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[binutils.git] / bfd / elf64-x86-64.c
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1 /* X86-64 specific support for 64-bit ELF
2 Copyright 2000, 2001, 2002, 2003, 2004, 2005
3 Free Software Foundation, Inc.
4 Contributed by Jan Hubicka <jh@suse.cz>.
6 This file is part of BFD, the Binary File Descriptor library.
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 2 of the License, or
11 (at your option) any later version.
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.
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, MA 02110-1301, USA. */
22 #include "bfd.h"
23 #include "sysdep.h"
24 #include "bfdlink.h"
25 #include "libbfd.h"
26 #include "elf-bfd.h"
28 #include "elf/x86-64.h"
30 /* In case we're on a 32-bit machine, construct a 64-bit "-1" value. */
31 #define MINUS_ONE (~ (bfd_vma) 0)
33 /* The relocation "howto" table. Order of fields:
34 type, size, bitsize, pc_relative, complain_on_overflow,
35 special_function, name, partial_inplace, src_mask, dst_pack, pcrel_offset. */
36 static reloc_howto_type x86_64_elf_howto_table[] =
38 HOWTO(R_X86_64_NONE, 0, 0, 0, FALSE, 0, complain_overflow_dont,
39 bfd_elf_generic_reloc, "R_X86_64_NONE", FALSE, 0x00000000, 0x00000000,
40 FALSE),
41 HOWTO(R_X86_64_64, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
42 bfd_elf_generic_reloc, "R_X86_64_64", FALSE, MINUS_ONE, MINUS_ONE,
43 FALSE),
44 HOWTO(R_X86_64_PC32, 0, 2, 32, TRUE, 0, complain_overflow_signed,
45 bfd_elf_generic_reloc, "R_X86_64_PC32", FALSE, 0xffffffff, 0xffffffff,
46 TRUE),
47 HOWTO(R_X86_64_GOT32, 0, 2, 32, FALSE, 0, complain_overflow_signed,
48 bfd_elf_generic_reloc, "R_X86_64_GOT32", FALSE, 0xffffffff, 0xffffffff,
49 FALSE),
50 HOWTO(R_X86_64_PLT32, 0, 2, 32, TRUE, 0, complain_overflow_signed,
51 bfd_elf_generic_reloc, "R_X86_64_PLT32", FALSE, 0xffffffff, 0xffffffff,
52 TRUE),
53 HOWTO(R_X86_64_COPY, 0, 2, 32, FALSE, 0, complain_overflow_bitfield,
54 bfd_elf_generic_reloc, "R_X86_64_COPY", FALSE, 0xffffffff, 0xffffffff,
55 FALSE),
56 HOWTO(R_X86_64_GLOB_DAT, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
57 bfd_elf_generic_reloc, "R_X86_64_GLOB_DAT", FALSE, MINUS_ONE,
58 MINUS_ONE, FALSE),
59 HOWTO(R_X86_64_JUMP_SLOT, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
60 bfd_elf_generic_reloc, "R_X86_64_JUMP_SLOT", FALSE, MINUS_ONE,
61 MINUS_ONE, FALSE),
62 HOWTO(R_X86_64_RELATIVE, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
63 bfd_elf_generic_reloc, "R_X86_64_RELATIVE", FALSE, MINUS_ONE,
64 MINUS_ONE, FALSE),
65 HOWTO(R_X86_64_GOTPCREL, 0, 2, 32, TRUE, 0, complain_overflow_signed,
66 bfd_elf_generic_reloc, "R_X86_64_GOTPCREL", FALSE, 0xffffffff,
67 0xffffffff, TRUE),
68 HOWTO(R_X86_64_32, 0, 2, 32, FALSE, 0, complain_overflow_unsigned,
69 bfd_elf_generic_reloc, "R_X86_64_32", FALSE, 0xffffffff, 0xffffffff,
70 FALSE),
71 HOWTO(R_X86_64_32S, 0, 2, 32, FALSE, 0, complain_overflow_signed,
72 bfd_elf_generic_reloc, "R_X86_64_32S", FALSE, 0xffffffff, 0xffffffff,
73 FALSE),
74 HOWTO(R_X86_64_16, 0, 1, 16, FALSE, 0, complain_overflow_bitfield,
75 bfd_elf_generic_reloc, "R_X86_64_16", FALSE, 0xffff, 0xffff, FALSE),
76 HOWTO(R_X86_64_PC16,0, 1, 16, TRUE, 0, complain_overflow_bitfield,
77 bfd_elf_generic_reloc, "R_X86_64_PC16", FALSE, 0xffff, 0xffff, TRUE),
78 HOWTO(R_X86_64_8, 0, 0, 8, FALSE, 0, complain_overflow_bitfield,
79 bfd_elf_generic_reloc, "R_X86_64_8", FALSE, 0xff, 0xff, FALSE),
80 HOWTO(R_X86_64_PC8, 0, 0, 8, TRUE, 0, complain_overflow_signed,
81 bfd_elf_generic_reloc, "R_X86_64_PC8", FALSE, 0xff, 0xff, TRUE),
82 HOWTO(R_X86_64_DTPMOD64, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
83 bfd_elf_generic_reloc, "R_X86_64_DTPMOD64", FALSE, MINUS_ONE,
84 MINUS_ONE, FALSE),
85 HOWTO(R_X86_64_DTPOFF64, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
86 bfd_elf_generic_reloc, "R_X86_64_DTPOFF64", FALSE, MINUS_ONE,
87 MINUS_ONE, FALSE),
88 HOWTO(R_X86_64_TPOFF64, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
89 bfd_elf_generic_reloc, "R_X86_64_TPOFF64", FALSE, MINUS_ONE,
90 MINUS_ONE, FALSE),
91 HOWTO(R_X86_64_TLSGD, 0, 2, 32, TRUE, 0, complain_overflow_signed,
92 bfd_elf_generic_reloc, "R_X86_64_TLSGD", FALSE, 0xffffffff,
93 0xffffffff, TRUE),
94 HOWTO(R_X86_64_TLSLD, 0, 2, 32, TRUE, 0, complain_overflow_signed,
95 bfd_elf_generic_reloc, "R_X86_64_TLSLD", FALSE, 0xffffffff,
96 0xffffffff, TRUE),
97 HOWTO(R_X86_64_DTPOFF32, 0, 2, 32, FALSE, 0, complain_overflow_signed,
98 bfd_elf_generic_reloc, "R_X86_64_DTPOFF32", FALSE, 0xffffffff,
99 0xffffffff, FALSE),
100 HOWTO(R_X86_64_GOTTPOFF, 0, 2, 32, TRUE, 0, complain_overflow_signed,
101 bfd_elf_generic_reloc, "R_X86_64_GOTTPOFF", FALSE, 0xffffffff,
102 0xffffffff, TRUE),
103 HOWTO(R_X86_64_TPOFF32, 0, 2, 32, FALSE, 0, complain_overflow_signed,
104 bfd_elf_generic_reloc, "R_X86_64_TPOFF32", FALSE, 0xffffffff,
105 0xffffffff, FALSE),
106 HOWTO(R_X86_64_PC64, 0, 4, 64, TRUE, 0, complain_overflow_bitfield,
107 bfd_elf_generic_reloc, "R_X86_64_PC64", FALSE, MINUS_ONE, MINUS_ONE,
108 TRUE),
109 HOWTO(R_X86_64_GOTOFF64, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
110 bfd_elf_generic_reloc, "R_X86_64_GOTOFF64",
111 FALSE, MINUS_ONE, MINUS_ONE, FALSE),
112 HOWTO(R_X86_64_GOTPC32, 0, 2, 32, TRUE, 0, complain_overflow_signed,
113 bfd_elf_generic_reloc, "R_X86_64_GOTPC32",
114 FALSE, 0xffffffff, 0xffffffff, TRUE),
116 /* We have a gap in the reloc numbers here.
