1 /* X86-64 specific support for 64-bit ELF 2 Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 3 Free Software Foundation, Inc. 4 Contributed by Jan Hubicka <jh@suse.cz>. 5 6 This file is part of BFD, the Binary File Descriptor library. 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 3 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program; if not, write to the Free Software 20 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 21 MA 02110-1301, USA. */ 22 23 #include "sysdep.h" 24 #include "bfd.h" 25 #include "bfdlink.h" 26 #include "libbfd.h" 27 #include "elf-bfd.h" 28 #include "bfd_stdint.h" 29 #include "objalloc.h" 30 #include "hashtab.h" 31 32 #include "elf/x86-64.h" 33 34 /* In case we're on a 32-bit machine, construct a 64-bit "-1" value. */ 35 #define MINUS_ONE (~ (bfd_vma) 0) 36 37 /* The relocation "howto" table. Order of fields: 38 type, rightshift, size, bitsize, pc_relative, bitpos, complain_on_overflow, 39 special_function, name, partial_inplace, src_mask, dst_mask, pcrel_offset. */ 40 static reloc_howto_type x86_64_elf_howto_table[] = 41 { 42 HOWTO(R_X86_64_NONE, 0, 0, 0, FALSE, 0, complain_overflow_dont, 43 bfd_elf_generic_reloc, "R_X86_64_NONE", FALSE, 0x00000000, 0x00000000, 44 FALSE), 45 HOWTO(R_X86_64_64, 0, 4, 64, FALSE, 0, complain_overflow_bitfield, 46 bfd_elf_generic_reloc, "R_X86_64_64", FALSE, MINUS_ONE, MINUS_ONE, 47 FALSE), 48 HOWTO(R_X86_64_PC32, 0, 2, 32, TRUE, 0, complain_overflow_signed, 49 bfd_elf_generic_reloc, "R_X86_64_PC32", FALSE, 0xffffffff, 0xffffffff, 50 TRUE), 51 HOWTO(R_X86_64_GOT32, 0, 2, 32, FALSE, 0, complain_overflow_signed, 52 bfd_elf_generic_reloc, "R_X86_64_GOT32", FALSE, 0xffffffff, 0xffffffff, 53 FALSE), 54 HOWTO(R_X86_64_PLT32, 0, 2, 32, TRUE, 0, complain_overflow_signed, 55 bfd_elf_generic_reloc, "R_X86_64_PLT32", FALSE, 0xffffffff, 0xffffffff, 56 TRUE), 57 HOWTO(R_X86_64_COPY, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, 58 bfd_elf_generic_reloc, "R_X86_64_COPY", FALSE, 0xffffffff, 0xffffffff, 59 FALSE), 60 HOWTO(R_X86_64_GLOB_DAT, 0, 4, 64, FALSE, 0, complain_overflow_bitfield, 61 bfd_elf_generic_reloc, "R_X86_64_GLOB_DAT", FALSE, MINUS_ONE, 62 MINUS_ONE, FALSE), 63 HOWTO(R_X86_64_JUMP_SLOT, 0, 4, 64, FALSE, 0, complain_overflow_bitfield, 64 bfd_elf_generic_reloc, "R_X86_64_JUMP_SLOT", FALSE, MINUS_ONE, 65 MINUS_ONE, FALSE), 66 HOWTO(R_X86_64_RELATIVE, 0, 4, 64, FALSE, 0, complain_overflow_bitfield, 67 bfd_elf_generic_reloc, "R_X86_64_RELATIVE", FALSE, MINUS_ONE, 68 MINUS_ONE, FALSE), 69 HOWTO(R_X86_64_GOTPCREL, 0, 2, 32, TRUE, 0, complain_overflow_signed, 70 bfd_elf_generic_reloc, "R_X86_64_GOTPCREL", FALSE, 0xffffffff, 71 0xffffffff, TRUE), 72 HOWTO(R_X86_64_32, 0, 2, 32, FALSE, 0, complain_overflow_unsigned, 73 bfd_elf_generic_reloc, "R_X86_64_32", FALSE, 0xffffffff, 0xffffffff, 74 FALSE), 75 HOWTO(R_X86_64_32S, 0, 2, 32, FALSE, 0, complain_overflow_signed, 76 bfd_elf_generic_reloc, "R_X86_64_32S", FALSE, 0xffffffff, 0xffffffff, 77 FALSE), 78 HOWTO(R_X86_64_16, 0, 1, 16, FALSE, 0, complain_overflow_bitfield, 79 bfd_elf_generic_reloc, "R_X86_64_16", FALSE, 0xffff, 0xffff, FALSE), 80 HOWTO(R_X86_64_PC16,0, 1, 16, TRUE, 0, complain_overflow_bitfield, 81 bfd_elf_generic_reloc, "R_X86_64_PC16", FALSE, 0xffff, 0xffff, TRUE), 82 HOWTO(R_X86_64_8, 0, 0, 8, FALSE, 0, complain_overflow_bitfield, 83 bfd_elf_generic_reloc, "R_X86_64_8", FALSE, 0xff, 0xff, FALSE), 84 HOWTO(R_X86_64_PC8, 0, 0, 8, TRUE, 0, complain_overflow_signed, 85 bfd_elf_generic_reloc, "R_X86_64_PC8", FALSE, 0xff, 0xff, TRUE), 86 HOWTO(R_X86_64_DTPMOD64, 0, 4, 64, FALSE, 0, complain_overflow_bitfield, 87 bfd_elf_generic_reloc, "R_X86_64_DTPMOD64", FALSE, MINUS_ONE, 88 MINUS_ONE, FALSE), 89 HOWTO(R_X86_64_DTPOFF64, 0, 4, 64, FALSE, 0, complain_overflow_bitfield, 90 bfd_elf_generic_reloc, "R_X86_64_DTPOFF64", FALSE, MINUS_ONE, 91 MINUS_ONE, FALSE), 92 HOWTO(R_X86_64_TPOFF64, 0, 4, 64, FALSE, 0, complain_overflow_bitfield, 93 bfd_elf_generic_reloc, "R_X86_64_TPOFF64", FALSE, MINUS_ONE, 94 MINUS_ONE, FALSE), 95 HOWTO(R_X86_64_TLSGD, 0, 2, 32, TRUE, 0, complain_overflow_signed, 96 bfd_elf_generic_reloc, "R_X86_64_TLSGD", FALSE, 0xffffffff, 97 0xffffffff, TRUE), 98 HOWTO(R_X86_64_TLSLD, 0, 2, 32, TRUE, 0, complain_overflow_signed, 99 bfd_elf_generic_reloc, "R_X86_64_TLSLD", FALSE, 0xffffffff, 100 0xffffffff, TRUE), 101 HOWTO(R_X86_64_DTPOFF32, 0, 2, 32, FALSE, 0, complain_overflow_signed, 102 bfd_elf_generic_reloc, "R_X86_64_DTPOFF32", FALSE, 0xffffffff, 103 0xffffffff, FALSE), 104 HOWTO(R_X86_64_GOTTPOFF, 0, 2, 32, TRUE, 0, complain_overflow_signed, 105 bfd_elf_generic_reloc, "R_X86_64_GOTTPOFF", FALSE, 0xffffffff, 106 0xffffffff, TRUE), 107 HOWTO(R_X86_64_TPOFF32, 0, 2, 32, FALSE, 0, complain_overflow_signed, 108 bfd_elf_generic_reloc, "R_X86_64_TPOFF32", FALSE, 0xffffffff, 109 0xffffffff, FALSE), 110 HOWTO(R_X86_64_PC64, 0, 4, 64, TRUE, 0, complain_overflow_bitfield, 111 bfd_elf_generic_reloc, "R_X86_64_PC64", FALSE, MINUS_ONE, MINUS_ONE, 112 TRUE), 113 HOWTO(R_X86_64_GOTOFF64, 0, 4, 64, FALSE, 0, complain_overflow_bitfield, 114 bfd_elf_generic_reloc, "R_X86_64_GOTOFF64", 115 FALSE, MINUS_ONE, MINUS_ONE, FALSE), 116 HOWTO(R_X86_64_GOTPC32, 0, 2, 32, TRUE, 0, complain_overflow_signed, 117 bfd_elf_generic_reloc, "R_X86_64_GOTPC32", 118 FALSE, 0xffffffff, 0xffffffff, TRUE), 119 HOWTO(R_X86_64_GOT64, 0, 4, 64, FALSE, 0, complain_overflow_signed, 120 bfd_elf_generic_reloc, "R_X86_64_GOT64", FALSE, MINUS_ONE, MINUS_ONE, 121 FALSE), 122 HOWTO(R_X86_64_GOTPCREL64, 0, 4, 64, TRUE, 0, complain_overflow_signed, 123 bfd_elf_generic_reloc, "R_X86_64_GOTPCREL64", FALSE, MINUS_ONE, 124 MINUS_ONE, TRUE), 125 HOWTO(R_X86_64_GOTPC64, 0, 4, 64, TRUE, 0, complain_overflow_signed, 126 bfd_elf_generic_reloc, "R_X86_64_GOTPC64", 127 FALSE, MINUS_ONE, MINUS_ONE, TRUE), 128 HOWTO(R_X86_64_GOTPLT64, 0, 4, 64, FALSE, 0, complain_overflow_signed, 129 bfd_elf_generic_reloc, "R_X86_64_GOTPLT64", FALSE, MINUS_ONE, 130 MINUS_ONE, FALSE), 131 HOWTO(R_X86_64_PLTOFF64, 0, 4, 64, FALSE, 0, complain_overflow_signed, 132 bfd_elf_generic_reloc, "R_X86_64_PLTOFF64", FALSE, MINUS_ONE, 133 MINUS_ONE, FALSE), 134 EMPTY_HOWTO (32), 135 EMPTY_HOWTO (33), 136 HOWTO(R_X86_64_GOTPC32_TLSDESC, 0, 2, 32, TRUE, 0, 137 complain_overflow_bitfield, bfd_elf_generic_reloc, 138 "R_X86_64_GOTPC32_TLSDESC", 139 FALSE, 0xffffffff, 0xffffffff, TRUE), 140 HOWTO(R_X86_64_TLSDESC_CALL, 0, 0, 0, FALSE, 0, 141 complain_overflow_dont, bfd_elf_generic_reloc, 142 "R_X86_64_TLSDESC_CALL", 143 FALSE, 0, 0, FALSE), 144 HOWTO(R_X86_64_TLSDESC, 0, 4, 64, FALSE, 0, 145 complain_overflow_bitfield, bfd_elf_generic_reloc, 146 "R_X86_64_TLSDESC", 147 FALSE, MINUS_ONE, MINUS_ONE, FALSE), 148 HOWTO(R_X86_64_IRELATIVE, 0, 4, 64, FALSE, 0, complain_overflow_bitfield, 149 bfd_elf_generic_reloc, "R_X86_64_IRELATIVE", FALSE, MINUS_ONE, 150 MINUS_ONE, FALSE), 151 152 /* We have a gap in the reloc numbers here. 153 R_X86_64_standard counts the number up to this point, and 154 R_X86_64_vt_offset is the value to subtract from a reloc type of 155 R_X86_64_GNU_VT* to form an index into this table. */ 156 #define R_X86_64_standard (R_X86_64_IRELATIVE + 1) 157 #define R_X86_64_vt_offset (R_X86_64_GNU_VTINHERIT - R_X86_64_standard) 158 159 /* GNU extension to record C++ vtable hierarchy. */ 160 HOWTO (R_X86_64_GNU_VTINHERIT, 0, 4, 0, FALSE, 0, complain_overflow_dont, 161 NULL, "R_X86_64_GNU_VTINHERIT", FALSE, 0, 0, FALSE), 162 163 /* GNU extension to record C++ vtable member usage. */ 164 HOWTO (R_X86_64_GNU_VTENTRY, 0, 4, 0, FALSE, 0, complain_overflow_dont, 165 _bfd_elf_rel_vtable_reloc_fn, "R_X86_64_GNU_VTENTRY", FALSE, 0, 0, 166 FALSE) 167 }; 168 169 #define IS_X86_64_PCREL_TYPE(TYPE) \ 170 ( ((TYPE) == R_X86_64_PC8) \ 171 || ((TYPE) == R_X86_64_PC16) \ 172 || ((TYPE) == R_X86_64_PC32) \ 173 || ((TYPE) == R_X86_64_PC64)) 174 175 /* Map BFD relocs to the x86_64 elf relocs. */ 176 struct elf_reloc_map 177 { 178 bfd_reloc_code_real_type bfd_reloc_val; 179 unsigned char elf_reloc_val; 180 }; 181 182 static const struct elf_reloc_map x86_64_reloc_map[] = 183 { 184 { BFD_RELOC_NONE, R_X86_64_NONE, }, 185 { BFD_RELOC_64, R_X86_64_64, }, 186 { BFD_RELOC_32_PCREL, R_X86_64_PC32, }, 187 { BFD_RELOC_X86_64_GOT32, R_X86_64_GOT32,}, 188 { BFD_RELOC_X86_64_PLT32, R_X86_64_PLT32,}, 189 { BFD_RELOC_X86_64_COPY, R_X86_64_COPY, }, 190 { BFD_RELOC_X86_64_GLOB_DAT, R_X86_64_GLOB_DAT, }, 191 { BFD_RELOC_X86_64_JUMP_SLOT, R_X86_64_JUMP_SLOT, }, 192 { BFD_RELOC_X86_64_RELATIVE, R_X86_64_RELATIVE, }, 193 { BFD_RELOC_X86_64_GOTPCREL, R_X86_64_GOTPCREL, }, 194 { BFD_RELOC_32, R_X86_64_32, }, 195 { BFD_RELOC_X86_64_32S, R_X86_64_32S, }, 196 { BFD_RELOC_16, R_X86_64_16, }, 197 { BFD_RELOC_16_PCREL, R_X86_64_PC16, }, 198 { BFD_RELOC_8, R_X86_64_8, }, 199 { BFD_RELOC_8_PCREL, R_X86_64_PC8, }, 200 { BFD_RELOC_X86_64_DTPMOD64, R_X86_64_DTPMOD64, }, 201 { BFD_RELOC_X86_64_DTPOFF64, R_X86_64_DTPOFF64, }, 202 { BFD_RELOC_X86_64_TPOFF64, R_X86_64_TPOFF64, }, 203 { BFD_RELOC_X86_64_TLSGD, R_X86_64_TLSGD, }, 204 { BFD_RELOC_X86_64_TLSLD, R_X86_64_TLSLD, }, 205 { BFD_RELOC_X86_64_DTPOFF32, R_X86_64_DTPOFF32, }, 206 { BFD_RELOC_X86_64_GOTTPOFF, R_X86_64_GOTTPOFF, }, 207 { BFD_RELOC_X86_64_TPOFF32, R_X86_64_TPOFF32, }, 208 { BFD_RELOC_64_PCREL, R_X86_64_PC64, }, 209 { BFD_RELOC_X86_64_GOTOFF64, R_X86_64_GOTOFF64, }, 210 { BFD_RELOC_X86_64_GOTPC32, R_X86_64_GOTPC32, }, 211 { BFD_RELOC_X86_64_GOT64, R_X86_64_GOT64, }, 212 { BFD_RELOC_X86_64_GOTPCREL64,R_X86_64_GOTPCREL64, }, 213 { BFD_RELOC_X86_64_GOTPC64, R_X86_64_GOTPC64, }, 214 { BFD_RELOC_X86_64_GOTPLT64, R_X86_64_GOTPLT64, }, 215 { BFD_RELOC_X86_64_PLTOFF64, R_X86_64_PLTOFF64, }, 216 { BFD_RELOC_X86_64_GOTPC32_TLSDESC, R_X86_64_GOTPC32_TLSDESC, }, 217 { BFD_RELOC_X86_64_TLSDESC_CALL, R_X86_64_TLSDESC_CALL, }, 218 { BFD_RELOC_X86_64_TLSDESC, R_X86_64_TLSDESC, }, 219 { BFD_RELOC_X86_64_IRELATIVE, R_X86_64_IRELATIVE, }, 220 { BFD_RELOC_VTABLE_INHERIT, R_X86_64_GNU_VTINHERIT, }, 221 { BFD_RELOC_VTABLE_ENTRY, R_X86_64_GNU_VTENTRY, }, 222 }; 223 224 static reloc_howto_type * 225 elf64_x86_64_rtype_to_howto (bfd *abfd, unsigned r_type) 226 { 227 unsigned i; 228 229 if (r_type < (unsigned int) R_X86_64_GNU_VTINHERIT 230 || r_type >= (unsigned int) R_X86_64_max) 231 { 232 if (r_type >= (unsigned int) R_X86_64_standard) 233 { 234 (*_bfd_error_handler) (_("%B: invalid relocation type %d"), 235 abfd, (int) r_type); 236 r_type = R_X86_64_NONE; 237 } 238 i = r_type; 239 } 240 else 241 i = r_type - (unsigned int) R_X86_64_vt_offset; 242 BFD_ASSERT (x86_64_elf_howto_table[i].type == r_type); 243 return &x86_64_elf_howto_table[i]; 244 } 245 246 /* Given a BFD reloc type, return a HOWTO structure. */ 247 static reloc_howto_type * 248 elf64_x86_64_reloc_type_lookup (bfd *abfd, 249 bfd_reloc_code_real_type code) 250 { 251 unsigned int i; 252 253 for (i = 0; i < sizeof (x86_64_reloc_map) / sizeof (struct elf_reloc_map); 254 i++) 255 { 256 if (x86_64_reloc_map[i].bfd_reloc_val == code) 257 return elf64_x86_64_rtype_to_howto (abfd, 258 x86_64_reloc_map[i].elf_reloc_val); 259 } 260 return 0; 261 } 262 263 static reloc_howto_type * 264 elf64_x86_64_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED, 265 const char *r_name) 266 { 267 unsigned int i; 268 269 for (i = 0; 270 i < (sizeof (x86_64_elf_howto_table) 271 / sizeof (x86_64_elf_howto_table[0])); 272 i++) 273 if (x86_64_elf_howto_table[i].name != NULL 274 && strcasecmp (x86_64_elf_howto_table[i].name, r_name) == 0) 275 return &x86_64_elf_howto_table[i]; 276 277 return NULL; 278 } 279 280 /* Given an x86_64 ELF reloc type, fill in an arelent structure. */ 281 282 static void 283 elf64_x86_64_info_to_howto (bfd *abfd ATTRIBUTE_UNUSED, arelent *cache_ptr, 284 Elf_Internal_Rela *dst) 285 { 286 unsigned r_type; 287 288 r_type = ELF64_R_TYPE (dst->r_info); 289 cache_ptr->howto = elf64_x86_64_rtype_to_howto (abfd, r_type); 290 BFD_ASSERT (r_type == cache_ptr->howto->type); 291 } 292 293 /* Support for core dump NOTE sections. */ 294 static bfd_boolean 295 elf64_x86_64_grok_prstatus (bfd *abfd, Elf_Internal_Note *note) 296 { 297 int offset; 298 size_t size; 299 300 switch (note->descsz) 301 { 302 default: 303 return FALSE; 304 305 case 336: /* sizeof(istruct elf_prstatus) on Linux/x86_64 */ 306 /* pr_cursig */ 307 elf_tdata (abfd)->core_signal 308 = bfd_get_16 (abfd, note->descdata + 12); 309 310 /* pr_pid */ 311 elf_tdata (abfd)->core_pid 312 = bfd_get_32 (abfd, note->descdata + 32); 313 314 /* pr_reg */ 315 offset = 112; 316 size = 216; 317 318 break; 319 } 320 321 /* Make a ".reg/999" section. */ 322 return _bfd_elfcore_make_pseudosection (abfd, ".reg", 323 size, note->descpos + offset); 324 } 325 326 static bfd_boolean 327 elf64_x86_64_grok_psinfo (bfd *abfd, Elf_Internal_Note *note) 328 { 329 switch (note->descsz) 330 { 331 default: 332 return FALSE; 333 334 case 136: /* sizeof(struct elf_prpsinfo) on Linux/x86_64 */ 335 elf_tdata (abfd)->core_program 336 = _bfd_elfcore_strndup (abfd, note->descdata + 40, 16); 337 elf_tdata (abfd)->core_command 338 = _bfd_elfcore_strndup (abfd, note->descdata + 56, 80); 339 } 340 341 /* Note that for some reason, a spurious space is tacked 342 onto the end of the args in some (at least one anyway) 343 implementations, so strip it off if it exists. */ 344 345 { 346 char *command = elf_tdata (abfd)->core_command; 347 int n = strlen (command); 348 349 if (0 < n && command[n - 1] == ' ') 350 command[n - 1] = '\0'; 351 } 352 353 return TRUE; 354 } 355 356 /* Functions for the x86-64 ELF linker. */ 357 358 /* The name of the dynamic interpreter. This is put in the .interp 359 section. */ 360 361 #define ELF_DYNAMIC_INTERPRETER "/lib/ld64.so.1" 362 363 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid 364 copying dynamic variables from a shared lib into an app's dynbss 365 section, and instead use a dynamic relocation to point into the 366 shared lib. */ 367 #define ELIMINATE_COPY_RELOCS 1 368 369 /* The size in bytes of an entry in the global offset table. */ 370 371 #define GOT_ENTRY_SIZE 8 372 373 /* The size in bytes of an entry in the procedure linkage table. */ 374 375 #define PLT_ENTRY_SIZE 16 376 377 /* The first entry in a procedure linkage table looks like this. See the 378 SVR4 ABI i386 supplement and the x86-64 ABI to see how this works. */ 379 380 static const bfd_byte elf64_x86_64_plt0_entry[PLT_ENTRY_SIZE] = 381 { 382 0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */ 383 0xff, 0x25, 16, 0, 0, 0, /* jmpq *GOT+16(%rip) */ 384 0x0f, 0x1f, 0x40, 0x00 /* nopl 0(%rax) */ 385 }; 386 387 /* Subsequent entries in a procedure linkage table look like this. */ 388 389 static const bfd_byte elf64_x86_64_plt_entry[PLT_ENTRY_SIZE] = 390 { 391 0xff, 0x25, /* jmpq *name@GOTPC(%rip) */ 392 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */ 393 0x68, /* pushq immediate */ 394 0, 0, 0, 0, /* replaced with index into relocation table. */ 395 0xe9, /* jmp relative */ 396 0, 0, 0, 0 /* replaced with offset to start of .plt0. */ 397 }; 398 399 /* x86-64 ELF linker hash entry. */ 400 401 struct elf64_x86_64_link_hash_entry 402 { 403 struct elf_link_hash_entry elf; 404 405 /* Track dynamic relocs copied for this symbol. */ 406 struct elf_dyn_relocs *dyn_relocs; 407 408 #define GOT_UNKNOWN 0 409 #define GOT_NORMAL 1 410 #define GOT_TLS_GD 2 411 #define GOT_TLS_IE 3 412 #define GOT_TLS_GDESC 4 413 #define GOT_TLS_GD_BOTH_P(type) \ 414 ((type) == (GOT_TLS_GD | GOT_TLS_GDESC)) 415 #define GOT_TLS_GD_P(type) \ 416 ((type) == GOT_TLS_GD || GOT_TLS_GD_BOTH_P (type)) 417 #define GOT_TLS_GDESC_P(type) \ 418 ((type) == GOT_TLS_GDESC || GOT_TLS_GD_BOTH_P (type)) 419 #define GOT_TLS_GD_ANY_P(type) \ 420 (GOT_TLS_GD_P (type) || GOT_TLS_GDESC_P (type)) 421 unsigned char tls_type; 422 423 /* Offset of the GOTPLT entry reserved for the TLS descriptor, 424 starting at the end of the jump table. */ 425 bfd_vma tlsdesc_got; 426 }; 427 428 #define elf64_x86_64_hash_entry(ent) \ 429 ((struct elf64_x86_64_link_hash_entry *)(ent)) 430 431 struct elf64_x86_64_obj_tdata 432 { 433 struct elf_obj_tdata root; 434 435 /* tls_type for each local got entry. */ 436 char *local_got_tls_type; 437 438 /* GOTPLT entries for TLS descriptors. */ 439 bfd_vma *local_tlsdesc_gotent; 440 }; 441 442 #define elf64_x86_64_tdata(abfd) \ 443 ((struct elf64_x86_64_obj_tdata *) (abfd)->tdata.any) 444 445 #define elf64_x86_64_local_got_tls_type(abfd) \ 446 (elf64_x86_64_tdata (abfd)->local_got_tls_type) 447 448 #define elf64_x86_64_local_tlsdesc_gotent(abfd) \ 449 (elf64_x86_64_tdata (abfd)->local_tlsdesc_gotent) 450 451 #define is_x86_64_elf(bfd) \ 452 (bfd_get_flavour (bfd) == bfd_target_elf_flavour \ 453 && elf_tdata (bfd) != NULL \ 454 && elf_object_id (bfd) == X86_64_ELF_TDATA) 455 456 static bfd_boolean 457 elf64_x86_64_mkobject (bfd *abfd) 458 { 459 return bfd_elf_allocate_object (abfd, sizeof (struct elf64_x86_64_obj_tdata), 460 X86_64_ELF_TDATA); 461 } 462 463 /* x86-64 ELF linker hash table. */ 464 465 struct elf64_x86_64_link_hash_table 466 { 467 struct elf_link_hash_table elf; 468 469 /* Short-cuts to get to dynamic linker sections. */ 470 asection *sdynbss; 471 asection *srelbss; 472 473 /* The offset into splt of the PLT entry for the TLS descriptor 474 resolver. Special values are 0, if not necessary (or not found 475 to be necessary yet), and -1 if needed but not determined 476 yet. */ 477 