
| 1949 | return false; |
| 1950 | } |
| 1951 | else |
| 1952 | { |
| 1953 | (*_bfd_error_handler) |
| 1954 | (_("%s(%s+0x%lx): reloc against `%s': error %d"), |
| 1955 | bfd_archive_filename (input_bfd), |
| 1956 | bfd_get_section_name (input_bfd, input_section), |
| 1957 | (long) rel->r_offset, name, (int) r); |
| 1958 | return false; |
| 1959 | } |
| 1960 | } |
| 1961 | } |
| 1962 | |
| 1963 | return true; |
| 1964 | } |
| 1965 | |
| 1966 | /* Finish up dynamic symbol handling. We set the contents of various |
| 1967 | dynamic sections here. */ |
| 1968 | |
| 1969 | static boolean |
| 1970 | elf64_x86_64_finish_dynamic_symbol (output_bfd, info, h, sym) |
| 1971 | bfd *output_bfd; |
| 1972 | struct bfd_link_info *info; |
| 1973 | struct elf_link_hash_entry *h; |
| 1974 | Elf_Internal_Sym *sym; |
| 1975 | { |
| 1976 | struct elf64_x86_64_link_hash_table *htab; |
| 1977 | |
| 1978 | htab = elf64_x86_64_hash_table (info); |
| 1979 | |
| 1980 | if (h->plt.offset != (bfd_vma) -1) |
| 1981 | { |
| 1982 | bfd_vma plt_index; |
| 1983 | bfd_vma got_offset; |
| 1984 | Elf_Internal_Rela rela; |
| 1985 | Elf64_External_Rela *loc; |
| 1986 | |
| 1987 | /* This symbol has an entry in the procedure linkage table. Set |
| 1988 | it up. */ |
| 1989 | |
| 1990 | if (h->dynindx == -1 |
| 1991 | || htab->splt == NULL |
| 1992 | || htab->sgotplt == NULL |
| 1993 | || htab->srelplt == NULL) |
| 1994 | abort (); |
| 1995 | |
| 1996 | /* Get the index in the procedure linkage table which |
| 1997 | corresponds to this symbol. This is the index of this symbol |
| 1998 | in all the symbols for which we are making plt entries. The |
| 1999 | first entry in the procedure linkage table is reserved. */ |
| 2000 | plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1; |
| 2001 | |
| 2002 | /* Get the offset into the .got table of the entry that |
| 2003 | corresponds to this function. Each .got entry is GOT_ENTRY_SIZE |
| 2004 | bytes. The first three are reserved for the dynamic linker. */ |
| 2005 | got_offset = (plt_index + 3) * GOT_ENTRY_SIZE; |
| 2006 | |
| 2007 | /* Fill in the entry in the procedure linkage table. */ |
| 2008 | memcpy (htab->splt->contents + h->plt.offset, elf64_x86_64_plt_entry, |
| 2009 | PLT_ENTRY_SIZE); |
| 2010 | |
| 2011 | /* Insert the relocation positions of the plt section. The magic |
| 2012 | numbers at the end of the statements are the positions of the |
| 2013 | relocations in the plt section. */ |
| 2014 | /* Put offset for jmp *name@GOTPCREL(%rip), since the |
| 2015 | instruction uses 6 bytes, subtract this value. */ |
| 2016 | bfd_put_32 (output_bfd, |
| 2017 | (htab->sgotplt->output_section->vma |
| 2018 | + htab->sgotplt->output_offset |
| 2019 | + got_offset |
| 2020 | - htab->splt->output_section->vma |
| 2021 | - htab->splt->output_offset |
| 2022 | - h->plt.offset |
| 2023 | - 6), |
| 2024 | htab->splt->contents + h->plt.offset + 2); |
| 2025 | /* Put relocation index. */ |
| 2026 | bfd_put_32 (output_bfd, plt_index, |