117 R_X86_64_standard counts the number up to this point, and
118 R_X86_64_vt_offset is the value to subtract from a reloc type of
119 R_X86_64_GNU_VT* to form an index into this table. */
120 #define R_X86_64_standard (R_X86_64_GOTPC32 + 1)
121 #define R_X86_64_vt_offset (R_X86_64_GNU_VTINHERIT - R_X86_64_standard)
123 /* GNU extension to record C++ vtable hierarchy. */
124 HOWTO (R_X86_64_GNU_VTINHERIT, 0, 4, 0, FALSE, 0, complain_overflow_dont,
125 NULL, "R_X86_64_GNU_VTINHERIT", FALSE, 0, 0, FALSE),
127 /* GNU extension to record C++ vtable member usage. */
128 HOWTO (R_X86_64_GNU_VTENTRY, 0, 4, 0, FALSE, 0, complain_overflow_dont,
129 _bfd_elf_rel_vtable_reloc_fn, "R_X86_64_GNU_VTENTRY", FALSE, 0, 0,
130 FALSE)
133 /* Map BFD relocs to the x86_64 elf relocs. */
134 struct elf_reloc_map
136 bfd_reloc_code_real_type bfd_reloc_val;
137 unsigned char elf_reloc_val;
140 static const struct elf_reloc_map x86_64_reloc_map[] =
142 { BFD_RELOC_NONE, R_X86_64_NONE, },
143 { BFD_RELOC_64, R_X86_64_64, },
144 { BFD_RELOC_32_PCREL, R_X86_64_PC32, },
145 { BFD_RELOC_X86_64_GOT32, R_X86_64_GOT32,},
146 { BFD_RELOC_X86_64_PLT32, R_X86_64_PLT32,},
147 { BFD_RELOC_X86_64_COPY, R_X86_64_COPY, },
148 { BFD_RELOC_X86_64_GLOB_DAT, R_X86_64_GLOB_DAT, },
149 { BFD_RELOC_X86_64_JUMP_SLOT, R_X86_64_JUMP_SLOT, },
150 { BFD_RELOC_X86_64_RELATIVE, R_X86_64_RELATIVE, },
151 { BFD_RELOC_X86_64_GOTPCREL, R_X86_64_GOTPCREL, },
152 { BFD_RELOC_32, R_X86_64_32, },
153 { BFD_RELOC_X86_64_32S, R_X86_64_32S, },
154 { BFD_RELOC_16, R_X86_64_16, },
155 { BFD_RELOC_16_PCREL, R_X86_64_PC16, },
156 { BFD_RELOC_8, R_X86_64_8, },
157 { BFD_RELOC_8_PCREL, R_X86_64_PC8, },
158 { BFD_RELOC_X86_64_DTPMOD64, R_X86_64_DTPMOD64, },
159 { BFD_RELOC_X86_64_DTPOFF64, R_X86_64_DTPOFF64, },
160 { BFD_RELOC_X86_64_TPOFF64, R_X86_64_TPOFF64, },
161 { BFD_RELOC_X86_64_TLSGD, R_X86_64_TLSGD, },
162 { BFD_RELOC_X86_64_TLSLD, R_X86_64_TLSLD, },
163 { BFD_RELOC_X86_64_DTPOFF32, R_X86_64_DTPOFF32, },
164 { BFD_RELOC_X86_64_GOTTPOFF, R_X86_64_GOTTPOFF, },
165 { BFD_RELOC_X86_64_TPOFF32, R_X86_64_TPOFF32, },
166 { BFD_RELOC_64_PCREL, R_X86_64_PC64, },
167 { BFD_RELOC_X86_64_GOTOFF64, R_X86_64_GOTOFF64, },
168 { BFD_RELOC_X86_64_GOTPC32, R_X86_64_GOTPC32, },
169 { BFD_RELOC_VTABLE_INHERIT, R_X86_64_GNU_VTINHERIT, },
170 { BFD_RELOC_VTABLE_ENTRY, R_X86_64_GNU_VTENTRY, },
174 /* Given a BFD reloc type, return a HOWTO structure. */
175 static reloc_howto_type *
176 elf64_x86_64_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED,
177 bfd_reloc_code_real_type code)
179 unsigned int i;
181 for (i = 0; i < sizeof (x86_64_reloc_map) / sizeof (struct elf_reloc_map);
182 i++)
184 if (x86_64_reloc_map[i].bfd_reloc_val == code)
185 return &x86_64_elf_howto_table[i];
187 return 0;
190 /* Given an x86_64 ELF reloc type, fill in an arelent structure. */
192 static void
193 elf64_x86_64_info_to_howto (bfd *abfd ATTRIBUTE_UNUSED, arelent *cache_ptr,
194 Elf_Internal_Rela *dst)
196 unsigned r_type, i;
198 r_type = ELF64_R_TYPE (dst->r_info);
199 if (r_type < (unsigned int) R_X86_64_GNU_VTINHERIT
200 || r_type >= (unsigned int) R_X86_64_max)
202 if (r_type >= (unsigned int) R_X86_64_standard)
204 (*_bfd_error_handler) (_("%B: invalid relocation type %d"),
205 abfd, (int) r_type);
206 r_type = R_X86_64_NONE;
208 i = r_type;
210 else
211 i = r_type - (unsigned int) R_X86_64_vt_offset;
212 cache_ptr->howto = &x86_64_elf_howto_table[i];
213 BFD_ASSERT (r_type == cache_ptr->howto->type);
216 /* Support for core dump NOTE sections. */
217 static bfd_boolean
218 elf64_x86_64_grok_prstatus (bfd *abfd, Elf_Internal_Note *note)
220 int offset;
221 size_t size;
223 switch (note->descsz)
225 default:
226 return FALSE;
228 case 336: /* sizeof(istruct elf_prstatus) on Linux/x86_64 */
229 /* pr_cursig */
230 elf_tdata (abfd)->core_signal
231 = bfd_get_16 (abfd, note->descdata + 12);
233 /* pr_pid */
234 elf_tdata (abfd)->core_pid
235 = bfd_get_32 (abfd, note->descdata + 32);
237 /* pr_reg */
238 offset = 112;
239 size = 216;
241 break;
244 /* Make a ".reg/999" section. */
245 return _bfd_elfcore_make_pseudosection (abfd, ".reg",
246 size, note->descpos + offset);
249 static bfd_boolean
250 elf64_x86_64_grok_psinfo (bfd *abfd, Elf_Internal_Note *note)
252 switch (note->descsz)
254 default:
255 return FALSE;
257 case 136: /* sizeof(struct elf_prpsinfo) on Linux/x86_64 */
258 elf_tdata (abfd)->core_program
259 = _bfd_elfcore_strndup (abfd, note->descdata + 40, 16);
260 elf_tdata (abfd)->core_command
261 = _bfd_elfcore_strndup (abfd, note->descdata + 56, 80);
264 /* Note that for some reason, a spurious space is tacked
265 onto the end of the args in some (at least one anyway)
266 implementations, so strip it off if it exists. */
269 char *command = elf_tdata (abfd)->core_command;
270 int n = strlen (command);
272 if (0 < n && command[n - 1] == ' ')
273 command[n - 1] = '\0';
276 return TRUE;
279 /* Functions for the x86-64 ELF linker. */
281 /* The name of the dynamic interpreter. This is put in the .interp
282 section. */
284 #define ELF_DYNAMIC_INTERPRETER "/lib/ld64.so.1"
286 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
287 copying dynamic variables from a shared lib into an app's dynbss
288 section, and instead use a dynamic relocation to point into the
289 shared lib. */
290 #define ELIMINATE_COPY_RELOCS 1
292 /* The size in bytes of an entry in the global offset table. */
294 #define GOT_ENTRY_SIZE 8
296 /* The size in bytes of an entry in the procedure linkage table. */
298 #define PLT_ENTRY_SIZE 16
300 /* The first entry in a procedure linkage table looks like this. See the
301 SVR4 ABI i386 supplement and the x86-64 ABI to see how this works. */
303 static const bfd_byte elf64_x86_64_plt0_entry[PLT_ENTRY_SIZE] =
305 0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */
306 0xff, 0x25, 16, 0, 0, 0, /* jmpq *GOT+16(%rip) */
307 0x90, 0x90, 0x90, 0x90 /* pad out to 16 bytes with nops. */
310 /* Subsequent entries in a procedure linkage table look like this. */
312 static const bfd_byte elf64_x86_64_plt_entry[PLT_ENTRY_SIZE] =
314 0xff, 0x25, /* jmpq *name@GOTPC(%rip) */
315 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */
316 0x68, /* pushq immediate */
317 0, 0, 0, 0, /* replaced with index into relocation table. */
318 0xe9, /* jmp relative */
319 0, 0, 0, 0 /* replaced with offset to start of .plt0. */
322 /* The x86-64 linker needs to keep track of the number of relocs that
323 it decides to copy as dynamic relocs in check_relocs for each symbol.