bfd_vma tlsdesc_plt; 478 /* The offset into sgot of the GOT entry used by the PLT entry 479 above. */ 480 bfd_vma tlsdesc_got; 481 482 union { 483 bfd_signed_vma refcount; 484 bfd_vma offset; 485 } tls_ld_got; 486 487 /* The amount of space used by the jump slots in the GOT. */ 488 bfd_vma sgotplt_jump_table_size; 489 490 /* Small local sym cache. */ 491 struct sym_cache sym_cache; 492 493 /* _TLS_MODULE_BASE_ symbol. */ 494 struct bfd_link_hash_entry *tls_module_base; 495 496 /* Used by local STT_GNU_IFUNC symbols. */ 497 htab_t loc_hash_table; 498 void *loc_hash_memory; 499 }; 500 501 /* Get the x86-64 ELF linker hash table from a link_info structure. */ 502 503 #define elf64_x86_64_hash_table(p) \ 504 ((struct elf64_x86_64_link_hash_table *) ((p)->hash)) 505 506 #define elf64_x86_64_compute_jump_table_size(htab) \ 507 ((htab)->elf.srelplt->reloc_count * GOT_ENTRY_SIZE) 508 509 /* Create an entry in an x86-64 ELF linker hash table. */ 510 511 static struct bfd_hash_entry * 512 elf64_x86_64_link_hash_newfunc (struct bfd_hash_entry *entry, 513 struct bfd_hash_table *table, 514 const char *string) 515 { 516 /* Allocate the structure if it has not already been allocated by a 517 subclass. */ 518 if (entry == NULL) 519 { 520 entry = (struct bfd_hash_entry *) 521 bfd_hash_allocate (table, 522 sizeof (struct elf64_x86_64_link_hash_entry)); 523 if (entry == NULL) 524 return entry; 525 } 526 527 /* Call the allocation method of the superclass. */ 528 entry = _bfd_elf_link_hash_newfunc (entry, table, string); 529 if (entry != NULL) 530 { 531 struct elf64_x86_64_link_hash_entry *eh; 532 533 eh = (struct elf64_x86_64_link_hash_entry *) entry; 534 eh->dyn_relocs = NULL; 535 eh->tls_type = GOT_UNKNOWN; 536 eh->tlsdesc_got = (bfd_vma) -1; 537 } 538 539 return entry; 540 } 541 542 /* Compute a hash of a local hash entry. We use elf_link_hash_entry 543 for local symbol so that we can handle local STT_GNU_IFUNC symbols 544 as global symbol. We reuse indx and dynstr_index for local symbol 545 hash since they aren't used by global symbols in this backend. */ 546 547 static hashval_t 548 elf64_x86_64_local_htab_hash (const void *ptr) 549 { 550 struct elf_link_hash_entry *h 551 = (struct elf_link_hash_entry *) ptr; 552 return ELF_LOCAL_SYMBOL_HASH (h->indx, h->dynstr_index); 553 } 554 555 /* Compare local hash entries. */ 556 557 static int 558 elf64_x86_64_local_htab_eq (const void *ptr1, const void *ptr2) 559 { 560 struct elf_link_hash_entry *h1 561 = (struct elf_link_hash_entry *) ptr1; 562 struct elf_link_hash_entry *h2 563 = (struct elf_link_hash_entry *) ptr2; 564 565 return h1->indx == h2->indx && h1->dynstr_index == h2->dynstr_index; 566 } 567 568 /* Find and/or create a hash entry for local symbol. */ 569 570 static struct elf_link_hash_entry * 571 elf64_x86_64_get_local_sym_hash (struct elf64_x86_64_link_hash_table *htab, 572 bfd *abfd, const Elf_Internal_Rela *rel, 573 bfd_boolean create) 574 { 575 struct elf64_x86_64_link_hash_entry e, *ret; 576 asection *sec = abfd->sections; 577 hashval_t h = ELF_LOCAL_SYMBOL_HASH (sec->id, 578 ELF64_R_SYM (rel->r_info)); 579 void **slot; 580 581 e.elf.indx = sec->id; 582 e.elf.dynstr_index = ELF64_R_SYM (rel->r_info); 583 slot = htab_find_slot_with_hash (htab->loc_hash_table, &e, h, 584 create ? INSERT : NO_INSERT); 585 586 if (!slot) 587 return NULL; 588 589 if (*slot) 590 { 591 ret = (struct elf64_x86_64_link_hash_entry *) *slot; 592 return &ret->elf; 593 } 594 595 ret = (struct elf64_x86_64_link_hash_entry *) 596 objalloc_alloc ((struct objalloc *) htab->loc_hash_memory, 597 sizeof (struct elf64_x86_64_link_hash_entry)); 598 if (ret) 599 { 600 memset (ret, 0, sizeof (*ret)); 601 ret->elf.indx = sec->id; 602 ret->elf.dynstr_index = ELF64_R_SYM (rel->r_info); 603 ret->elf.dynindx = -1; 604 ret->elf.plt.offset = (bfd_vma) -1; 605 ret->elf.got.offset = (bfd_vma) -1; 606 *slot = ret; 607 } 608 return &ret->elf; 609 } 610 611 /* Create an X86-64 ELF linker hash table. */ 612 613 static struct bfd_link_hash_table * 614 elf64_x86_64_link_hash_table_create (bfd *abfd) 615 { 616 struct elf64_x86_64_link_hash_table *ret; 617 bfd_size_type amt = sizeof (struct elf64_x86_64_link_hash_table); 618 619 ret = (struct elf64_x86_64_link_hash_table *) bfd_malloc (amt); 620 if (ret == NULL) 621 return NULL; 622 623 if (!_bfd_elf_link_hash_table_init (&ret->elf, abfd, 624 elf64_x86_64_link_hash_newfunc, 625 sizeof (struct elf64_x86_64_link_hash_entry))) 626 { 627 free (ret); 628 return NULL; 629 } 630 631 ret->sdynbss = NULL; 632 ret->srelbss = NULL; 633 ret->sym_cache.abfd = NULL; 634 ret->tlsdesc_plt = 0; 635 ret->tlsdesc_got = 0; 636 ret->tls_ld_got.refcount = 0; 637 ret->sgotplt_jump_table_size = 0; 638 ret->tls_module_base = NULL; 639 640 ret->loc_hash_table = htab_try_create (1024, 641 elf64_x86_64_local_htab_hash, 642 elf64_x86_64_local_htab_eq, 643 NULL); 644 ret->loc_hash_memory = objalloc_create (); 645 if (!ret->loc_hash_table || !ret->loc_hash_memory) 646 { 647 free (ret); 648 return NULL; 649 } 650 651 return &ret->elf.root; 652 } 653 654 /* Destroy an X86-64 ELF linker hash table. */ 655 656 static void 657 elf64_x86_64_link_hash_table_free (struct bfd_link_hash_table *hash) 658 { 659 struct elf64_x86_64_link_hash_table *htab 660 = (struct elf64_x86_64_link_hash_table *) hash; 661 662 if (htab->loc_hash_table) 663 htab_delete (htab->loc_hash_table); 664 if (htab->loc_hash_memory) 665 objalloc_free ((struct objalloc *) htab->loc_hash_memory); 666 _bfd_generic_link_hash_table_free (hash); 667 } 668 669 /* Create .plt, .rela.plt, .got, .got.plt, .rela.got, .dynbss, and 670 .rela.bss sections in DYNOBJ, and set up shortcuts to them in our 671 hash table. */ 672 673 static bfd_boolean 674 elf64_x86_64_create_dynamic_sections (bfd *dynobj, struct bfd_link_info *info) 675 { 676 struct elf64_x86_64_link_hash_table *htab; 677 678 if (!_bfd_elf_create_dynamic_sections (dynobj, info)) 679 return FALSE; 680 681 htab = elf64_x86_64_hash_table (info); 682 htab->sdynbss = bfd_get_section_by_name (dynobj, ".dynbss"); 683 if (!info->shared) 684 htab->srelbss = bfd_get_section_by_name (dynobj, ".rela.bss"); 685 686 if (!htab->sdynbss 687 || (!info->shared && !htab->srelbss)) 688 abort (); 689 690 return TRUE; 691 } 692 693 /* Copy the extra info we tack onto an elf_link_hash_entry. */ 694 695 static void 696 elf64_x86_64_copy_indirect_symbol (struct bfd_link_info *info, 697 struct elf_link_hash_entry *dir, 698 struct elf_link_hash_entry *ind) 699 { 700 struct elf64_x86_64_link_hash_entry *edir, *eind; 701 702 edir = (struct elf64_x86_64_link_hash_entry *) dir; 703 eind = (struct elf64_x86_64_link_hash_entry *) ind; 704 705 if (eind->dyn_relocs != NULL) 706 { 707 if (edir->dyn_relocs != NULL) 708 { 709 struct elf_dyn_relocs **pp; 710 struct elf_dyn_relocs *p; 711 712 /* Add reloc counts against the indirect sym to the direct sym 713 list. Merge any entries against the same section. */ 714 for (pp = &eind->dyn_relocs; (p = *pp) != NULL; ) 715 { 716 struct elf_dyn_relocs *q; 717 718 for (q = edir->dyn_relocs; q != NULL; q = q->next) 719 if (q->sec == p->sec) 720 { 721 q->pc_count += p->pc_count; 722 q->count += p->count; 723 *pp = p->next; 724 break; 725 } 726 if (q == NULL) 727 pp = &p->next; 728 } 729 *pp = edir->dyn_relocs; 730 } 731 732 edir->dyn_relocs = eind->dyn_relocs; 733 eind->dyn_relocs = NULL; 734 } 735 736 if (ind->root.type == bfd_link_hash_indirect 737 && dir->got.refcount <= 0) 738 { 739 edir->tls_type = eind->tls_type; 740 eind->tls_type = GOT_UNKNOWN; 741 } 742 743 if (ELIMINATE_COPY_RELOCS 744 && ind->root.type != bfd_link_hash_indirect 745 && dir->dynamic_adjusted) 746 { 747 /* If called to transfer flags for a weakdef during processing 748 of elf_adjust_dynamic_symbol, don't copy non_got_ref. 749 We clear it ourselves for ELIMINATE_COPY_RELOCS. */ 750 dir->ref_dynamic |= ind->ref_dynamic; 751 dir->ref_regular |= ind->ref_regular; 752 dir->ref_regular_nonweak |= ind->ref_regular_nonweak; 753 dir->needs_plt |= ind->needs_plt; 754 dir->pointer_equality_needed |= ind->pointer_equality_needed; 755 } 756 else 757 _bfd_elf_link_hash_copy_indirect (info, dir, ind); 758 } 759 760 static bfd_boolean 761 elf64_x86_64_elf_object_p (bfd *abfd) 762 { 763 /* Set the right machine number for an x86-64 elf64 file. */ 764 bfd_default_set_arch_mach (abfd, bfd_arch_i386, bfd_mach_x86_64); 765 return TRUE; 766 } 767 768 typedef union 769 { 770 unsigned char c[2]; 771 uint16_t i; 772 } 773 x86_64_opcode16; 774 775 typedef union 776 { 777 unsigned char c[4]; 778 uint32_t i; 779 } 780 x86_64_opcode32; 781 782 /* Return TRUE if the TLS access code sequence support transition 783 from R_TYPE. */ 784 785 static bfd_boolean 786 elf64_x86_64_check_tls_transition (bfd *abfd, asection *sec, 787 bfd_byte *contents, 788 Elf_Internal_Shdr *symtab_hdr, 789 struct elf_link_hash_entry **sym_hashes, 790 unsigned int r_type, 791 const Elf_Internal_Rela *rel, 792 const Elf_Internal_Rela *relend) 793 { 794 unsigned int val; 795 unsigned long r_symndx; 796 struct elf_link_hash_entry *h; 797 bfd_vma offset; 798 799 /* Get the section contents. */ 800 if (contents == NULL) 801 { 802 if (elf_section_data (sec)->this_hdr.contents != NULL) 803 contents = elf_section_data (sec)->this_hdr.contents; 804 else 805 { 806 /* FIXME: How to better handle error condition? */ 807 if (!bfd_malloc_and_get_section (abfd, sec, &contents)) 808 return FALSE; 809 810 /* Cache the section contents for elf_link_input_bfd. */ 811 elf_section_data (sec)->this_hdr.contents = contents; 812 } 813 } 814 815 offset = rel->r_offset; 816 switch (r_type) 817 { 818 case R_X86_64_TLSGD: 819 case R_X86_64_TLSLD: 820 if ((rel + 1) >= relend) 821 return FALSE; 822 823 if (r_type == R_X86_64_TLSGD) 824 { 825 /* Check transition from GD access model. Only 826 .byte 0x66; leaq foo@tlsgd(%rip), %rdi 827 .word 0x6666; rex64; call __tls_get_addr 828 can transit to different access model. */ 829 830 static x86_64_opcode32 leaq = { { 0x66, 0x48, 0x8d, 0x3d } }, 831 call = { { 0x66, 0x66, 0x48, 0xe8 } }; 832 if (offset < 4 833 || (offset + 12) > sec->size 834 || bfd_get_32 (abfd, contents + offset - 4) != leaq.i 835 || bfd_get_32 (abfd, contents + offset + 4) != call.i) 836 return FALSE; 837 } 838 else 839 { 840 /* Check transition from LD access model. Only 841 leaq foo@tlsld(%rip), %rdi; 842 call __tls_get_addr 843 can transit to different access model. */ 844 845 static x86_64_opcode32 ld = { { 0x48, 0x8d, 0x3d, 0xe8 } }; 846 x86_64_opcode32 op; 847 848 if (offset < 3 || (offset + 9) > sec->size) 849 return FALSE; 850 851 op.i = bfd_get_32 (abfd, contents + offset - 3); 852 op.c[3] = bfd_get_8 (abfd, contents + offset + 4); 853 if (op.i != ld.i) 854 return FALSE; 855 } 856 857 r_symndx = ELF64_R_SYM (rel[1].r_info); 858 if (r_symndx < symtab_hdr->sh_info) 859 return FALSE; 860 861 h = sym_hashes[r_symndx - symtab_hdr->sh_info]; 862 /* Use strncmp to check __tls_get_addr since __tls_get_addr 863 may be versioned. */ 864 return (h != NULL 865 && h->root.root.string != NULL 866 && (ELF64_R_TYPE (rel[1].r_info) == R_X86_64_PC32 867 || ELF64_R_TYPE (rel[1].r_info) == R_X86_64_PLT32) 868 && (strncmp (h->root.root.string, 869 "__tls_get_addr", 14) == 0)); 870 871 case R_X86_64_GOTTPOFF: 872 /* Check transition from IE access model: 873 movq foo@gottpoff(%rip), %reg 874 addq foo@gottpoff(%rip), %reg 875 */ 876 877 if (offset < 3 || (offset + 4) > sec->size) 878 return FALSE; 879 880 val = bfd_get_8 (abfd, contents + offset - 3); 881 if (val != 0x48 && val != 0x4c) 882 return FALSE; 883 884 val = bfd_get_8 (abfd, contents + offset - 2); 885 if (val != 0x8b && val != 0x03) 886 return FALSE; 887 888 val = bfd_get_8 (abfd, contents + offset - 1); 889 return (val & 0xc7) == 5; 890 891 case R_X86_64_GOTPC32_TLSDESC: 892 /* Check transition from GDesc access model: 893 leaq x@tlsdesc(%rip), %rax 894 895 Make sure it's a leaq adding rip to a 32-bit offset 896 into any register, although it's probably almost always 897 going to be rax. */ 898 899 if (offset < 3 || (offset + 4) > sec->size) 900 return FALSE; 901 902 val = bfd_get_8 (abfd, contents + offset - 3); 903 if ((val & 0xfb) != 0x48) 904 return FALSE; 905 906 if (bfd_get_8 (abfd, contents + offset - 2) != 0x8d) 907 return FALSE; 908 909 val = bfd_get_8 (abfd, contents + offset - 1); 910 return (val & 0xc7) == 0x05; 911 912 case R_X86_64_TLSDESC_CALL: 913 /* Check transition from GDesc access model: 914 call *x@tlsdesc(%rax) 915 */ 916 if (offset + 2 <= sec->size) 917 { 918 /* Make sure that it's a call *x@tlsdesc(%rax). */ 919 static x86_64_opcode16 call = { { 0xff, 0x10 } }; 920 return bfd_get_16 (abfd, contents + offset) == call.i; 921 } 922 923 return FALSE; 924 925 default: 926 abort (); 927 } 928 } 929 930 /* Return TRUE if the TLS access transition is OK or no transition 931 will be performed. Update R_TYPE if there is a transition. */ 932 933 static bfd_boolean 934 elf64_x86_64_tls_transition (struct bfd_link_info *info, bfd *abfd, 935 asection *sec, bfd_byte *contents, 936 Elf_Internal_Shdr *symtab_hdr, 937 struct elf_link_hash_entry **sym_hashes, 938 unsigned int *r_type, int tls_type, 939 const Elf_Internal_Rela *rel, 940 const Elf_Internal_Rela *relend, 941 struct elf_link_hash_entry *h, 942 unsigned long r_symndx) 943 { 944 unsigned int from_type = *r_type; 945 unsigned int to_type = from_type; 946 bfd_boolean check = TRUE; 947 948 switch (from_type) 949 { 950 case R_X86_64_TLSGD: 951 case R_X86_64_GOTPC32_TLSDESC: 952 case R_X86_64_TLSDESC_CALL: 953 case R_X86_64_GOTTPOFF: 954 if (info->executable) 955 { 956 if (h == NULL) 957 to_type = R_X86_64_TPOFF32; 958 else 959 to_type = R_X86_64_GOTTPOFF; 960 } 961 962 /* When we are called from elf64_x86_64_relocate_section, 963 CONTENTS isn't NULL and there may be additional transitions 964 based on TLS_TYPE. */ 965 if (contents != NULL) 966 { 967 unsigned int new_to_type = to_type; 968 969 if (info->executable 970 && h != NULL 971 && h->dynindx == -1 972 && tls_type == GOT_TLS_IE) 973 new_to_type = R_X86_64_TPOFF32; 974 975 if (to_type == R_X86_64_TLSGD 976 || to_type == R_X86_64_GOTPC32_TLSDESC 977 || to_type == R_X86_64_TLSDESC_CALL) 978 { 979 if (tls_type == GOT_TLS_IE) 980 new_to_type = R_X86_64_GOTTPOFF; 981 } 982 983 /* We checked the transition before when we were called from 984 elf64_x86_64_check_relocs. We only want to check the new 985 transition which hasn't been checked before. */ 986 check = new_to_type != to_type && from_type == to_type; 987 to_type = new_to_type; 988 } 989 990 break; 991 992 case R_X86_64_TLSLD: 993 if (info->executable) 994 to_type = R_X86_64_TPOFF32; 995 break; 996 997 default: 998 return TRUE; 999 } 1000 1001 /* Return TRUE if there is no transition. */ 1002 if (from_type == to_type) 1003 return TRUE; 1004 1005 /* Check if the transition can be performed. */ 1006 if (check 1007 && ! elf64_x86_64_check_tls_transition (abfd, sec, contents, 1008 symtab_hdr, sym_hashes, 1009 from_type, rel, relend)) 1010 { 1011 reloc_howto_type *from, *to; 1012 const char *name; 1013 1014 from = elf64_x86_64_rtype_to_howto (abfd, from_type); 1015 to = elf64_x86_64_rtype_to_howto (abfd, to_type); 1016 1017 if (h) 1018 name = h->root.root.string; 1019 else 1020 { 1021 Elf_Internal_Sym *isym; 1022 struct elf64_x86_64_link_hash_table *htab; 1023 htab = elf64_x86_64_hash_table (info); 1024 isym = bfd_sym_from_r_symndx (&htab->sym_cache, 1025 abfd, r_symndx); 1026 name = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL); 1027 } 1028 1029 (*_bfd_error_handler) 1030 (_("%B: TLS transition from %s to %s against `%s' at 0x%lx " 1031 "in section `%A' failed"), 1032 abfd, sec, from->name, to->name, name, 1033 (unsigned long) rel->r_offset); 1034 bfd_set_error (bfd_error_bad_value); 1035 return FALSE; 1036 } 1037 1038 *r_type = to_type; 1039 return TRUE; 1040 } 1041 1042 /* Look through the relocs for a section during the first phase, and 1043 calculate needed space in the global offset table, procedure 1044 linkage table, and dynamic reloc sections. */ 1045 1046 static bfd_boolean 1047 elf64_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, 1048 asection *sec, 1049 const Elf_Internal_Rela *relocs) 1050 { 1051 struct elf64_x86_64_link_hash_table *htab; 1052 Elf_Internal_Shdr *symtab_hdr; 1053 struct elf_link_hash_entry **sym_hashes; 1054 const Elf_Internal_Rela *rel; 1055 const Elf_Internal_Rela *rel_end; 1056 asection *sreloc; 1057 1058 if (info->relocatable) 1059 return TRUE; 1060 1061 BFD_ASSERT (is_x86_64_elf (abfd)); 1062 1063 htab = elf64_x86_64_hash_table (info); 1064 symtab_hdr = &elf_symtab_hdr (abfd); 1065 sym_hashes = elf_sym_hashes (abfd); 1066 1067 sreloc = NULL; 1068 1069 rel_end = relocs + sec->reloc_count; 1070 for (rel = relocs; rel < rel_end; rel++) 1071 { 1072 unsigned int r_type; 1073 unsigned long r_symndx; 1074 struct elf_link_hash_entry *h; 1075 Elf_Internal_Sym *isym; 1076 const char *name; 1077 1078 r_symndx = ELF64_R_SYM (rel->r_info); 1079 r_type = ELF64_R_TYPE (rel->r_info); 1080 1081 if (r_symndx >= NUM_SHDR_ENTRIES (symtab_hdr)) 1082 { 1083 (*_bfd_error_handler) (_("%B: bad symbol index: %d"), 1084 abfd, r_symndx); 1085 return FALSE; 1086 } 1087 1088 if (r_symndx < symtab_hdr->sh_info) 1089 { 1090 /* A local symbol. */ 1091 isym = bfd_sym_from_r_symndx (&htab->sym_cache, 1092 abfd, r_symndx); 1093 if (isym == NULL) 1094 return FALSE; 1095 1096 /* Check relocation against local STT_GNU_IFUNC symbol. */ 1097 if (ELF64_ST_TYPE (isym->st_info) == STT_GNU_IFUNC) 1098 { 1099 h = elf64_x86_64_get_local_sym_hash (htab, abfd, rel, 1100 TRUE); 1101 if (h == NULL) 1102 return FALSE; 1103 1104 /* Fake a STT_GNU_IFUNC symbol. */ 1105 h->type = STT_GNU_IFUNC; 1106 h->def_regular = 1; 1107 h->ref_regular = 1; 1108 h->forced_local = 1; 1109 h->root.type = bfd_link_hash_defined; 1110 } 1111 else 1112 h = NULL; 1113 } 1114 else 1115 { 1116 isym = NULL; 1117 h = sym_hashes[r_symndx - symtab_hdr->sh_info]; 1118 while (h->root.type == bfd_link_hash_indirect 1119 || h->root.type == bfd_link_hash_warning) 1120 h = (struct elf_link_hash_entry *) h->root.u.i.link; 1121 } 1122 1123 if (h != NULL) 1124 { 1125 /* Create the ifunc sections for static executables. If we 1126 never see an indirect function symbol nor we are building 1127 a static executable, those sections will be empty and 1128 won't appear in output. */ 1129 switch (r_type) 1130 { 1131 default: 1132 break; 1133 1134 case R_X86_64_32S: 1135 case R_X86_64_32: 1136 case R_X86_64_64: 1137 case R_X86_64_PC32: 1138 case R_X86_64_PC64: 1139 case R_X86_64_PLT32: 1140 case R_X86_64_GOTPCREL: 1141 case R_X86_64_GOTPCREL64: 1142 if (!