* elf64-x86-64.c (elf64_x86_64_relocate_section): Fix linking of
[binutils.git] / bfd / elf64-x86-64.c
blob7b37d9644338a86afc19e4bcca290cb7f1dc2d2d
1 /* X86-64 specific support for 64-bit ELF
2 Copyright 2000, 2001 Free Software Foundation, Inc.
3 Contributed by Jan Hubicka <jh@suse.cz>.
5 This file is part of BFD, the Binary File Descriptor library.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
21 #include "bfd.h"
22 #include "sysdep.h"
23 #include "libbfd.h"
24 #include "elf-bfd.h"
26 #include "elf/x86-64.h"
28 /* We use only the RELA entries. */
29 #define USE_RELA
31 /* In case we're on a 32-bit machine, construct a 64-bit "-1" value. */
32 #define MINUS_ONE (~ (bfd_vma) 0)
34 /* The relocation "howto" table. Order of fields:
35 type, size, bitsize, pc_relative, complain_on_overflow,
36 special_function, name, partial_inplace, src_mask, dst_pack, pcrel_offset. */
37 static reloc_howto_type x86_64_elf_howto_table[] =
39 HOWTO(R_X86_64_NONE, 0, 0, 0, false, 0, complain_overflow_dont,
40 bfd_elf_generic_reloc, "R_X86_64_NONE", false, 0x00000000, 0x00000000,
41 false),
42 HOWTO(R_X86_64_64, 0, 4, 64, false, 0, complain_overflow_bitfield,
43 bfd_elf_generic_reloc, "R_X86_64_64", false, MINUS_ONE, MINUS_ONE,
44 false),
45 HOWTO(R_X86_64_PC32, 0, 4, 32, true, 0, complain_overflow_signed,
46 bfd_elf_generic_reloc, "R_X86_64_PC32", false, 0xffffffff, 0xffffffff,
47 true),
48 HOWTO(R_X86_64_GOT32, 0, 4, 32, false, 0, complain_overflow_signed,
49 bfd_elf_generic_reloc, "R_X86_64_GOT32", false, 0xffffffff, 0xffffffff,
50 false),
51 HOWTO(R_X86_64_PLT32, 0, 4, 32, true, 0, complain_overflow_signed,
52 bfd_elf_generic_reloc, "R_X86_64_PLT32", false, 0xffffffff, 0xffffffff,
53 true),
54 HOWTO(R_X86_64_COPY, 0, 4, 32, false, 0, complain_overflow_bitfield,
55 bfd_elf_generic_reloc, "R_X86_64_COPY", false, 0xffffffff, 0xffffffff,
56 false),
57 HOWTO(R_X86_64_GLOB_DAT, 0, 4, 64, false, 0, complain_overflow_bitfield,
58 bfd_elf_generic_reloc, "R_X86_64_GLOB_DAT", false, MINUS_ONE,
59 MINUS_ONE, false),
60 HOWTO(R_X86_64_JUMP_SLOT, 0, 4, 64, false, 0, complain_overflow_bitfield,
61 bfd_elf_generic_reloc, "R_X86_64_JUMP_SLOT", false, MINUS_ONE,
62 MINUS_ONE, false),
63 HOWTO(R_X86_64_RELATIVE, 0, 4, 64, false, 0, complain_overflow_bitfield,
64 bfd_elf_generic_reloc, "R_X86_64_RELATIVE", false, MINUS_ONE,
65 MINUS_ONE, false),
66 HOWTO(R_X86_64_GOTPCREL, 0, 4, 32, true,0 , complain_overflow_signed,
67 bfd_elf_generic_reloc, "R_X86_64_GOTPCREL", false, 0xffffffff,
68 0xffffffff, true),
69 HOWTO(R_X86_64_32, 0, 4, 32, false, 0, complain_overflow_unsigned,
70 bfd_elf_generic_reloc, "R_X86_64_32", false, 0xffffffff, 0xffffffff,
71 false),
72 HOWTO(R_X86_64_32S, 0, 4, 32, false, 0, complain_overflow_signed,
73 bfd_elf_generic_reloc, "R_X86_64_32S", false, 0xffffffff, 0xffffffff,
74 false),
75 HOWTO(R_X86_64_16, 0, 1, 16, false, 0, complain_overflow_bitfield,
76 bfd_elf_generic_reloc, "R_X86_64_16", false, 0xffff, 0xffff, false),
77 HOWTO(R_X86_64_PC16,0, 1, 16, true, 0, complain_overflow_bitfield,
78 bfd_elf_generic_reloc, "R_X86_64_PC16", false, 0xffff, 0xffff, true),
79 HOWTO(R_X86_64_8, 0, 0, 8, false, 0, complain_overflow_signed,
80 bfd_elf_generic_reloc, "R_X86_64_8", false, 0xff, 0xff, false),
81 HOWTO(R_X86_64_PC8, 0, 0, 8, true, 0, complain_overflow_signed,
82 bfd_elf_generic_reloc, "R_X86_64_PC8", false, 0xff, 0xff, true),
84 /* GNU extension to record C++ vtable hierarchy. */
85 HOWTO (R_X86_64_GNU_VTINHERIT, 0, 4, 0, false, 0, complain_overflow_dont,
86 NULL, "R_X86_64_GNU_VTINHERIT", false, 0, 0, false),
88 /* GNU extension to record C++ vtable member usage. */
89 HOWTO (R_X86_64_GNU_VTENTRY, 0, 4, 0, false, 0, complain_overflow_dont,
90 _bfd_elf_rel_vtable_reloc_fn, "R_X86_64_GNU_VTENTRY", false, 0, 0,
91 false)
94 /* Map BFD relocs to the x86_64 elf relocs. */
95 struct elf_reloc_map
97 bfd_reloc_code_real_type bfd_reloc_val;
98 unsigned char elf_reloc_val;
101 static CONST struct elf_reloc_map x86_64_reloc_map[] =
103 { BFD_RELOC_NONE, R_X86_64_NONE, },
104 { BFD_RELOC_64, R_X86_64_64, },
105 { BFD_RELOC_32_PCREL, R_X86_64_PC32, },
106 { BFD_RELOC_X86_64_GOT32, R_X86_64_GOT32,},
107 { BFD_RELOC_X86_64_PLT32, R_X86_64_PLT32,},
108 { BFD_RELOC_X86_64_COPY, R_X86_64_COPY, },
109 { BFD_RELOC_X86_64_GLOB_DAT, R_X86_64_GLOB_DAT, },
110 { BFD_RELOC_X86_64_JUMP_SLOT, R_X86_64_JUMP_SLOT, },
111 { BFD_RELOC_X86_64_RELATIVE, R_X86_64_RELATIVE, },
112 { BFD_RELOC_X86_64_GOTPCREL, R_X86_64_GOTPCREL, },
113 { BFD_RELOC_32, R_X86_64_32, },
114 { BFD_RELOC_X86_64_32S, R_X86_64_32S, },
115 { BFD_RELOC_16, R_X86_64_16, },
116 { BFD_RELOC_16_PCREL, R_X86_64_PC16, },
117 { BFD_RELOC_8, R_X86_64_8, },
118 { BFD_RELOC_8_PCREL, R_X86_64_PC8, },
119 { BFD_RELOC_VTABLE_INHERIT, R_X86_64_GNU_VTINHERIT, },
120 { BFD_RELOC_VTABLE_ENTRY, R_X86_64_GNU_VTENTRY, },
123 static reloc_howto_type *elf64_x86_64_reloc_type_lookup
124 PARAMS ((bfd *, bfd_reloc_code_real_type));
125 static void elf64_x86_64_info_to_howto
126 PARAMS ((bfd *, arelent *, Elf64_Internal_Rela *));
127 static struct bfd_link_hash_table *elf64_x86_64_link_hash_table_create
128 PARAMS ((bfd *));
130 static struct bfd_hash_entry *elf64_x86_64_link_hash_newfunc
131 PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *, const char *));
132 static boolean elf64_x86_64_adjust_dynamic_symbol
133 PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *));
135 static boolean elf64_x86_64_size_dynamic_sections
136 PARAMS ((bfd *, struct bfd_link_info *));
137 static boolean elf64_x86_64_relocate_section
138 PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
139 Elf_Internal_Rela *, Elf_Internal_Sym *, asection **));
140 static boolean elf64_x86_64_finish_dynamic_symbol
141 PARAMS ((bfd *, struct bfd_link_info *, struct elf_link_hash_entry *,
142 Elf_Internal_Sym *sym));
143 static boolean elf64_x86_64_finish_dynamic_sections
144 PARAMS ((bfd *, struct bfd_link_info *));
146 /* Given a BFD reloc type, return a HOWTO structure. */
147 static reloc_howto_type *
148 elf64_x86_64_reloc_type_lookup (abfd, code)
149 bfd *abfd ATTRIBUTE_UNUSED;
150 bfd_reloc_code_real_type code;
152 unsigned int i;
153 for (i = 0; i < sizeof (x86_64_reloc_map) / sizeof (struct elf_reloc_map);
154 i++)
156 if (x86_64_reloc_map[i].bfd_reloc_val == code)
157 return &x86_64_elf_howto_table[(int)
158 x86_64_reloc_map[i].elf_reloc_val];
160 return 0;
163 /* Given an x86_64 ELF reloc type, fill in an arelent structure. */