324 This is so that it can later discard them if they are found to be
325 unnecessary. We store the information in a field extending the
326 regular ELF linker hash table. */
328 struct elf64_x86_64_dyn_relocs
330 /* Next section. */
331 struct elf64_x86_64_dyn_relocs *next;
333 /* The input section of the reloc. */
334 asection *sec;
336 /* Total number of relocs copied for the input section. */
337 bfd_size_type count;
339 /* Number of pc-relative relocs copied for the input section. */
340 bfd_size_type pc_count;
343 /* x86-64 ELF linker hash entry. */
345 struct elf64_x86_64_link_hash_entry
347 struct elf_link_hash_entry elf;
349 /* Track dynamic relocs copied for this symbol. */
350 struct elf64_x86_64_dyn_relocs *dyn_relocs;
352 #define GOT_UNKNOWN 0
353 #define GOT_NORMAL 1
354 #define GOT_TLS_GD 2
355 #define GOT_TLS_IE 3
356 unsigned char tls_type;
359 #define elf64_x86_64_hash_entry(ent) \
360 ((struct elf64_x86_64_link_hash_entry *)(ent))
362 struct elf64_x86_64_obj_tdata
364 struct elf_obj_tdata root;
366 /* tls_type for each local got entry. */
367 char *local_got_tls_type;
370 #define elf64_x86_64_tdata(abfd) \
371 ((struct elf64_x86_64_obj_tdata *) (abfd)->tdata.any)
373 #define elf64_x86_64_local_got_tls_type(abfd) \
374 (elf64_x86_64_tdata (abfd)->local_got_tls_type)
377 /* x86-64 ELF linker hash table. */
379 struct elf64_x86_64_link_hash_table
381 struct elf_link_hash_table elf;
383 /* Short-cuts to get to dynamic linker sections. */
384 asection *sgot;
385 asection *sgotplt;
386 asection *srelgot;
387 asection *splt;
388 asection *srelplt;
389 asection *sdynbss;
390 asection *srelbss;
392 union {
393 bfd_signed_vma refcount;
394 bfd_vma offset;
395 } tls_ld_got;
397 /* Small local sym to section mapping cache. */
398 struct sym_sec_cache sym_sec;
401 /* Get the x86-64 ELF linker hash table from a link_info structure. */
403 #define elf64_x86_64_hash_table(p) \
404 ((struct elf64_x86_64_link_hash_table *) ((p)->hash))
406 /* Create an entry in an x86-64 ELF linker hash table. */
408 static struct bfd_hash_entry *
409 link_hash_newfunc (struct bfd_hash_entry *entry, struct bfd_hash_table *table,
410 const char *string)
412 /* Allocate the structure if it has not already been allocated by a
413 subclass. */
414 if (entry == NULL)
416 entry = bfd_hash_allocate (table,
417 sizeof (struct elf64_x86_64_link_hash_entry));
418 if (entry == NULL)
419 return entry;
422 /* Call the allocation method of the superclass. */
423 entry = _bfd_elf_link_hash_newfunc (entry, table, string);
424 if (entry != NULL)
426 struct elf64_x86_64_link_hash_entry *eh;
428 eh = (struct elf64_x86_64_link_hash_entry *) entry;
429 eh->dyn_relocs = NULL;
430 eh->tls_type = GOT_UNKNOWN;
433 return entry;
436 /* Create an X86-64 ELF linker hash table. */
438 static struct bfd_link_hash_table *
439 elf64_x86_64_link_hash_table_create (bfd *abfd)
441 struct elf64_x86_64_link_hash_table *ret;
442 bfd_size_type amt = sizeof (struct elf64_x86_64_link_hash_table);
444 ret = (struct elf64_x86_64_link_hash_table *) bfd_malloc (amt);
445 if (ret == NULL)
446 return NULL;
448 if (! _bfd_elf_link_hash_table_init (&ret->elf, abfd, link_hash_newfunc))
450 free (ret);
451 return NULL;
454 ret->sgot = NULL;
455 ret->sgotplt = NULL;
456 ret->srelgot = NULL;
457 ret->splt = NULL;
458 ret->srelplt = NULL;
459 ret->sdynbss = NULL;
460 ret->srelbss = NULL;
461 ret->sym_sec.abfd = NULL;
462 ret->tls_ld_got.refcount = 0;
464 return &ret->elf.root;
467 /* Create .got, .gotplt, and .rela.got sections in DYNOBJ, and set up
468 shortcuts to them in our hash table. */
470 static bfd_boolean
471 create_got_section (bfd *dynobj, struct bfd_link_info *info)
473 struct elf64_x86_64_link_hash_table *htab;
475 if (! _bfd_elf_create_got_section (dynobj, info))
476 return FALSE;
478 htab = elf64_x86_64_hash_table (info);
479 htab->sgot = bfd_get_section_by_name (dynobj, ".got");
480 htab->sgotplt = bfd_get_section_by_name (dynobj, ".got.plt");
481 if (!htab->sgot || !htab->sgotplt)
482 abort ();
484 htab->srelgot = bfd_make_section_with_flags (dynobj, ".rela.got",
485 (SEC_ALLOC | SEC_LOAD
486 | SEC_HAS_CONTENTS
487 | SEC_IN_MEMORY
488 | SEC_LINKER_CREATED
489 | SEC_READONLY));
490 if (htab->srelgot == NULL
491 || ! bfd_set_section_alignment (dynobj, htab->srelgot, 3))
492 return FALSE;
493 return TRUE;
496 /* Create .plt, .rela.plt, .got, .got.plt, .rela.got, .dynbss, and
497 .rela.bss sections in DYNOBJ, and set up shortcuts to them in our
498 hash table. */
500 static bfd_boolean
501 elf64_x86_64_create_dynamic_sections (bfd *dynobj, struct bfd_link_info *info)
503 struct elf64_x86_64_link_hash_table *htab;
505 htab = elf64_x86_64_hash_table (info);
506 if (!htab->sgot && !create_got_section (dynobj, info))
507 return FALSE;
509 if (!_bfd_elf_create_dynamic_sections (dynobj, info))
510 return FALSE;
512 htab->splt = bfd_get_section_by_name (dynobj, ".plt");
513 htab->srelplt = bfd_get_section_by_name (dynobj, ".rela.plt");
514 htab->sdynbss = bfd_get_section_by_name (dynobj, ".dynbss");
515 if (!info->shared)
516 htab->srelbss = bfd_get_section_by_name (dynobj, ".rela.bss");
518 if (!htab->splt || !htab->srelplt || !htab->sdynbss
519 || (!info->shared && !htab->srelbss))
520 abort ();
522 return TRUE;
525 /* Copy the extra info we tack onto an elf_link_hash_entry. */
527 static void
528 elf64_x86_64_copy_indirect_symbol (const struct elf_backend_data *bed,
529 struct elf_link_hash_entry *dir,
530 struct elf_link_hash_entry *ind)
532 struct elf64_x86_64_link_hash_entry *edir, *eind;
534 edir = (struct elf64_x86_64_link_hash_entry *) dir;
535 eind = (struct elf64_x86_64_link_hash_entry *) ind;
537 if (eind->dyn_relocs != NULL)
539 if (edir->dyn_relocs != NULL)
541 struct elf64_x86_64_dyn_relocs **pp;
542 struct elf64_x86_64_dyn_relocs *p;
544 if (ind->root.type == bfd_link_hash_indirect)
545 abort ();
547 /* Add reloc counts against the weak sym to the strong sym
548 list. Merge any entries against the same section. */
549 for (pp = &eind->dyn_relocs; (p = *pp) != NULL; )
551 struct elf64_x86_64_dyn_relocs *q;
553 for (q = edir->dyn_relocs; q != NULL; q = q->next)
554 if (q->sec == p->sec)
556 q->pc_count += p->pc_count;
557 q->count += p->count;
558 *pp = p->next;
559 break;
561 if (q == NULL)
562 pp = &p->next;
564 *pp = edir->dyn_relocs;
567 edir->dyn_relocs = eind->dyn_relocs;
568 eind->dyn_relocs = NULL;
571 if (ind->root.type == bfd_link_hash_indirect
572 && dir->got.refcount <= 0)
574 edir->tls_type = eind->tls_type;
575 eind->tls_type = GOT_UNKNOWN;
578 if (ELIMINATE_COPY_RELOCS
579 && ind->root.type != bfd_link_hash_indirect
580 && dir->dynamic_adjusted)
582 /* If called to transfer flags for a weakdef during processing
583 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
584 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
585 dir->ref_dynamic |= ind->ref_dynamic;
586 dir->ref_regular |= ind->ref_regular;
587 dir->ref_regular_nonweak |= ind->ref_regular_nonweak;
588 dir->needs_plt |= ind->needs_plt;
589 dir->pointer_equality_needed |= ind->pointer_equality_needed;
591 else
592 _bfd_elf_link_hash_copy_indirect (bed, dir, ind);
595 static bfd_boolean
596 elf64_x86_64_mkobject (bfd *abfd)
598 bfd_size_type amt = sizeof (struct elf64_x86_64_obj_tdata);
599 abfd->tdata.any = bfd_zalloc (abfd, amt);
600 if (abfd->tdata.any == NULL)
601 return FALSE;
602 return TRUE;
605 static bfd_boolean
606 elf64_x86_64_elf_object_p (bfd *abfd)
608 /* Set the right machine number for an x86-64 elf64 file. */
609 bfd_default_set_arch_mach (abfd, bfd_arch_i386, bfd_mach_x86_64);
610 return TRUE;
613 static int
614 elf64_x86_64_tls_transition (struct bfd_link_info *info, int r_type, int is_local)
616 if (info->shared)
617 return r_type;
619 switch (r_type)
621 case R_X86_64_TLSGD:
622 case R_X86_64_GOTTPOFF:
623 if (is_local)
624 return R_X86_64_TPOFF32;
625 return R_X86_64_GOTTPOFF;
626 case R_X86_64_TLSLD:
627 return R_X86_64_TPOFF32;
630 return r_type;
633 /* Look through the relocs for a section during the first phase, and
634 calculate needed space in the global offset table, procedure
635 linkage table, and dynamic reloc sections. */
637 static bfd_boolean
638 elf64_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, asection *sec,
639 const Elf_Internal_Rela *relocs)
641 struct elf64_x86_64_link_hash_table *htab;
642 Elf_Internal_Shdr *symtab_hdr;
643 struct elf_link_hash_entry **sym_hashes;
644 const Elf_Internal_Rela *rel;
645 const Elf_Internal_Rela *rel_end;
646 asection *sreloc;
648 if (info->relocatable)
649 return TRUE;
651 htab = elf64_x86_64_hash_table (info);
652 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
653 sym_hashes = elf_sym_hashes (abfd);
655 sreloc = NULL;
657 rel_end = relocs + sec->reloc_count;
658 for (rel = relocs; rel < rel_end; rel++)
660 unsigned int r_type;
661 unsigned long r_symndx;
662 struct elf_link_hash_entry *h;
664 r_symndx = ELF64_R_SYM (rel->r_info);
665 r_type = ELF64_R_TYPE (rel->r_info);
667 if (r_symndx >= NUM_SHDR_ENTRIES (symtab_hdr))