_bfd_elf_create_ifunc_sections (abfd, info)) 1143 return FALSE; 1144 break; 1145 } 1146 1147 /* Since STT_GNU_IFUNC symbol must go through PLT, we handle 1148 it here if it is defined in a non-shared object. */ 1149 if (h->type == STT_GNU_IFUNC 1150 && h->def_regular) 1151 { 1152 /* It is referenced by a non-shared object. */ 1153 h->ref_regular = 1; 1154 h->needs_plt = 1; 1155 1156 /* STT_GNU_IFUNC symbol must go through PLT. */ 1157 h->plt.refcount += 1; 1158 1159 /* STT_GNU_IFUNC needs dynamic sections. */ 1160 if (htab->elf.dynobj == NULL) 1161 htab->elf.dynobj = abfd; 1162 1163 switch (r_type) 1164 { 1165 default: 1166 if (h->root.root.string) 1167 name = h->root.root.string; 1168 else 1169 name = bfd_elf_sym_name (abfd, symtab_hdr, isym, 1170 NULL); 1171 (*_bfd_error_handler) 1172 (_("%B: relocation %s against STT_GNU_IFUNC " 1173 "symbol `%s' isn't handled by %s"), abfd, 1174 x86_64_elf_howto_table[r_type].name, 1175 name, __FUNCTION__); 1176 bfd_set_error (bfd_error_bad_value); 1177 return FALSE; 1178 1179 case R_X86_64_64: 1180 h->non_got_ref = 1; 1181 h->pointer_equality_needed = 1; 1182 if (info->shared) 1183 { 1184 /* We must copy these reloc types into the output 1185 file. Create a reloc section in dynobj and 1186 make room for this reloc. */ 1187 sreloc = _bfd_elf_create_ifunc_dyn_reloc 1188 (abfd, info, sec, sreloc, 1189 &((struct elf64_x86_64_link_hash_entry *) h)->dyn_relocs); 1190 if (sreloc == NULL) 1191 return FALSE; 1192 } 1193 break; 1194 1195 case R_X86_64_32S: 1196 case R_X86_64_32: 1197 case R_X86_64_PC32: 1198 case R_X86_64_PC64: 1199 h->non_got_ref = 1; 1200 if (r_type != R_X86_64_PC32 1201 && r_type != R_X86_64_PC64) 1202 h->pointer_equality_needed = 1; 1203 break; 1204 1205 case R_X86_64_PLT32: 1206 break; 1207 1208 case R_X86_64_GOTPCREL: 1209 case R_X86_64_GOTPCREL64: 1210 h->got.refcount += 1; 1211 if (htab->elf.sgot == NULL 1212 && !_bfd_elf_create_got_section (htab->elf.dynobj, 1213 info)) 1214 return FALSE; 1215 break; 1216 } 1217 1218 continue; 1219 } 1220 } 1221 1222 if (! elf64_x86_64_tls_transition (info, abfd, sec, NULL, 1223 symtab_hdr, sym_hashes, 1224 &r_type, GOT_UNKNOWN, 1225 rel, rel_end, h, r_symndx)) 1226 return FALSE; 1227 1228 switch (r_type) 1229 { 1230 case R_X86_64_TLSLD: 1231 htab->tls_ld_got.refcount += 1; 1232 goto create_got; 1233 1234 case R_X86_64_TPOFF32: 1235 if (!info->executable) 1236 { 1237 if (h) 1238 name = h->root.root.string; 1239 else 1240 name = bfd_elf_sym_name (abfd, symtab_hdr, isym, 1241 NULL); 1242 (*_bfd_error_handler) 1243 (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"), 1244 abfd, 1245 x86_64_elf_howto_table[r_type].name, name); 1246 bfd_set_error (bfd_error_bad_value); 1247 return FALSE; 1248 } 1249 break; 1250 1251 case R_X86_64_GOTTPOFF: 1252 if (!info->executable) 1253 info->flags |= DF_STATIC_TLS; 1254 /* Fall through */ 1255 1256 case R_X86_64_GOT32: 1257 case R_X86_64_GOTPCREL: 1258 case R_X86_64_TLSGD: 1259 case R_X86_64_GOT64: 1260 case R_X86_64_GOTPCREL64: 1261 case R_X86_64_GOTPLT64: 1262 case R_X86_64_GOTPC32_TLSDESC: 1263 case R_X86_64_TLSDESC_CALL: 1264 /* This symbol requires a global offset table entry. */ 1265 { 1266 int tls_type, old_tls_type; 1267 1268 switch (r_type) 1269 { 1270 default: tls_type = GOT_NORMAL; break; 1271 case R_X86_64_TLSGD: tls_type = GOT_TLS_GD; break; 1272 case R_X86_64_GOTTPOFF: tls_type = GOT_TLS_IE; break; 1273 case R_X86_64_GOTPC32_TLSDESC: 1274 case R_X86_64_TLSDESC_CALL: 1275 tls_type = GOT_TLS_GDESC; break; 1276 } 1277 1278 if (h != NULL) 1279 { 1280 if (r_type == R_X86_64_GOTPLT64) 1281 { 1282 /* This relocation indicates that we also need 1283 a PLT entry, as this is a function. We don't need 1284 a PLT entry for local symbols. */ 1285 h->needs_plt = 1; 1286 h->plt.refcount += 1; 1287 } 1288 h->got.refcount += 1; 1289 old_tls_type = elf64_x86_64_hash_entry (h)->tls_type; 1290 } 1291 else 1292 { 1293 bfd_signed_vma *local_got_refcounts; 1294 1295 /* This is a global offset table entry for a local symbol. */ 1296 local_got_refcounts = elf_local_got_refcounts (abfd); 1297 if (local_got_refcounts == NULL) 1298 { 1299 bfd_size_type size; 1300 1301 size = symtab_hdr->sh_info; 1302 size *= sizeof (bfd_signed_vma) 1303 + sizeof (bfd_vma) + sizeof (char); 1304 local_got_refcounts = ((bfd_signed_vma *) 1305 bfd_zalloc (abfd, size)); 1306 if (local_got_refcounts == NULL) 1307 return FALSE; 1308 elf_local_got_refcounts (abfd) = local_got_refcounts; 1309 elf64_x86_64_local_tlsdesc_gotent (abfd) 1310 = (bfd_vma *) (local_got_refcounts + symtab_hdr->sh_info); 1311 elf64_x86_64_local_got_tls_type (abfd) 1312 = (char *) (local_got_refcounts + 2 * symtab_hdr->sh_info); 1313 } 1314 local_got_refcounts[r_symndx] += 1; 1315 old_tls_type 1316 = elf64_x86_64_local_got_tls_type (abfd) [r_symndx]; 1317 } 1318 1319 /* If a TLS symbol is accessed using IE at least once, 1320 there is no point to use dynamic model for it. */ 1321 if (old_tls_type != tls_type && old_tls_type != GOT_UNKNOWN 1322 && (! GOT_TLS_GD_ANY_P (old_tls_type) 1323 || tls_type != GOT_TLS_IE)) 1324 { 1325 if (old_tls_type == GOT_TLS_IE && GOT_TLS_GD_ANY_P (tls_type)) 1326 tls_type = old_tls_type; 1327 else if (GOT_TLS_GD_ANY_P (old_tls_type) 1328 && GOT_TLS_GD_ANY_P (tls_type)) 1329 tls_type |= old_tls_type; 1330 else 1331 { 1332 if (h) 1333 name = h->root.root.string; 1334 else 1335 name = bfd_elf_sym_name (abfd, symtab_hdr, 1336 isym, NULL); 1337 (*_bfd_error_handler) 1338 (_("%B: '%s' accessed both as normal and thread local symbol"), 1339 abfd, name); 1340 return FALSE; 1341 } 1342 } 1343 1344 if (old_tls_type != tls_type) 1345 { 1346 if (h != NULL) 1347 elf64_x86_64_hash_entry (h)->tls_type = tls_type; 1348 else 1349 elf64_x86_64_local_got_tls_type (abfd) [r_symndx] = tls_type; 1350 } 1351 } 1352 /* Fall through */ 1353 1354 case R_X86_64_GOTOFF64: 1355 case R_X86_64_GOTPC32: 1356 case R_X86_64_GOTPC64: 1357 create_got: 1358 if (htab->elf.sgot == NULL) 1359 { 1360 if (htab->elf.dynobj == NULL) 1361 htab->elf.dynobj = abfd; 1362 if (!_bfd_elf_create_got_section (htab->elf.dynobj, 1363 info)) 1364 return FALSE; 1365 } 1366 break; 1367 1368 case R_X86_64_PLT32: 1369 /* This symbol requires a procedure linkage table entry. We 1370 actually build the entry in adjust_dynamic_symbol, 1371 because this might be a case of linking PIC code which is 1372 never referenced by a dynamic object, in which case we 1373 don't need to generate a procedure linkage table entry 1374 after all. */ 1375 1376 /* If this is a local symbol, we resolve it directly without 1377 creating a procedure linkage table entry. */ 1378 if (h == NULL) 1379 continue; 1380 1381 h->needs_plt = 1; 1382 h->plt.refcount += 1; 1383 break; 1384 1385 case R_X86_64_PLTOFF64: 1386 /* This tries to form the 'address' of a function relative 1387 to GOT. For global symbols we need a PLT entry. */ 1388 if (h != NULL) 1389 { 1390 h->needs_plt = 1; 1391 h->plt.refcount += 1; 1392 } 1393 goto create_got; 1394 1395 case R_X86_64_8: 1396 case R_X86_64_16: 1397 case R_X86_64_32: 1398 case R_X86_64_32S: 1399 /* Let's help debug shared library creation. These relocs 1400 cannot be used in shared libs. Don't error out for 1401 sections we don't care about, such as debug sections or 1402 non-constant sections. */ 1403 if (info->shared 1404 && (sec->flags & SEC_ALLOC) != 0 1405 && (sec->flags & SEC_READONLY) != 0) 1406 { 1407 if (h) 1408 name = h->root.root.string; 1409 else 1410 name = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL); 1411 (*_bfd_error_handler) 1412 (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"), 1413 abfd, x86_64_elf_howto_table[r_type].name, name); 1414 bfd_set_error (bfd_error_bad_value); 1415 return FALSE; 1416 } 1417 /* Fall through. */ 1418 1419 case R_X86_64_PC8: 1420 case R_X86_64_PC16: 1421 case R_X86_64_PC32: 1422 case R_X86_64_PC64: 1423 case R_X86_64_64: 1424 if (h != NULL && info->executable) 1425 { 1426 /* If this reloc is in a read-only section, we might 1427 need a copy reloc. We can't check reliably at this 1428 stage whether the section is read-only, as input 1429 sections have not yet been mapped to output sections. 1430 Tentatively set the flag for now, and correct in 1431 adjust_dynamic_symbol. */ 1432 h->non_got_ref = 1; 1433 1434 /* We may need a .plt entry if the function this reloc 1435 refers to is in a shared lib. */ 1436 h->plt.refcount += 1; 1437 if (r_type != R_X86_64_PC32 && r_type != R_X86_64_PC64) 1438 h->pointer_equality_needed = 1; 1439 } 1440 1441 /* If we are creating a shared library, and this is a reloc 1442 against a global symbol, or a non PC relative reloc 1443 against a local symbol, then we need to copy the reloc 1444 into the shared library. However, if we are linking with 1445 -Bsymbolic, we do not need to copy a reloc against a 1446 global symbol which is defined in an object we are 1447 including in the link (i.e., DEF_REGULAR is set). At 1448 this point we have not seen all the input files, so it is 1449 possible that DEF_REGULAR is not set now but will be set 1450 later (it is never cleared). In case of a weak definition, 1451 DEF_REGULAR may be cleared later by a strong definition in 1452 a shared library. We account for that possibility below by 1453 storing information in the relocs_copied field of the hash 1454 table entry. A similar situation occurs when creating 1455 shared libraries and symbol visibility changes render the 1456 symbol local. 1457 1458 If on the other hand, we are creating an executable, we 1459 may need to keep relocations for symbols satisfied by a 1460 dynamic library if we manage to avoid copy relocs for the 1461 symbol. */ 1462 if ((info->shared 1463 && (sec->flags & SEC_ALLOC) != 0 1464 && (! IS_X86_64_PCREL_TYPE (r_type) 1465 || (h != NULL 1466 && (! SYMBOLIC_BIND (info, h) 1467 || h->root.type == bfd_link_hash_defweak 1468 || !h->def_regular)))) 1469 || (ELIMINATE_COPY_RELOCS 1470 && !info->shared 1471 && (sec->flags & SEC_ALLOC) != 0 1472 && h != NULL 1473 && (h->root.type == bfd_link_hash_defweak 1474 || !h->def_regular))) 1475 { 1476 struct elf_dyn_relocs *p; 1477 struct elf_dyn_relocs **head; 1478 1479 /* We must copy these reloc types into the output file. 1480 Create a reloc section in dynobj and make room for 1481 this reloc. */ 1482 if (sreloc == NULL) 1483 { 1484 if (htab->elf.dynobj == NULL) 1485 htab->elf.dynobj = abfd; 1486 1487 sreloc = _bfd_elf_make_dynamic_reloc_section 1488 (sec, htab->elf.dynobj, 3, abfd, /*rela?*/ TRUE); 1489 1490 if (sreloc == NULL) 1491 return FALSE; 1492 } 1493 1494 /* If this is a global symbol, we count the number of 1495 relocations we need for this symbol. */ 1496 if (h != NULL) 1497 { 1498 head = &((struct elf64_x86_64_link_hash_entry *) h)->dyn_relocs; 1499 } 1500 else 1501 { 1502 /* Track dynamic relocs needed for local syms too. 1503 We really need local syms available to do this 1504 easily. Oh well. */ 1505 asection *s; 1506 void **vpp; 1507 Elf_Internal_Sym *isym; 1508 1509 isym = bfd_sym_from_r_symndx (&htab->sym_cache, 1510 abfd, r_symndx); 1511 if (isym == NULL) 1512 return FALSE; 1513 1514 s = bfd_section_from_elf_index (abfd, isym->st_shndx); 1515 if (s == NULL) 1516 s = sec; 1517 1518 /* Beware of type punned pointers vs strict aliasing 1519 rules. */ 1520 vpp = &(elf_section_data (s)->local_dynrel); 1521 head = (struct elf_dyn_relocs **)vpp; 1522 } 1523 1524 p = *head; 1525 if (p == NULL || p->sec != sec) 1526 { 1527 bfd_size_type amt = sizeof *p; 1528 1529 p = ((struct elf_dyn_relocs *) 1530 bfd_alloc (htab->elf.dynobj, amt)); 1531 if (p == NULL) 1532 return FALSE; 1533 p->next = *head; 1534 *head = p; 1535 p->sec = sec; 1536 p->count = 0; 1537 p->pc_count = 0; 1538 } 1539 1540 p->count += 1; 1541 if (IS_X86_64_PCREL_TYPE (r_type)) 1542 p->pc_count += 1; 1543 } 1544 break; 1545 1546 /* This relocation describes the C++ object vtable hierarchy. 1547 Reconstruct it for later use during GC. */ 1548 case R_X86_64_GNU_VTINHERIT: 1549 if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset)) 1550 return FALSE; 1551 break; 1552 1553 /* This relocation describes which C++ vtable entries are actually 1554 used. Record for later use during GC. */ 1555 case R_X86_64_GNU_VTENTRY: 1556 BFD_ASSERT (h != NULL); 1557 if (h != NULL 1558 && !bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend)) 1559 return FALSE; 1560 break; 1561 1562 default: 1563 break; 1564 } 1565 } 1566 1567 return TRUE; 1568 } 1569 1570 /* Return the section that should be marked against GC for a given 1571 relocation. */ 1572 1573 static asection * 1574 elf64_x86_64_gc_mark_hook (asection *sec, 1575 struct bfd_link_info *info, 1576 Elf_Internal_Rela *rel, 1577 struct elf_link_hash_entry *h, 1578 Elf_Internal_Sym *sym) 1579 { 1580 if (h != NULL) 1581 switch (ELF64_R_TYPE (rel->r_info)) 1582 { 1583 case R_X86_64_GNU_VTINHERIT: 1584 case R_X86_64_GNU_VTENTRY: 1585 return NULL; 1586 } 1587 1588 return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym); 1589 } 1590 1591 /* Update the got entry reference counts for the section being removed. */ 1592 1593 static bfd_boolean 1594 elf64_x86_64_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info, 1595 asection *sec, 1596 const Elf_Internal_Rela *relocs) 1597 { 1598 Elf_Internal_Shdr *symtab_hdr; 1599 struct elf_link_hash_entry **sym_hashes; 1600 bfd_signed_vma *local_got_refcounts; 1601 const Elf_Internal_Rela *rel, *relend; 1602 1603 if (info->relocatable) 1604 return TRUE; 1605 1606 elf_section_data (sec)->local_dynrel = NULL; 1607 1608 symtab_hdr = &elf_symtab_hdr (abfd); 1609 sym_hashes = elf_sym_hashes (abfd); 1610 local_got_refcounts = elf_local_got_refcounts (abfd); 1611 1612 relend = relocs + sec->reloc_count; 1613 for (rel = relocs; rel < relend; rel++) 1614 { 1615 unsigned long r_symndx; 1616 unsigned int r_type; 1617 struct elf_link_hash_entry *h = NULL; 1618 1619 r_symndx = ELF64_R_SYM (rel->r_info); 1620 if (r_symndx >= symtab_hdr->sh_info) 1621 { 1622 struct elf64_x86_64_link_hash_entry *eh; 1623 struct elf_dyn_relocs **pp; 1624 struct elf_dyn_relocs *p; 1625 1626 h = sym_hashes[r_symndx - symtab_hdr->sh_info]; 1627 while (h->root.type == bfd_link_hash_indirect 1628 || h->root.type == bfd_link_hash_warning) 1629 h = (struct elf_link_hash_entry *) h->root.u.i.link; 1630 eh = (struct elf64_x86_64_link_hash_entry *) h; 1631 1632 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; pp = &p->next) 1633 if (p->sec == sec) 1634 { 1635 /* Everything must go for SEC. */ 1636 *pp = p->next; 1637 break; 1638 } 1639 } 1640 1641 r_type = ELF64_R_TYPE (rel->r_info); 1642 if (! elf64_x86_64_tls_transition (info, abfd, sec, NULL, 1643 symtab_hdr, sym_hashes, 1644 &r_type, GOT_UNKNOWN, 1645 rel, relend, h, r_symndx)) 1646 return FALSE; 1647 1648 switch (r_type) 1649 { 1650 case R_X86_64_TLSLD: 1651 if (elf64_x86_64_hash_table (info)->tls_ld_got.refcount > 0) 1652 elf64_x86_64_hash_table (info)->tls_ld_got.refcount -= 1; 1653 break; 1654 1655 case R_X86_64_TLSGD: 1656 case R_X86_64_GOTPC32_TLSDESC: 1657 case R_X86_64_TLSDESC_CALL: 1658 case R_X86_64_GOTTPOFF: 1659 case R_X86_64_GOT32: 1660 case R_X86_64_GOTPCREL: 1661 case R_X86_64_GOT64: 1662 case R_X86_64_GOTPCREL64: 1663 case R_X86_64_GOTPLT64: 1664 if (h != NULL) 1665 { 1666 if (r_type == R_X86_64_GOTPLT64 && h->plt.refcount > 0) 1667 h->plt.refcount -= 1; 1668 if (h->got.refcount > 0) 1669 h->got.refcount -= 1; 1670 } 1671 else if (local_got_refcounts != NULL) 1672 { 1673 if (local_got_refcounts[r_symndx] > 0) 1674 local_got_refcounts[r_symndx] -= 1; 1675 } 1676 break; 1677 1678 case R_X86_64_8: 1679 case R_X86_64_16: 1680 case R_X86_64_32: 1681 case R_X86_64_64: 1682 case R_X86_64_32S: 1683 case R_X86_64_PC8: 1684 case R_X86_64_PC16: 1685 case R_X86_64_PC32: 1686 case R_X86_64_PC64: 1687 if (info->shared) 1688 break; 1689 /* Fall thru */ 1690 1691 case R_X86_64_PLT32: 1692 case R_X86_64_PLTOFF64: 1693 if (h != NULL) 1694 { 1695 if (h->plt.refcount > 0) 1696 h->plt.refcount -= 1; 1697 } 1698 break; 1699 1700 default: 1701 break; 1702 } 1703 } 1704 1705 return TRUE; 1706 } 1707 1708 /* Adjust