165 static void
166 elf64_x86_64_info_to_howto (abfd, cache_ptr, dst)
167 bfd *abfd ATTRIBUTE_UNUSED;
168 arelent *cache_ptr;
169 Elf64_Internal_Rela *dst;
171 unsigned r_type, i;
173 r_type = ELF64_R_TYPE (dst->r_info);
174 if (r_type < (unsigned int) R_X86_64_GNU_VTINHERIT)
176 BFD_ASSERT (r_type <= (unsigned int) R_X86_64_PC8);
177 i = r_type;
179 else
181 BFD_ASSERT (r_type < (unsigned int) R_X86_64_max);
182 i = r_type - ((unsigned int) R_X86_64_GNU_VTINHERIT - R_X86_64_PC8 - 1);
184 cache_ptr->howto = &x86_64_elf_howto_table[i];
185 BFD_ASSERT (r_type == cache_ptr->howto->type);
188 /* Functions for the x86-64 ELF linker. */
190 /* The name of the dynamic interpreter. This is put in the .interp
191 section. */
193 #define ELF_DYNAMIC_INTERPRETER "/lib/ld64.so.1"
195 /* The size in bytes of an entry in the global offset table. */
197 #define GOT_ENTRY_SIZE 8
199 /* The size in bytes of an entry in the procedure linkage table. */
201 #define PLT_ENTRY_SIZE 16
203 /* The first entry in a procedure linkage table looks like this. See the
204 SVR4 ABI i386 supplement and the x86-64 ABI to see how this works. */
206 static const bfd_byte elf64_x86_64_plt0_entry[PLT_ENTRY_SIZE] =
208 0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */
209 0xff, 0x25, 16, 0, 0, 0, /* jmpq *GOT+16(%rip) */
210 0x90, 0x90, 0x90, 0x90 /* pad out to 16 bytes with nops. */
213 /* Subsequent entries in a procedure linkage table look like this. */
215 static const bfd_byte elf64_x86_64_plt_entry[PLT_ENTRY_SIZE] =
217 0xff, 0x25, /* jmpq *name@GOTPC(%rip) */
218 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */
219 0x68, /* pushq immediate */
220 0, 0, 0, 0, /* replaced with index into relocation table. */
221 0xe9, /* jmp relative */
222 0, 0, 0, 0 /* replaced with offset to start of .plt0. */
225 /* The x86-64 linker needs to keep track of the number of relocs that
226 it decides to copy in check_relocs for each symbol. This is so
227 that it can discard PC relative relocs if it doesn't need them when
228 linking with -Bsymbolic. We store the information in a field
229 extending the regular ELF linker hash table. */
231 /* This structure keeps track of the number of PC relative relocs we
232 have copied for a given symbol. */
234 struct elf64_x86_64_pcrel_relocs_copied
236 /* Next section. */
237 struct elf64_x86_64_pcrel_relocs_copied *next;
238 /* A section in dynobj. */
239 asection *section;
240 /* Number of relocs copied in this section. */
241 bfd_size_type count;
244 /* x86-64 ELF linker hash entry. */
246 struct elf64_x86_64_link_hash_entry
248 struct elf_link_hash_entry root;
250 /* Number of PC relative relocs copied for this symbol. */
251 struct elf64_x86_64_pcrel_relocs_copied *pcrel_relocs_copied;
254 /* x86-64 ELF linker hash table. */
256 struct elf64_x86_64_link_hash_table
258 struct elf_link_hash_table root;
261 /* Declare this now that the above structures are defined. */
263 static boolean elf64_x86_64_discard_copies
264 PARAMS ((struct elf64_x86_64_link_hash_entry *, PTR));
266 /* Traverse an x86-64 ELF linker hash table. */
268 #define elf64_x86_64_link_hash_traverse(table, func, info) \
269 (elf_link_hash_traverse \
270 (&(table)->root, \
271 (boolean (*) PARAMS ((struct elf_link_hash_entry *, PTR))) (func), \
272 (info)))
274 /* Get the x86-64 ELF linker hash table from a link_info structure. */
276 #define elf64_x86_64_hash_table(p) \
277 ((struct elf64_x86_64_link_hash_table *) ((p)->hash))
279 /* Create an entry in an x86-64 ELF linker hash table. */
281 static struct bfd_hash_entry *
282 elf64_x86_64_link_hash_newfunc (entry, table, string)
283 struct bfd_hash_entry *entry;
284 struct bfd_hash_table *table;
285 const char *string;
287 struct elf64_x86_64_link_hash_entry *ret =
288 (struct elf64_x86_64_link_hash_entry *) entry;
290 /* Allocate the structure if it has not already been allocated by a
291 subclass. */
292 if (ret == (struct elf64_x86_64_link_hash_entry *) NULL)
293 ret = ((struct elf64_x86_64_link_hash_entry *)
294 bfd_hash_allocate (table,
295 sizeof (struct elf64_x86_64_link_hash_entry)));
296 if (ret == (struct elf64_x86_64_link_hash_entry *) NULL)
297 return (struct bfd_hash_entry *) ret;
299 /* Call the allocation method of the superclass. */
300 ret = ((struct elf64_x86_64_link_hash_entry *)
301 _bfd_elf_link_hash_newfunc ((struct bfd_hash_entry *) ret,
302 table, string));
303 if (ret != (struct elf64_x86_64_link_hash_entry *) NULL)
305 ret->pcrel_relocs_copied = NULL;
308 return (struct bfd_hash_entry *) ret;
311 /* Create an X86-64 ELF linker hash table. */
313 static struct bfd_link_hash_table *
314 elf64_x86_64_link_hash_table_create (abfd)
315 bfd *abfd;
317 struct elf64_x86_64_link_hash_table *ret;
319 ret = ((struct elf64_x86_64_link_hash_table *)
320 bfd_alloc (abfd, sizeof (struct elf64_x86_64_link_hash_table)));
321 if (ret == (struct elf64_x86_64_link_hash_table *) NULL)
322 return NULL;
324 if (! _bfd_elf_link_hash_table_init (&ret->root, abfd,
325 elf64_x86_64_link_hash_newfunc))
327 bfd_release (abfd, ret);
328 return NULL;
331 return &ret->root.root;
334 boolean
335 elf64_x86_64_elf_object_p (abfd)
336 bfd *abfd;
338 /* Set the right machine number for an x86-64 elf64 file. */
339 bfd_default_set_arch_mach (abfd, bfd_arch_i386, bfd_mach_x86_64);
340 return true;
343 /* Look through the relocs for a section during the first phase, and
344 allocate space in the global offset table or procedure linkage
345 table. */
347 static boolean
348 elf64_x86_64_check_relocs (abfd, info, sec, relocs)
349 bfd *abfd;
350 struct bfd_link_info *info;
351 asection *sec;
352 const Elf_Internal_Rela *relocs;
354 bfd *dynobj;
355 Elf_Internal_Shdr *symtab_hdr;
356 struct elf_link_hash_entry **sym_hashes;
357 bfd_signed_vma *local_got_refcounts;
358 const Elf_Internal_Rela *rel;
359 const Elf_Internal_Rela *rel_end;
360 asection *sgot;
361 asection *srelgot;
362 asection *sreloc;
364 if (info->relocateable)
365 return true;
367 dynobj = elf_hash_table (info)->dynobj;
368 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
369 sym_hashes = elf_sym_hashes (abfd);
370 local_got_refcounts = elf_local_got_refcounts (abfd);
372 sgot = srelgot = sreloc = NULL;
373 rel_end = relocs + sec->reloc_count;
374 for (rel = relocs; rel < rel_end; rel++)
376 unsigned long r_symndx;
377 struct elf_link_hash_entry *h;
379 r_symndx = ELF64_R_SYM (rel->r_info);
380 if (r_symndx < symtab_hdr->sh_info)
381 h = NULL;
382 else