669 (*_bfd_error_handler) (_("%B: bad symbol index: %d"),
670 abfd, r_symndx);
671 return FALSE;
674 if (r_symndx < symtab_hdr->sh_info)
675 h = NULL;
676 else
678 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
679 while (h->root.type == bfd_link_hash_indirect
680 || h->root.type == bfd_link_hash_warning)
681 h = (struct elf_link_hash_entry *) h->root.u.i.link;
684 r_type = elf64_x86_64_tls_transition (info, r_type, h == NULL);
685 switch (r_type)
687 case R_X86_64_TLSLD:
688 htab->tls_ld_got.refcount += 1;
689 goto create_got;
691 case R_X86_64_TPOFF32:
692 if (info->shared)
694 (*_bfd_error_handler)
695 (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
696 abfd,
697 x86_64_elf_howto_table[r_type].name,
698 (h) ? h->root.root.string : "a local symbol");
699 bfd_set_error (bfd_error_bad_value);
700 return FALSE;
702 break;
704 case R_X86_64_GOTTPOFF:
705 if (info->shared)
706 info->flags |= DF_STATIC_TLS;
707 /* Fall through */
709 case R_X86_64_GOT32:
710 case R_X86_64_GOTPCREL:
711 case R_X86_64_TLSGD:
712 /* This symbol requires a global offset table entry. */
714 int tls_type, old_tls_type;
716 switch (r_type)
718 default: tls_type = GOT_NORMAL; break;
719 case R_X86_64_TLSGD: tls_type = GOT_TLS_GD; break;
720 case R_X86_64_GOTTPOFF: tls_type = GOT_TLS_IE; break;
723 if (h != NULL)
725 h->got.refcount += 1;
726 old_tls_type = elf64_x86_64_hash_entry (h)->tls_type;
728 else
730 bfd_signed_vma *local_got_refcounts;
732 /* This is a global offset table entry for a local symbol. */
733 local_got_refcounts = elf_local_got_refcounts (abfd);
734 if (local_got_refcounts == NULL)
736 bfd_size_type size;
738 size = symtab_hdr->sh_info;
739 size *= sizeof (bfd_signed_vma) + sizeof (char);
740 local_got_refcounts = ((bfd_signed_vma *)
741 bfd_zalloc (abfd, size));
742 if (local_got_refcounts == NULL)
743 return FALSE;
744 elf_local_got_refcounts (abfd) = local_got_refcounts;
745 elf64_x86_64_local_got_tls_type (abfd)
746 = (char *) (local_got_refcounts + symtab_hdr->sh_info);
748 local_got_refcounts[r_symndx] += 1;
749 old_tls_type
750 = elf64_x86_64_local_got_tls_type (abfd) [r_symndx];
753 /* If a TLS symbol is accessed using IE at least once,
754 there is no point to use dynamic model for it. */
755 if (old_tls_type != tls_type && old_tls_type != GOT_UNKNOWN
756 && (old_tls_type != GOT_TLS_GD || tls_type != GOT_TLS_IE))
758 if (old_tls_type == GOT_TLS_IE && tls_type == GOT_TLS_GD)
759 tls_type = old_tls_type;
760 else
762 (*_bfd_error_handler)
763 (_("%B: %s' accessed both as normal and thread local symbol"),
764 abfd, h ? h->root.root.string : "<local>");
765 return FALSE;
769 if (old_tls_type != tls_type)
771 if (h != NULL)
772 elf64_x86_64_hash_entry (h)->tls_type = tls_type;
773 else
774 elf64_x86_64_local_got_tls_type (abfd) [r_symndx] = tls_type;
777 /* Fall through */
779 case R_X86_64_GOTOFF64:
780 case R_X86_64_GOTPC32:
781 create_got:
782 if (htab->sgot == NULL)
784 if (htab->elf.dynobj == NULL)
785 htab->elf.dynobj = abfd;
786 if (!create_got_section (htab->elf.dynobj, info))
787 return FALSE;
789 break;
791 case R_X86_64_PLT32:
792 /* This symbol requires a procedure linkage table entry. We
793 actually build the entry in adjust_dynamic_symbol,
794 because this might be a case of linking PIC code which is
795 never referenced by a dynamic object, in which case we
796 don't need to generate a procedure linkage table entry
797 after all. */
799 /* If this is a local symbol, we resolve it directly without
800 creating a procedure linkage table entry. */
801 if (h == NULL)
802 continue;
804 h->needs_plt = 1;
805 h->plt.refcount += 1;
806 break;
808 case R_X86_64_8:
809 case R_X86_64_16:
810 case R_X86_64_32:
811 case R_X86_64_32S:
812 /* Let's help debug shared library creation. These relocs
813 cannot be used in shared libs. Don't error out for
814 sections we don't care about, such as debug sections or
815 non-constant sections. */
816 if (info->shared
817 && (sec->flags & SEC_ALLOC) != 0
818 && (sec->flags & SEC_READONLY) != 0)
820 (*_bfd_error_handler)
821 (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
822 abfd,
823 x86_64_elf_howto_table[r_type].name,
824 (h) ? h->root.root.string : "a local symbol");
825 bfd_set_error (bfd_error_bad_value);
826 return FALSE;
828 /* Fall through. */
830 case R_X86_64_PC8:
831 case R_X86_64_PC16:
832 case R_X86_64_PC32:
833 case R_X86_64_PC64:
834 case R_X86_64_64:
835 if (h != NULL && !info->shared)
837 /* If this reloc is in a read-only section, we might
838 need a copy reloc. We can't check reliably at this
839 stage whether the section is read-only, as input
840 sections have not yet been mapped to output sections.
841 Tentatively set the flag for now, and correct in
842 adjust_dynamic_symbol. */
843 h->non_got_ref = 1;
845 /* We may need a .plt entry if the function this reloc
846 refers to is in a shared lib. */
847 h->plt.refcount += 1;
848 if (r_type != R_X86_64_PC32 && r_type != R_X86_64_PC64)
849 h->pointer_equality_needed = 1;
852 /* If we are creating a shared library, and this is a reloc
853 against a global symbol, or a non PC relative reloc
854 against a local symbol, then we need to copy the reloc
855 into the shared library. However, if we are linking with
856 -Bsymbolic, we do not need to copy a reloc against a
857 global symbol which is defined in an object we are
858 including in the link (i.e., DEF_REGULAR is set). At
859 this point we have not seen all the input files, so it is
860 possible that DEF_REGULAR is not set now but will be set
861 later (it is never cleared). In case of a weak definition,
862 DEF_REGULAR may be cleared later by a strong definition in
863 a shared library. We account for that possibility below by
864 storing information in the relocs_copied field of the hash
865 table entry. A similar situation occurs when creating
866 shared libraries and symbol visibility changes render the
867 symbol local.
869 If on the other hand, we are creating an executable, we
870 may need to keep relocations for symbols satisfied by a
871 dynamic library if we manage to avoid copy relocs for the
872 symbol. */
873 if ((info->shared
874 && (sec->flags & SEC_ALLOC) != 0
875 && (((r_type != R_X86_64_PC8)
876 && (r_type != R_X86_64_PC16)
877 && (r_type != R_X86_64_PC32)
878 && (r_type != R_X86_64_PC64))
879 || (h != NULL
880 && (! info->symbolic
881 || h->root.type == bfd_link_hash_defweak
882 || !h->def_regular))))
883 || (ELIMINATE_COPY_RELOCS
884 && !info->shared
885 && (sec->flags & SEC_ALLOC) != 0
886 && h != NULL
887 && (h->root.type == bfd_link_hash_defweak
888 || !h->def_regular)))
890 struct elf64_x86_64_dyn_relocs *p;
891 struct elf64_x86_64_dyn_relocs **head;
893 /* We must copy these reloc types into the output file.
894 Create a reloc section in dynobj and make room for
895 this reloc. */
896 if (sreloc == NULL)
898 const char *name;
899 bfd *dynobj;
901 name = (bfd_elf_string_from_elf_section
902 (abfd,
903 elf_elfheader (abfd)->e_shstrndx,
904 elf_section_data (sec)->rel_hdr.sh_name));
905 if (name == NULL)
906 return FALSE;
908 if (strncmp (name, ".rela", 5) != 0
909 || strcmp (bfd_get_section_name (abfd, sec),
910 name + 5) != 0)
912 (*_bfd_error_handler)
913 (_("%B: bad relocation section name `%s\'"),
914 abfd, name);
917 if (htab->elf.dynobj == NULL)
918 htab->elf.dynobj = abfd;
920 dynobj = htab->elf.dynobj;
922 sreloc = bfd_get_section_by_name (dynobj, name);
923 if (sreloc == NULL)
925 flagword flags;
927 flags = (SEC_HAS_CONTENTS | SEC_READONLY
928 | SEC_IN_MEMORY | SEC_LINKER_CREATED);
929 if ((sec->flags & SEC_ALLOC) != 0)
930 flags |= SEC_ALLOC | SEC_LOAD;
931 sreloc = bfd_make_section_with_flags (dynobj,
932 name,
933 flags);
934 if (sreloc == NULL
935 || ! bfd_set_section_alignment (dynobj, sreloc, 3))
936 return FALSE;
938 elf_section_data (sec)->sreloc = sreloc;
941 /* If this is a global symbol, we count the number of
942 relocations we need for this symbol. */
943 if (h != NULL)
945 head = &((struct elf64_x86_64_link_hash_entry *) h)->dyn_relocs;
947 else
949 void **vpp;
950 /* Track dynamic relocs needed for local syms too.
951 We really need local syms available to do this
952 easily. Oh well. */
954 asection *s;
955 s = bfd_section_from_r_symndx (abfd, &htab->sym_sec,
956 sec, r_symndx);
957 if (s == NULL)
958 return FALSE;
960 /* Beware of type punned pointers vs strict aliasing
961 rules. */
962 vpp = &(elf_section_data (s)->local_dynrel);
963 head = (struct elf64_x86_64_dyn_relocs **)vpp;
966 p = *head;
967 if (p == NULL || p->sec != sec)
969 bfd_size_type amt = sizeof *p;
970 p = ((struct elf64_x86_64_dyn_relocs *)
971 bfd_alloc (htab->elf.dynobj, amt));
972 if (p == NULL)
973 return FALSE;
974 p->next = *head;
975 *head = p;
976 p->sec = sec;
977 p->count = 0;
978 p->pc_count = 0;
981 p->count += 1;
982 if (r_type == R_X86_64_PC8
983 || r_type == R_X86_64_PC16
984 || r_type == R_X86_64_PC32
985 || r_type == R_X86_64_PC64)
986 p->pc_count += 1;
988 break;
990 /* This relocation describes the C++ object vtable hierarchy.