| 2027 | htab->splt->contents + h->plt.offset + 7); |
| 2028 | /* Put offset for jmp .PLT0. */ |
| 2029 | bfd_put_32 (output_bfd, - (h->plt.offset + PLT_ENTRY_SIZE), |
| 2030 | htab->splt->contents + h->plt.offset + 12); |
| 2031 | |
| 2032 | /* Fill in the entry in the global offset table, initially this |
| 2033 | points to the pushq instruction in the PLT which is at offset 6. */ |
| 2034 | bfd_put_64 (output_bfd, (htab->splt->output_section->vma |
| 2035 | + htab->splt->output_offset |
| 2036 | + h->plt.offset + 6), |
| 2037 | htab->sgotplt->contents + got_offset); |
| 2038 | |
| 2039 | /* Fill in the entry in the .rela.plt section. */ |
| 2040 | rela.r_offset = (htab->sgotplt->output_section->vma |
| 2041 | + htab->sgotplt->output_offset |
| 2042 | + got_offset); |
| 2043 | rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_JUMP_SLOT); |
| 2044 | rela.r_addend = 0; |
| 2045 | loc = (Elf64_External_Rela *) htab->srelplt->contents + plt_index; |
| 2046 | bfd_elf64_swap_reloca_out (output_bfd, &rela, loc); |
| 2047 | |
| 2048 | if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) |
| 2049 | { |
| 2050 | /* Mark the symbol as undefined, rather than as defined in |
| 2051 | the .plt section. Leave the value alone. This is a clue |
| 2052 | for the dynamic linker, to make function pointer |
| 2053 | comparisons work between an application and shared |
| 2054 | library. */ |
| 2055 | sym->st_shndx = SHN_UNDEF; |
| 2056 | } |
| 2057 | } |
| 2058 | |
| 2059 | if (h->got.offset != (bfd_vma) -1) |
| 2060 | { |
| 2061 | Elf_Internal_Rela rela; |
| 2062 | Elf64_External_Rela *loc; |
| 2063 | |
| 2064 | /* This symbol has an entry in the global offset table. Set it |
| 2065 | up. */ |
| 2066 | |
| 2067 | if (htab->sgot == NULL || htab->srelgot == NULL) |
| 2068 | abort (); |
| 2069 | |
| 2070 | rela.r_offset = (htab->sgot->output_section->vma |
| 2071 | + htab->sgot->output_offset |
| 2072 | + (h->got.offset &~ (bfd_vma) 1)); |
| 2073 | |
| 2074 | /* If this is a static link, or it is a -Bsymbolic link and the |
| 2075 | symbol is defined locally or was forced to be local because |
| 2076 | of a version file, we just want to emit a RELATIVE reloc. |
| 2077 | The entry in the global offset table will already have been |
| 2078 | initialized in the relocate_section function. */ |
| 2079 | if (info->shared |
| 2080 | && (info->symbolic |
| 2081 | || h->dynindx == -1 |
| 2082 | || (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL)) |
| 2083 | && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)) |
| 2084 | { |
| 2085 | BFD_ASSERT((h->got.offset & 1) != 0); |
| 2086 | rela.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE); |
| 2087 | rela.r_addend = (h->root.u.def.value |
| 2088 | + h->root.u.def.section->output_section->vma |
| 2089 | + h->root.u.def.section->output_offset); |
| 2090 | } |
| 2091 | else |
| 2092 | { |
| 2093 | BFD_ASSERT((h->got.offset & 1) == 0); |
| 2094 | bfd_put_64 (output_bfd, (bfd_vma) 0, |
| 2095 | htab->sgot->contents + h->got.offset); |