a symbol defined by a dynamic object and referenced by a 1709 regular object. The current definition is in some section of the 1710 dynamic object, but we're not including those sections. We have to 1711 change the definition to something the rest of the link can 1712 understand. */ 1713 1714 static bfd_boolean 1715 elf64_x86_64_adjust_dynamic_symbol (struct bfd_link_info *info, 1716 struct elf_link_hash_entry *h) 1717 { 1718 struct elf64_x86_64_link_hash_table *htab; 1719 asection *s; 1720 1721 /* STT_GNU_IFUNC symbol must go through PLT. */ 1722 if (h->type == STT_GNU_IFUNC) 1723 { 1724 if (h->plt.refcount <= 0) 1725 { 1726 h->plt.offset = (bfd_vma) -1; 1727 h->needs_plt = 0; 1728 } 1729 return TRUE; 1730 } 1731 1732 /* If this is a function, put it in the procedure linkage table. We 1733 will fill in the contents of the procedure linkage table later, 1734 when we know the address of the .got section. */ 1735 if (h->type == STT_FUNC 1736 || h->needs_plt) 1737 { 1738 if (h->plt.refcount <= 0 1739 || SYMBOL_CALLS_LOCAL (info, h) 1740 || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT 1741 && h->root.type == bfd_link_hash_undefweak)) 1742 { 1743 /* This case can occur if we saw a PLT32 reloc in an input 1744 file, but the symbol was never referred to by a dynamic 1745 object, or if all references were garbage collected. In 1746 such a case, we don't actually need to build a procedure 1747 linkage table, and we can just do a PC32 reloc instead. */ 1748 h->plt.offset = (bfd_vma) -1; 1749 h->needs_plt = 0; 1750 } 1751 1752 return TRUE; 1753 } 1754 else 1755 /* It's possible that we incorrectly decided a .plt reloc was 1756 needed for an R_X86_64_PC32 reloc to a non-function sym in 1757 check_relocs. We can't decide accurately between function and 1758 non-function syms in check-relocs; Objects loaded later in 1759 the link may change h->type. So fix it now. */ 1760 h->plt.offset = (bfd_vma) -1; 1761 1762 /* If this is a weak symbol, and there is a real definition, the 1763 processor independent code will have arranged for us to see the 1764 real definition first, and we can just use the same value. */ 1765 if (h->u.weakdef != NULL) 1766 { 1767 BFD_ASSERT (h->u.weakdef->root.type == bfd_link_hash_defined 1768 || h->u.weakdef->root.type == bfd_link_hash_defweak); 1769 h->root.u.def.section = h->u.weakdef->root.u.def.section; 1770 h->root.u.def.value = h->u.weakdef->root.u.def.value; 1771 if (ELIMINATE_COPY_RELOCS || info->nocopyreloc) 1772 h->non_got_ref = h->u.weakdef->non_got_ref; 1773 return TRUE; 1774 } 1775 1776 /* This is a reference to a symbol defined by a dynamic object which 1777 is not a function. */ 1778 1779 /* If we are creating a shared library, we must presume that the 1780 only references to the symbol are via the global offset table. 1781 For such cases we need not do anything here; the relocations will 1782 be handled correctly by relocate_section. */ 1783 if (info->shared) 1784 return TRUE; 1785 1786 /* If there are no references to this symbol that do not use the 1787 GOT, we don't need to generate a copy reloc. */ 1788 if (!h->non_got_ref) 1789 return TRUE; 1790 1791 /* If -z nocopyreloc was given, we won't generate them either. */ 1792 if (info->nocopyreloc) 1793 { 1794 h->non_got_ref = 0; 1795 return TRUE; 1796 } 1797 1798 if (ELIMINATE_COPY_RELOCS) 1799 { 1800 struct elf64_x86_64_link_hash_entry * eh; 1801 struct elf_dyn_relocs *p; 1802 1803 eh = (struct elf64_x86_64_link_hash_entry *) h; 1804 for (p = eh->dyn_relocs; p != NULL; p = p->next) 1805 { 1806 s = p->sec->output_section; 1807 if (s != NULL && (s->flags & SEC_READONLY) != 0) 1808 break; 1809 } 1810 1811 /* If we didn't find any dynamic relocs in read-only sections, then 1812 we'll be keeping the dynamic relocs and avoiding the copy reloc. */ 1813 if (p == NULL) 1814 { 1815 h->non_got_ref = 0; 1816 return TRUE; 1817 } 1818 } 1819 1820 if (h->size == 0) 1821 { 1822 (*_bfd_error_handler) (_("dynamic variable `%s' is zero size"), 1823 h->root.root.string); 1824 return TRUE; 1825 } 1826 1827 /* We must allocate the symbol in our .dynbss section, which will 1828 become part of the .bss section of the executable. There will be 1829 an entry for this symbol in the .dynsym section. The dynamic 1830 object will contain position independent code, so all references 1831 from the dynamic object to this symbol will go through the global 1832 offset table. The dynamic linker will use the .dynsym entry to 1833 determine the address it must put in the global offset table, so 1834 both the dynamic object and the regular object will refer to the 1835 same memory location for the variable. */ 1836 1837 htab = elf64_x86_64_hash_table (info); 1838 1839 /* We must generate a R_X86_64_COPY reloc to tell the dynamic linker 1840 to copy the initial value out of the dynamic object and into the 1841 runtime process image. */ 1842 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0) 1843 { 1844 htab->srelbss->size += sizeof (Elf64_External_Rela); 1845 h->needs_copy = 1; 1846 } 1847 1848 s = htab->sdynbss; 1849 1850 return _bfd_elf_adjust_dynamic_copy (h, s); 1851 } 1852 1853 /* Allocate space in .plt, .got and associated reloc sections for 1854 dynamic relocs. */ 1855 1856 static bfd_boolean 1857 elf64_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) 1858 { 1859 struct bfd_link_info *info; 1860 struct elf64_x86_64_link_hash_table *htab; 1861 struct elf64_x86_64_link_hash_entry *eh; 1862 struct elf_dyn_relocs *p; 1863 1864 if (h->root.type == bfd_link_hash_indirect) 1865 return TRUE; 1866 1867 if (h->root.type == bfd_link_hash_warning) 1868 h = (struct elf_link_hash_entry *) h->root.u.i.link; 1869 eh = (struct elf64_x86_64_link_hash_entry *) h; 1870 1871 info = (struct bfd_link_info *) inf; 1872 htab = elf64_x86_64_hash_table (info); 1873 1874 /* Since STT_GNU_IFUNC symbol must go through PLT, we handle it 1875 here if it is defined and referenced in a non-shared object. */ 1876 if (h->type == STT_GNU_IFUNC 1877 && h->def_regular) 1878 return _bfd_elf_allocate_ifunc_dyn_relocs (info, h, 1879 &eh->dyn_relocs, 1880 PLT_ENTRY_SIZE, 1881 GOT_ENTRY_SIZE); 1882 else if (htab->elf.dynamic_sections_created 1883 && h->plt.refcount > 0) 1884 { 1885 /* Make sure this symbol is output as a dynamic symbol. 1886 Undefined weak syms won't yet be marked as dynamic. */ 1887 if (h->dynindx == -1 1888 && !h->forced_local) 1889 { 1890 if (! bfd_elf_link_record_dynamic_symbol (info, h)) 1891 return FALSE; 1892 } 1893 1894 if (info->shared 1895 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h)) 1896 { 1897 asection *s = htab->elf.splt; 1898 1899 /* If this is the first .plt entry, make room for the special 1900 first entry. */ 1901 if (s->size == 0) 1902 s->size += PLT_ENTRY_SIZE; 1903 1904 h->plt.offset = s->size; 1905 1906 /* If this symbol is not defined in a regular file, and we are 1907 not generating a shared library, then set the symbol to this 1908 location in the .plt. This is required to make function 1909 pointers compare as equal between the normal executable and 1910 the shared library. */ 1911 if (! info->shared 1912 && !h->def_regular) 1913 { 1914 h->root.u.def.section = s; 1915 h->root.u.def.value = h->plt.offset; 1916 } 1917 1918 /* Make room for this entry. */ 1919 s->size += PLT_ENTRY_SIZE; 1920 1921 /* We also need to make an entry in the .got.plt section, which 1922 will be placed in the .got section by the linker script. */ 1923 htab->elf.sgotplt->size += GOT_ENTRY_SIZE; 1924 1925 /* We also need to make an entry in the .rela.plt section. */ 1926 htab->elf.srelplt->size += sizeof (Elf64_External_Rela); 1927 htab->elf.srelplt->reloc_count++; 1928 } 1929 else 1930 { 1931 h->plt.offset = (bfd_vma) -1; 1932 h->needs_plt = 0; 1933 } 1934 } 1935 else 1936 { 1937 h->plt.offset = (bfd_vma) -1; 1938 h->needs_plt = 0; 1939 } 1940 1941 eh->tlsdesc_got = (bfd_vma) -1; 1942 1943 /* If R_X86_64_GOTTPOFF symbol is now local to the binary, 1944 make it a R_X86_64_TPOFF32 requiring no GOT entry. */ 1945 if (h->got.refcount > 0 1946 && info->executable 1947 && h->dynindx == -1 1948 && elf64_x86_64_hash_entry (h)->tls_type == GOT_TLS_IE) 1949 { 1950 h->got.offset = (bfd_vma) -1; 1951 } 1952 else if (h->got.refcount > 0) 1953 { 1954 asection *s; 1955 bfd_boolean dyn; 1956 int tls_type = elf64_x86_64_hash_entry (h)->tls_type; 1957 1958 /* Make sure this symbol is output as a dynamic symbol. 1959 Undefined weak syms won't yet be marked as dynamic. */ 1960 if (h->dynindx == -1 1961 && !h->forced_local) 1962 { 1963 if (! bfd_elf_link_record_dynamic_symbol (info, h)) 1964 return FALSE; 1965 } 1966 1967 if (GOT_TLS_GDESC_P (tls_type)) 1968 { 1969 eh->tlsdesc_got = htab->elf.sgotplt->size 1970 - elf64_x86_64_compute_jump_table_size (htab); 1971 htab->elf.sgotplt->size += 2 * GOT_ENTRY_SIZE; 1972 h->got.offset = (bfd_vma) -2; 1973 } 1974 if (! GOT_TLS_GDESC_P (tls_type) 1975 || GOT_TLS_GD_P (tls_type)) 1976 { 1977 s = htab->elf.sgot; 1978 h->got.offset = s->size; 1979 s->size += GOT_ENTRY_SIZE; 1980 if (GOT_TLS_GD_P (tls_type)) 1981 s->size += GOT_ENTRY_SIZE; 1982 } 1983 dyn = htab->elf.dynamic_sections_created; 1984 /* R_X86_64_TLSGD needs one dynamic relocation if local symbol 1985 and two if global. 1986 R_X86_64_GOTTPOFF needs one dynamic relocation. */ 1987 if ((GOT_TLS_GD_P (tls_type) && h->dynindx == -1) 1988 || tls_type == GOT_TLS_IE) 1989 htab->elf.srelgot->size += sizeof (Elf64_External_Rela); 1990 else if (GOT_TLS_GD_P (tls_type)) 1991 htab->elf.srelgot->size += 2 * sizeof (Elf64_External_Rela); 1992 else if (! GOT_TLS_GDESC_P (tls_type) 1993 && (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT 1994 || h->root.type != bfd_link_hash_undefweak) 1995 && (info->shared 1996 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h))) 1997 htab->elf.srelgot->size += sizeof (Elf64_External_Rela); 1998 if (GOT_TLS_GDESC_P (tls_type)) 1999 { 2000 htab->elf.srelplt->size += sizeof (Elf64_External_Rela); 2001 htab->tlsdesc_plt = (bfd_vma) -1; 2002 } 2003 } 2004 else 2005 h->got.offset = (bfd_vma) -1; 2006 2007 if (eh->dyn_relocs == NULL) 2008 return TRUE; 2009 2010 /* In the shared -Bsymbolic case, discard space allocated for 2011 dynamic pc-relative relocs against symbols which turn out to be 2012 defined in regular objects. For the normal shared case, discard 2013 space for pc-relative relocs that have become local due to symbol 2014 visibility changes. */ 2015 2016 if (info->shared) 2017 { 2018 /* Relocs that use pc_count are those that appear on a call 2019 insn, or certain REL relocs that can generated via assembly. 2020 We want calls to protected symbols to resolve directly to the 2021 function rather than going via the plt. If people want 2022 function pointer comparisons to work as expected then they 2023 should avoid writing weird assembly. */ 2024 if (SYMBOL_CALLS_LOCAL (info, h)) 2025 { 2026 struct elf_dyn_relocs **pp; 2027 2028 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) 2029 { 2030 p->count -= p->pc_count; 2031 p->pc_count = 0; 2032 if (p->count == 0) 2033 *pp = p->next; 2034 else 2035 pp = &p->next; 2036 } 2037 } 2038 2039 /* Also discard relocs on undefined weak syms with non-default 2040 visibility. */ 2041 if (eh->dyn_relocs != NULL 2042 && h->root.type == bfd_link_hash_undefweak) 2043 { 2044 if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT) 2045 eh->dyn_relocs = NULL; 2046 2047 /* Make sure undefined weak symbols are output as a dynamic 2048 symbol in PIEs. */ 2049 else if (h->dynindx == -1 2050 && ! h->forced_local 2051 && ! bfd_elf_link_record_dynamic_symbol (info, h)) 2052 return FALSE; 2053 } 2054 2055 } 2056 else if (ELIMINATE_COPY_RELOCS) 2057 { 2058 /* For the non-shared case, discard space for relocs against 2059 symbols which turn out to need copy relocs or are not 2060 dynamic. */ 2061 2062 if (!h->non_got_ref 2063 && ((h->def_dynamic 2064 && !h->def_regular) 2065 || (htab->elf.dynamic_sections_created 2066 && (h->root.type == bfd_link_hash_undefweak 2067 || h->root.type == bfd_link_hash_undefined)))) 2068 { 2069 /* Make sure this symbol is output as a dynamic symbol. 2070 Undefined weak syms won't yet be marked as dynamic. */ 2071 if (h->dynindx == -1 2072 && ! h->forced_local 2073 && ! bfd_elf_link_record_dynamic_symbol (info, h)) 2074 return FALSE; 2075 2076 /* If that succeeded, we know we'll be keeping all the 2077 relocs. */ 2078 if (h->dynindx != -1) 2079 goto keep; 2080 } 2081 2082 eh->dyn_relocs = NULL; 2083 2084 keep: ; 2085 } 2086 2087 /* Finally, allocate space. */ 2088 for (p = eh->dyn_relocs; p != NULL; p = p->next) 2089 { 2090 asection * sreloc; 2091 2092 sreloc = elf_section_data (p->sec)->sreloc; 2093 2094 BFD_ASSERT (sreloc != NULL); 2095 2096 sreloc->size += p->count * sizeof (Elf64_External_Rela); 2097 } 2098 2099 return TRUE; 2100 } 2101 2102 /* Allocate space in .plt, .got and associated reloc sections for 2103 local dynamic relocs. */ 2104 2105 static bfd_boolean 2106 elf64_x86_64_allocate_local_dynrelocs (void **slot, void *inf) 2107 { 2108 struct elf_link_hash_entry *h 2109 = (struct elf_link_hash_entry *) *slot; 2110 2111 if (h->type != STT_GNU_IFUNC 2112 || !h->def_regular 2113 || !h->ref_regular 2114 || !h->forced_local 2115 || h->root.type != bfd_link_hash_defined) 2116 abort (); 2117 2118 return elf64_x86_64_allocate_dynrelocs (h, inf); 2119 } 2120 2121 /* Find any dynamic relocs that apply to read-only sections. */ 2122 2123 static bfd_boolean 2124 elf64_x86_64_readonly_dynrelocs (struct elf_link_hash_entry *h, void * inf) 2125 { 2126 struct elf64_x86_64_link_hash_entry *eh; 2127 struct elf_dyn_relocs *p; 2128 2129 if (h->root.type == bfd_link_hash_warning) 2130 h = (struct elf_link_hash_entry *) h->root.u.i.link; 2131 2132 eh = (struct elf64_x86_64_link_hash_entry *) h; 2133 for (p = eh->dyn_relocs; p != NULL; p = p->next) 2134 { 2135 asection *s = p->sec->output_section; 2136 2137 if (s != NULL && (s->flags & SEC_READONLY) != 0) 2138 { 2139 struct bfd_link_info *info = (struct bfd_link_info *) inf; 2140 2141 info->flags |= DF_TEXTREL; 2142 2143 /* Not an error, just cut short the traversal. */ 2144 return FALSE; 2145 } 2146 } 2147 return TRUE; 2148 } 2149 2150 /* Set the sizes of the dynamic sections. */ 2151 2152 static bfd_boolean 2153 elf64_x86_64_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED, 2154 struct bfd_link_info *info) 2155 { 2156 struct elf64_x86_64_link_hash_table *htab; 2157 bfd *dynobj; 2158 asection *s; 2159 bfd_boolean relocs; 2160 bfd *ibfd; 2161 2162 htab = elf64_x86_64_hash_table (info); 2163 dynobj = htab->elf.dynobj; 2164 if (dynobj == NULL) 2165 abort (); 2166 2167 if (htab->elf.dynamic_sections_created) 2168 { 2169 /* Set the contents of the .interp section to the interpreter. */ 2170 if (info->executable) 2171 { 2172 s = bfd_get_section_by_name (dynobj, ".interp"); 2173 if (s == NULL) 2174 abort (); 2175 s->size = sizeof ELF_DYNAMIC_INTERPRETER; 2176 s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER; 2177 } 2178 } 2179 2180 /* Set up .got offsets for local syms, and space for local dynamic 2181 relocs. */ 2182 for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next) 2183 { 2184 bfd_signed_vma *local_got; 2185 bfd_signed_vma *end_local_got; 2186 char *local_tls_type; 2187 bfd_vma *local_tlsdesc_gotent; 2188 bfd_size_type locsymcount; 2189 Elf_Internal_Shdr *symtab_hdr; 2190 asection *srel; 2191 2192 if (! is_x86_64_elf (ibfd)) 2193 continue; 2194 2195 for (s = ibfd->sections; s != NULL; s = s->next) 2196 { 2197 struct elf_dyn_relocs *p; 2198 2199 for (p = (struct elf_dyn_relocs *) 2200 (elf_section_data (s)->local_dynrel); 2201 p != NULL; 2202 p = p->next) 2203 { 2204 if (!bfd_is_abs_section (p->sec) 2205 && bfd_is_abs_section (p->sec->output_section)) 2206 { 2207 /* Input section has been discarded, either because 2208 it is a copy of a linkonce section or due to 2209 linker script /DISCARD/, so we'll be discarding 2210 the relocs too. */ 2211 } 2212 else if (p->count != 0) 2213 { 2214 srel = elf_section_data (p->sec)->sreloc; 2215 srel->size += p->count * sizeof (Elf64_External_Rela); 2216 if ((p->sec->output_section->flags & SEC_READONLY) != 0) 2217 info->flags |= DF_TEXTREL; 2218 } 2219 } 2220 } 2221 2222 local_got = elf_local_got_refcounts (ibfd); 2223 if (!local_got) 2224 continue; 2225 2226 symtab_hdr = &elf_symtab_hdr (ibfd); 2227 locsymcount = symtab_hdr->sh_info; 2228 end_local_got = local_got + locsymcount; 2229 local_tls_type = elf64_x86_64_local_got_tls_type (ibfd); 2230 local_tlsdesc_gotent = elf64_x86_64_local_tlsdesc_gotent (ibfd); 2231 s = htab->elf.sgot; 2232 srel = htab->elf.srelgot; 2233 for (; local_got < end_local_got; 2234 ++local_got, ++local_tls_type, ++local_tlsdesc_gotent) 2235 { 2236 *local_tlsdesc_gotent = (bfd_vma) -1; 2237 if (*local_got > 0) 2238 { 2239 if (GOT_TLS_GDESC_P (*local_tls_type)) 2240 { 2241 *local_tlsdesc_gotent = htab->elf.sgotplt->size 2242 - elf64_x86_64_compute_jump_table_size (htab); 2243 htab->elf.sgotplt->size += 2 * GOT_ENTRY_SIZE; 2244 *local_got = (bfd_vma) -2; 2245 } 2246 if (! GOT_TLS_GDESC_P (*local_tls_type) 2247 || GOT_TLS_GD_P (*local_tls_type)) 2248 { 2249 *local_got = s->size; 2250 s->size += GOT_ENTRY_SIZE; 2251 if (GOT_TLS_GD_P (*local_tls_type)) 2252 s->size += GOT_ENTRY_SIZE; 2253 } 2254 if (info->shared 2255 || GOT_TLS_GD_ANY_P (*local_tls_type) 2256 || *local_tls_type == GOT_TLS_IE) 2257 { 2258 if (GOT_TLS_GDESC_P (*local_tls_type)) 2259 { 2260 htab->elf.srelplt->size 2261 += sizeof (Elf64_External_Rela); 2262 htab->tlsdesc_plt = (bfd_vma) -1; 2263 } 2264 if (! GOT_TLS_GDESC_P (*local_tls_type) 2265 || GOT_TLS_GD_P (*local_tls_type)) 2266 srel->size += sizeof (Elf64_External_Rela); 2267 } 2268 } 2269 else 2270 *local_got = (bfd_vma) -1; 2271 } 2272 } 2273 2274 if (htab->tls_ld_got.refcount > 0) 2275 { 2276 /* Allocate 2 got entries and 1 dynamic reloc for R_X86_64_TLSLD 2277 relocs. */ 2278 htab->tls_ld_got.offset = htab->elf.sgot->size; 2279 htab->elf.sgot->size += 2 * GOT_ENTRY_SIZE; 2280 htab->elf.srelgot->size += sizeof (Elf64_External_Rela); 2281 } 2282 else 2283 htab->tls_ld_got.offset = -1; 2284 2285 /* Allocate global sym .plt and .got entries, and space for global 2286 sym dynamic relocs. */ 2287 elf_link_hash_traverse (&htab->elf, elf64_x86_64_allocate_dynrelocs, 2288 info); 2289 2290 /* Allocate .plt and .got entries, and space for local symbols. */ 2291 htab_traverse (htab->loc_hash_table, 2292 elf64_x86_64_allocate_local_dynrelocs, 2293 info); 2294 2295 /* For every jump slot reserved in the sgotplt, reloc_count is 2296 incremented. However, when we reserve space for TLS descriptors, 2297 it's not incremented, so in order to compute the space reserved 2298 for them, it suffices to multiply the reloc count by the jump 2299 slot size. */ 2300 if (htab->elf.srelplt) 2301 htab->sgotplt_jump_table_size 2302 = elf64_x86_64_compute_jump_table_size (htab); 2303 2304 if (htab->tlsdesc_plt) 2305 { 2306 /* If we're not using lazy TLS relocations, don't generate the 2307 PLT and GOT entries they require. */ 2308 if ((info->flags & DF_BIND_NOW)) 2309 htab->tlsdesc_plt = 0; 2310 else 2311 { 2312 htab->tlsdesc_got = htab->elf.sgot->size; 2313 htab->elf.sgot->size += GOT_ENTRY_SIZE; 2314 /* Reserve room for the initial entry. 