383 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
385 /* Some relocs require a global offset table. */
386 if (dynobj == NULL)
388 switch (ELF64_R_TYPE (rel->r_info))
390 case R_X86_64_GOT32:
391 case R_X86_64_GOTPCREL:
392 elf_hash_table (info)->dynobj = dynobj = abfd;
393 if (! _bfd_elf_create_got_section (dynobj, info))
394 return false;
395 break;
399 switch (ELF64_R_TYPE (rel->r_info))
401 case R_X86_64_GOTPCREL:
402 case R_X86_64_GOT32:
403 /* This symbol requires a global offset table entry. */
405 if (sgot == NULL)
407 sgot = bfd_get_section_by_name (dynobj, ".got");
408 BFD_ASSERT (sgot != NULL);
411 if (srelgot == NULL && (h != NULL || info->shared))
413 srelgot = bfd_get_section_by_name (dynobj, ".rela.got");
414 if (srelgot == NULL)
416 srelgot = bfd_make_section (dynobj, ".rela.got");
417 if (srelgot == NULL
418 || ! bfd_set_section_flags (dynobj, srelgot,
419 (SEC_ALLOC
420 | SEC_LOAD
421 | SEC_HAS_CONTENTS
422 | SEC_IN_MEMORY
423 | SEC_LINKER_CREATED
424 | SEC_READONLY))
425 || ! bfd_set_section_alignment (dynobj, srelgot, 3))
426 return false;
430 if (h != NULL)
432 if (h->got.refcount == -1)
434 h->got.refcount = 1;
436 /* Make sure this symbol is output as a dynamic symbol. */
437 if (h->dynindx == -1)
439 if (! bfd_elf64_link_record_dynamic_symbol (info, h))
440 return false;
443 sgot->_raw_size += GOT_ENTRY_SIZE;
444 srelgot->_raw_size += sizeof (Elf64_External_Rela);
446 else
447 h->got.refcount += 1;
449 else
451 /* This is a global offset table entry for a local symbol. */
452 if (local_got_refcounts == NULL)
454 size_t size;
456 size = symtab_hdr->sh_info * sizeof (bfd_signed_vma);
457 local_got_refcounts = ((bfd_signed_vma *)
458 bfd_alloc (abfd, size));
459 if (local_got_refcounts == NULL)
460 return false;
461 elf_local_got_refcounts (abfd) = local_got_refcounts;
462 memset (local_got_refcounts, -1, size);
464 if (local_got_refcounts[r_symndx] == -1)
466 local_got_refcounts[r_symndx] = 1;
468 sgot->_raw_size += GOT_ENTRY_SIZE;
469 if (info->shared)
471 /* If we are generating a shared object, we need to
472 output a R_X86_64_RELATIVE reloc so that the dynamic
473 linker can adjust this GOT entry. */
474 srelgot->_raw_size += sizeof (Elf64_External_Rela);
477 else
478 local_got_refcounts[r_symndx] += 1;
480 break;
482 case R_X86_64_PLT32:
483 /* This symbol requires a procedure linkage table entry. We
484 actually build the entry in adjust_dynamic_symbol,
485 because this might be a case of linking PIC code which is
486 never referenced by a dynamic object, in which case we
487 don't need to generate a procedure linkage table entry
488 after all. */
490 /* If this is a local symbol, we resolve it directly without
491 creating a procedure linkage table entry. */
492 if (h == NULL)
493 continue;
495 h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_PLT;
496 if (h->plt.refcount == -1)
497 h->plt.refcount = 1;
498 else
499 h->plt.refcount += 1;
500 break;
502 case R_X86_64_8:
503 case R_X86_64_16:
504 case R_X86_64_32:
505 case R_X86_64_64:
506 case R_X86_64_32S:
507 case R_X86_64_PC32:
508 if (h != NULL)
509 h->elf_link_hash_flags |= ELF_LINK_NON_GOT_REF;
511 /* If we are creating a shared library, and this is a reloc
512 against a global symbol, or a non PC relative reloc
513 against a local symbol, then we need to copy the reloc
514 into the shared library. However, if we are linking with
515 -Bsymbolic, we do not need to copy a reloc against a
516 global symbol which is defined in an object we are
517 including in the link (i.e., DEF_REGULAR is set). At
518 this point we have not seen all the input files, so it is
519 possible that DEF_REGULAR is not set now but will be set
520 later (it is never cleared). We account for that
521 possibility below by storing information in the
522 pcrel_relocs_copied field of the hash table entry.
523 A similar situation occurs when creating shared libraries
524 and symbol visibility changes render the symbol local. */
525 if (info->shared
526 && (sec->flags & SEC_ALLOC) != 0
527 && (((ELF64_R_TYPE (rel->r_info) != R_X86_64_PC8)
528 && (ELF64_R_TYPE (rel->r_info) != R_X86_64_PC16)
529 && (ELF64_R_TYPE (rel->r_info) != R_X86_64_PC32))
530 || (h != NULL
531 && (! info->symbolic
532 || (h->elf_link_hash_flags
533 & ELF_LINK_HASH_DEF_REGULAR) == 0))))
535 /* When creating a shared object, we must copy these
536 reloc types into the output file. We create a reloc
537 section in dynobj and make room for this reloc. */
538 if (sreloc == NULL)
540 const char *name;
542 name = (bfd_elf_string_from_elf_section
543 (abfd,
544 elf_elfheader (abfd)->e_shstrndx,
545 elf_section_data (sec)->rel_hdr.sh_name));
546 if (name == NULL)
547 return false;
549 BFD_ASSERT (strncmp (name, ".rela", 5) == 0
550 && strcmp (bfd_get_section_name (abfd, sec),
551 name + 5) == 0);
553 sreloc = bfd_get_section_by_name (dynobj, name);
554 if (sreloc == NULL)
556 flagword flags;
558 sreloc = bfd_make_section (dynobj, name);
559 flags = (SEC_HAS_CONTENTS | SEC_READONLY
560 | SEC_IN_MEMORY | SEC_LINKER_CREATED);
561 if ((sec->flags & SEC_ALLOC) != 0)
562 flags |= SEC_ALLOC | SEC_LOAD;
563 if (sreloc == NULL
564 || ! bfd_set_section_flags (dynobj, sreloc, flags)
565 || ! bfd_set_section_alignment (dynobj, sreloc, 3))
566 return false;
570 sreloc->_raw_size += sizeof (Elf64_External_Rela);
572 /* If this is a global symbol, we count the number of PC
573 relative relocations we have entered for this symbol,
574 so that we can discard them later as necessary. Note
575 that this function is only called if we are using an
576 elf64_x86_64 linker hash table, which means that h is
577 really a pointer to an elf64_x86_64_link_hash_entry. */
578 if (h != NULL
579 && ((ELF64_R_TYPE (rel->r_info) == R_X86_64_PC8)
580 || (ELF64_R_TYPE (rel->r_info) == R_X86_64_PC16)
581 || (ELF64_R_TYPE (rel->r_info) == R_X86_64_PC32)))
583 struct elf64_x86_64_link_hash_entry *eh;
584 struct elf64_x86_64_pcrel_relocs_copied *p;
586 eh = (struct elf64_x86_64_link_hash_entry *) h;
588 for (p = eh->pcrel_relocs_copied; p != NULL; p = p->next)
589 if (p->section == sreloc)
590 break;
592 if (p == NULL)
594 p = ((struct elf64_x86_64_pcrel_relocs_copied *)
595 bfd_alloc (dynobj, sizeof *p));
596 if (p == NULL)
597 return false;
598 p->next = eh->pcrel_relocs_copied;
599 eh->pcrel_relocs_copied = p;
600 p->section = sreloc;
601 p->count = 0;
604 ++p->count;
607 break;
609 /* This relocation describes the C++ object vtable hierarchy.