| 2096 | rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_GLOB_DAT); |
| 2097 | rela.r_addend = 0; |
| 2098 | } |
| 2099 | |
| 2100 | loc = (Elf64_External_Rela *) htab->srelgot->contents; |
| 2101 | loc += htab->srelgot->reloc_count++; |
| 2102 | bfd_elf64_swap_reloca_out (output_bfd, &rela, loc); |
| 2103 | } |
| 2104 | |
| 2105 | if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_COPY) != 0) |
| 2106 | { |
| 2107 | Elf_Internal_Rela rela; |
| 2108 | Elf64_External_Rela *loc; |
| 2109 | |
| 2110 | /* This symbol needs a copy reloc. Set it up. */ |
| 2111 | |
| 2112 | if (h->dynindx == -1 |
| 2113 | || (h->root.type != bfd_link_hash_defined |
| 2114 | && h->root.type != bfd_link_hash_defweak) |
| 2115 | || htab->srelbss == NULL) |
| 2116 | abort (); |
| 2117 | |
| 2118 | rela.r_offset = (h->root.u.def.value |
| 2119 | + h->root.u.def.section->output_section->vma |
| 2120 | + h->root.u.def.section->output_offset); |
| 2121 | rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_COPY); |
| 2122 | rela.r_addend = 0; |
| 2123 | loc = (Elf64_External_Rela *) htab->srelbss->contents; |
| 2124 | loc += htab->srelbss->reloc_count++; |
| 2125 | bfd_elf64_swap_reloca_out (output_bfd, &rela, loc); |
| 2126 | } |
| 2127 | |
| 2128 | /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */ |
| 2129 | if (strcmp (h->root.root.string, "_DYNAMIC") == 0 |
| 2130 | || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0) |
| 2131 | sym->st_shndx = SHN_ABS; |
| 2132 | |
| 2133 | return true; |
| 2134 | } |
| 2135 | |
| 2136 | /* Used to decide how to sort relocs in an optimal manner for the |
| 2137 | dynamic linker, before writing them out. */ |
| 2138 | |
| 2139 | static enum elf_reloc_type_class |
| 2140 | elf64_x86_64_reloc_type_class (rela) |
| 2141 | const Elf_Internal_Rela *rela; |
| 2142 | { |
| 2143 | switch ((int) ELF64_R_TYPE (rela->r_info)) |
| 2144 | { |
| 2145 | case R_X86_64_RELATIVE: |
| 2146 | return reloc_class_relative; |
| 2147 | case R_X86_64_JUMP_SLOT: |
| 2148 | return reloc_class_plt; |
| 2149 | case R_X86_64_COPY: |
| 2150 | return reloc_class_copy; |
| 2151 | default: |
| 2152 | return reloc_class_normal; |
| 2153 | } |
| 2154 | } |
| 2155 | |
| 2156 | /* Finish up the dynamic sections. */ |
| 2157 | |
| 2158 | static boolean |
| 2159 | elf64_x86_64_finish_dynamic_sections (output_bfd, info) |
| 2160 | bfd *output_bfd; |
| 2161 | struct bfd_link_info *info; |
| 2162 | { |
| 2163 | struct elf64_x86_64_link_hash_table *htab; |
| 2164 | bfd *dynobj; |
| 2165 | asection *sdyn; |
| 2166 | |
| 2167 | htab = elf64_x86_64_hash_table (info); |
| 2168 | dynobj = htab->elf.dynobj; |
| 2169 | sdyn = bfd_get_section_by_name (dynobj, ".dynamic"); |
| 2170 | |
| 2171 | if (htab->elf.dynamic_sections_created) |
| 2172 | { |
| 2173 | Elf64_External_Dyn *dyncon, *dynconend; |
| 2174 | |
| 2175 | if (sdyn == NULL || htab->sgot == NULL) |
| 2176 | abort (); |
| 2177 | |
| 2178 | dyncon = (Elf64_External_Dyn *) sdyn->contents; |