991 Reconstruct it for later use during GC. */
992 case R_X86_64_GNU_VTINHERIT:
993 if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
994 return FALSE;
995 break;
997 /* This relocation describes which C++ vtable entries are actually
998 used. Record for later use during GC. */
999 case R_X86_64_GNU_VTENTRY:
1000 if (!bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend))
1001 return FALSE;
1002 break;
1004 default:
1005 break;
1009 return TRUE;
1012 /* Return the section that should be marked against GC for a given
1013 relocation. */
1015 static asection *
1016 elf64_x86_64_gc_mark_hook (asection *sec,
1017 struct bfd_link_info *info ATTRIBUTE_UNUSED,
1018 Elf_Internal_Rela *rel,
1019 struct elf_link_hash_entry *h,
1020 Elf_Internal_Sym *sym)
1022 if (h != NULL)
1024 switch (ELF64_R_TYPE (rel->r_info))
1026 case R_X86_64_GNU_VTINHERIT:
1027 case R_X86_64_GNU_VTENTRY:
1028 break;
1030 default:
1031 switch (h->root.type)
1033 case bfd_link_hash_defined:
1034 case bfd_link_hash_defweak:
1035 return h->root.u.def.section;
1037 case bfd_link_hash_common:
1038 return h->root.u.c.p->section;
1040 default:
1041 break;
1045 else
1046 return bfd_section_from_elf_index (sec->owner, sym->st_shndx);
1048 return NULL;
1051 /* Update the got entry reference counts for the section being removed. */
1053 static bfd_boolean
1054 elf64_x86_64_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info,
1055 asection *sec, const Elf_Internal_Rela *relocs)
1057 Elf_Internal_Shdr *symtab_hdr;
1058 struct elf_link_hash_entry **sym_hashes;
1059 bfd_signed_vma *local_got_refcounts;
1060 const Elf_Internal_Rela *rel, *relend;
1062 elf_section_data (sec)->local_dynrel = NULL;
1064 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
1065 sym_hashes = elf_sym_hashes (abfd);
1066 local_got_refcounts = elf_local_got_refcounts (abfd);
1068 relend = relocs + sec->reloc_count;
1069 for (rel = relocs; rel < relend; rel++)
1071 unsigned long r_symndx;
1072 unsigned int r_type;
1073 struct elf_link_hash_entry *h = NULL;
1075 r_symndx = ELF64_R_SYM (rel->r_info);
1076 if (r_symndx >= symtab_hdr->sh_info)
1078 struct elf64_x86_64_link_hash_entry *eh;
1079 struct elf64_x86_64_dyn_relocs **pp;
1080 struct elf64_x86_64_dyn_relocs *p;
1082 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
1083 while (h->root.type == bfd_link_hash_indirect
1084 || h->root.type == bfd_link_hash_warning)
1085 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1086 eh = (struct elf64_x86_64_link_hash_entry *) h;
1088 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; pp = &p->next)
1089 if (p->sec == sec)
1091 /* Everything must go for SEC. */
1092 *pp = p->next;
1093 break;
1097 r_type = ELF64_R_TYPE (rel->r_info);
1098 r_type = elf64_x86_64_tls_transition (info, r_type, h != NULL);
1099 switch (r_type)
1101 case R_X86_64_TLSLD:
1102 if (elf64_x86_64_hash_table (info)->tls_ld_got.refcount > 0)
1103 elf64_x86_64_hash_table (info)->tls_ld_got.refcount -= 1;
1104 break;
1106 case R_X86_64_TLSGD:
1107 case R_X86_64_GOTTPOFF:
1108 case R_X86_64_GOT32:
1109 case R_X86_64_GOTPCREL:
1110 if (h != NULL)
1112 if (h->got.refcount > 0)
1113 h->got.refcount -= 1;
1115 else if (local_got_refcounts != NULL)
1117 if (local_got_refcounts[r_symndx] > 0)
1118 local_got_refcounts[r_symndx] -= 1;
1120 break;
1122 case R_X86_64_8:
1123 case R_X86_64_16:
1124 case R_X86_64_32:
1125 case R_X86_64_64:
1126 case R_X86_64_32S:
1127 case R_X86_64_PC8:
1128 case R_X86_64_PC16:
1129 case R_X86_64_PC32:
1130 case R_X86_64_PC64:
1131 if (info->shared)
1132 break;
1133 /* Fall thru */
1135 case R_X86_64_PLT32:
1136 if (h != NULL)
1138 if (h->plt.refcount > 0)
1139 h->plt.refcount -= 1;
1141 break;
1143 default:
1144 break;
1148 return TRUE;
1151 /* Adjust a symbol defined by a dynamic object and referenced by a
1152 regular object. The current definition is in some section of the
1153 dynamic object, but we're not including those sections. We have to
1154 change the definition to something the rest of the link can
1155 understand. */
1157 static bfd_boolean
1158 elf64_x86_64_adjust_dynamic_symbol (struct bfd_link_info *info,
1159 struct elf_link_hash_entry *h)
1161 struct elf64_x86_64_link_hash_table *htab;
1162 asection *s;
1163 unsigned int power_of_two;
1165 /* If this is a function, put it in the procedure linkage table. We
1166 will fill in the contents of the procedure linkage table later,
1167 when we know the address of the .got section. */
1168 if (h->type == STT_FUNC
1169 || h->needs_plt)
1171 if (h->plt.refcount <= 0
1172 || SYMBOL_CALLS_LOCAL (info, h)
1173 || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1174 && h->root.type == bfd_link_hash_undefweak))
1176 /* This case can occur if we saw a PLT32 reloc in an input
1177 file, but the symbol was never referred to by a dynamic
1178 object, or if all references were garbage collected. In
1179 such a case, we don't actually need to build a procedure
1180 linkage table, and we can just do a PC32 reloc instead. */
1181 h->plt.offset = (bfd_vma) -1;
1182 h->needs_plt = 0;
1185 return TRUE;
1187 else
1188 /* It's possible that we incorrectly decided a .plt reloc was
1189 needed for an R_X86_64_PC32 reloc to a non-function sym in
1190 check_relocs. We can't decide accurately between function and
1191 non-function syms in check-relocs; Objects loaded later in
1192 the link may change h->type. So fix it now. */
1193 h->plt.offset = (bfd_vma) -1;
1195 /* If this is a weak symbol, and there is a real definition, the
1196 processor independent code will have arranged for us to see the
1197 real definition first, and we can just use the same value. */
1198 if (h->u.weakdef != NULL)
1200 BFD_ASSERT (h->u.weakdef->root.type == bfd_link_hash_defined
1201 || h->u.weakdef->root.type == bfd_link_hash_defweak);
1202 h->root.u.def.section = h->u.weakdef->root.u.def.section;
1203 h->root.u.def.value = h->u.weakdef->root.u.def.value;
1204 if (ELIMINATE_COPY_RELOCS || info->nocopyreloc)
1205 h->non_got_ref = h->u.weakdef->non_got_ref;
1206 return TRUE;
1209 /* This is a reference to a symbol defined by a dynamic object which
1210 is not a function. */
1212 /* If we are creating a shared library, we must presume that the
1213 only references to the symbol are via the global offset table.
1214 For such cases we need not do anything here; the relocations will
1215 be handled correctly by relocate_section. */
1216 if (info->shared)
1217 return TRUE;
1219 /* If there are no references to this symbol that do not use the
1220 GOT, we don't need to generate a copy reloc. */
1221 if (!h->non_got_ref)
1222 return TRUE;
1224 /* If -z nocopyreloc was given, we won't generate them either. */
1225 if (info->nocopyreloc)
1227 h->non_got_ref = 0;
1228 return TRUE;
1231 if (ELIMINATE_COPY_RELOCS)
1233 struct elf64_x86_64_link_hash_entry * eh;
1234 struct elf64_x86_64_dyn_relocs *p;
1236 eh = (struct elf64_x86_64_link_hash_entry *) h;
1237 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1239 s = p->sec->output_section;
1240 if (s != NULL && (s->flags & SEC_READONLY) != 0)
1241 break;
1244 /* If we didn't find any dynamic relocs in read-only sections, then
1245 we'll be keeping the dynamic relocs and avoiding the copy reloc. */
1246 if (p == NULL)
1248 h->non_got_ref = 0;
1249 return TRUE;
1253 if (h->size == 0)
1255 (*_bfd_error_handler) (_("dynamic variable `%s' is zero size"),
1256 h->root.root.string);
1257 return TRUE;
1260 /* We must allocate the symbol in our .dynbss section, which will
1261 become part of the .bss section of the executable. There will be
1262 an entry for this symbol in the .dynsym section. The dynamic
1263 object will contain position independent code, so all references
1264 from the dynamic object to this symbol will go through the global
1265 offset table. The dynamic linker will use the .dynsym entry to
1266 determine the address it must put in the global offset table, so
1267 both the dynamic object and the regular object will refer to the
1268 same memory location for the variable. */
1270 htab = elf64_x86_64_hash_table (info);
1272 /* We must generate a R_X86_64_COPY reloc to tell the dynamic linker
1273 to copy the initial value out of the dynamic object and into the
1274 runtime process image. */
1275 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0)
1277 htab->srelbss->size += sizeof (Elf64_External_Rela);
1278 h->needs_copy = 1;
1281 /* We need to figure out the alignment required for this symbol. I
1282 have no idea how ELF linkers handle this. 16-bytes is the size
1283 of the largest type that requires hard alignment -- long double. */
1284 /* FIXME: This is VERY ugly. Should be fixed for all architectures using
1285 this construct. */
1286 power_of_two = bfd_log2 (h->size);
1287 if (power_of_two > 4)
1288 power_of_two = 4;
1290 /* Apply the required alignment. */
1291 s = htab->sdynbss;
1292 s->size = BFD_ALIGN (s->size, (bfd_size_type) (1 << power_of_two));
1293 if (power_of_two > bfd_get_section_alignment (htab->elf.dynobj, s))
1295 if (! bfd_set_section_alignment (htab->elf.dynobj, s, power_of_two))
1296 return FALSE;
1299 /* Define the symbol as being at this point in the section. */
1300 h->root.u.def.section = s;
1301 h->root.u.def.value = s->size;
1303 /* Increment the section size to make room for the symbol. */
1304 s->size += h->size;
1306 return TRUE;
1309 /* Allocate space in .plt, .got and associated reloc sections for
1310 dynamic relocs. */
1312 static bfd_boolean
1313 allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
1315 struct bfd_link_info *info;
1316 struct elf64_x86_64_link_hash_table *htab;
1317 struct elf64_x86_64_link_hash_entry *eh;
1318 struct elf64_x86_64_dyn_relocs *p;
1320 if (h->root.type == bfd_link_hash_indirect)
1321 return TRUE;
1323 if (h->root.type == bfd_link_hash_warning)
1324 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1326 info = (struct bfd_link_info *) inf;
1327 htab = elf64_x86_64_hash_table (info);
1329 if (htab->elf.dynamic_sections_created
1330 && h->plt.refcount > 0)
1332 /* Make sure this symbol is output as a dynamic symbol.