610 Reconstruct it for later use during GC. */
611 case R_X86_64_GNU_VTINHERIT:
612 if (!_bfd_elf64_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
613 return false;
614 break;
616 /* This relocation describes which C++ vtable entries are actually
617 used. Record for later use during GC. */
618 case R_X86_64_GNU_VTENTRY:
619 if (!_bfd_elf64_gc_record_vtentry (abfd, sec, h, rel->r_addend))
620 return false;
621 break;
625 return true;
628 /* Return the section that should be marked against GC for a given
629 relocation. */
631 static asection *
632 elf64_x86_64_gc_mark_hook (abfd, info, rel, h, sym)
633 bfd *abfd;
634 struct bfd_link_info *info ATTRIBUTE_UNUSED;
635 Elf_Internal_Rela *rel ATTRIBUTE_UNUSED;
636 struct elf_link_hash_entry *h;
637 Elf_Internal_Sym *sym;
639 if (h != NULL)
641 switch (ELF64_R_TYPE (rel->r_info))
643 case R_X86_64_GNU_VTINHERIT:
644 case R_X86_64_GNU_VTENTRY:
645 break;
647 default:
648 switch (h->root.type)
650 case bfd_link_hash_defined:
651 case bfd_link_hash_defweak:
652 return h->root.u.def.section;
654 case bfd_link_hash_common:
655 return h->root.u.c.p->section;
657 default:
658 break;
662 else
664 if (!(elf_bad_symtab (abfd)
665 && ELF_ST_BIND (sym->st_info) != STB_LOCAL)
666 && ! ((sym->st_shndx <= 0 || sym->st_shndx >= SHN_LORESERVE)
667 && sym->st_shndx != SHN_COMMON))
669 return bfd_section_from_elf_index (abfd, sym->st_shndx);
673 return NULL;
676 /* Update the got entry reference counts for the section being removed. */
678 static boolean
679 elf64_x86_64_gc_sweep_hook (abfd, info, sec, relocs)
680 bfd *abfd;
681 struct bfd_link_info *info ATTRIBUTE_UNUSED;
682 asection *sec;
683 const Elf_Internal_Rela *relocs;
685 Elf_Internal_Shdr *symtab_hdr;
686 struct elf_link_hash_entry **sym_hashes;
687 bfd_signed_vma *local_got_refcounts;
688 const Elf_Internal_Rela *rel, *relend;
689 unsigned long r_symndx;
690 struct elf_link_hash_entry *h;
691 bfd *dynobj;
692 asection *sgot;
693 asection *srelgot;
695 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
696 sym_hashes = elf_sym_hashes (abfd);
697 local_got_refcounts = elf_local_got_refcounts (abfd);
699 dynobj = elf_hash_table (info)->dynobj;
700 if (dynobj == NULL)
701 return true;
703 sgot = bfd_get_section_by_name (dynobj, ".got");
704 srelgot = bfd_get_section_by_name (dynobj, ".rela.got");
706 relend = relocs + sec->reloc_count;
707 for (rel = relocs; rel < relend; rel++)
708 switch (ELF64_R_TYPE (rel->r_info))
710 case R_X86_64_GOT32:
711 case R_X86_64_GOTPCREL:
712 r_symndx = ELF64_R_SYM (rel->r_info);
713 if (r_symndx >= symtab_hdr->sh_info)
715 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
716 if (h->got.refcount > 0)
718 h->got.refcount -= 1;
719 if (h->got.refcount == 0)
721 sgot->_raw_size -= GOT_ENTRY_SIZE;
722 srelgot->_raw_size -= sizeof (Elf64_External_Rela);
726 else if (local_got_refcounts != NULL)
728 if (local_got_refcounts[r_symndx] > 0)
730 local_got_refcounts[r_symndx] -= 1;
731 if (local_got_refcounts[r_symndx] == 0)
733 sgot->_raw_size -= GOT_ENTRY_SIZE;
734 if (info->shared)
735 srelgot->_raw_size -= sizeof (Elf64_External_Rela);
739 break;
741 case R_X86_64_PLT32:
742 r_symndx = ELF64_R_SYM (rel->r_info);
743 if (r_symndx >= symtab_hdr->sh_info)
745 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
746 if (h->plt.refcount > 0)
747 h->plt.refcount -= 1;
749 break;
751 default:
752 break;
755 return true;
758 /* Adjust a symbol defined by a dynamic object and referenced by a
759 regular object. The current definition is in some section of the
760 dynamic object, but we're not including those sections. We have to
761 change the definition to something the rest of the link can
762 understand. */
764 static boolean
765 elf64_x86_64_adjust_dynamic_symbol (info, h)
766 struct bfd_link_info *info;
767 struct elf_link_hash_entry *h;
769 bfd *dynobj;
770 asection *s;
771 unsigned int power_of_two;
773 dynobj = elf_hash_table (info)->dynobj;
775 /* Make sure we know what is going on here. */
776 BFD_ASSERT (dynobj != NULL
777 && ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT)
778 || h->weakdef != NULL
779 || ((h->elf_link_hash_flags
780 & ELF_LINK_HASH_DEF_DYNAMIC) != 0
781 && (h->elf_link_hash_flags
782 & ELF_LINK_HASH_REF_REGULAR) != 0
783 && (h->elf_link_hash_flags
784 & ELF_LINK_HASH_DEF_REGULAR) == 0)));
786 /* If this is a function, put it in the procedure linkage table. We
787 will fill in the contents of the procedure linkage table later,
788 when we know the address of the .got section. */
789 if (h->type == STT_FUNC
790 || (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0)
792 if ((! info->shared
793 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
794 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) == 0)
795 || (info->shared && h->plt.refcount <= 0))
797 /* This case can occur if we saw a PLT32 reloc in an input
798 file, but the symbol was never referred to by a dynamic
799 object, or if all references were garbage collected. In
800 such a case, we don't actually need to build a procedure
801 linkage table, and we can just do a PC32 reloc instead. */
802 h->plt.offset = (bfd_vma) -1;
803 h->elf_link_hash_flags &= ~ELF_LINK_HASH_NEEDS_PLT;
804 return true;
807 /* Make sure this symbol is output as a dynamic symbol. */
808 if (h->dynindx == -1)
810 if (! bfd_elf64_link_record_dynamic_symbol (info, h))
811 return false;
814 s = bfd_get_section_by_name (dynobj, ".plt");
815 BFD_ASSERT (s != NULL);
817 /* If this is the first .plt entry, make room for the special
818 first entry. */
819 if (s->_raw_size == 0)
820 s->_raw_size = PLT_ENTRY_SIZE;
822 /* If this symbol is not defined in a regular file, and we are
823 not generating a shared library, then set the symbol to this
824 location in the .plt. This is required to make function
825 pointers compare as equal between the normal executable and
826 the shared library. */
827 if (! info->shared
828 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
830 h->root.u.def.section = s;
831 h->root.u.def.value = s->_raw_size;
834 h->plt.offset = s->_raw_size;
836 /* Make room for this entry. */
837 s->_raw_size += PLT_ENTRY_SIZE;
839 /* We also need to make an entry in the .got.plt section, which
840 will be placed in the .got section by the linker script. */
841 s = bfd_get_section_by_name (dynobj, ".got.plt");
842 BFD_ASSERT (s != NULL);
843 s->_raw_size += GOT_ENTRY_SIZE;
845 /* We also need to make an entry in the .rela.plt section. */
846 s = bfd_get_section_by_name (dynobj, ".rela.plt");
847 BFD_ASSERT (s != NULL);
848 s->_raw_size += sizeof (Elf64_External_Rela);
850 return true;
853 /* If this is a weak symbol, and there is a real definition, the
854 processor independent code will have arranged for us to see the
855 real definition first, and we can just use the same value. */
856 if (h->weakdef != NULL)
858 BFD_ASSERT (h->weakdef->root.type == bfd_link_hash_defined
859 || h->weakdef->root.type == bfd_link_hash_defweak);
860 h->root.u.def.section = h->weakdef->root.u.def.section;
861 h->root.u.def.value = h->weakdef->root.u.def.value;
862 return true;
865 /* This is a reference to a symbol defined by a dynamic object which
866 is not a function. */
868 /* If we are creating a shared library, we must presume that the
869 only references to the symbol are via the global offset table.
870 For such cases we need not do anything here; the relocations will
871 be handled correctly by relocate_section. */
872 if (info->shared)
873 return true;
875 /* If there are no references to this symbol that do not use the
876 GOT, we don't need to generate a copy reloc. */
877 if ((h->elf_link_hash_flags & ELF_LINK_NON_GOT_REF) == 0)
878 return true;
880 /* We must allocate the symbol in our .dynbss section, which will
881 become part of the .bss section of the executable. There will be
882 an entry for this symbol in the .dynsym section. The dynamic
883 object will contain position independent code, so all references
884 from the dynamic object to this symbol will go through the global
885 offset table. The dynamic linker will use the .dynsym entry to
886 determine the address it must put in the global offset table, so
887 both the dynamic object and the regular object will refer to the
888 same memory location for the variable. */
890 s = bfd_get_section_by_name (dynobj, ".dynbss");
891 BFD_ASSERT (s != NULL);
893 /* We must generate a R_X86_64_COPY reloc to tell the dynamic linker
894 to copy the initial value out of the dynamic object and into the
895 runtime process image. We need to remember the offset into the
896 .rela.bss section we are going to use. */
897 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0)
899 asection *srel;
901 srel = bfd_get_section_by_name (dynobj, ".rela.bss");
902 BFD_ASSERT (srel != NULL);
903 srel->_raw_size += sizeof (Elf64_External_Rela);
904 h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_COPY;
907 /* We need to figure out the alignment required for this symbol. I
908 have no idea how ELF linkers handle this. 16-bytes is the size
909 of the largest type that requires hard alignment -- long double. */
910 /* FIXME: This is VERY ugly. Should be fixed for all architectures using
911 this construct. */
912 power_of_two = bfd_log2 (h->size);
913 if (power_of_two > 4)
914 power_of_two = 4;
916 /* Apply the required alignment. */
917 s->_raw_size = BFD_ALIGN (s->_raw_size, (bfd_size_type) (1 << power_of_two));
918 if (power_of_two > bfd_get_section_alignment (dynobj, s))
920 if (! bfd_set_section_alignment (dynobj, s, power_of_two))
921 return false;
924 /* Define the symbol as being at this point in the section. */
925 h->root.u.def.section = s;
926 h->root.u.def.value = s->_raw_size;
928 /* Increment the section size to make room for the symbol. */
929 s->_raw_size += h->size;
931 return true;
934 /* Set the sizes of the dynamic sections. */
936 static boolean
937 elf64_x86_64_size_dynamic_sections (output_bfd, info)
938 bfd *output_bfd;
939 struct bfd_link_info *info;
941 bfd *dynobj;
942 asection *s;
943 boolean plt;
944 boolean relocs;
945 boolean reltext;
947 dynobj = elf_hash_table (info)->dynobj;
948 BFD_ASSERT (dynobj != NULL);
950 if (elf_hash_table (info)->dynamic_sections_created)
952 /* Set the contents of the .interp section to the interpreter. */
953 if (! info->shared)
955 s = bfd_get_section_by_name (dynobj, ".interp");
956 BFD_ASSERT (s != NULL);
957 s->_raw_size = sizeof ELF_DYNAMIC_INTERPRETER;
958 s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER;
961 else
963 /* We may have created entries in the .rela.got section.