2315 FIXME: we could probably do away with it in this case. */ 2316 if (htab->elf.splt->size == 0) 2317 htab->elf.splt->size += PLT_ENTRY_SIZE; 2318 htab->tlsdesc_plt = htab->elf.splt->size; 2319 htab->elf.splt->size += PLT_ENTRY_SIZE; 2320 } 2321 } 2322 2323 /* We now have determined the sizes of the various dynamic sections. 2324 Allocate memory for them. */ 2325 relocs = FALSE; 2326 for (s = dynobj->sections; s != NULL; s = s->next) 2327 { 2328 if ((s->flags & SEC_LINKER_CREATED) == 0) 2329 continue; 2330 2331 if (s == htab->elf.splt 2332 || s == htab->elf.sgot 2333 || s == htab->elf.sgotplt 2334 || s == htab->elf.iplt 2335 || s == htab->elf.igotplt 2336 || s == htab->sdynbss) 2337 { 2338 /* Strip this section if we don't need it; see the 2339 comment below. */ 2340 } 2341 else if (CONST_STRNEQ (bfd_get_section_name (dynobj, s), ".rela")) 2342 { 2343 if (s->size != 0 && s != htab->elf.srelplt) 2344 relocs = TRUE; 2345 2346 /* We use the reloc_count field as a counter if we need 2347 to copy relocs into the output file. */ 2348 if (s != htab->elf.srelplt) 2349 s->reloc_count = 0; 2350 } 2351 else 2352 { 2353 /* It's not one of our sections, so don't allocate space. */ 2354 continue; 2355 } 2356 2357 if (s->size == 0) 2358 { 2359 /* If we don't need this section, strip it from the 2360 output file. This is mostly to handle .rela.bss and 2361 .rela.plt. We must create both sections in 2362 create_dynamic_sections, because they must be created 2363 before the linker maps input sections to output 2364 sections. The linker does that before 2365 adjust_dynamic_symbol is called, and it is that 2366 function which decides whether anything needs to go 2367 into these sections. */ 2368 2369 s->flags |= SEC_EXCLUDE; 2370 continue; 2371 } 2372 2373 if ((s->flags & SEC_HAS_CONTENTS) == 0) 2374 continue; 2375 2376 /* Allocate memory for the section contents. We use bfd_zalloc 2377 here in case unused entries are not reclaimed before the 2378 section's contents are written out. This should not happen, 2379 but this way if it does, we get a R_X86_64_NONE reloc instead 2380 of garbage. */ 2381 s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->size); 2382 if (s->contents == NULL) 2383 return FALSE; 2384 } 2385 2386 if (htab->elf.dynamic_sections_created) 2387 { 2388 /* Add some entries to the .dynamic section. We fill in the 2389 values later, in elf64_x86_64_finish_dynamic_sections, but we 2390 must add the entries now so that we get the correct size for 2391 the .dynamic section. The DT_DEBUG entry is filled in by the 2392 dynamic linker and used by the debugger. */ 2393 #define add_dynamic_entry(TAG, VAL) \ 2394 _bfd_elf_add_dynamic_entry (info, TAG, VAL) 2395 2396 if (info->executable) 2397 { 2398 if (!add_dynamic_entry (DT_DEBUG, 0)) 2399 return FALSE; 2400 } 2401 2402 if (htab->elf.splt->size != 0) 2403 { 2404 if (!add_dynamic_entry (DT_PLTGOT, 0) 2405 || !add_dynamic_entry (DT_PLTRELSZ, 0) 2406 || !add_dynamic_entry (DT_PLTREL, DT_RELA) 2407 || !add_dynamic_entry (DT_JMPREL, 0)) 2408 return FALSE; 2409 2410 if (htab->tlsdesc_plt 2411 && (!add_dynamic_entry (DT_TLSDESC_PLT, 0) 2412 || !add_dynamic_entry (DT_TLSDESC_GOT, 0))) 2413 return FALSE; 2414 } 2415 2416 if (relocs) 2417 { 2418 if (!add_dynamic_entry (DT_RELA, 0) 2419 || !add_dynamic_entry (DT_RELASZ, 0) 2420 || !add_dynamic_entry (DT_RELAENT, sizeof (Elf64_External_Rela))) 2421 return FALSE; 2422 2423 /* If any dynamic relocs apply to a read-only section, 2424 then we need a DT_TEXTREL entry. */ 2425 if ((info->flags & DF_TEXTREL) == 0) 2426 elf_link_hash_traverse (&htab->elf, 2427 elf64_x86_64_readonly_dynrelocs, 2428 info); 2429 2430 if ((info->flags & DF_TEXTREL) != 0) 2431 { 2432 if (!add_dynamic_entry (DT_TEXTREL, 0)) 2433 return FALSE; 2434 } 2435 } 2436 } 2437 #undef add_dynamic_entry 2438 2439 return TRUE; 2440 } 2441 2442 static bfd_boolean 2443 elf64_x86_64_always_size_sections (bfd *output_bfd, 2444 struct bfd_link_info *info) 2445 { 2446 asection *tls_sec = elf_hash_table (info)->tls_sec; 2447 2448 if (tls_sec) 2449 { 2450 struct elf_link_hash_entry *tlsbase; 2451 2452 tlsbase = elf_link_hash_lookup (elf_hash_table (info), 2453 "_TLS_MODULE_BASE_", 2454 FALSE, FALSE, FALSE); 2455 2456 if (tlsbase && tlsbase->type == STT_TLS) 2457 { 2458 struct bfd_link_hash_entry *bh = NULL; 2459 const struct elf_backend_data *bed 2460 = get_elf_backend_data (output_bfd); 2461 2462 if (!(_bfd_generic_link_add_one_symbol 2463 (info, output_bfd, "_TLS_MODULE_BASE_", BSF_LOCAL, 2464 tls_sec, 0, NULL, FALSE, 2465 bed->collect, &bh))) 2466 return FALSE; 2467 2468 elf64_x86_64_hash_table (info)->tls_module_base = bh; 2469 2470 tlsbase = (struct elf_link_hash_entry *)bh; 2471 tlsbase->def_regular = 1; 2472 tlsbase->other = STV_HIDDEN; 2473 (*bed->elf_backend_hide_symbol) (info, tlsbase, TRUE); 2474 } 2475 } 2476 2477 return TRUE; 2478 } 2479 2480 /* _TLS_MODULE_BASE_ needs to be treated especially when linking 2481 executables. Rather than setting it to the beginning of the TLS 2482 section, we have to set it to the end. This function may be called 2483 multiple times, it is idempotent. */ 2484 2485 static void 2486 elf64_x86_64_set_tls_module_base (struct bfd_link_info *info) 2487 { 2488 struct bfd_link_hash_entry *base; 2489 2490 if (!info->executable) 2491 return; 2492 2493 base = elf64_x86_64_hash_table (info)->tls_module_base; 2494 2495 if (!base) 2496 return; 2497 2498 base->u.def.value = elf_hash_table (info)->tls_size; 2499 } 2500 2501 /* Return the base VMA address which should be subtracted from real addresses 2502 when resolving @dtpoff relocation. 2503 This is PT_TLS segment p_vaddr. */ 2504 2505 static bfd_vma 2506 elf64_x86_64_dtpoff_base (struct bfd_link_info *info) 2507 { 2508 /* If tls_sec is NULL, we should have signalled an error already. */ 2509 if (elf_hash_table (info)->tls_sec == NULL) 2510 return 0; 2511 return elf_hash_table (info)->tls_sec->vma; 2512 } 2513 2514 /* Return the relocation value for @tpoff relocation 2515 if STT_TLS virtual address is ADDRESS. */ 2516 2517 static bfd_vma 2518 elf64_x86_64_tpoff (struct bfd_link_info *info, bfd_vma address) 2519 { 2520 struct elf_link_hash_table *htab = elf_hash_table (info); 2521 2522 /* If tls_segment is NULL, we should have signalled an error already. */ 2523 if (htab->tls_sec == NULL) 2524 return 0; 2525 return address - htab->tls_size - htab->tls_sec->vma; 2526 } 2527 2528 /* Is the instruction before OFFSET in CONTENTS a 32bit relative 2529 branch? */ 2530 2531 static bfd_boolean 2532 is_32bit_relative_branch (bfd_byte *contents, bfd_vma offset) 2533 { 2534 /* Opcode Instruction 2535 0xe8 call 2536 0xe9 jump 2537 0x0f 0x8x conditional jump */ 2538 return ((offset > 0 2539 && (contents [offset - 1] == 0xe8 2540 || contents [offset - 1] == 0xe9)) 2541 || (offset > 1 2542 && contents [offset - 2] == 0x0f 2543 && (contents [offset - 1] & 0xf0) == 0x80)); 2544 } 2545 2546 /* Relocate an x86_64 ELF section. */ 2547 2548 static bfd_boolean 2549 elf64_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info, 2550 bfd *input_bfd, asection *input_section, 2551 bfd_byte *contents, Elf_Internal_Rela *relocs, 2552 Elf_Internal_Sym *local_syms, 2553 asection **local_sections) 2554 { 2555 struct elf64_x86_64_link_hash_table *htab; 2556 Elf_Internal_Shdr *symtab_hdr; 2557 struct elf_link_hash_entry **sym_hashes; 2558 bfd_vma *local_got_offsets; 2559 bfd_vma *local_tlsdesc_gotents; 2560 Elf_Internal_Rela *rel; 2561 Elf_Internal_Rela *relend; 2562 2563 BFD_ASSERT (is_x86_64_elf (input_bfd)); 2564 2565 htab = elf64_x86_64_hash_table (info); 2566 symtab_hdr = &elf_symtab_hdr (input_bfd); 2567 sym_hashes = elf_sym_hashes (input_bfd); 2568 local_got_offsets = elf_local_got_offsets (input_bfd); 2569 local_tlsdesc_gotents = elf64_x86_64_local_tlsdesc_gotent (input_bfd); 2570 2571 elf64_x86_64_set_tls_module_base (info); 2572 2573 rel = relocs; 2574 relend = relocs + input_section->reloc_count; 2575 for (; rel < relend; rel++) 2576 { 2577 unsigned int r_type; 2578 reloc_howto_type *howto; 2579 unsigned long r_symndx; 2580 struct elf_link_hash_entry *h; 2581 Elf_Internal_Sym *sym; 2582 asection *sec; 2583 bfd_vma off, offplt; 2584 bfd_vma relocation; 2585 bfd_boolean unresolved_reloc; 2586 bfd_reloc_status_type r; 2587 int tls_type; 2588 asection *base_got; 2589 2590 r_type = ELF64_R_TYPE (rel->r_info); 2591 if (r_type == (int) R_X86_64_GNU_VTINHERIT 2592 || r_type == (int) R_X86_64_GNU_VTENTRY) 2593 continue; 2594 2595 if (r_type >= R_X86_64_max) 2596 { 2597 bfd_set_error (bfd_error_bad_value); 2598 return FALSE; 2599 } 2600 2601 howto = x86_64_elf_howto_table + r_type; 2602 r_symndx = ELF64_R_SYM (rel->r_info); 2603 h = NULL; 2604 sym = NULL; 2605 sec = NULL; 2606 unresolved_reloc = FALSE; 2607 if (r_symndx < symtab_hdr->sh_info) 2608 { 2609 sym = local_syms + r_symndx; 2610 sec = local_sections[r_symndx]; 2611 2612 relocation = _bfd_elf_rela_local_sym (output_bfd, sym, 2613 &sec, rel); 2614 2615 /* Relocate against local STT_GNU_IFUNC symbol. */ 2616 if (!info->relocatable 2617 && ELF64_ST_TYPE (sym->st_info) == STT_GNU_IFUNC) 2618 { 2619 h = elf64_x86_64_get_local_sym_hash (htab, input_bfd, 2620 rel, FALSE); 2621 if (h == NULL) 2622 abort (); 2623 2624 /* Set STT_GNU_IFUNC symbol value. */ 2625 h->root.u.def.value = sym->st_value; 2626 h->root.u.def.section = sec; 2627 } 2628 } 2629 else 2630 { 2631 bfd_boolean warned; 2632 2633 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel, 2634 r_symndx, symtab_hdr, sym_hashes, 2635 h, sec, relocation, 2636 unresolved_reloc, warned); 2637 } 2638 2639 if (sec != NULL && elf_discarded_section (sec)) 2640 { 2641 /* For relocs against symbols from removed linkonce sections, 2642 or sections discarded by a linker script, we just want the 2643 section contents zeroed. Avoid any special processing. */ 2644 _bfd_clear_contents (howto, input_bfd, contents + rel->r_offset); 2645 rel->r_info = 0; 2646 rel->r_addend = 0; 2647 continue; 2648 } 2649 2650 if (info->relocatable) 2651 continue; 2652 2653 /* Since STT_GNU_IFUNC symbol must go through PLT, we handle 2654 it here if it is defined in a non-shared object. */ 2655 if (h != NULL 2656 && h->type == STT_GNU_IFUNC 2657 && h->def_regular) 2658 { 2659 asection *plt; 2660 bfd_vma plt_index; 2661 const char *name; 2662 2663 if ((input_section->flags & SEC_ALLOC) == 0 2664 || h->plt.offset == (bfd_vma) -1) 2665 abort (); 2666 2667 /* STT_GNU_IFUNC symbol must go through PLT. */ 2668 plt = htab->elf.splt ? htab->elf.splt : htab->elf.iplt; 2669 relocation = (plt->output_section->vma 2670 + plt->output_offset + h->plt.offset); 2671 2672 switch (r_type) 2673 { 2674 default: 2675 if (h->root.root.string) 2676 name = h->root.root.string; 2677 else 2678 name = bfd_elf_sym_name (input_bfd, symtab_hdr, sym, 2679 NULL); 2680 (*_bfd_error_handler) 2681 (_("%B: relocation %s against STT_GNU_IFUNC " 2682 "symbol `%s' isn't handled by %s"), input_bfd, 2683 x86_64_elf_howto_table[r_type].name, 2684 name, __FUNCTION__); 2685 bfd_set_error (bfd_error_bad_value); 2686 return FALSE; 2687 2688 case R_X86_64_32S: 2689 if (info->shared) 2690 abort (); 2691 goto do_relocation; 2692 2693 case R_X86_64_64: 2694 if (rel->r_addend != 0) 2695 { 2696 if (h->root.root.string) 2697 name = h->root.root.string; 2698 else 2699 name = bfd_elf_sym_name (input_bfd, symtab_hdr, 2700 sym, NULL); 2701 (*_bfd_error_handler) 2702 (_("%B: relocation %s against STT_GNU_IFUNC " 2703 "symbol `%s' has non-zero addend: %d"), 2704 input_bfd, x86_64_elf_howto_table[r_type].name, 2705 name, rel->r_addend); 2706 bfd_set_error (bfd_error_bad_value); 2707 return FALSE; 2708 } 2709 2710 /* Generate dynamic relcoation only when there is a 2711 non-GOF reference in a shared object. */ 2712 if (info->shared && h->non_got_ref) 2713 { 2714 Elf_Internal_Rela outrel; 2715 bfd_byte *loc; 2716 asection *sreloc; 2717 2718 /* Need a dynamic relocation to get the real function 2719 address. */ 2720 outrel.r_offset = _bfd_elf_section_offset (output_bfd, 2721 info, 2722 input_section, 2723 rel->r_offset); 2724 if (outrel.r_offset == (bfd_vma) -1 2725 || outrel.r_offset == (bfd_vma) -2) 2726 abort (); 2727 2728 outrel.r_offset += (input_section->output_section->vma 2729 + input_section->output_offset); 2730 2731 if (h->dynindx == -1 2732 || h->forced_local 2733 || info->executable) 2734 { 2735 /* This symbol is resolved locally. */ 2736 outrel.r_info = ELF64_R_INFO (0, R_X86_64_IRELATIVE); 2737 outrel.r_addend = (h->root.u.def.value 2738 + h->root.u.def.section->output_section->vma 2739 + h->root.u.def.section->output_offset); 2740 } 2741 else 2742 { 2743 outrel.r_info = ELF64_R_INFO (h->dynindx, r_type); 2744 outrel.r_addend = 0; 2745 } 2746 2747 sreloc = htab->elf.irelifunc; 2748 loc = sreloc->contents; 2749 loc += (sreloc->reloc_count++ 2750 * sizeof (Elf64_External_Rela)); 2751 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc); 2752 2753 /* If this reloc is against an external symbol, we 2754 do not want to fiddle with the addend. Otherwise, 2755 we need to include the symbol value so that it 2756 becomes an addend for the dynamic reloc. For an 2757 internal symbol, we have updated addend. */ 2758 continue; 2759 } 2760 2761 case R_X86_64_32: 2762 case R_X86_64_PC32: 2763 case R_X86_64_PC64: 2764 case R_X86_64_PLT32: 2765 goto do_relocation; 2766 2767 case R_X86_64_GOTPCREL: 2768 case R_X86_64_GOTPCREL64: 2769 base_got = htab->elf.sgot; 2770 off = h->got.offset; 2771 2772 if (base_got == NULL) 2773 abort (); 2774 2775 if (off == (bfd_vma) -1) 2776 { 2777 /* We can't use h->got.offset here to save state, or 2778 even just remember the offset, as finish_dynamic_symbol 2779 would use that as offset into .got. */ 2780 2781 if (htab->elf.splt != NULL) 2782 { 2783 plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1; 2784 off = (plt_index + 3) * GOT_ENTRY_SIZE; 2785 base_got = htab->elf.sgotplt; 2786 } 2787 else 2788 { 2789 plt_index = h->plt.offset / PLT_ENTRY_SIZE; 2790 off = plt_index * GOT_ENTRY_SIZE; 2791 base_got = htab->elf.igotplt; 2792 } 2793 2794 if (h->dynindx == -1 2795 || h->forced_local 2796 || info->symbolic) 2797 { 2798 /* This references the local defitionion. We must 2799 initialize this entry in the global offset table. 2800 Since the offset must always be a multiple of 8, 2801 we use the least significant bit to record 2802 whether we have initialized it already. 2803 2804 When doing a dynamic link, we create a .rela.got 2805 relocation entry to initialize the value. This 2806 is done in the finish_dynamic_symbol routine. */ 2807 if ((off & 1) != 0) 2808 off &= ~1; 2809 else 2810 { 2811 bfd_put_64 (output_bfd, relocation, 2812 base_got->contents + off); 2813 /* Note that this is harmless for the GOTPLT64 2814 case, as -1 | 1 still is -1. */ 2815 h->got.offset |= 1; 2816 } 2817 } 2818 } 2819 2820 relocation = (base_got->output_section->vma 2821 + base_got->output_offset + off); 2822 2823 if (r_type != R_X86_64_GOTPCREL 2824 && r_type != R_X86_64_GOTPCREL64) 2825 { 2826 asection *gotplt; 2827 if (htab->elf.splt != NULL) 2828 gotplt = htab->elf.sgotplt; 2829 else 2830 gotplt = htab->elf.igotplt; 2831 relocation -= (gotplt->output_section->vma 2832 - gotplt->output_offset); 2833 } 2834 2835 goto do_relocation; 2836 } 2837 } 2838 2839 /* When generating a shared object, the relocations handled here are 2840 copied into the output file to be resolved at run time. */ 2841 switch (r_type) 2842 { 2843 case R_X86_64_GOT32: 2844 case R_X86_64_GOT64: 2845 /* Relocation is to the entry for this symbol in the global 2846 offset table. */ 2847 case R_X86_64_GOTPCREL: 2848 case R_X86_64_GOTPCREL64: 2849 /* Use global offset table entry as symbol value. */ 2850 case R_X86_64_GOTPLT64: 2851 /* This is the same as GOT64 for relocation purposes, but 2852 indicates the existence of a PLT entry. The difficulty is, 2853 that we must calculate the GOT slot offset from the PLT 2854 offset, if this symbol got a PLT entry (it was global). 