1333 Undefined weak syms won't yet be marked as dynamic. */
1334 if (h->dynindx == -1
1335 && !h->forced_local)
1337 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1338 return FALSE;
1341 if (info->shared
1342 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
1344 asection *s = htab->splt;
1346 /* If this is the first .plt entry, make room for the special
1347 first entry. */
1348 if (s->size == 0)
1349 s->size += PLT_ENTRY_SIZE;
1351 h->plt.offset = s->size;
1353 /* If this symbol is not defined in a regular file, and we are
1354 not generating a shared library, then set the symbol to this
1355 location in the .plt. This is required to make function
1356 pointers compare as equal between the normal executable and
1357 the shared library. */
1358 if (! info->shared
1359 && !h->def_regular)
1361 h->root.u.def.section = s;
1362 h->root.u.def.value = h->plt.offset;
1365 /* Make room for this entry. */
1366 s->size += PLT_ENTRY_SIZE;
1368 /* We also need to make an entry in the .got.plt section, which
1369 will be placed in the .got section by the linker script. */
1370 htab->sgotplt->size += GOT_ENTRY_SIZE;
1372 /* We also need to make an entry in the .rela.plt section. */
1373 htab->srelplt->size += sizeof (Elf64_External_Rela);
1375 else
1377 h->plt.offset = (bfd_vma) -1;
1378 h->needs_plt = 0;
1381 else
1383 h->plt.offset = (bfd_vma) -1;
1384 h->needs_plt = 0;
1387 /* If R_X86_64_GOTTPOFF symbol is now local to the binary,
1388 make it a R_X86_64_TPOFF32 requiring no GOT entry. */
1389 if (h->got.refcount > 0
1390 && !info->shared
1391 && h->dynindx == -1
1392 && elf64_x86_64_hash_entry (h)->tls_type == GOT_TLS_IE)
1393 h->got.offset = (bfd_vma) -1;
1394 else if (h->got.refcount > 0)
1396 asection *s;
1397 bfd_boolean dyn;
1398 int tls_type = elf64_x86_64_hash_entry (h)->tls_type;
1400 /* Make sure this symbol is output as a dynamic symbol.
1401 Undefined weak syms won't yet be marked as dynamic. */
1402 if (h->dynindx == -1
1403 && !h->forced_local)
1405 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1406 return FALSE;
1409 s = htab->sgot;
1410 h->got.offset = s->size;
1411 s->size += GOT_ENTRY_SIZE;
1412 /* R_X86_64_TLSGD needs 2 consecutive GOT slots. */
1413 if (tls_type == GOT_TLS_GD)
1414 s->size += GOT_ENTRY_SIZE;
1415 dyn = htab->elf.dynamic_sections_created;
1416 /* R_X86_64_TLSGD needs one dynamic relocation if local symbol
1417 and two if global.
1418 R_X86_64_GOTTPOFF needs one dynamic relocation. */
1419 if ((tls_type == GOT_TLS_GD && h->dynindx == -1)
1420 || tls_type == GOT_TLS_IE)
1421 htab->srelgot->size += sizeof (Elf64_External_Rela);
1422 else if (tls_type == GOT_TLS_GD)
1423 htab->srelgot->size += 2 * sizeof (Elf64_External_Rela);
1424 else if ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
1425 || h->root.type != bfd_link_hash_undefweak)
1426 && (info->shared
1427 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h)))
1428 htab->srelgot->size += sizeof (Elf64_External_Rela);
1430 else
1431 h->got.offset = (bfd_vma) -1;
1433 eh = (struct elf64_x86_64_link_hash_entry *) h;
1434 if (eh->dyn_relocs == NULL)
1435 return TRUE;
1437 /* In the shared -Bsymbolic case, discard space allocated for
1438 dynamic pc-relative relocs against symbols which turn out to be
1439 defined in regular objects. For the normal shared case, discard
1440 space for pc-relative relocs that have become local due to symbol
1441 visibility changes. */
1443 if (info->shared)
1445 /* Relocs that use pc_count are those that appear on a call
1446 insn, or certain REL relocs that can generated via assembly.
1447 We want calls to protected symbols to resolve directly to the
1448 function rather than going via the plt. If people want
1449 function pointer comparisons to work as expected then they
1450 should avoid writing weird assembly. */
1451 if (SYMBOL_CALLS_LOCAL (info, h))
1453 struct elf64_x86_64_dyn_relocs **pp;
1455 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
1457 p->count -= p->pc_count;
1458 p->pc_count = 0;
1459 if (p->count == 0)
1460 *pp = p->next;
1461 else
1462 pp = &p->next;
1466 /* Also discard relocs on undefined weak syms with non-default
1467 visibility. */
1468 if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1469 && h->root.type == bfd_link_hash_undefweak)
1470 eh->dyn_relocs = NULL;
1472 else if (ELIMINATE_COPY_RELOCS)
1474 /* For the non-shared case, discard space for relocs against
1475 symbols which turn out to need copy relocs or are not
1476 dynamic. */
1478 if (!h->non_got_ref
1479 && ((h->def_dynamic
1480 && !h->def_regular)
1481 || (htab->elf.dynamic_sections_created
1482 && (h->root.type == bfd_link_hash_undefweak
1483 || h->root.type == bfd_link_hash_undefined))))
1485 /* Make sure this symbol is output as a dynamic symbol.
1486 Undefined weak syms won't yet be marked as dynamic. */
1487 if (h->dynindx == -1
1488 && !h->forced_local)
1490 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1491 return FALSE;
1494 /* If that succeeded, we know we'll be keeping all the
1495 relocs. */
1496 if (h->dynindx != -1)
1497 goto keep;
1500 eh->dyn_relocs = NULL;
1502 keep: ;
1505 /* Finally, allocate space. */
1506 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1508 asection *sreloc = elf_section_data (p->sec)->sreloc;
1509 sreloc->size += p->count * sizeof (Elf64_External_Rela);
1512 return TRUE;
1515 /* Find any dynamic relocs that apply to read-only sections. */
1517 static bfd_boolean
1518 readonly_dynrelocs (struct elf_link_hash_entry *h, void * inf)
1520 struct elf64_x86_64_link_hash_entry *eh;
1521 struct elf64_x86_64_dyn_relocs *p;
1523 if (h->root.type == bfd_link_hash_warning)
1524 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1526 eh = (struct elf64_x86_64_link_hash_entry *) h;
1527 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1529 asection *s = p->sec->output_section;
1531 if (s != NULL && (s->flags & SEC_READONLY) != 0)
1533 struct bfd_link_info *info = (struct bfd_link_info *) inf;
1535 info->flags |= DF_TEXTREL;
1537 /* Not an error, just cut short the traversal. */
1538 return FALSE;
1541 return TRUE;
1544 /* Set the sizes of the dynamic sections. */
1546 static bfd_boolean
1547 elf64_x86_64_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED,
1548 struct bfd_link_info *info)
1550 struct elf64_x86_64_link_hash_table *htab;
1551 bfd *dynobj;
1552 asection *s;
1553 bfd_boolean relocs;
1554 bfd *ibfd;
1556 htab = elf64_x86_64_hash_table (info);
1557 dynobj = htab->elf.dynobj;
1558 if (dynobj == NULL)
1559 abort ();
1561 if (htab->elf.dynamic_sections_created)
1563 /* Set the contents of the .interp section to the interpreter. */
1564 if (info->executable)
1566 s = bfd_get_section_by_name (dynobj, ".interp");
1567 if (s == NULL)
1568 abort ();
1569 s->size = sizeof ELF_DYNAMIC_INTERPRETER;
1570 s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER;
1574 /* Set up .got offsets for local syms, and space for local dynamic
1575 relocs. */
1576 for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next)
1578 bfd_signed_vma *local_got;
1579 bfd_signed_vma *end_local_got;
1580 char *local_tls_type;
1581 bfd_size_type locsymcount;
1582 Elf_Internal_Shdr *symtab_hdr;
1583 asection *srel;
1585 if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour)
1586 continue;
1588 for (s = ibfd->sections; s != NULL; s = s->next)
1590 struct elf64_x86_64_dyn_relocs *p;
1592 for (p = (struct elf64_x86_64_dyn_relocs *)
1593 (elf_section_data (s)->local_dynrel);
1594 p != NULL;
1595 p = p->next)
1597 if (!bfd_is_abs_section (p->sec)
1598 && bfd_is_abs_section (p->sec->output_section))
1600 /* Input section has been discarded, either because
1601 it is a copy of a linkonce section or due to
1602 linker script /DISCARD/, so we'll be discarding
1603 the relocs too. */
1605 else if (p->count != 0)
1607 srel = elf_section_data (p->sec)->sreloc;
1608 srel->size += p->count * sizeof (Elf64_External_Rela);
1609 if ((p->sec->output_section->flags & SEC_READONLY) != 0)
1610 info->flags |= DF_TEXTREL;
1616 local_got = elf_local_got_refcounts (ibfd);
1617 if (!local_got)
1618 continue;
1620 symtab_hdr = &elf_tdata (ibfd)->symtab_hdr;
1621 locsymcount = symtab_hdr->sh_info;
1622 end_local_got = local_got + locsymcount;
1623 local_tls_type = elf64_x86_64_local_got_tls_type (ibfd);
1624 s = htab->sgot;
1625 srel = htab->srelgot;
1626 for (; local_got < end_local_got; ++local_got, ++local_tls_type)
1628 if (*local_got > 0)
1630 *local_got = s->size;
1631 s->size += GOT_ENTRY_SIZE;
1632 if (*local_tls_type == GOT_TLS_GD)
1633 s->size += GOT_ENTRY_SIZE;
1634 if (info->shared
1635 || *local_tls_type == GOT_TLS_GD
1636 || *local_tls_type == GOT_TLS_IE)
1637 srel->size += sizeof (Elf64_External_Rela);
1639 else
1640 *local_got = (bfd_vma) -1;
1644 if (htab->tls_ld_got.refcount > 0)
1646 /* Allocate 2 got entries and 1 dynamic reloc for R_X86_64_TLSLD
1647 relocs. */
1648 htab->tls_ld_got.offset = htab->sgot->size;
1649 htab->sgot->size += 2 * GOT_ENTRY_SIZE;
1650 htab->srelgot->size += sizeof (Elf64_External_Rela);
1652 else
1653 htab->tls_ld_got.offset = -1;
1655 /* Allocate global sym .plt and .got entries, and space for global
1656 sym dynamic relocs. */
1657 elf_link_hash_traverse (&htab->elf, allocate_dynrelocs, (PTR) info);
1659 /* We now have determined the sizes of the various dynamic sections.