964 However, if we are not creating the dynamic sections, we will
965 not actually use these entries. Reset the size of .rela.got,
966 which will cause it to get stripped from the output file
967 below. */
968 s = bfd_get_section_by_name (dynobj, ".rela.got");
969 if (s != NULL)
970 s->_raw_size = 0;
973 /* If this is a -Bsymbolic shared link, then we need to discard all
974 PC relative relocs against symbols defined in a regular object.
975 We allocated space for them in the check_relocs routine, but we
976 will not fill them in in the relocate_section routine. */
977 if (info->shared)
978 elf64_x86_64_link_hash_traverse (elf64_x86_64_hash_table (info),
979 elf64_x86_64_discard_copies,
980 (PTR) info);
982 /* The check_relocs and adjust_dynamic_symbol entry points have
983 determined the sizes of the various dynamic sections. Allocate
984 memory for them. */
985 plt = relocs = reltext = false;
986 for (s = dynobj->sections; s != NULL; s = s->next)
988 const char *name;
989 boolean strip;
991 if ((s->flags & SEC_LINKER_CREATED) == 0)
992 continue;
994 /* It's OK to base decisions on the section name, because none
995 of the dynobj section names depend upon the input files. */
996 name = bfd_get_section_name (dynobj, s);
998 strip = false;
999 if (strcmp (name, ".plt") == 0)
1001 if (s->_raw_size == 0)
1003 /* Strip this section if we don't need it; see the
1004 comment below. */
1005 strip = true;
1007 else
1009 /* Remember whether there is a PLT. */
1010 plt = true;
1013 else if (strncmp (name, ".rela", 5) == 0)
1015 if (s->_raw_size == 0)
1017 /* If we don't need this section, strip it from the
1018 output file. This is mostly to handle .rela.bss and
1019 .rela.plt. We must create both sections in
1020 create_dynamic_sections, because they must be created
1021 before the linker maps input sections to output
1022 sections. The linker does that before
1023 adjust_dynamic_symbol is called, and it is that
1024 function which decides whether anything needs to go
1025 into these sections. */
1026 strip = true;
1028 else
1030 asection *target;
1032 /* Remember whether there are any reloc sections other
1033 than .rela.plt. */
1034 if (strcmp (name, ".rela.plt") != 0)
1036 const char *outname;
1038 relocs = true;
1040 /* If this relocation section applies to a read only
1041 section, then we probably need a DT_TEXTREL
1042 entry. The entries in the .rela.plt section
1043 really apply to the .got section, which we
1044 created ourselves and so know is not readonly. */
1045 outname = bfd_get_section_name (output_bfd,
1046 s->output_section);
1047 target = bfd_get_section_by_name (output_bfd, outname + 5);
1048 if (target != NULL
1049 && (target->flags & SEC_READONLY) != 0
1050 && (target->flags & SEC_ALLOC) != 0)
1051 reltext = true;
1054 /* We use the reloc_count field as a counter if we need
1055 to copy relocs into the output file. */
1056 s->reloc_count = 0;
1059 else if (strncmp (name, ".got", 4) != 0)
1061 /* It's not one of our sections, so don't allocate space. */
1062 continue;
1065 if (strip)
1067 _bfd_strip_section_from_output (info, s);
1068 continue;
1071 /* Allocate memory for the section contents. We use bfd_zalloc
1072 here in case unused entries are not reclaimed before the
1073 section's contents are written out. This should not happen,
1074 but this way if it does, we get a R_X86_64_NONE reloc instead
1075 of garbage. */
1076 s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->_raw_size);
1077 if (s->contents == NULL && s->_raw_size != 0)
1078 return false;
1081 if (elf_hash_table (info)->dynamic_sections_created)
1083 /* Add some entries to the .dynamic section. We fill in the
1084 values later, in elf64_x86_64_finish_dynamic_sections, but we
1085 must add the entries now so that we get the correct size for
1086 the .dynamic section. The DT_DEBUG entry is filled in by the
1087 dynamic linker and used by the debugger. */
1088 if (! info->shared)
1090 if (! bfd_elf64_add_dynamic_entry (info, DT_DEBUG, 0))
1091 return false;
1094 if (plt)
1096 if (! bfd_elf64_add_dynamic_entry (info, DT_PLTGOT, 0)
1097 || ! bfd_elf64_add_dynamic_entry (info, DT_PLTRELSZ, 0)
1098 || ! bfd_elf64_add_dynamic_entry (info, DT_PLTREL, DT_RELA)
1099 || ! bfd_elf64_add_dynamic_entry (info, DT_JMPREL, 0))
1100 return false;
1103 if (relocs)
1105 if (! bfd_elf64_add_dynamic_entry (info, DT_RELA, 0)
1106 || ! bfd_elf64_add_dynamic_entry (info, DT_RELASZ, 0)
1107 || ! bfd_elf64_add_dynamic_entry (info, DT_RELAENT,
1108 sizeof (Elf64_External_Rela)))
1109 return false;
1112 if (reltext)
1114 if (! bfd_elf64_add_dynamic_entry (info, DT_TEXTREL, 0))
1115 return false;
1116 info->flags |= DF_TEXTREL;
1120 return true;
1123 /* This function is called via elf64_x86_64_link_hash_traverse if we are
1124 creating a shared object. In the -Bsymbolic case, it discards the
1125 space allocated to copy PC relative relocs against symbols which
1126 are defined in regular objects. For the normal non-symbolic case,
1127 we also discard space for relocs that have become local due to
1128 symbol visibility changes. We allocated space for them in the
1129 check_relocs routine, but we won't fill them in in the
1130 relocate_section routine. */
1132 static boolean
1133 elf64_x86_64_discard_copies (h, inf)
1134 struct elf64_x86_64_link_hash_entry *h;
1135 PTR inf;
1137 struct elf64_x86_64_pcrel_relocs_copied *s;
1138 struct bfd_link_info *info = (struct bfd_link_info *) inf;
1140 /* If a symbol has been forced local or we have found a regular
1141 definition for the symbolic link case, then we won't be needing
1142 any relocs. */
1143 if ((h->root.elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
1144 && ((h->root.elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0
1145 || info->symbolic))
1147 for (s = h->pcrel_relocs_copied; s != NULL; s = s->next)
1148 s->section->_raw_size -= s->count * sizeof (Elf64_External_Rela);
1151 return true;
1154 /* Relocate an x86_64 ELF section. */
1156 static boolean
1157 elf64_x86_64_relocate_section (output_bfd, info, input_bfd, input_section,
1158 contents, relocs, local_syms, local_sections)
1159 bfd *output_bfd;
1160 struct bfd_link_info *info;
1161 bfd *input_bfd;
1162 asection *input_section;
1163 bfd_byte *contents;
1164 Elf_Internal_Rela *relocs;
1165 Elf_Internal_Sym *local_syms;
1166 asection **local_sections;
1168 bfd *dynobj;
1169 Elf_Internal_Shdr *symtab_hdr;
1170 struct elf_link_hash_entry **sym_hashes;
1171 bfd_vma *local_got_offsets;
1172 asection *sgot;
1173 asection *splt;
1174 asection *sreloc;
1175 Elf_Internal_Rela *rela;
1176 Elf_Internal_Rela *relend;
1178 dynobj = elf_hash_table (info)->dynobj;
1179 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
1180 sym_hashes = elf_sym_hashes (input_bfd);
1181 local_got_offsets = elf_local_got_offsets (input_bfd);
1183 sreloc = splt = sgot = NULL;
1184 if (dynobj != NULL)
1186 splt = bfd_get_section_by_name (dynobj, ".plt");
1187 sgot = bfd_get_section_by_name (dynobj, ".got");
1190 rela = relocs;
1191 relend = relocs + input_section->reloc_count;
1192 for (; rela < relend; rela++)
1194 int r_type;
1195 reloc_howto_type *howto;
1196 unsigned long r_symndx;
1197 struct elf_link_hash_entry *h;
1198 Elf_Internal_Sym *sym;
1199 asection *sec;
1200 bfd_vma relocation;
1201 bfd_reloc_status_type r;
1202 unsigned int indx;
1204 r_type = ELF64_R_TYPE (rela->r_info);
1205 if (r_type == (int) R_X86_64_GNU_VTINHERIT
1206 || r_type == (int) R_X86_64_GNU_VTENTRY)
1207 continue;
1209 if ((indx = (unsigned) r_type) >= R_X86_64_max)
1211 bfd_set_error (bfd_error_bad_value);
1212 return false;