| 2179 | dynconend = (Elf64_External_Dyn *) (sdyn->contents + sdyn->_raw_size); |
| 2180 | for (; dyncon < dynconend; dyncon++) |
| 2181 | { |
| 2182 | Elf_Internal_Dyn dyn; |
| 2183 | asection *s; |
| 2184 | |
| 2185 | bfd_elf64_swap_dyn_in (dynobj, dyncon, &dyn); |
| 2186 | |
| 2187 | switch (dyn.d_tag) |
| 2188 | { |
| 2189 | default: |
| 2190 | continue; |
| 2191 | |
| 2192 | case DT_PLTGOT: |
| 2193 | dyn.d_un.d_ptr = htab->sgot->output_section->vma; |
| 2194 | break; |
| 2195 | |
| 2196 | case DT_JMPREL: |
| 2197 | dyn.d_un.d_ptr = htab->srelplt->output_section->vma; |
| 2198 | break; |
| 2199 | |
| 2200 | case DT_PLTRELSZ: |
| 2201 | s = htab->srelplt->output_section; |
| 2202 | if (s->_cooked_size != 0) |
| 2203 | dyn.d_un.d_val = s->_cooked_size; |
| 2204 | else |
| 2205 | dyn.d_un.d_val = s->_raw_size; |
| 2206 | break; |
| 2207 | |
| 2208 | case DT_RELASZ: |
| 2209 | /* The procedure linkage table relocs (DT_JMPREL) should |
| 2210 | not be included in the overall relocs (DT_RELA). |
| 2211 | Therefore, we override the DT_RELASZ entry here to |
| 2212 | make it not include the JMPREL relocs. Since the |
| 2213 | linker script arranges for .rela.plt to follow all |
| 2214 | other relocation sections, we don't have to worry |
| 2215 | about changing the DT_RELA entry. */ |
| 2216 | if (htab->srelplt != NULL) |
| 2217 | { |
| 2218 | s = htab->srelplt->output_section; |
| 2219 | if (s->_cooked_size != 0) |
| 2220 | dyn.d_un.d_val -= s->_cooked_size; |
| 2221 | else |
| 2222 | dyn.d_un.d_val -= s->_raw_size; |
| 2223 | } |
| 2224 | break; |
| 2225 | } |
| 2226 | |
| 2227 | bfd_elf64_swap_dyn_out (output_bfd, &dyn, dyncon); |
| 2228 | } |
| 2229 | |
| 2230 | /* Fill in the special first entry in the procedure linkage table. */ |
| 2231 | if (htab->splt && htab->splt->_raw_size > 0) |
| 2232 | { |
| 2233 | /* Fill in the first entry in the procedure linkage table. */ |
| 2234 | memcpy (htab->splt->contents, elf64_x86_64_plt0_entry, |
| 2235 | PLT_ENTRY_SIZE); |
| 2236 | /* Add offset for pushq GOT+8(%rip), since the instruction |
| 2237 | uses 6 bytes subtract this value. */ |
| 2238 | bfd_put_32 (output_bfd, |
| 2239 | (htab->sgotplt->output_section->vma |
| 2240 | + htab->sgotplt->output_offset |
| 2241 | + 8 |
| 2242 | - htab->splt->output_section->vma |
| 2243 | - htab->splt->output_offset |
| 2244 | - 6), |
| 2245 | htab->splt->contents + 2); |
| 2246 | /* Add offset for jmp *GOT+16(%rip). The 12 is the offset to |
| 2247 | the end of the instruction. */ |
| 2248 | bfd_put_32 (output_bfd, |
| 2249 | (htab->sgotplt->output_section->vma |
| 2250 | + htab->sgotplt->output_offset |
| 2251 | + 16 |
| 2252 | - htab->splt->output_section->vma |
| 2253 | - htab->splt->output_offset |
| 2254 | - 12), |
| 2255 | htab->splt->contents + 8); |
| 2256 | |
| 2257 | elf_section_data (htab->splt->output_section)->this_hdr.sh_entsize = |
| 2258 | PLT_ENTRY_SIZE; |
| 2259 | } |
| 2260 | } |
| 2261 | |
| 2262 | if (htab->sgotplt) |
| 2263 | { |
| 2264 | /* Fill in the first three entries in the global offset table. */ |