1660 Allocate memory for them. */
1661 relocs = FALSE;
1662 for (s = dynobj->sections; s != NULL; s = s->next)
1664 if ((s->flags & SEC_LINKER_CREATED) == 0)
1665 continue;
1667 if (s == htab->splt
1668 || s == htab->sgot
1669 || s == htab->sgotplt
1670 || s == htab->sdynbss)
1672 /* Strip this section if we don't need it; see the
1673 comment below. */
1675 else if (strncmp (bfd_get_section_name (dynobj, s), ".rela", 5) == 0)
1677 if (s->size != 0 && s != htab->srelplt)
1678 relocs = TRUE;
1680 /* We use the reloc_count field as a counter if we need
1681 to copy relocs into the output file. */
1682 s->reloc_count = 0;
1684 else
1686 /* It's not one of our sections, so don't allocate space. */
1687 continue;
1690 if (s->size == 0)
1692 /* If we don't need this section, strip it from the
1693 output file. This is mostly to handle .rela.bss and
1694 .rela.plt. We must create both sections in
1695 create_dynamic_sections, because they must be created
1696 before the linker maps input sections to output
1697 sections. The linker does that before
1698 adjust_dynamic_symbol is called, and it is that
1699 function which decides whether anything needs to go
1700 into these sections. */
1702 s->flags |= SEC_EXCLUDE;
1703 continue;
1706 if ((s->flags & SEC_HAS_CONTENTS) == 0)
1707 continue;
1709 /* Allocate memory for the section contents. We use bfd_zalloc
1710 here in case unused entries are not reclaimed before the
1711 section's contents are written out. This should not happen,
1712 but this way if it does, we get a R_X86_64_NONE reloc instead
1713 of garbage. */
1714 s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->size);
1715 if (s->contents == NULL)
1716 return FALSE;
1719 if (htab->elf.dynamic_sections_created)
1721 /* Add some entries to the .dynamic section. We fill in the
1722 values later, in elf64_x86_64_finish_dynamic_sections, but we
1723 must add the entries now so that we get the correct size for
1724 the .dynamic section. The DT_DEBUG entry is filled in by the
1725 dynamic linker and used by the debugger. */
1726 #define add_dynamic_entry(TAG, VAL) \
1727 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
1729 if (info->executable)
1731 if (!add_dynamic_entry (DT_DEBUG, 0))
1732 return FALSE;
1735 if (htab->splt->size != 0)
1737 if (!add_dynamic_entry (DT_PLTGOT, 0)
1738 || !add_dynamic_entry (DT_PLTRELSZ, 0)
1739 || !add_dynamic_entry (DT_PLTREL, DT_RELA)
1740 || !add_dynamic_entry (DT_JMPREL, 0))
1741 return FALSE;
1744 if (relocs)
1746 if (!add_dynamic_entry (DT_RELA, 0)
1747 || !add_dynamic_entry (DT_RELASZ, 0)
1748 || !add_dynamic_entry (DT_RELAENT, sizeof (Elf64_External_Rela)))
1749 return FALSE;
1751 /* If any dynamic relocs apply to a read-only section,
1752 then we need a DT_TEXTREL entry. */
1753 if ((info->flags & DF_TEXTREL) == 0)
1754 elf_link_hash_traverse (&htab->elf, readonly_dynrelocs,
1755 (PTR) info);
1757 if ((info->flags & DF_TEXTREL) != 0)
1759 if (!add_dynamic_entry (DT_TEXTREL, 0))
1760 return FALSE;
1764 #undef add_dynamic_entry
1766 return TRUE;
1769 /* Return the base VMA address which should be subtracted from real addresses
1770 when resolving @dtpoff relocation.
1771 This is PT_TLS segment p_vaddr. */
1773 static bfd_vma
1774 dtpoff_base (struct bfd_link_info *info)
1776 /* If tls_sec is NULL, we should have signalled an error already. */
1777 if (elf_hash_table (info)->tls_sec == NULL)
1778 return 0;
1779 return elf_hash_table (info)->tls_sec->vma;
1782 /* Return the relocation value for @tpoff relocation
1783 if STT_TLS virtual address is ADDRESS. */
1785 static bfd_vma
1786 tpoff (struct bfd_link_info *info, bfd_vma address)
1788 struct elf_link_hash_table *htab = elf_hash_table (info);
1790 /* If tls_segment is NULL, we should have signalled an error already. */
1791 if (htab->tls_sec == NULL)
1792 return 0;
1793 return address - htab->tls_size - htab->tls_sec->vma;
1796 /* Is the instruction before OFFSET in CONTENTS a 32bit relative
1797 branch? */
1799 static bfd_boolean
1800 is_32bit_relative_branch (bfd_byte *contents, bfd_vma offset)
1802 /* Opcode Instruction
1803 0xe8 call
1804 0xe9 jump
1805 0x0f 0x8x conditional jump */
1806 return ((offset > 0
1807 && (contents [offset - 1] == 0xe8
1808 || contents [offset - 1] == 0xe9))
1809 || (offset > 1
1810 && contents [offset - 2] == 0x0f
1811 && (contents [offset - 1] & 0xf0) == 0x80));
1814 /* Relocate an x86_64 ELF section. */
1816 static bfd_boolean
1817 elf64_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
1818 bfd *input_bfd, asection *input_section,
1819 bfd_byte *contents, Elf_Internal_Rela *relocs,
1820 Elf_Internal_Sym *local_syms,
1821 asection **local_sections)
1823 struct elf64_x86_64_link_hash_table *htab;
1824 Elf_Internal_Shdr *symtab_hdr;
1825 struct elf_link_hash_entry **sym_hashes;
1826 bfd_vma *local_got_offsets;
1827 Elf_Internal_Rela *rel;
1828 Elf_Internal_Rela *relend;
1830 if (info->relocatable)
1831 return TRUE;
1833 htab = elf64_x86_64_hash_table (info);
1834 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
1835 sym_hashes = elf_sym_hashes (input_bfd);
1836 local_got_offsets = elf_local_got_offsets (input_bfd);
1838 rel = relocs;
1839 relend = relocs + input_section->reloc_count;
1840 for (; rel < relend; rel++)
1842 unsigned int r_type;
1843 reloc_howto_type *howto;
1844 unsigned long r_symndx;
1845 struct elf_link_hash_entry *h;
1846 Elf_Internal_Sym *sym;
1847 asection *sec;
1848 bfd_vma off;
1849 bfd_vma relocation;
1850 bfd_boolean unresolved_reloc;
1851 bfd_reloc_status_type r;
1852 int tls_type;
1854 r_type = ELF64_R_TYPE (rel->r_info);
1855 if (r_type == (int) R_X86_64_GNU_VTINHERIT
1856 || r_type == (int) R_X86_64_GNU_VTENTRY)
1857 continue;
1859 if (r_type >= R_X86_64_max)
1861 bfd_set_error (bfd_error_bad_value);
1862 return FALSE;
1865 howto = x86_64_elf_howto_table + r_type;
1866 r_symndx = ELF64_R_SYM (rel->r_info);
1867 h = NULL;
1868 sym = NULL;
1869 sec = NULL;
1870 unresolved_reloc = FALSE;
1871 if (r_symndx < symtab_hdr->sh_info)
1873 sym = local_syms + r_symndx;
1874 sec = local_sections[r_symndx];
1876 relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
1878 else
1880 bfd_boolean warned;
1882 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
1883 r_symndx, symtab_hdr, sym_hashes,
1884 h, sec, relocation,
1885 unresolved_reloc, warned);
1887 /* When generating a shared object, the relocations handled here are
1888 copied into the output file to be resolved at run time. */
1889 switch (r_type)
1891 case R_X86_64_GOT32:
1892 /* Relocation is to the entry for this symbol in the global
1893 offset table. */
1894 case R_X86_64_GOTPCREL:
1895 /* Use global offset table as symbol value. */
1896 if (htab->sgot == NULL)
1897 abort ();
1899 if (h != NULL)
1901 bfd_boolean dyn;
1903 off = h->got.offset;
1904 dyn = htab->elf.dynamic_sections_created;
1906 if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info->shared, h)
1907 || (info->shared
1908 && SYMBOL_REFERENCES_LOCAL (info, h))
1909 || (ELF_ST_VISIBILITY (h->other)
1910 && h->root.type == bfd_link_hash_undefweak))
1912 /* This is actually a static link, or it is a -Bsymbolic
1913 link and the symbol is defined locally, or the symbol
1914 was forced to be local because of a version file. We
1915 must initialize this entry in the global offset table.