2855 Additionally if it's computed from the PLT entry, then that 2856 GOT offset is relative to .got.plt, not to .got. */ 2857 base_got = htab->elf.sgot; 2858 2859 if (htab->elf.sgot == NULL) 2860 abort (); 2861 2862 if (h != NULL) 2863 { 2864 bfd_boolean dyn; 2865 2866 off = h->got.offset; 2867 if (h->needs_plt 2868 && h->plt.offset != (bfd_vma)-1 2869 && off == (bfd_vma)-1) 2870 { 2871 /* We can't use h->got.offset here to save 2872 state, or even just remember the offset, as 2873 finish_dynamic_symbol would use that as offset into 2874 .got. */ 2875 bfd_vma plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1; 2876 off = (plt_index + 3) * GOT_ENTRY_SIZE; 2877 base_got = htab->elf.sgotplt; 2878 } 2879 2880 dyn = htab->elf.dynamic_sections_created; 2881 2882 if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info->shared, h) 2883 || (info->shared 2884 && SYMBOL_REFERENCES_LOCAL (info, h)) 2885 || (ELF_ST_VISIBILITY (h->other) 2886 && h->root.type == bfd_link_hash_undefweak)) 2887 { 2888 /* This is actually a static link, or it is a -Bsymbolic 2889 link and the symbol is defined locally, or the symbol 2890 was forced to be local because of a version file. We 2891 must initialize this entry in the global offset table. 2892 Since the offset must always be a multiple of 8, we 2893 use the least significant bit to record whether we 2894 have initialized it already. 2895 2896 When doing a dynamic link, we create a .rela.got 2897 relocation entry to initialize the value. This is 2898 done in the finish_dynamic_symbol routine. */ 2899 if ((off & 1) != 0) 2900 off &= ~1; 2901 else 2902 { 2903 bfd_put_64 (output_bfd, relocation, 2904 base_got->contents + off); 2905 /* Note that this is harmless for the GOTPLT64 case, 2906 as -1 | 1 still is -1. */ 2907 h->got.offset |= 1; 2908 } 2909 } 2910 else 2911 unresolved_reloc = FALSE; 2912 } 2913 else 2914 { 2915 if (local_got_offsets == NULL) 2916 abort (); 2917 2918 off = local_got_offsets[r_symndx]; 2919 2920 /* The offset must always be a multiple of 8. We use 2921 the least significant bit to record whether we have 2922 already generated the necessary reloc. */ 2923 if ((off & 1) != 0) 2924 off &= ~1; 2925 else 2926 { 2927 bfd_put_64 (output_bfd, relocation, 2928 base_got->contents + off); 2929 2930 if (info->shared) 2931 { 2932 asection *s; 2933 Elf_Internal_Rela outrel; 2934 bfd_byte *loc; 2935 2936 /* We need to generate a R_X86_64_RELATIVE reloc 2937 for the dynamic linker. */ 2938 s = htab->elf.srelgot; 2939 if (s == NULL) 2940 abort (); 2941 2942 outrel.r_offset = (base_got->output_section->vma 2943 + base_got->output_offset 2944 + off); 2945 outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE); 2946 outrel.r_addend = relocation; 2947 loc = s->contents; 2948 loc += s->reloc_count++ * sizeof (Elf64_External_Rela); 2949 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc); 2950 } 2951 2952 local_got_offsets[r_symndx] |= 1; 2953 } 2954 } 2955 2956 if (off >= (bfd_vma) -2) 2957 abort (); 2958 2959 relocation = base_got->output_section->vma 2960 + base_got->output_offset + off; 2961 if (r_type != R_X86_64_GOTPCREL && r_type != R_X86_64_GOTPCREL64) 2962 relocation -= htab->elf.sgotplt->output_section->vma 2963 - htab->elf.sgotplt->output_offset; 2964 2965 break; 2966 2967 case R_X86_64_GOTOFF64: 2968 /* Relocation is relative to the start of the global offset 2969 table. */ 2970 2971 /* Check to make sure it isn't a protected function symbol 2972 for shared library since it may not be local when used 2973 as function address. */ 2974 if (info->shared 2975 && h 2976 && h->def_regular 2977 && h->type == STT_FUNC 2978 && ELF_ST_VISIBILITY (h->other) == STV_PROTECTED) 2979 { 2980 (*_bfd_error_handler) 2981 (_("%B: relocation R_X86_64_GOTOFF64 against protected function `%s' can not be used when making a shared object"), 2982 input_bfd, h->root.root.string); 2983 bfd_set_error (bfd_error_bad_value); 2984 return FALSE; 2985 } 2986 2987 /* Note that sgot is not involved in this 2988 calculation. We always want the start of .got.plt. If we 2989 defined _GLOBAL_OFFSET_TABLE_ in a different way, as is 2990 permitted by the ABI, we might have to change this 2991 calculation. */ 2992 relocation -= htab->elf.sgotplt->output_section->vma 2993 + htab->elf.sgotplt->output_offset; 2994 break; 2995 2996 case R_X86_64_GOTPC32: 2997 case R_X86_64_GOTPC64: 2998 /* Use global offset table as symbol value. */ 2999 relocation = htab->elf.sgotplt->output_section->vma 3000 + htab->elf.sgotplt->output_offset; 3001 unresolved_reloc = FALSE; 3002 break; 3003 3004 case R_X86_64_PLTOFF64: 3005 /* Relocation is PLT entry relative to GOT. For local 3006 symbols it's the symbol itself relative to GOT. */ 3007 if (h != NULL 3008 /* See PLT32 handling. */ 3009 && h->plt.offset != (bfd_vma) -1 3010 && htab->elf.splt != NULL) 3011 { 3012 relocation = (htab->elf.splt->output_section->vma 3013 + htab->elf.splt->output_offset 3014 + h->plt.offset); 3015 unresolved_reloc = FALSE; 3016 } 3017 3018 relocation -= htab->elf.sgotplt->output_section->vma 3019 + htab->elf.sgotplt->output_offset; 3020 break; 3021 3022 case R_X86_64_PLT32: 3023 /* Relocation is to the entry for this symbol in the 3024 procedure linkage table. */ 3025 3026 /* Resolve a PLT32 reloc against a local symbol directly, 3027 without using the procedure linkage table. */ 3028 if (h == NULL) 3029 break; 3030 3031 if (h->plt.offset == (bfd_vma) -1 3032 || htab->elf.splt == NULL) 3033 { 3034 /* We didn't make a PLT entry for this symbol. This 3035 happens when statically linking PIC code, or when 3036 using -Bsymbolic. */ 3037 break; 3038 } 3039 3040 relocation = (htab->elf.splt->output_section->vma 3041 + htab->elf.splt->output_offset 3042 + h->plt.offset); 3043 unresolved_reloc = FALSE; 3044 break; 3045 3046 case R_X86_64_PC8: 3047 case R_X86_64_PC16: 3048 case R_X86_64_PC32: 3049 if (info->shared 3050 && (input_section->flags & SEC_ALLOC) != 0 3051 && (input_section->flags & SEC_READONLY) != 0 3052 && h != NULL) 3053 { 3054 bfd_boolean fail = FALSE; 3055 bfd_boolean branch 3056 = (r_type == R_X86_64_PC32 3057 && is_32bit_relative_branch (contents, rel->r_offset)); 3058 3059 if (SYMBOL_REFERENCES_LOCAL (info, h)) 3060 { 3061 /* Symbol is referenced locally. Make sure it is 3062 defined locally or for a branch. */ 3063 fail = !h->def_regular && !branch; 3064 } 3065 else 3066 { 3067 /* Symbol isn't referenced locally. We only allow 3068 branch to symbol with non-default visibility. */ 3069 fail = (!branch 3070 || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT); 3071 } 3072 3073 if (fail) 3074 { 3075 const char *fmt; 3076 const char *v; 3077 const char *pic = ""; 3078 3079 switch (ELF_ST_VISIBILITY (h->other)) 3080 { 3081 case STV_HIDDEN: 3082 v = _("hidden symbol"); 3083 break; 3084 case STV_INTERNAL: 3085 v = _("internal symbol"); 3086 break; 3087 case STV_PROTECTED: 3088 v = _("protected symbol"); 3089 break; 3090 default: 3091 v = _("symbol"); 3092 pic = _("; recompile with -fPIC"); 3093 break; 3094 } 3095 3096 if (h->def_regular) 3097 fmt = _("%B: relocation %s against %s `%s' can not be used when making a shared object%s"); 3098 else 3099 fmt = _("%B: relocation %s against undefined %s `%s' can not be used when making a shared object%s"); 3100 3101 (*_bfd_error_handler) (fmt, input_bfd, 3102 x86_64_elf_howto_table[r_type].name, 3103 v, h->root.root.string, pic); 3104 bfd_set_error (bfd_error_bad_value); 3105 return FALSE; 3106 } 3107 } 3108 /* Fall through. */ 3109 3110 case R_X86_64_8: 3111 case R_X86_64_16: 3112 case R_X86_64_32: 3113 case R_X86_64_PC64: 3114 case R_X86_64_64: 3115 /* FIXME: The ABI says the linker should make sure the value is 3116 the same when it's zeroextended to 64 bit. */ 3117 3118 if ((input_section->flags & SEC_ALLOC) == 0) 3119 break; 3120 3121 if ((info->shared 3122 && (h == NULL 3123 || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT 3124 || h->root.type != bfd_link_hash_undefweak) 3125 && (! IS_X86_64_PCREL_TYPE (r_type) 3126 || ! SYMBOL_CALLS_LOCAL (info, h))) 3127 || (ELIMINATE_COPY_RELOCS 3128 && !info->shared 3129 && h != NULL 3130 && h->dynindx != -1 3131 && !h->non_got_ref 3132 && ((h->def_dynamic 3133 && !h->def_regular) 3134 || h->root.type == bfd_link_hash_undefweak 3135 || h->root.type == bfd_link_hash_undefined))) 3136 { 3137 Elf_Internal_Rela outrel; 3138 bfd_byte *loc; 3139 bfd_boolean skip, relocate; 3140 asection *sreloc; 3141 3142 /* When generating a shared object, these relocations 3143 are copied into the output file to be resolved at run 3144 time. */ 3145 skip = FALSE; 3146 relocate = FALSE; 3147 3148 outrel.r_offset = 3149 _bfd_elf_section_offset (output_bfd, info, input_section, 3150 rel->r_offset); 3151 if (outrel.r_offset == (bfd_vma) -1) 3152 skip = TRUE; 3153 else if (outrel.r_offset == (bfd_vma) -2) 3154 skip = TRUE, relocate = TRUE; 3155 3156 outrel.r_offset += (input_section->output_section->vma 3157 + input_section->output_offset); 3158 3159 if (skip) 3160 memset (&outrel, 0, sizeof outrel); 3161 3162 /* h->dynindx may be -1 if this symbol was marked to 3163 become local. */ 3164 else if (h != NULL 3165 && h->dynindx != -1 3166 && (IS_X86_64_PCREL_TYPE (r_type) 3167 || ! info->shared 3168 || ! SYMBOLIC_BIND (info, h) 3169 || ! h->def_regular)) 3170 { 3171 outrel.r_info = ELF64_R_INFO (h->dynindx, r_type); 3172 outrel.r_addend = rel->r_addend; 3173 } 3174 else 3175 { 3176 /* This symbol is local, or marked to become local. */ 3177 if (r_type == R_X86_64_64) 3178 { 3179 relocate = TRUE; 3180 outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE); 3181 outrel.r_addend = relocation + rel->r_addend; 3182 } 3183 else 3184 { 3185 long sindx; 3186 3187 if (bfd_is_abs_section (sec)) 3188 sindx = 0; 3189 else if (sec == NULL || sec->owner == NULL) 3190 { 3191 bfd_set_error (bfd_error_bad_value); 3192 return FALSE; 3193 } 3194 else 3195 { 3196 asection *osec; 3197 3198 /* We are turning this relocation into one 3199 against a section symbol. It would be 3200 proper to subtract the symbol's value, 3201 osec->vma, from the emitted reloc addend, 3202 but ld.so expects buggy relocs. */ 3203 osec = sec->output_section; 3204 sindx = elf_section_data (osec)->dynindx; 3205 if (sindx == 0) 3206 { 3207 asection *oi = htab->elf.text_index_section; 3208 sindx = elf_section_data (oi)->dynindx; 3209 } 3210 BFD_ASSERT (sindx != 0); 3211 } 3212 3213 outrel.r_info = ELF64_R_INFO (sindx, r_type); 3214 outrel.r_addend = relocation + rel->r_addend; 3215 } 3216 } 3217 3218 sreloc = elf_section_data (input_section)->sreloc; 3219 3220 BFD_ASSERT (sreloc != NULL && sreloc->contents != NULL); 3221 3222 loc = sreloc->contents; 3223 loc += sreloc->reloc_count++ * sizeof (Elf64_External_Rela); 3224 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc); 3225 3226 /* If this reloc is against an external symbol, we do 3227 not want to fiddle with the addend. Otherwise, we 3228 need to include the symbol value so that it becomes 3229 an addend for the dynamic reloc. */ 3230 if (! relocate) 3231 continue; 3232 } 3233 3234 break; 3235 3236 case R_X86_64_TLSGD: 3237 case R_X86_64_GOTPC32_TLSDESC: 3238 case R_X86_64_TLSDESC_CALL: 3239 case R_X86_64_GOTTPOFF: 3240 tls_type = GOT_UNKNOWN; 3241 if (h == NULL && local_got_offsets) 3242 tls_type = elf64_x86_64_local_got_tls_type (input_bfd) [r_symndx]; 3243 else if (h != NULL) 3244 tls_type = elf64_x86_64_hash_entry (h)->tls_type; 3245 3246 if (! elf64_x86_64_tls_transition (info, input_bfd, 3247 input_section, contents, 3248 symtab_hdr, sym_hashes, 3249 &r_type, tls_type, rel, 3250 relend, h, r_symndx)) 3251 return FALSE; 3252 3253 if (r_type == R_X86_64_TPOFF32) 3254 { 3255 bfd_vma roff = rel->r_offset; 3256 3257 BFD_ASSERT (! unresolved_reloc); 3258 3259 if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSGD) 3260 { 3261 /* GD->LE transition. 3262 .byte 0x66; leaq foo@tlsgd(%rip), %rdi 3263 .word 0x6666; rex64; call __tls_get_addr 3264 Change it into: 3265 movq %fs:0, %rax 3266 leaq foo@tpoff(%rax), %rax */ 3267 memcpy (contents + roff - 4, 3268 "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0", 3269 16); 3270 bfd_put_32 (output_bfd, 3271 elf64_x86_64_tpoff (info, relocation), 3272 contents + roff + 8); 3273 /* Skip R_X86_64_PC32/R_X86_64_PLT32. */ 3274 rel++; 3275 continue; 3276 } 3277 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_GOTPC32_TLSDESC) 3278 { 3279 /* GDesc -> LE transition. 3280 It's originally something like: 3281 leaq x@tlsdesc(%rip), %rax 3282 3283 Change it to: 3284 movl $x@tpoff, %rax 3285 */ 3286 3287 unsigned int val, type, type2; 3288 3289 type = bfd_get_8 (input_bfd, contents + roff - 3); 3290 type2 = bfd_get_8 (input_bfd, contents + roff - 2); 3291 val = bfd_get_8 (input_bfd, contents + roff - 1); 3292 bfd_put_8 (output_bfd, 0x48 | ((type >> 2) & 1), 3293 contents + roff - 3); 3294 bfd_put_8 (output_bfd, 0xc7, contents + roff - 2); 3295 bfd_put_8 (output_bfd, 0xc0 | ((val >> 3) & 7), 3296 contents + roff - 1); 3297 bfd_put_32 (output_bfd, 3298 elf64_x86_64_tpoff (info, relocation), 3299 contents + roff); 3300 continue; 3301 } 3302 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSDESC_CALL) 3303 { 3304 /* GDesc -> LE transition. 3305 It's originally: 3306 call *(%rax) 3307 Turn it into: 3308 xchg %ax,%ax. */ 3309 bfd_put_8 (output_bfd, 0x66, contents + roff); 3310 bfd_put_8 (output_bfd, 0x90, contents + roff + 1); 3311 continue; 3312 } 3313 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_GOTTPOFF) 3314 { 3315 /* IE->LE transition: 3316 Originally it can be one of: 3317 movq foo@gottpoff(%rip), %reg 3318 addq foo@gottpoff(%rip), %reg 3319 We change it into: 3320 movq $foo, %reg 3321 leaq foo(%reg), %reg 3322 addq $foo, %reg. */ 3323 3324 unsigned int val, type, reg; 3325 3326 val = bfd_get_8 (input_bfd, contents + roff - 3); 3327 type = bfd_get_8 (input_bfd, contents + roff - 2); 3328 reg = bfd_get_8 (input_bfd, contents + roff - 1); 3329 reg >>= 3; 3330 if (type == 0x8b) 3331 { 3332 /* movq */ 3333 if (val == 0x4c) 3334 bfd_put_8 (output_bfd, 0x49, 3335 contents + roff - 3); 3336 bfd_put_8 (output_bfd, 0xc7, 3337 contents + roff - 2); 3338 bfd_put_8 (output_bfd, 0xc0 | reg, 3339 contents + roff - 1); 3340 } 3341 else if (reg == 4) 3342 { 3343 /* addq -> addq - addressing with %rsp/%r12 is 3344 special */ 3345 if (val == 0x4c) 3346 bfd_put_8 (output_bfd, 0x49, 3347 contents + roff - 3); 3348 bfd_put_8 (output_bfd, 0x81, 3349 contents + roff - 2); 3350 bfd_put_8 (output_bfd, 0xc0 | reg, 3351 contents + roff - 1); 3352 } 3353 else 3354 { 3355 /* addq -> leaq */ 3356 if (val == 0x4c) 3357 bfd_put_8 (output_bfd, 0x4d, 3358 contents + roff - 3); 3359 bfd_put_8 (output_bfd, 0x8d, 3360 contents + roff - 2); 3361 bfd_put_8 (output_bfd, 0x80 | reg | (reg << 3), 3362 contents + roff - 1); 3363 } 3364 bfd_put_32 (output_bfd, 3365 elf64_x86_64_tpoff (info, relocation), 3366 contents + roff); 3367 continue; 3368 } 3369 else 3370 BFD_ASSERT (FALSE); 3371 } 3372 3373 if (htab->elf.sgot == NULL) 3374 abort (); 3375 3376 if (h != NULL) 3377 { 3378 off = h->got.offset; 3379 offplt = elf64_x86_64_hash_entry (h)->tlsdesc_got; 3380 } 3381 else 3382 { 3383 if (local_got_offsets == NULL) 3384 abort (); 3385 3386 off = local_got_offsets[r_symndx]; 3387 offplt = local_tlsdesc_gotents[r_symndx]; 3388 } 3389 3390 if ((off & 1) != 0) 3391 off &= ~1; 3392 else 3393 { 3394 Elf_Internal_Rela outrel; 3395 bfd_byte *loc; 3396 int dr_type, indx; 3397 asection *sreloc; 3398 3399 if (htab->elf.srelgot == NULL) 3400 abort (); 3401 3402 indx = h && h->dynindx != -1 ? h->dynindx : 0; 3403 3404 if (GOT_TLS_GDESC_P (tls_type)) 3405 { 3406 outrel.r_info = ELF64_R_INFO (indx, R_X86_64_TLSDESC); 3407 BFD_ASSERT (htab->sgotplt_jump_table_size + offplt 3408 + 2 * GOT_ENTRY_SIZE <= htab->elf.sgotplt->size); 3409 outrel.r_offset = (htab->elf.sgotplt->output_section->vma 3410 + htab->elf.sgotplt->output_offset 3411 + offplt 3412 + htab->sgotplt_jump_table_size); 3413 sreloc = htab->elf.srelplt; 3414 loc = sreloc->contents; 3415 loc += sreloc->reloc_count++ 3416 * sizeof (Elf64_External_Rela); 3417 BFD_ASSERT (loc + sizeof (Elf64_External_Rela) 3418 <= sreloc->contents + sreloc->size); 3419 if (indx == 0) 3420 outrel.r_addend = relocation - elf64_x86_64_dtpoff_base (info); 3421 else 3422 outrel.r_addend = 0; 3423 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc); 3424 } 3425 3426 sreloc = htab->elf.srelgot; 3427 3428 outrel.r_offset = (htab->elf.sgot->output_section->vma 3429 + htab->elf.sgot->output_offset + off); 3430 3431 if (GOT_TLS_GD_P (tls_type)) 3432 dr_type = R_X86_64_DTPMOD64; 3433 else if (GOT_TLS_GDESC_P (tls_type)) 3434 goto dr_done; 3435 else 3436 dr_type = R_X86_64_TPOFF64; 3437 3438 bfd_put_64 (output_bfd, 0, htab->elf.sgot->contents + off); 3439 outrel.r_addend = 0; 3440 if ((dr_type == R_X86_64_TPOFF64 3441 || dr_type == R_X86_64_TLSDESC) && indx == 0) 3442 outrel.r_addend = relocation - elf64_x86_64_dtpoff_base (info); 3443 outrel.r_info = ELF64_R_INFO (indx, dr_type); 3444 3445 loc = sreloc->contents; 3446 loc += sreloc->reloc_count++ * sizeof (Elf64_External_Rela); 3447 BFD_ASSERT (loc + sizeof (Elf64_External_Rela) 3448 <= sreloc->contents + sreloc->size); 3449 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc); 3450 3451 if (GOT_TLS_GD_P (tls_type)) 3452 { 3453 if (indx == 0) 3454 { 3455 BFD_ASSERT (! unresolved_reloc); 3456 bfd_put_64 (output_bfd, 3457 relocation - elf64_x86_64_dtpoff_base (info), 3458 htab->elf.sgot->contents + off + GOT_ENTRY_SIZE); 3459 } 3460 else 3461 { 3462 bfd_put_64 (output_bfd, 0, 3463 htab->elf.sgot->contents + off + GOT_ENTRY_SIZE); 3464 outrel.r_info = ELF64_R_INFO (indx, 3465 R_X86_64_DTPOFF64); 3466 outrel.r_offset += GOT_ENTRY_SIZE; 3467 sreloc->reloc_count++; 3468 loc += sizeof (Elf64_External_Rela); 3469 BFD_ASSERT (loc + sizeof (Elf64_External_Rela) 3470 <= sreloc->contents + sreloc->size); 3471 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc); 3472 } 3473 } 3474 3475 dr_done: 3476 if (h != NULL) 3477 h->got.offset |= 1; 3478 else 3479 local_got_offsets[r_symndx] |= 1; 3480 } 3481 3482 if (off >= (bfd_vma) -2 3483 && ! GOT_TLS_GDESC_P (tls_type)) 3484 abort (); 3485 if (r_type == ELF64_R_TYPE (rel->r_info)) 3486 { 3487 if (r_type == R_X86_64_GOTPC32_TLSDESC 3488 || r_type == R_X86_64_TLSDESC_CALL) 3489 relocation = htab->elf.sgotplt->output_section->vma 3490 + htab->elf.sgotplt->output_offset 3491 + offplt + htab->sgotplt_jump_table_size; 3492 else 3493 relocation = htab->elf.sgot->output_section->vma 3494 + htab->elf.sgot->output_offset + off; 3495 unresolved_reloc = FALSE; 3496 } 3497 else 3498 { 3499 bfd_vma roff = rel->r_offset; 3500 3501 if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSGD) 3502 { 3503 /* GD->IE transition. 