1214 howto = x86_64_elf_howto_table + indx;
1216 r_symndx = ELF64_R_SYM (rela->r_info);
1218 if (info->relocateable)
1220 /* This is a relocateable link. We don't have to change
1221 anything, unless the reloc is against a section symbol,
1222 in which case we have to adjust according to where the
1223 section symbol winds up in the output section. */
1224 if (r_symndx < symtab_hdr->sh_info)
1226 sym = local_syms + r_symndx;
1227 if (ELF_ST_TYPE (sym->st_info) == STT_SECTION)
1229 sec = local_sections[r_symndx];
1230 rela->r_addend += sec->output_offset + sym->st_value;
1234 continue;
1237 /* This is a final link. */
1238 h = NULL;
1239 sym = NULL;
1240 sec = NULL;
1241 if (r_symndx < symtab_hdr->sh_info)
1243 sym = local_syms + r_symndx;
1244 sec = local_sections[r_symndx];
1245 relocation = (sec->output_section->vma
1246 + sec->output_offset
1247 + sym->st_value);
1249 else
1251 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
1252 while (h->root.type == bfd_link_hash_indirect
1253 || h->root.type == bfd_link_hash_warning)
1254 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1255 if (h->root.type == bfd_link_hash_defined
1256 || h->root.type == bfd_link_hash_defweak)
1258 sec = h->root.u.def.section;
1259 if ((r_type == R_X86_64_PLT32
1260 && splt != NULL
1261 && h->plt.offset != (bfd_vma) -1)
1262 || ((r_type == R_X86_64_GOT32 || r_type == R_X86_64_GOTPCREL)
1263 && elf_hash_table (info)->dynamic_sections_created
1264 && (!info->shared
1265 || (! info->symbolic && h->dynindx != -1)
1266 || (h->elf_link_hash_flags
1267 & ELF_LINK_HASH_DEF_REGULAR) == 0))
1268 || (info->shared
1269 && ((! info->symbolic && h->dynindx != -1)
1270 || (h->elf_link_hash_flags
1271 & ELF_LINK_HASH_DEF_REGULAR) == 0)
1272 && (r_type == R_X86_64_8
1273 || r_type == R_X86_64_16
1274 || r_type == R_X86_64_32
1275 || r_type == R_X86_64_64
1276 || r_type == R_X86_64_PC8
1277 || r_type == R_X86_64_PC16
1278 || r_type == R_X86_64_PC32)
1279 && ((input_section->flags & SEC_ALLOC) != 0
1280 /* DWARF will emit R_X86_64_32 relocations in its
1281 sections against symbols defined externally
1282 in shared libraries. We can't do anything
1283 with them here. */
1284 || ((input_section->flags & SEC_DEBUGGING) != 0
1285 && (h->elf_link_hash_flags
1286 & ELF_LINK_HASH_DEF_DYNAMIC) != 0))))
1288 /* In these cases, we don't need the relocation
1289 value. We check specially because in some
1290 obscure cases sec->output_section will be NULL. */
1291 relocation = 0;
1293 else if (sec->output_section == NULL)
1295 (*_bfd_error_handler)
1296 (_("%s: warning: unresolvable relocation against symbol `%s' from %s section"),
1297 bfd_get_filename (input_bfd), h->root.root.string,
1298 bfd_get_section_name (input_bfd, input_section));
1299 relocation = 0;
1301 else
1302 relocation = (h->root.u.def.value
1303 + sec->output_section->vma
1304 + sec->output_offset);
1306 else if (h->root.type == bfd_link_hash_undefweak)
1307 relocation = 0;
1308 else if (info->shared && !info->symbolic && !info->no_undefined
1309 && ELF_ST_VISIBILITY (h->other) == STV_DEFAULT)
1310 relocation = 0;
1311 else
1313 if (! ((*info->callbacks->undefined_symbol)
1314 (info, h->root.root.string, input_bfd,
1315 input_section, rela->r_offset,
1316 (!info->shared || info->no_undefined
1317 || ELF_ST_VISIBILITY (h->other)))))
1318 return false;
1319 relocation = 0;
1323 /* When generating a shared object, the relocations handled here are
1324 copied into the output file to be resolved at run time. */
1325 switch (r_type)
1327 case R_X86_64_GOT32:
1328 /* Relocation is to the entry for this symbol in the global
1329 offset table. */
1330 case R_X86_64_GOTPCREL:
1331 /* Use global offset table as symbol value. */
1332 BFD_ASSERT (sgot != NULL);
1334 if (h != NULL)
1336 bfd_vma off = h->got.offset;
1337 BFD_ASSERT (off != (bfd_vma) -1);
1339 if (! elf_hash_table (info)->dynamic_sections_created
1340 || (info->shared
1341 && (info->symbolic || h->dynindx == -1)
1342 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
1344 /* This is actually a static link, or it is a -Bsymbolic
1345 link and the symbol is defined locally, or the symbol
1346 was forced to be local because of a version file. We
1347 must initialize this entry in the global offset table.
1348 Since the offset must always be a multiple of 8, we
1349 use the least significant bit to record whether we
1350 have initialized it already.
1352 When doing a dynamic link, we create a .rela.got
1353 relocation entry to initialize the value. This is
1354 done in the finish_dynamic_symbol routine. */
1355 if ((off & 1) != 0)
1356 off &= ~1;
1357 else
1359 bfd_put_64 (output_bfd, relocation,
1360 sgot->contents + off);
1361 h->got.offset |= 1;
1364 if (r_type == R_X86_64_GOTPCREL)
1365 relocation = sgot->output_section->vma + sgot->output_offset + off;
1366 else
1367 relocation = sgot->output_offset + off;
1369 else
1371 bfd_vma off;
1373 BFD_ASSERT (local_got_offsets != NULL
1374 && local_got_offsets[r_symndx] != (bfd_vma) -1);
1376 off = local_got_offsets[r_symndx];
1378 /* The offset must always be a multiple of 8. We use
1379 the least significant bit to record whether we have
1380 already generated the necessary reloc. */
1381 if ((off & 1) != 0)
1382 off &= ~1;
1383 else
1385 bfd_put_64 (output_bfd, relocation, sgot->contents + off);
1387 if (info->shared)
1389 asection *srelgot;
1390 Elf_Internal_Rela outrel;
1392 /* We need to generate a R_X86_64_RELATIVE reloc
1393 for the dynamic linker. */
1394 srelgot = bfd_get_section_by_name (dynobj, ".rela.got");
1395 BFD_ASSERT (srelgot != NULL);
1397 outrel.r_offset = (sgot->output_section->vma
1398 + sgot->output_offset
1399 + off);
1400 outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE);
1401 outrel.r_addend = relocation;
1402 bfd_elf64_swap_reloca_out (output_bfd, &outrel,
1403 (((Elf64_External_Rela *)
1404 srelgot->contents)
1405 + srelgot->reloc_count));
1406 ++srelgot->reloc_count;
1409 local_got_offsets[r_symndx] |= 1;
1412 if (r_type == R_X86_64_GOTPCREL)
1413 relocation = sgot->output_section->vma + sgot->output_offset + off;
1414 else
1415 relocation = sgot->output_offset + off;
1418 break;
1420 case R_X86_64_PLT32:
1421 /* Relocation is to the entry for this symbol in the
1422 procedure linkage table. */
1424 /* Resolve a PLT32 reloc against a local symbol directly,
1425 without using the procedure linkage table. */
1426 if (h == NULL)
1427 break;
1429 if (h->plt.offset == (bfd_vma) -1 || splt == NULL)
1431 /* We didn't make a PLT entry for this symbol. This
1432 happens when statically linking PIC code, or when
1433 using -Bsymbolic. */
1434 break;
1437 relocation = (splt->output_section->vma
1438 + splt->output_offset
1439 + h->plt.offset);
1440 break;
1442 case R_X86_64_PC8:
1443 case R_X86_64_PC16:
1444 case R_X86_64_PC32:
1445 if (h == NULL || h->dynindx == -1
1446 || (info->symbolic
1447 && h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))
1448 break;
1449 /* Fall through. */
1450 case R_X86_64_8:
1451 case R_X86_64_16:
1452 case R_X86_64_32:
1453 case R_X86_64_64:
1454 /* FIXME: The ABI says the linker should make sure the value is
1455 the same when it's zeroextended to 64 bit. */
1456 if (info->shared && (input_section->flags & SEC_ALLOC) != 0)
1458 Elf_Internal_Rela outrel;
1459 boolean skip, relocate;
1461 /* When generating a shared object, these relocations
1462 are copied into the output file to be resolved at run
1463 time. */
1465 if (sreloc == NULL)
1467 const char *name;
1469 name = (bfd_elf_string_from_elf_section
1470 (input_bfd,
1471 elf_elfheader (input_bfd)->e_shstrndx,