| 2265 | if (htab->sgotplt->_raw_size > 0) |
| 2266 | { |
| 2267 | /* Set the first entry in the global offset table to the address of |
| 2268 | the dynamic section. */ |
| 2269 | if (sdyn == NULL) |
| 2270 | bfd_put_64 (output_bfd, (bfd_vma) 0, htab->sgotplt->contents); |
| 2271 | else |
| 2272 | bfd_put_64 (output_bfd, |
| 2273 | sdyn->output_section->vma + sdyn->output_offset, |
| 2274 | htab->sgotplt->contents); |
| 2275 | /* Write GOT[1] and GOT[2], needed for the dynamic linker. */ |
| 2276 | bfd_put_64 (output_bfd, (bfd_vma) 0, htab->sgotplt->contents + GOT_ENTRY_SIZE); |
| 2277 | bfd_put_64 (output_bfd, (bfd_vma) 0, htab->sgotplt->contents + GOT_ENTRY_SIZE*2); |
| 2278 | } |
| 2279 | |
| 2280 | elf_section_data (htab->sgotplt->output_section)->this_hdr.sh_entsize = |
| 2281 | GOT_ENTRY_SIZE; |
| 2282 | } |
| 2283 | |
| 2284 | return true; |
| 2285 | } |
| 2286 | |
| 2287 | |
| 2288 | #define TARGET_LITTLE_SYM bfd_elf64_x86_64_vec |
| 2289 | #define TARGET_LITTLE_NAME "elf64-x86-64" |
| 2290 | #define ELF_ARCH bfd_arch_i386 |
| 2291 | #define ELF_MACHINE_CODE EM_X86_64 |
| 2292 | #define ELF_MAXPAGESIZE 0x100000 |
| 2293 | |
| 2294 | #define elf_backend_can_gc_sections 1 |
| 2295 | #define elf_backend_can_refcount 1 |
| 2296 | #define elf_backend_want_got_plt 1 |
| 2297 | #define elf_backend_plt_readonly 1 |
| 2298 | #define elf_backend_want_plt_sym 0 |
| 2299 | #define elf_backend_got_header_size (GOT_ENTRY_SIZE*3) |
| 2300 | #define elf_backend_plt_header_size PLT_ENTRY_SIZE |
| 2301 | #define elf_backend_rela_normal 1 |
| 2302 | |
| 2303 | #define elf_info_to_howto elf64_x86_64_info_to_howto |
| 2304 | |
| 2305 | #define bfd_elf64_bfd_link_hash_table_create \ |
| 2306 | elf64_x86_64_link_hash_table_create |
| 2307 | #define bfd_elf64_bfd_reloc_type_lookup elf64_x86_64_reloc_type_lookup |
| 2308 | |
| 2309 | #define elf_backend_adjust_dynamic_symbol elf64_x86_64_adjust_dynamic_symbol |
| 2310 | #define elf_backend_check_relocs elf64_x86_64_check_relocs |
| 2311 | #define elf_backend_copy_indirect_symbol elf64_x86_64_copy_indirect_symbol |
| 2312 | #define elf_backend_create_dynamic_sections elf64_x86_64_create_dynamic_sections |
| 2313 | #define elf_backend_finish_dynamic_sections elf64_x86_64_finish_dynamic_sections |
| 2314 | #define elf_backend_finish_dynamic_symbol elf64_x86_64_finish_dynamic_symbol |
| 2315 | #define elf_backend_gc_mark_hook elf64_x86_64_gc_mark_hook |
| 2316 | #define elf_backend_gc_sweep_hook elf64_x86_64_gc_sweep_hook |
| 2317 | #define elf_backend_grok_prstatus elf64_x86_64_grok_prstatus |
| 2318 | #define elf_backend_grok_psinfo elf64_x86_64_grok_psinfo |
| 2319 | #define elf_backend_reloc_type_class elf64_x86_64_reloc_type_class |
| 2320 | #define elf_backend_relocate_section elf64_x86_64_relocate_section |
| 2321 | #define elf_backend_size_dynamic_sections elf64_x86_64_size_dynamic_sections |
| 2322 | #define elf_backend_object_p elf64_x86_64_elf_object_p |
| 2323 | |
| 2324 | #include "elf64-target.h" |