3504 .byte 0x66; leaq foo@tlsgd(%rip), %rdi 3505 .word 0x6666; rex64; call __tls_get_addr@plt 3506 Change it into: 3507 movq %fs:0, %rax 3508 addq foo@gottpoff(%rip), %rax */ 3509 memcpy (contents + roff - 4, 3510 "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0", 3511 16); 3512 3513 relocation = (htab->elf.sgot->output_section->vma 3514 + htab->elf.sgot->output_offset + off 3515 - roff 3516 - input_section->output_section->vma 3517 - input_section->output_offset 3518 - 12); 3519 bfd_put_32 (output_bfd, relocation, 3520 contents + roff + 8); 3521 /* Skip R_X86_64_PLT32. */ 3522 rel++; 3523 continue; 3524 } 3525 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_GOTPC32_TLSDESC) 3526 { 3527 /* GDesc -> IE transition. 3528 It's originally something like: 3529 leaq x@tlsdesc(%rip), %rax 3530 3531 Change it to: 3532 movq x@gottpoff(%rip), %rax # before xchg %ax,%ax 3533 */ 3534 3535 unsigned int val, type, type2; 3536 3537 type = bfd_get_8 (input_bfd, contents + roff - 3); 3538 type2 = bfd_get_8 (input_bfd, contents + roff - 2); 3539 val = bfd_get_8 (input_bfd, contents + roff - 1); 3540 3541 /* Now modify the instruction as appropriate. To 3542 turn a leaq into a movq in the form we use it, it 3543 suffices to change the second byte from 0x8d to 3544 0x8b. */ 3545 bfd_put_8 (output_bfd, 0x8b, contents + roff - 2); 3546 3547 bfd_put_32 (output_bfd, 3548 htab->elf.sgot->output_section->vma 3549 + htab->elf.sgot->output_offset + off 3550 - rel->r_offset 3551 - input_section->output_section->vma 3552 - input_section->output_offset 3553 - 4, 3554 contents + roff); 3555 continue; 3556 } 3557 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSDESC_CALL) 3558 { 3559 /* GDesc -> IE transition. 3560 It's originally: 3561 call *(%rax) 3562 3563 Change it to: 3564 xchg %ax,%ax. */ 3565 3566 unsigned int val, type; 3567 3568 type = bfd_get_8 (input_bfd, contents + roff); 3569 val = bfd_get_8 (input_bfd, contents + roff + 1); 3570 bfd_put_8 (output_bfd, 0x66, contents + roff); 3571 bfd_put_8 (output_bfd, 0x90, contents + roff + 1); 3572 continue; 3573 } 3574 else 3575 BFD_ASSERT (FALSE); 3576 } 3577 break; 3578 3579 case R_X86_64_TLSLD: 3580 if (! elf64_x86_64_tls_transition (info, input_bfd, 3581 input_section, contents, 3582 symtab_hdr, sym_hashes, 3583 &r_type, GOT_UNKNOWN, 3584 rel, relend, h, r_symndx)) 3585 return FALSE; 3586 3587 if (r_type != R_X86_64_TLSLD) 3588 { 3589 /* LD->LE transition: 3590 leaq foo@tlsld(%rip), %rdi; call __tls_get_addr. 3591 We change it into: 3592 .word 0x6666; .byte 0x66; movl %fs:0, %rax. */ 3593 3594 BFD_ASSERT (r_type == R_X86_64_TPOFF32); 3595 memcpy (contents + rel->r_offset - 3, 3596 "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0", 12); 3597 /* Skip R_X86_64_PC32/R_X86_64_PLT32. */ 3598 rel++; 3599 continue; 3600 } 3601 3602 if (htab->elf.sgot == NULL) 3603 abort (); 3604 3605 off = htab->tls_ld_got.offset; 3606 if (off & 1) 3607 off &= ~1; 3608 else 3609 { 3610 Elf_Internal_Rela outrel; 3611 bfd_byte *loc; 3612 3613 if (htab->elf.srelgot == NULL) 3614 abort (); 3615 3616 outrel.r_offset = (htab->elf.sgot->output_section->vma 3617 + htab->elf.sgot->output_offset + off); 3618 3619 bfd_put_64 (output_bfd, 0, 3620 htab->elf.sgot->contents + off); 3621 bfd_put_64 (output_bfd, 0, 3622 htab->elf.sgot->contents + off + GOT_ENTRY_SIZE); 3623 outrel.r_info = ELF64_R_INFO (0, R_X86_64_DTPMOD64); 3624 outrel.r_addend = 0; 3625 loc = htab->elf.srelgot->contents; 3626 loc += htab->elf.srelgot->reloc_count++ * sizeof (Elf64_External_Rela); 3627 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc); 3628 htab->tls_ld_got.offset |= 1; 3629 } 3630 relocation = htab->elf.sgot->output_section->vma 3631 + htab->elf.sgot->output_offset + off; 3632 unresolved_reloc = FALSE; 3633 break; 3634 3635 case R_X86_64_DTPOFF32: 3636 if (!info->executable|| (input_section->flags & SEC_CODE) == 0) 3637 relocation -= elf64_x86_64_dtpoff_base (info); 3638 else 3639 relocation = elf64_x86_64_tpoff (info, relocation); 3640 break; 3641 3642 case R_X86_64_TPOFF32: 3643 BFD_ASSERT (info->executable); 3644 relocation = elf64_x86_64_tpoff (info, relocation); 3645 break; 3646 3647 default: 3648 break; 3649 } 3650 3651 /* Dynamic relocs are not propagated for SEC_DEBUGGING sections 3652 because such sections are not SEC_ALLOC and thus ld.so will 3653 not process them. */ 3654 if (unresolved_reloc 3655 && !((input_section->flags & SEC_DEBUGGING) != 0 3656 && h->def_dynamic)) 3657 (*_bfd_error_handler) 3658 (_("%B(%A+0x%lx): unresolvable %s relocation against symbol `%s'"), 3659 input_bfd, 3660 input_section, 3661 (long) rel->r_offset, 3662 howto->name, 3663 h->root.root.string); 3664 3665 do_relocation: 3666 r = _bfd_final_link_relocate (howto, input_bfd, input_section, 3667 contents, rel->r_offset, 3668 relocation, rel->r_addend); 3669 3670 if (r != bfd_reloc_ok) 3671 { 3672 const char *name; 3673 3674 if (h != NULL) 3675 name = h->root.root.string; 3676 else 3677 { 3678 name = bfd_elf_string_from_elf_section (input_bfd, 3679 symtab_hdr->sh_link, 3680 sym->st_name); 3681 if (name == NULL) 3682 return FALSE; 3683 if (*name == '\0') 3684 name = bfd_section_name (input_bfd, sec); 3685 } 3686 3687 if (r == bfd_reloc_overflow) 3688 { 3689 if (! ((*info->callbacks->reloc_overflow) 3690 (info, (h ? &h->root : NULL), name, howto->name, 3691 (bfd_vma) 0, input_bfd, input_section, 3692 rel->r_offset))) 3693 return FALSE; 3694 } 3695 else 3696 { 3697 (*_bfd_error_handler) 3698 (_("%B(%A+0x%lx): reloc against `%s': error %d"), 3699 input_bfd, input_section, 3700 (long) rel->r_offset, name, (int) r); 3701 return FALSE; 3702 } 3703 } 3704 } 3705 3706 return TRUE; 3707 } 3708 3709 /* Finish up dynamic symbol handling. We set the contents of various 3710 dynamic sections here. */ 3711 3712 static bfd_boolean 3713 elf64_x86_64_finish_dynamic_symbol (bfd *output_bfd, 3714 struct bfd_link_info *info, 3715 struct elf_link_hash_entry *h, 3716 Elf_Internal_Sym *sym) 3717 { 3718 struct elf64_x86_64_link_hash_table *htab; 3719 3720 htab = elf64_x86_64_hash_table (info); 3721 3722 if (h->plt.offset != (bfd_vma) -1) 3723 { 3724 bfd_vma plt_index; 3725 bfd_vma got_offset; 3726 Elf_Internal_Rela rela; 3727 bfd_byte *loc; 3728 asection *plt, *gotplt, *relplt; 3729 3730 /* When building a static executable, use .iplt, .igot.plt and 3731 .rela.iplt sections for STT_GNU_IFUNC symbols. */ 3732 if (htab->elf.splt != NULL) 3733 { 3734 plt = htab->elf.splt; 3735 gotplt = htab->elf.sgotplt; 3736 relplt = htab->elf.srelplt; 3737 } 3738 else 3739 { 3740 plt = htab->elf.iplt; 3741 gotplt = htab->elf.igotplt; 3742 relplt = htab->elf.irelplt; 3743 } 3744 3745 /* This symbol has an entry in the procedure linkage table. Set 3746 it up. */ 3747 if ((h->dynindx == -1 3748 && !((h->forced_local || info->executable) 3749 && h->def_regular 3750 && h->type == STT_GNU_IFUNC)) 3751 || plt == NULL 3752 || gotplt == NULL 3753 || relplt == NULL) 3754 abort (); 3755 3756 /* Get the index in the procedure linkage table which 3757 corresponds to this symbol. This is the index of this symbol 3758 in all the symbols for which we are making plt entries. The 3759 first entry in the procedure linkage table is reserved. 3760 3761 Get the offset into the .got table of the entry that 3762 corresponds to this function. Each .got entry is GOT_ENTRY_SIZE 3763 bytes. The first three are reserved for the dynamic linker. 3764 3765 For static executables, we don't reserve anything. */ 3766 3767 if (plt == htab->elf.splt) 3768 { 3769 plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1; 3770 got_offset = (plt_index + 3) * GOT_ENTRY_SIZE; 3771 } 3772 else 3773 { 3774 plt_index = h->plt.offset / PLT_ENTRY_SIZE; 3775 got_offset = plt_index * GOT_ENTRY_SIZE; 3776 } 3777 3778 /* Fill in the entry in the procedure linkage table. */ 3779 memcpy (plt->contents + h->plt.offset, elf64_x86_64_plt_entry, 3780 PLT_ENTRY_SIZE); 3781 3782 /* Insert the relocation positions of the plt section. The magic 3783 numbers at the end of the statements are the positions of the 3784 relocations in the plt section. */ 3785 /* Put offset for jmp *name@GOTPCREL(%rip), since the 3786 instruction uses 6 bytes, subtract this value. */ 3787 bfd_put_32 (output_bfd, 3788 (gotplt->output_section->vma 3789 + gotplt->output_offset 3790 + got_offset 3791 - plt->output_section->vma 3792 - plt->output_offset 3793 - h->plt.offset 3794 - 6), 3795 plt->contents + h->plt.offset + 2); 3796 3797 /* Don't fill PLT entry for static executables. */ 3798 if (plt == htab->elf.splt) 3799 { 3800 /* Put relocation index. */ 3801 bfd_put_32 (output_bfd, plt_index, 3802 plt->contents + h->plt.offset + 7); 3803 /* Put offset for jmp .PLT0. */ 3804 bfd_put_32 (output_bfd, - (h->plt.offset + PLT_ENTRY_SIZE), 3805 plt->contents + h->plt.offset + 12); 3806 } 3807 3808 /* Fill in the entry in the global offset table, initially this 3809 points to the pushq instruction in the PLT which is at offset 6. */ 3810 bfd_put_64 (output_bfd, (plt->output_section->vma 3811 + plt->output_offset 3812 + h->plt.offset + 6), 3813 gotplt->contents + got_offset); 3814 3815 /* Fill in the entry in the .rela.plt section. */ 3816 rela.r_offset = (gotplt->output_section->vma 3817 + gotplt->output_offset 3818 + got_offset); 3819 if (h->dynindx == -1 3820 || ((info->executable 3821 || ELF_ST_VISIBILITY (h->other) != STV_DEFAULT) 3822 && h->def_regular 3823 && h->type == STT_GNU_IFUNC)) 3824 { 3825 /* If an STT_GNU_IFUNC symbol is locally defined, generate 3826 R_X86_64_IRELATIVE instead of R_X86_64_JUMP_SLOT. */ 3827 rela.r_info = ELF64_R_INFO (0, R_X86_64_IRELATIVE); 3828 rela.r_addend = (h->root.u.def.value 3829 + h->root.u.def.section->output_section->vma 3830 + h->root.u.def.section->output_offset); 3831 } 3832 else 3833 { 3834 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_JUMP_SLOT); 3835 rela.r_addend = 0; 3836 } 3837 loc = relplt->contents + plt_index * sizeof (Elf64_External_Rela); 3838 bfd_elf64_swap_reloca_out (output_bfd, &rela, loc); 3839 3840 if (!h->def_regular) 3841 { 3842 /* Mark the symbol as undefined, rather than as defined in 3843 the .plt section. Leave the value if there were any 3844 relocations where pointer equality matters (this is a clue 3845 for the dynamic linker, to make function pointer 3846 comparisons work between an application and shared 3847 library), otherwise set it to zero. If a function is only 3848 called from a binary, there is no need to slow down 3849 shared libraries because of that. */ 3850 sym->st_shndx = SHN_UNDEF; 3851 if (!h->pointer_equality_needed) 3852 sym->st_value = 0; 3853 } 3854 } 3855 3856 if (h->got.offset != (bfd_vma) -1 3857 && ! GOT_TLS_GD_ANY_P (elf64_x86_64_hash_entry (h)->tls_type) 3858 && elf64_x86_64_hash_entry (h)->tls_type != GOT_TLS_IE) 3859 { 3860 Elf_Internal_Rela rela; 3861 bfd_byte *loc; 3862 3863 /* This symbol has an entry in the global offset table. Set it 3864 up. */ 3865 if (htab->elf.sgot == NULL || htab->elf.srelgot == NULL) 3866 abort (); 3867 3868 rela.r_offset = (htab->elf.sgot->output_section->vma 3869 + htab->elf.sgot->output_offset 3870 + (h->got.offset &~ (bfd_vma) 1)); 3871 3872 /* If this is a static link, or it is a -Bsymbolic link and the 3873 symbol is defined locally or was forced to be local because 3874 of a version file, we just want to emit a RELATIVE reloc. 3875 The entry in the global offset table will already have been 3876 initialized in the relocate_section function. */ 3877 if (h->def_regular 3878 && h->type == STT_GNU_IFUNC) 3879 { 3880 if (info->shared) 3881 { 3882 /* Generate R_X86_64_GLOB_DAT. */ 3883 goto do_glob_dat; 3884 } 3885 else 3886 { 3887 asection *plt; 3888 3889 if (!h->pointer_equality_needed) 3890 abort (); 3891 3892 /* For non-shared object, we can't use .got.plt, which 3893 contains the real function addres if we need pointer 3894 equality. We load the GOT entry with the PLT entry. */ 3895 plt = htab->elf.splt ? htab->elf.splt : htab->elf.iplt; 3896 bfd_put_64 (output_bfd, (plt->output_section->vma 3897 + plt->output_offset 3898 + h->plt.offset), 3899 htab->elf.sgot->contents + h->got.offset); 3900 return TRUE; 3901 } 3902 } 3903 else if (info->shared 3904 && SYMBOL_REFERENCES_LOCAL (info, h)) 3905 { 3906 if (!h->def_regular) 3907 return FALSE; 3908 BFD_ASSERT((h->got.offset & 1) != 0); 3909 rela.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE); 3910 rela.r_addend = (h->root.u.def.value 3911 + h->root.u.def.section->output_section->vma 3912 + h->root.u.def.section->output_offset); 3913 } 3914 else 3915 { 3916 BFD_ASSERT((h->got.offset & 1) == 0); 3917 do_glob_dat: 3918 bfd_put_64 (output_bfd, (bfd_vma) 0, 3919 htab->elf.sgot->contents + h->got.offset); 3920 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_GLOB_DAT); 3921 rela.r_addend = 0; 3922 } 3923 3924 loc = htab->elf.srelgot->contents; 3925 loc += htab->elf.srelgot->reloc_count++ * sizeof (Elf64_External_Rela); 3926 bfd_elf64_swap_reloca_out (output_bfd, &rela, loc); 3927 } 3928 3929 if (h->needs_copy) 3930 { 3931 Elf_Internal_Rela rela; 3932 bfd_byte *loc; 3933 3934 /* This symbol needs a copy reloc. Set it up. */ 3935 3936 if (h->dynindx == -1 3937 || (h->root.type != bfd_link_hash_defined 3938 && h->root.type != bfd_link_hash_defweak) 3939 || htab->srelbss == NULL) 3940 abort (); 3941 3942 rela.r_offset = (h->root.u.def.value 3943 + h->root.u.def.section->output_section->vma 3944 + h->root.u.def.section->output_offset); 3945 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_COPY); 3946 rela.r_addend = 0; 3947 loc = htab->srelbss->contents; 3948 loc += htab->srelbss->reloc_count++ * sizeof (Elf64_External_Rela); 3949 bfd_elf64_swap_reloca_out (output_bfd, &rela, loc); 3950 } 3951 3952 /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. SYM may 3953 be NULL for local symbols. */ 3954 if (sym != NULL 3955 && (strcmp (h->root.root.string, "_DYNAMIC") == 0 3956 || h == htab->elf.hgot)) 3957 sym->st_shndx = SHN_ABS; 3958 3959 return TRUE; 3960 } 3961 3962 /* Finish up local dynamic symbol handling. We set the contents of 3963 various dynamic sections here. */ 3964 3965 static bfd_boolean 3966 elf64_x86_64_finish_local_dynamic_symbol (void **slot, void *inf) 3967 { 3968 struct elf_link_hash_entry *h 3969 = (struct elf_link_hash_entry *) *slot; 3970 struct bfd_link_info *info 3971 = (struct bfd_link_info *) inf; 3972 3973 return elf64_x86_64_finish_dynamic_symbol (info->output_bfd, 3974 info, h, NULL); 3975 } 3976 3977 /* Used to decide how to sort relocs in an optimal manner for the 3978 dynamic linker, before writing them out. */ 3979 3980 static enum elf_reloc_type_class 3981 elf64_x86_64_reloc_type_class (const Elf_Internal_Rela *rela) 3982 { 3983 switch ((int) ELF64_R_TYPE (rela->r_info)) 3984 { 3985 case R_X86_64_RELATIVE: 3986 return reloc_class_relative; 3987 case R_X86_64_JUMP_SLOT: 3988 return reloc_class_plt; 3989 case R_X86_64_COPY: 3990 return reloc_class_copy; 3991 default: 3992 return reloc_class_normal; 3993 } 3994 } 3995 3996 /* Finish up the dynamic sections. */ 3997 3998 static bfd_boolean 3999 elf64_x86_64_finish_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info) 4000 { 4001 struct elf64_x86_64_link_hash_table *htab; 4002 bfd *dynobj; 4003 asection *sdyn; 4004 4005 htab = elf64_x86_64_hash_table (info); 4006 dynobj = htab->elf.dynobj; 4007 sdyn = bfd_get_section_by_name (dynobj, ".dynamic"); 4008 4009 if (htab->elf.dynamic_sections_created) 4010 { 4011 Elf64_External_Dyn *dyncon, *dynconend; 4012 4013 if (sdyn == NULL || htab->elf.sgot == NULL) 4014 abort (); 4015 4016 dyncon = (Elf64_External_Dyn *) sdyn->contents; 4017 dynconend = (Elf64_External_Dyn *) (sdyn->contents + sdyn->size); 4018 for (; dyncon < dynconend; dyncon++) 4019 { 4020 Elf_Internal_Dyn dyn; 4021 asection *s; 4022 4023 bfd_elf64_swap_dyn_in (dynobj, dyncon, &dyn); 4024 4025 switch (dyn.d_tag) 4026 { 4027 default: 4028 continue; 4029 4030 case DT_PLTGOT: 4031 s = htab->elf.sgotplt; 4032 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset; 4033 break; 4034 4035 case DT_JMPREL: 4036 dyn.d_un.d_ptr = htab->elf.srelplt->output_section->vma; 4037 break; 4038 4039 case DT_PLTRELSZ: 4040 s = htab->elf.srelplt->output_section; 4041 dyn.d_un.d_val = s->size; 4042 break; 4043 4044 case DT_RELASZ: 4045 /* The procedure linkage table relocs (DT_JMPREL) should 4046 not be included in the overall relocs (DT_RELA). 