1472 elf_section_data (input_section)->rel_hdr.sh_name));
1473 if (name == NULL)
1474 return false;
1476 BFD_ASSERT (strncmp (name, ".rela", 5) == 0
1477 && strcmp (bfd_get_section_name (input_bfd,
1478 input_section),
1479 name + 5) == 0);
1481 sreloc = bfd_get_section_by_name (dynobj, name);
1482 BFD_ASSERT (sreloc != NULL);
1485 skip = false;
1487 if (elf_section_data (input_section)->stab_info == NULL)
1488 outrel.r_offset = rela->r_offset;
1489 else
1491 bfd_vma off;
1493 off = (_bfd_stab_section_offset
1494 (output_bfd, &elf_hash_table (info)->stab_info,
1495 input_section,
1496 &elf_section_data (input_section)->stab_info,
1497 rela->r_offset));
1498 if (off == (bfd_vma) -1)
1499 skip = true;
1500 outrel.r_offset = off;
1503 outrel.r_offset += (input_section->output_section->vma
1504 + input_section->output_offset);
1506 if (skip)
1508 memset (&outrel, 0, sizeof outrel);
1509 relocate = false;
1511 /* h->dynindx may be -1 if this symbol was marked to
1512 become local. */
1513 else if (h != NULL
1514 && ((! info->symbolic && h->dynindx != -1)
1515 || (h->elf_link_hash_flags
1516 & ELF_LINK_HASH_DEF_REGULAR) == 0))
1518 BFD_ASSERT (h->dynindx != -1);
1519 relocate = false;
1520 outrel.r_info = ELF64_R_INFO (h->dynindx, r_type);
1521 outrel.r_addend = relocation + rela->r_addend;
1523 else
1525 if (r_type == R_X86_64_64)
1527 relocate = true;
1528 outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE);
1529 outrel.r_addend = relocation + rela->r_addend;
1531 else
1533 long indx;
1535 if (h == NULL)
1536 sec = local_sections[r_symndx];
1537 else
1539 BFD_ASSERT (h->root.type == bfd_link_hash_defined
1540 || (h->root.type
1541 == bfd_link_hash_defweak));
1542 sec = h->root.u.def.section;
1544 if (sec != NULL && bfd_is_abs_section (sec))
1545 indx = 0;
1546 else if (sec == NULL || sec->owner == NULL)
1548 bfd_set_error (bfd_error_bad_value);
1549 return false;
1551 else
1553 asection *osec;
1555 osec = sec->output_section;
1556 indx = elf_section_data (osec)->dynindx;
1557 BFD_ASSERT (indx > 0);
1560 relocate = false;
1561 outrel.r_info = ELF64_R_INFO (indx, r_type);
1562 outrel.r_addend = relocation + rela->r_addend;
1567 bfd_elf64_swap_reloca_out (output_bfd, &outrel,
1568 (((Elf64_External_Rela *)
1569 sreloc->contents)
1570 + sreloc->reloc_count));
1571 ++sreloc->reloc_count;
1573 /* If this reloc is against an external symbol, we do
1574 not want to fiddle with the addend. Otherwise, we
1575 need to include the symbol value so that it becomes
1576 an addend for the dynamic reloc. */
1577 if (! relocate)
1578 continue;
1581 break;
1583 default:
1584 break;
1587 r = _bfd_final_link_relocate (howto, input_bfd, input_section,
1588 contents, rela->r_offset,
1589 relocation, rela->r_addend);
1591 if (r != bfd_reloc_ok)
1593 switch (r)
1595 default:
1596 case bfd_reloc_outofrange:
1597 abort ();
1598 case bfd_reloc_overflow:
1600 const char *name;
1602 if (h != NULL)
1603 name = h->root.root.string;
1604 else
1606 name = bfd_elf_string_from_elf_section (input_bfd,
1607 symtab_hdr->sh_link,
1608 sym->st_name);
1609 if (name == NULL)
1610 return false;
1611 if (*name == '\0')
1612 name = bfd_section_name (input_bfd, sec);
1614 if (! ((*info->callbacks->reloc_overflow)
1615 (info, name, howto->name, (bfd_vma) 0,
1616 input_bfd, input_section, rela->r_offset)))
1617 return false;
1619 break;
1624 return true;
1627 /* Finish up dynamic symbol handling. We set the contents of various
1628 dynamic sections here. */
1630 static boolean
1631 elf64_x86_64_finish_dynamic_symbol (output_bfd, info, h, sym)
1632 bfd *output_bfd;
1633 struct bfd_link_info *info;
1634 struct elf_link_hash_entry *h;
1635 Elf_Internal_Sym *sym;
1637 bfd *dynobj;
1639 dynobj = elf_hash_table (info)->dynobj;
1641 if (h->plt.offset != (bfd_vma) -1)
1643 asection *splt;
1644 asection *sgot;
1645 asection *srela;
1646 bfd_vma plt_index;
1647 bfd_vma got_offset;
1648 Elf_Internal_Rela rela;
1650 /* This symbol has an entry in the procedure linkage table. Set
1651 it up. */
1653 BFD_ASSERT (h->dynindx != -1);
1655 splt = bfd_get_section_by_name (dynobj, ".plt");
1656 sgot = bfd_get_section_by_name (dynobj, ".got.plt");
1657 srela = bfd_get_section_by_name (dynobj, ".rela.plt");
1658 BFD_ASSERT (splt != NULL && sgot != NULL && srela != NULL);
1660 /* Get the index in the procedure linkage table which
1661 corresponds to this symbol. This is the index of this symbol
1662 in all the symbols for which we are making plt entries. The
1663 first entry in the procedure linkage table is reserved. */
1664 plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1;
1666 /* Get the offset into the .got table of the entry that
1667 corresponds to this function. Each .got entry is GOT_ENTRY_SIZE
1668 bytes. The first three are reserved for the dynamic linker. */
1669 got_offset = (plt_index + 3) * GOT_ENTRY_SIZE;
1671 /* Fill in the entry in the procedure linkage table. */
1672 memcpy (splt->contents + h->plt.offset, elf64_x86_64_plt_entry,
1673 PLT_ENTRY_SIZE);
1675 /* Insert the relocation positions of the plt section. The magic
1676 numbers at the end of the statements are the positions of the
1677 relocations in the plt section. */
1678 /* Put offset for jmp *name@GOTPCREL(%rip), since the
1679 instruction uses 6 bytes, subtract this value. */
1680 bfd_put_32 (output_bfd,
1681 (sgot->output_section->vma
1682 + sgot->output_offset
1683 + got_offset
1684 - splt->output_section->vma
1685 - splt->output_offset
1686 - h->plt.offset
1687 - 6),
1688 splt->contents + h->plt.offset + 2);
1689 /* Put relocation index. */
1690 bfd_put_32 (output_bfd, plt_index,
1691 splt->contents + h->plt.offset + 7);
1692 /* Put offset for jmp .PLT0. */
1693 bfd_put_32 (output_bfd, - (h->plt.offset + PLT_ENTRY_SIZE),
1694 splt->contents + h->plt.offset + 12);
1696 /* Fill in the entry in the global offset table, initially this
1697 points to the pushq instruction in the PLT which is at offset 6. */
1698 bfd_put_64 (output_bfd, (splt->output_section->vma + splt->output_offset
1699 + h->plt.offset + 6),
1700 sgot->contents + got_offset);
1702 /* Fill in the entry in the .rela.plt section. */
1703 rela.r_offset = (sgot->output_section->vma
1704 + sgot->output_offset
1705 + got_offset);
1706 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_JUMP_SLOT);
1707 rela.r_addend = 0;
1708 bfd_elf64_swap_reloca_out (output_bfd, &rela,
1709 ((Elf64_External_Rela *) srela->contents
1710 + plt_index));
1712 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
1714 /* Mark the symbol as undefined, rather than as defined in
1715 the .plt section. Leave the value alone. */
1716 sym->st_shndx = SHN_UNDEF;
1717 /* If the symbol is weak, we do need to clear the value.
1718 Otherwise, the PLT entry would provide a definition for
1719 the symbol even if the symbol wasn't defined anywhere,
1720 and so the symbol would never be NULL. */
1721 if ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR_NONWEAK)
1722 == 0)
1723 sym->st_value = 0;
1727 if (h->got.offset != (bfd_vma) -1)
1729 asection *sgot;
1730 asection *srela;
1731 Elf_Internal_Rela rela;
1733 /* This symbol has an entry in the global offset table. Set it
1734 up. */
1736 sgot = bfd_get_section_by_name (dynobj, ".got");
1737 srela = bfd_get_section_by_name (dynobj, ".rela.got");
1738 BFD_ASSERT (sgot != NULL && srela != NULL);
1740 rela.r_offset = (sgot->output_section->vma
1741 + sgot->output_offset
1742 + (h->got.offset &~ 1));
1744 /* If this is a static link, or it is a -Bsymbolic link and the
1745 symbol is defined locally or was forced to be local because
1746 of a version file, we just want to emit a RELATIVE reloc.