4047 Therefore, we override the DT_RELASZ entry here to 4048 make it not include the JMPREL relocs. Since the 4049 linker script arranges for .rela.plt to follow all 4050 other relocation sections, we don't have to worry 4051 about changing the DT_RELA entry. */ 4052 if (htab->elf.srelplt != NULL) 4053 { 4054 s = htab->elf.srelplt->output_section; 4055 dyn.d_un.d_val -= s->size; 4056 } 4057 break; 4058 4059 case DT_TLSDESC_PLT: 4060 s = htab->elf.splt; 4061 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset 4062 + htab->tlsdesc_plt; 4063 break; 4064 4065 case DT_TLSDESC_GOT: 4066 s = htab->elf.sgot; 4067 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset 4068 + htab->tlsdesc_got; 4069 break; 4070 } 4071 4072 bfd_elf64_swap_dyn_out (output_bfd, &dyn, dyncon); 4073 } 4074 4075 /* Fill in the special first entry in the procedure linkage table. */ 4076 if (htab->elf.splt && htab->elf.splt->size > 0) 4077 { 4078 /* Fill in the first entry in the procedure linkage table. */ 4079 memcpy (htab->elf.splt->contents, elf64_x86_64_plt0_entry, 4080 PLT_ENTRY_SIZE); 4081 /* Add offset for pushq GOT+8(%rip), since the instruction 4082 uses 6 bytes subtract this value. */ 4083 bfd_put_32 (output_bfd, 4084 (htab->elf.sgotplt->output_section->vma 4085 + htab->elf.sgotplt->output_offset 4086 + 8 4087 - htab->elf.splt->output_section->vma 4088 - htab->elf.splt->output_offset 4089 - 6), 4090 htab->elf.splt->contents + 2); 4091 /* Add offset for jmp *GOT+16(%rip). The 12 is the offset to 4092 the end of the instruction. */ 4093 bfd_put_32 (output_bfd, 4094 (htab->elf.sgotplt->output_section->vma 4095 + htab->elf.sgotplt->output_offset 4096 + 16 4097 - htab->elf.splt->output_section->vma 4098 - htab->elf.splt->output_offset 4099 - 12), 4100 htab->elf.splt->contents + 8); 4101 4102 elf_section_data (htab->elf.splt->output_section)->this_hdr.sh_entsize = 4103 PLT_ENTRY_SIZE; 4104 4105 if (htab->tlsdesc_plt) 4106 { 4107 bfd_put_64 (output_bfd, (bfd_vma) 0, 4108 htab->elf.sgot->contents + htab->tlsdesc_got); 4109 4110 memcpy (htab->elf.splt->contents + htab->tlsdesc_plt, 4111 elf64_x86_64_plt0_entry, 4112 PLT_ENTRY_SIZE); 4113 4114 /* Add offset for pushq GOT+8(%rip), since the 4115 instruction uses 6 bytes subtract this value. */ 4116 bfd_put_32 (output_bfd, 4117 (htab->elf.sgotplt->output_section->vma 4118 + htab->elf.sgotplt->output_offset 4119 + 8 4120 - htab->elf.splt->output_section->vma 4121 - htab->elf.splt->output_offset 4122 - htab->tlsdesc_plt 4123 - 6), 4124 htab->elf.splt->contents + htab->tlsdesc_plt + 2); 4125 /* Add offset for jmp *GOT+TDG(%rip), where TGD stands for 4126 htab->tlsdesc_got. The 12 is the offset to the end of 4127 the instruction. */ 4128 bfd_put_32 (output_bfd, 4129 (htab->elf.sgot->output_section->vma 4130 + htab->elf.sgot->output_offset 4131 + htab->tlsdesc_got 4132 - htab->elf.splt->output_section->vma 4133 - htab->elf.splt->output_offset 4134 - htab->tlsdesc_plt 4135 - 12), 4136 htab->elf.splt->contents + htab->tlsdesc_plt + 8); 4137 } 4138 } 4139 } 4140 4141 if (htab->elf.sgotplt) 4142 { 4143 /* Fill in the first three entries in the global offset table. */ 4144 if (htab->elf.sgotplt->size > 0) 4145 { 4146 /* Set the first entry in the global offset table to the address of 4147 the dynamic section. */ 4148 if (sdyn == NULL) 4149 bfd_put_64 (output_bfd, (bfd_vma) 0, htab->elf.sgotplt->contents); 4150 else 4151 bfd_put_64 (output_bfd, 4152 sdyn->output_section->vma + sdyn->output_offset, 4153 htab->elf.sgotplt->contents); 4154 /* Write GOT[1] and GOT[2], needed for the dynamic linker. */ 4155 bfd_put_64 (output_bfd, (bfd_vma) 0, htab->elf.sgotplt->contents + GOT_ENTRY_SIZE); 4156 bfd_put_64 (output_bfd, (bfd_vma) 0, htab->elf.sgotplt->contents + GOT_ENTRY_SIZE*2); 4157 } 4158 4159 elf_section_data (htab->elf.sgotplt->output_section)->this_hdr.sh_entsize = 4160 GOT_ENTRY_SIZE; 4161 } 4162 4163 if (htab->elf.sgot && htab->elf.sgot->size > 0) 4164 elf_section_data (htab->elf.sgot->output_section)->this_hdr.sh_entsize 4165 = GOT_ENTRY_SIZE; 4166 4167 /* Fill PLT and GOT entries for local STT_GNU_IFUNC symbols. */ 4168 htab_traverse (htab->loc_hash_table, 4169 elf64_x86_64_finish_local_dynamic_symbol, 4170 info); 4171 4172 return TRUE; 4173 } 4174 4175 /* Return address for Ith PLT stub in section PLT, for relocation REL 4176 or (bfd_vma) -1 if it should not be included. */ 4177 4178 static bfd_vma 4179 elf64_x86_64_plt_sym_val (bfd_vma i, const asection *plt, 4180 const arelent *rel ATTRIBUTE_UNUSED) 4181 { 4182 return plt->vma + (i + 1) * PLT_ENTRY_SIZE; 4183 } 4184 4185 /* Handle an x86-64 specific section when reading an object file. This 4186 is called when elfcode.h finds a section with an unknown type. */ 4187 4188 static bfd_boolean 4189 elf64_x86_64_section_from_shdr (bfd *abfd, 4190 Elf_Internal_Shdr *hdr, 4191 const char *name, 4192 int shindex) 4193 { 4194 if (hdr->sh_type != SHT_X86_64_UNWIND) 4195 return FALSE; 4196 4197 if (! _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex)) 4198 return FALSE; 4199 4200 return TRUE; 4201 } 4202 4203 /* Hook called by the linker routine which adds symbols from an object 4204 file. We use it to put SHN_X86_64_LCOMMON items in .lbss, instead 4205 of .bss. */ 4206 4207 static bfd_boolean 4208 elf64_x86_64_add_symbol_hook (bfd *abfd, 4209 struct bfd_link_info *info, 4210 Elf_Internal_Sym *sym, 4211 const char **namep ATTRIBUTE_UNUSED, 4212 flagword *flagsp ATTRIBUTE_UNUSED, 4213 asection **secp, 4214 bfd_vma *valp) 4215 { 4216 asection *lcomm; 4217 4218 switch (sym->st_shndx) 4219 { 4220 case SHN_X86_64_LCOMMON: 4221 lcomm = bfd_get_section_by_name (abfd, "LARGE_COMMON"); 4222 if (lcomm == NULL) 4223 { 4224 lcomm = bfd_make_section_with_flags (abfd, 4225 "LARGE_COMMON", 4226 (SEC_ALLOC 4227 | SEC_IS_COMMON 4228 | SEC_LINKER_CREATED)); 4229 if (lcomm == NULL) 4230 return FALSE; 4231 elf_section_flags (lcomm) |= SHF_X86_64_LARGE; 4232 } 4233 *secp = lcomm; 4234 *valp = sym->st_size; 4235 break; 4236 } 4237 4238 if (ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC) 4239 elf_tdata (info->output_bfd)->has_ifunc_symbols = TRUE; 4240 4241 return TRUE; 4242 } 4243 4244 4245 /* Given a BFD section, try to locate the corresponding ELF section 4246 index. */ 4247 4248 static bfd_boolean 4249 elf64_x86_64_elf_section_from_bfd_section (bfd *abfd ATTRIBUTE_UNUSED, 4250 asection *sec, int *index) 4251 { 4252 if (sec == &_bfd_elf_large_com_section) 4253 { 4254 *index = SHN_X86_64_LCOMMON; 4255 return TRUE; 4256 } 4257 return FALSE; 4258 } 4259 4260 /* Process a symbol. */ 4261 4262 static void 4263 elf64_x86_64_symbol_processing (bfd *abfd ATTRIBUTE_UNUSED, 4264 asymbol *asym) 4265 { 4266 elf_symbol_type *elfsym = (elf_symbol_type *) asym; 4267 4268 switch (elfsym->internal_elf_sym.st_shndx) 4269 { 4270 case SHN_X86_64_LCOMMON: 4271 asym->section = &_bfd_elf_large_com_section; 4272 asym->value = elfsym->internal_elf_sym.st_size; 4273 /* Common symbol doesn't set BSF_GLOBAL. */ 4274 asym->flags &= ~BSF_GLOBAL; 4275 break; 4276 } 4277 } 4278 4279 static bfd_boolean 4280 elf64_x86_64_common_definition (Elf_Internal_Sym *sym) 4281 { 4282 return (sym->st_shndx == SHN_COMMON 4283 || sym->st_shndx == SHN_X86_64_LCOMMON); 4284 } 4285 4286 static unsigned int 4287 elf64_x86_64_common_section_index (asection *sec) 4288 { 4289 if ((elf_section_flags (sec) & SHF_X86_64_LARGE) == 0) 4290 return SHN_COMMON; 4291 else 4292 return SHN_X86_64_LCOMMON; 4293 } 4294 4295 static asection * 4296 elf64_x86_64_common_section (asection *sec) 4297 { 4298 if ((elf_section_flags (sec) & SHF_X86_64_LARGE) == 0) 4299 return bfd_com_section_ptr; 4300 else 4301 return &_bfd_elf_large_com_section; 4302 } 4303 4304 static bfd_boolean 4305 elf64_x86_64_merge_symbol (struct bfd_link_info *info ATTRIBUTE_UNUSED, 4306 struct elf_link_hash_entry **sym_hash ATTRIBUTE_UNUSED, 4307 struct elf_link_hash_entry *h, 4308 Elf_Internal_Sym *sym, 4309 asection **psec, 4310 bfd_vma *pvalue ATTRIBUTE_UNUSED, 4311 unsigned int *pold_alignment ATTRIBUTE_UNUSED, 4312 bfd_boolean *skip ATTRIBUTE_UNUSED, 4313 bfd_boolean *override ATTRIBUTE_UNUSED, 4314 bfd_boolean *type_change_ok ATTRIBUTE_UNUSED, 4315 bfd_boolean *size_change_ok ATTRIBUTE_UNUSED, 4316 bfd_boolean *newdef ATTRIBUTE_UNUSED, 4317 bfd_boolean *newdyn, 4318 bfd_boolean *newdyncommon ATTRIBUTE_UNUSED, 4319 bfd_boolean *newweak ATTRIBUTE_UNUSED, 4320 bfd *abfd ATTRIBUTE_UNUSED, 4321 asection **sec, 4322 bfd_boolean *olddef ATTRIBUTE_UNUSED, 4323 bfd_boolean *olddyn, 4324 bfd_boolean *olddyncommon ATTRIBUTE_UNUSED, 4325 bfd_boolean *oldweak ATTRIBUTE_UNUSED, 4326 bfd *oldbfd, 4327 asection **oldsec) 4328 { 4329 /* A normal common symbol and a large common symbol result in a 4330 normal common symbol. We turn the large common symbol into a 4331 normal one. */ 4332 if (!*olddyn 4333 && h->root.type == bfd_link_hash_common 4334 && !*newdyn 4335 && bfd_is_com_section (*sec) 4336 && *oldsec != *sec) 4337 { 4338 if (sym->st_shndx == SHN_COMMON 4339 && (elf_section_flags (*oldsec) & SHF_X86_64_LARGE) != 0) 4340 { 4341 h->root.u.c.p->section 4342 = bfd_make_section_old_way (oldbfd, "COMMON"); 4343 h->root.u.c.p->section->flags = SEC_ALLOC; 4344 } 4345 else if (sym->st_shndx == SHN_X86_64_LCOMMON 4346 && (elf_section_flags (*oldsec) & SHF_X86_64_LARGE) == 0) 4347 *psec = *sec = bfd_com_section_ptr; 4348 } 4349 4350 return TRUE; 4351 } 4352 4353 static int 4354 elf64_x86_64_additional_program_headers (bfd *abfd, 4355 struct bfd_link_info *info ATTRIBUTE_UNUSED) 4356 { 4357 asection *s; 4358 int count = 0; 4359 4360 /* Check to see if we need a large readonly segment. */ 4361 s = bfd_get_section_by_name (abfd, ".lrodata"); 4362 if (s && (s->flags & SEC_LOAD)) 4363 count++; 4364 4365 /* Check to see if we need a large data segment. Since .lbss sections 4366 is placed right after the .bss section, there should be no need for 4367 a large data segment just because of .lbss. */ 4368 s = bfd_get_section_by_name (abfd, ".ldata"); 4369 if (s && (s->flags & SEC_LOAD)) 4370 count++; 4371 4372 return count; 4373 } 4374 4375 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */ 4376 4377 static bfd_boolean 4378 elf64_x86_64_hash_symbol (struct elf_link_hash_entry *h) 4379 { 4380 if (h->plt.offset != (bfd_vma) -1 4381 && !h->def_regular 4382 && !h->pointer_equality_needed) 4383 return FALSE; 4384 4385 return _bfd_elf_hash_symbol (h); 4386 } 4387 4388 static const struct bfd_elf_special_section 4389 elf64_x86_64_special_sections[]= 4390 { 4391 { STRING_COMMA_LEN (".gnu.linkonce.lb"), -2, SHT_NOBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE}, 4392 { STRING_COMMA_LEN (".gnu.linkonce.lr"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_X86_64_LARGE}, 4393 { STRING_COMMA_LEN (".gnu.linkonce.lt"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR + SHF_X86_64_LARGE}, 4394 { STRING_COMMA_LEN (".lbss"), -2, SHT_NOBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE}, 4395 { STRING_COMMA_LEN (".ldata"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE}, 4396 { STRING_COMMA_LEN (".lrodata"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_X86_64_LARGE}, 4397 { NULL, 0, 0, 0, 0 } 4398 }; 4399 4400 #define TARGET_LITTLE_SYM bfd_elf64_x86_64_vec 4401 #define TARGET_LITTLE_NAME "elf64-x86-64" 4402 #define ELF_ARCH bfd_arch_i386 4403 #define ELF_MACHINE_CODE EM_X86_64 4404 #define ELF_MAXPAGESIZE 0x200000 4405 #define ELF_MINPAGESIZE 0x1000 4406 #define ELF_COMMONPAGESIZE 0x1000 4407 4408 #define elf_backend_can_gc_sections 1 4409 #define elf_backend_can_refcount 1 4410 #define elf_backend_want_got_plt 1 4411 #define elf_backend_plt_readonly 1 4412 #define elf_backend_want_plt_sym 0 4413 #define elf_backend_got_header_size (GOT_ENTRY_SIZE*3) 4414 #define elf_backend_rela_normal 1 4415 4416 #define elf_info_to_howto elf64_x86_64_info_to_howto 4417 4418 #define bfd_elf64_bfd_link_hash_table_create \ 4419 elf64_x86_64_link_hash_table_create 4420 #define bfd_elf64_bfd_link_hash_table_free \ 4421 elf64_x86_64_link_hash_table_free 4422 #define bfd_elf64_bfd_reloc_type_lookup elf64_x86_64_reloc_type_lookup 4423 #define bfd_elf64_bfd_reloc_name_lookup \ 4424 elf64_x86_64_reloc_name_lookup 4425 4426 #define elf_backend_adjust_dynamic_symbol elf64_x86_64_adjust_dynamic_symbol 4427 #define elf_backend_relocs_compatible _bfd_elf_relocs_compatible 4428 #define elf_backend_check_relocs elf64_x86_64_check_relocs 4429 #define elf_backend_copy_indirect_symbol elf64_x86_64_copy_indirect_symbol 4430 #define elf_backend_create_dynamic_sections elf64_x86_64_create_dynamic_sections 4431 #define elf_backend_finish_dynamic_sections elf64_x86_64_finish_dynamic_sections 4432 #define elf_backend_finish_dynamic_symbol elf64_x86_64_finish_dynamic_symbol 4433 #define elf_backend_gc_mark_hook elf64_x86_64_gc_mark_hook 4434 #define elf_backend_gc_sweep_hook elf64_x86_64_gc_sweep_hook 4435 #define elf_backend_grok_prstatus elf64_x86_64_grok_prstatus 4436 #define elf_backend_grok_psinfo elf64_x86_64_grok_psinfo 4437 #define elf_backend_reloc_type_class elf64_x86_64_reloc_type_class 4438 #define elf_backend_relocate_section elf64_x86_64_relocate_section 4439 #define elf_backend_size_dynamic_sections elf64_x86_64_size_dynamic_sections 4440 #define elf_backend_always_size_sections elf64_x86_64_always_size_sections 4441 #define elf_backend_init_index_section _bfd_elf_init_1_index_section 4442 #define elf_backend_plt_sym_val elf64_x86_64_plt_sym_val 4443 #define elf_backend_object_p elf64_x86_64_elf_object_p 4444 #define bfd_elf64_mkobject elf64_x86_64_mkobject 4445 4446 #define elf_backend_section_from_shdr \ 4447 elf64_x86_64_section_from_shdr 4448 4449 #define elf_backend_section_from_bfd_section \ 4450 elf64_x86_64_elf_section_from_bfd_section 4451 #define elf_backend_add_symbol_hook \ 4452 elf64_x86_64_add_symbol_hook 4453 #define elf_backend_symbol_processing \ 4454 elf64_x86_64_symbol_processing 4455 #define elf_backend_common_section_index \ 4456 elf64_x86_64_common_section_index 4457 #define elf_backend_common_section \ 4458 elf64_x86_64_common_section 4459 #define elf_backend_common_definition \ 4460 elf64_x86_64_common_definition 4461 #define elf_backend_merge_symbol \ 4462 elf64_x86_64_merge_symbol 4463 #define elf_backend_special_sections \ 4464 elf64_x86_64_special_sections 4465 #define elf_backend_additional_program_headers \ 4466 elf64_x86_64_additional_program_headers 4467 #define elf_backend_hash_symbol \ 4468 elf64_x86_64_hash_symbol 4469 4470 #undef elf_backend_post_process_headers 4471 #define elf_backend_post_process_headers _bfd_elf_set_osabi 4472 4473 #include "elf64-target.h" 4474 4475 /* FreeBSD support. */ 4476 4477 #undef TARGET_LITTLE_SYM 4478 #define TARGET_LITTLE_SYM bfd_elf64_x86_64_freebsd_vec 4479 #undef TARGET_LITTLE_NAME 4480 #define TARGET_LITTLE_NAME "elf64-x86-64-freebsd" 4481 4482 #undef ELF_OSABI 4483 #define ELF_OSABI ELFOSABI_FREEBSD 4484 4485 #undef elf64_bed 4486 #define elf64_bed elf64_x86_64_fbsd_bed 4487 4488 #include "elf64-target.h" 4489 4490 /* Intel L1OM support. */ 4491 4492 static bfd_boolean 4493 elf64_l1om_elf_object_p (bfd *abfd) 4494 { 4495 /* Set the right machine number for an L1OM elf64 file. */ 4496 bfd_default_set_arch_mach (abfd, bfd_arch_l1om, bfd_mach_l1om); 4497 return TRUE; 4498 } 4499 4500 #undef TARGET_LITTLE_SYM 4501 #define TARGET_LITTLE_SYM bfd_elf64_l1om_vec 4502 #undef TARGET_LITTLE_NAME 4503 #define TARGET_LITTLE_NAME "elf64-l1om" 4504 #undef ELF_ARCH 4505 #define ELF_ARCH bfd_arch_l1om 4506 4507 #undef ELF_MACHINE_CODE 4508 #define ELF_MACHINE_CODE EM_L1OM 4509 4510 #undef ELF_OSABI 4511 4512 #undef elf64_bed 4513 #define elf64_bed elf64_l1om_bed 4514 4515 #undef elf_backend_object_p 4516 #define elf_backend_object_p elf64_l1om_elf_object_p 4517 4518 #undef elf_backend_post_process_headers 4519 4520 #include "elf64-target.h" 4521 4522 /* FreeBSD L1OM support. */ 4523 4524 #undef TARGET_LITTLE_SYM 4525 #define TARGET_LITTLE_SYM bfd_elf64_l1om_freebsd_vec 4526 #undef TARGET_LITTLE_NAME 4527 #define TARGET_LITTLE_NAME "elf64-l1om-freebsd" 4528 4529 #undef ELF_OSABI 4530 #define ELF_OSABI ELFOSABI_FREEBSD 4531 4532 #undef elf64_bed 4533 #define elf64_bed elf64_l1om_fbsd_bed 4534 4535 #undef elf_backend_post_process_headers 4536 #define elf_backend_post_process_headers _bfd_elf_set_osabi 4537 4538 #include "elf64-target.h" 4539