1747 The entry in the global offset table will already have been
1748 initialized in the relocate_section function. */
1749 if (! elf_hash_table (info)->dynamic_sections_created
1750 || (info->shared
1751 && (info->symbolic || h->dynindx == -1)
1752 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
1754 BFD_ASSERT((h->got.offset & 1) != 0);
1755 rela.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE);
1756 rela.r_addend = (h->root.u.def.value
1757 + h->root.u.def.section->output_section->vma
1758 + h->root.u.def.section->output_offset);
1760 else
1762 BFD_ASSERT((h->got.offset & 1) == 0);
1763 bfd_put_64 (output_bfd, (bfd_vma) 0, sgot->contents + h->got.offset);
1764 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_GLOB_DAT);
1765 rela.r_addend = 0;
1768 bfd_elf64_swap_reloca_out (output_bfd, &rela,
1769 ((Elf64_External_Rela *) srela->contents
1770 + srela->reloc_count));
1771 ++srela->reloc_count;
1774 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_COPY) != 0)
1776 asection *s;
1777 Elf_Internal_Rela rela;
1779 /* This symbol needs a copy reloc. Set it up. */
1781 BFD_ASSERT (h->dynindx != -1
1782 && (h->root.type == bfd_link_hash_defined
1783 || h->root.type == bfd_link_hash_defweak));
1785 s = bfd_get_section_by_name (h->root.u.def.section->owner,
1786 ".rela.bss");
1787 BFD_ASSERT (s != NULL);
1789 rela.r_offset = (h->root.u.def.value
1790 + h->root.u.def.section->output_section->vma
1791 + h->root.u.def.section->output_offset);
1792 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_COPY);
1793 rela.r_addend = 0;
1794 bfd_elf64_swap_reloca_out (output_bfd, &rela,
1795 ((Elf64_External_Rela *) s->contents
1796 + s->reloc_count));
1797 ++s->reloc_count;
1800 /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */
1801 if (strcmp (h->root.root.string, "_DYNAMIC") == 0
1802 || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0)
1803 sym->st_shndx = SHN_ABS;
1805 return true;
1808 /* Finish up the dynamic sections. */
1810 static boolean
1811 elf64_x86_64_finish_dynamic_sections (output_bfd, info)
1812 bfd *output_bfd;
1813 struct bfd_link_info *info;
1815 bfd *dynobj;
1816 asection *sdyn;
1817 asection *sgot;
1819 dynobj = elf_hash_table (info)->dynobj;
1821 sgot = bfd_get_section_by_name (dynobj, ".got.plt");
1822 BFD_ASSERT (sgot != NULL);
1823 sdyn = bfd_get_section_by_name (dynobj, ".dynamic");
1825 if (elf_hash_table (info)->dynamic_sections_created)
1827 asection *splt;
1828 Elf64_External_Dyn *dyncon, *dynconend;
1830 BFD_ASSERT (sdyn != NULL);
1832 dyncon = (Elf64_External_Dyn *) sdyn->contents;
1833 dynconend = (Elf64_External_Dyn *) (sdyn->contents + sdyn->_raw_size);
1834 for (; dyncon < dynconend; dyncon++)
1836 Elf_Internal_Dyn dyn;
1837 const char *name;
1838 asection *s;
1840 bfd_elf64_swap_dyn_in (dynobj, dyncon, &dyn);
1842 switch (dyn.d_tag)
1844 default:
1845 continue;
1847 case DT_PLTGOT:
1848 name = ".got";
1849 goto get_vma;
1851 case DT_JMPREL:
1852 name = ".rela.plt";
1854 get_vma:
1855 s = bfd_get_section_by_name (output_bfd, name);
1856 BFD_ASSERT (s != NULL);
1857 dyn.d_un.d_ptr = s->vma;
1858 break;
1860 case DT_RELASZ:
1861 /* FIXME: This comment and code is from elf64-alpha.c: */
1862 /* My interpretation of the TIS v1.1 ELF document indicates
1863 that RELASZ should not include JMPREL. This is not what
1864 the rest of the BFD does. It is, however, what the
1865 glibc ld.so wants. Do this fixup here until we found
1866 out who is right. */
1867 s = bfd_get_section_by_name (output_bfd, ".rela.plt");
1868 if (s)
1870 /* Subtract JMPREL size from RELASZ. */
1871 dyn.d_un.d_val -=
1872 (s->_cooked_size ? s->_cooked_size : s->_raw_size);
1874 break;
1876 case DT_PLTRELSZ:
1877 s = bfd_get_section_by_name (output_bfd, ".rela.plt");
1878 BFD_ASSERT (s != NULL);
1879 dyn.d_un.d_val =
1880 (s->_cooked_size != 0 ? s->_cooked_size : s->_raw_size);
1881 break;
1883 bfd_elf64_swap_dyn_out (output_bfd, &dyn, dyncon);
1886 /* Initialize the contents of the .plt section. */
1887 splt = bfd_get_section_by_name (dynobj, ".plt");
1888 BFD_ASSERT (splt != NULL);
1889 if (splt->_raw_size > 0)
1891 /* Fill in the first entry in the procedure linkage table. */
1892 memcpy (splt->contents, elf64_x86_64_plt0_entry, PLT_ENTRY_SIZE);
1893 /* Add offset for pushq GOT+8(%rip), since the instruction
1894 uses 6 bytes subtract this value. */
1895 bfd_put_32 (output_bfd,
1896 (sgot->output_section->vma
1897 + sgot->output_offset
1899 - splt->output_section->vma
1900 - splt->output_offset
1901 - 6),
1902 splt->contents + 2);
1903 /* Add offset for jmp *GOT+16(%rip). The 12 is the offset to
1904 the end of the instruction. */
1905 bfd_put_32 (output_bfd,
1906 (sgot->output_section->vma
1907 + sgot->output_offset
1908 + 16
1909 - splt->output_section->vma
1910 - splt->output_offset
1911 - 12),
1912 splt->contents + 8);
1916 elf_section_data (splt->output_section)->this_hdr.sh_entsize =
1917 PLT_ENTRY_SIZE;
1920 /* Set the first entry in the global offset table to the address of
1921 the dynamic section. */
1922 if (sgot->_raw_size > 0)
1924 if (sdyn == NULL)
1925 bfd_put_64 (output_bfd, (bfd_vma) 0, sgot->contents);
1926 else
1927 bfd_put_64 (output_bfd,
1928 sdyn->output_section->vma + sdyn->output_offset,
1929 sgot->contents);
1930 /* Write GOT[1] and GOT[2], needed for the dynamic linker. */
1931 bfd_put_64 (output_bfd, (bfd_vma) 0, sgot->contents + GOT_ENTRY_SIZE);
1932 bfd_put_64 (output_bfd, (bfd_vma) 0, sgot->contents + GOT_ENTRY_SIZE*2);
1935 elf_section_data (sgot->output_section)->this_hdr.sh_entsize =
1936 GOT_ENTRY_SIZE;
1938 return true;
1941 #define TARGET_LITTLE_SYM bfd_elf64_x86_64_vec
1942 #define TARGET_LITTLE_NAME "elf64-x86-64"
1943 #define ELF_ARCH bfd_arch_i386
1944 #define ELF_MACHINE_CODE EM_X86_64
1945 #define ELF_MAXPAGESIZE 0x100000
1947 #define elf_backend_can_gc_sections 1
1948 #define elf_backend_want_got_plt 1
1949 #define elf_backend_plt_readonly 1
1950 #define elf_backend_want_plt_sym 0
1951 #define elf_backend_got_header_size (GOT_ENTRY_SIZE*3)
1952 #define elf_backend_plt_header_size PLT_ENTRY_SIZE
1954 #define elf_info_to_howto elf64_x86_64_info_to_howto
1956 #define bfd_elf64_bfd_final_link _bfd_elf64_gc_common_final_link
1957 #define bfd_elf64_bfd_link_hash_table_create \
1958 elf64_x86_64_link_hash_table_create
1959 #define bfd_elf64_bfd_reloc_type_lookup elf64_x86_64_reloc_type_lookup
1961 #define elf_backend_adjust_dynamic_symbol elf64_x86_64_adjust_dynamic_symbol
1962 #define elf_backend_check_relocs elf64_x86_64_check_relocs
1963 #define elf_backend_create_dynamic_sections _bfd_elf_create_dynamic_sections
1964 #define elf_backend_finish_dynamic_sections \
1965 elf64_x86_64_finish_dynamic_sections
1966 #define elf_backend_finish_dynamic_symbol elf64_x86_64_finish_dynamic_symbol
1967 #define elf_backend_gc_mark_hook elf64_x86_64_gc_mark_hook
1968 #define elf_backend_gc_sweep_hook elf64_x86_64_gc_sweep_hook
1969 #define elf_backend_relocate_section elf64_x86_64_relocate_section
1970 #define elf_backend_size_dynamic_sections elf64_x86_64_size_dynamic_sections
1971 #define elf_backend_object_p elf64_x86_64_elf_object_p
1973 #include "elf64-target.h"