1916 Since the offset must always be a multiple of 8, we
1917 use the least significant bit to record whether we
1918 have initialized it already.
1920 When doing a dynamic link, we create a .rela.got
1921 relocation entry to initialize the value. This is
1922 done in the finish_dynamic_symbol routine. */
1923 if ((off & 1) != 0)
1924 off &= ~1;
1925 else
1927 bfd_put_64 (output_bfd, relocation,
1928 htab->sgot->contents + off);
1929 h->got.offset |= 1;
1932 else
1933 unresolved_reloc = FALSE;
1935 else
1937 if (local_got_offsets == NULL)
1938 abort ();
1940 off = local_got_offsets[r_symndx];
1942 /* The offset must always be a multiple of 8. We use
1943 the least significant bit to record whether we have
1944 already generated the necessary reloc. */
1945 if ((off & 1) != 0)
1946 off &= ~1;
1947 else
1949 bfd_put_64 (output_bfd, relocation,
1950 htab->sgot->contents + off);
1952 if (info->shared)
1954 asection *s;
1955 Elf_Internal_Rela outrel;
1956 bfd_byte *loc;
1958 /* We need to generate a R_X86_64_RELATIVE reloc
1959 for the dynamic linker. */
1960 s = htab->srelgot;
1961 if (s == NULL)
1962 abort ();
1964 outrel.r_offset = (htab->sgot->output_section->vma
1965 + htab->sgot->output_offset
1966 + off);
1967 outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE);
1968 outrel.r_addend = relocation;
1969 loc = s->contents;
1970 loc += s->reloc_count++ * sizeof (Elf64_External_Rela);
1971 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
1974 local_got_offsets[r_symndx] |= 1;
1978 if (off >= (bfd_vma) -2)
1979 abort ();
1981 relocation = htab->sgot->output_section->vma
1982 + htab->sgot->output_offset + off;
1983 if (r_type != R_X86_64_GOTPCREL)
1984 relocation -= htab->sgotplt->output_section->vma
1985 - htab->sgotplt->output_offset;
1987 break;
1989 case R_X86_64_GOTOFF64:
1990 /* Relocation is relative to the start of the global offset
1991 table. */
1993 /* Check to make sure it isn't a protected function symbol
1994 for shared library since it may not be local when used
1995 as function address. */
1996 if (info->shared
1997 && h
1998 && h->def_regular
1999 && h->type == STT_FUNC
2000 && ELF_ST_VISIBILITY (h->other) == STV_PROTECTED)
2002 (*_bfd_error_handler)
2003 (_("%B: relocation R_X86_64_GOTOFF64 against protected function `%s' can not be used when making a shared object"),
2004 input_bfd, h->root.root.string);
2005 bfd_set_error (bfd_error_bad_value);
2006 return FALSE;
2009 /* Note that sgot is not involved in this
2010 calculation. We always want the start of .got.plt. If we
2011 defined _GLOBAL_OFFSET_TABLE_ in a different way, as is
2012 permitted by the ABI, we might have to change this
2013 calculation. */
2014 relocation -= htab->sgotplt->output_section->vma
2015 + htab->sgotplt->output_offset;
2016 break;
2018 case R_X86_64_GOTPC32:
2019 /* Use global offset table as symbol value. */
2020 relocation = htab->sgotplt->output_section->vma
2021 + htab->sgotplt->output_offset;
2022 unresolved_reloc = FALSE;
2023 break;
2025 case R_X86_64_PLT32:
2026 /* Relocation is to the entry for this symbol in the
2027 procedure linkage table. */
2029 /* Resolve a PLT32 reloc against a local symbol directly,
2030 without using the procedure linkage table. */
2031 if (h == NULL)
2032 break;
2034 if (h->plt.offset == (bfd_vma) -1
2035 || htab->splt == NULL)
2037 /* We didn't make a PLT entry for this symbol. This
2038 happens when statically linking PIC code, or when
2039 using -Bsymbolic. */
2040 break;
2043 relocation = (htab->splt->output_section->vma
2044 + htab->splt->output_offset
2045 + h->plt.offset);
2046 unresolved_reloc = FALSE;
2047 break;
2049 case R_X86_64_PC8:
2050 case R_X86_64_PC16:
2051 case R_X86_64_PC32:
2052 if (info->shared
2053 && !SYMBOL_REFERENCES_LOCAL (info, h)
2054 && (input_section->flags & SEC_ALLOC) != 0
2055 && (input_section->flags & SEC_READONLY) != 0
2056 && (!h->def_regular
2057 || r_type != R_X86_64_PC32
2058 || h->type != STT_FUNC
2059 || ELF_ST_VISIBILITY (h->other) != STV_PROTECTED
2060 || !is_32bit_relative_branch (contents,
2061 rel->r_offset)))
2063 if (h->def_regular
2064 && r_type == R_X86_64_PC32
2065 && h->type == STT_FUNC
2066 && ELF_ST_VISIBILITY (h->other) == STV_PROTECTED)
2067 (*_bfd_error_handler)
2068 (_("%B: relocation R_X86_64_PC32 against protected function `%s' can not be used when making a shared object"),
2069 input_bfd, h->root.root.string);
2070 else
2071 (*_bfd_error_handler)
2072 (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
2073 input_bfd, x86_64_elf_howto_table[r_type].name,
2074 h->root.root.string);
2075 bfd_set_error (bfd_error_bad_value);
2076 return FALSE;
2078 /* Fall through. */
2080 case R_X86_64_8:
2081 case R_X86_64_16:
2082 case R_X86_64_32:
2083 case R_X86_64_PC64:
2084 case R_X86_64_64:
2085 /* FIXME: The ABI says the linker should make sure the value is
2086 the same when it's zeroextended to 64 bit. */
2088 /* r_symndx will be zero only for relocs against symbols
2089 from removed linkonce sections, or sections discarded by
2090 a linker script. */
2091 if (r_symndx == 0
2092 || (input_section->flags & SEC_ALLOC) == 0)
2093 break;
2095 if ((info->shared
2096 && (h == NULL
2097 || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
2098 || h->root.type != bfd_link_hash_undefweak)
2099 && ((r_type != R_X86_64_PC8
2100 && r_type != R_X86_64_PC16
2101 && r_type != R_X86_64_PC32
2102 && r_type != R_X86_64_PC64)
2103 || !SYMBOL_CALLS_LOCAL (info, h)))
2104 || (ELIMINATE_COPY_RELOCS
2105 && !info->shared
2106 && h != NULL
2107 && h->dynindx != -1
2108 && !h->non_got_ref
2109 && ((h->def_dynamic
2110 && !h->def_regular)
2111 || h->root.type == bfd_link_hash_undefweak
2112 || h->root.type == bfd_link_hash_undefined)))
2114 Elf_Internal_Rela outrel;
2115 bfd_byte *loc;
2116 bfd_boolean skip, relocate;
2117 asection *sreloc;
2119 /* When generating a shared object, these relocations
2120 are copied into the output file to be resolved at run
2121 time. */
2122 skip = FALSE;
2123 relocate = FALSE;
2125 outrel.r_offset =
2126 _bfd_elf_section_offset (output_bfd, info, input_section,
2127 rel->r_offset);
2128 if (outrel.r_offset == (bfd_vma) -1)
2129 skip = TRUE;
2130 else if (outrel.r_offset == (bfd_vma) -2)
2131 skip = TRUE, relocate = TRUE;
2133 outrel.r_offset += (input_section->output_section->vma
2134 + input_section->output_offset);
2136 if (skip)
2137 memset (&outrel, 0, sizeof outrel);
2139 /* h->dynindx may be -1 if this symbol was marked to
2140 become local. */
2141 else if (h != NULL
2142 && h->dynindx != -1
2143 && (r_type == R_X86_64_PC8
2144 || r_type == R_X86_64_PC16
2145 || r_type == R_X86_64_PC32
2146 || r_type == R_X86_64_PC64
2147 || !info->shared
2148 || !info->symbolic
2149 || !h->def_regular))
2151 outrel.r_info = ELF64_R_INFO (h->dynindx, r_type);
2152 outrel.r_addend = rel->r_addend;
2154 else
2156 /* This symbol is local, or marked to become local. */
2157 if (r_type == R_X86_64_64)
2159 relocate = TRUE;
2160 outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE);
2161 outrel.r_addend = relocation + rel->r_addend;
2163 else
2165 long sindx;
2167 if (bfd_is_abs_section (sec))
2168 sindx = 0;
2169 else if (sec == NULL || sec->owner == NULL)
2171 bfd_set_error (bfd_error_bad_value);
2172 return FALSE;
2174 else
2176 asection *osec;
2178 osec = sec->output_section;
2179 sindx = elf_section_data (osec)->dynindx;
2180 BFD_ASSERT (sindx > 0);
2183 outrel.r_info = ELF64_R_INFO (sindx, r_type);
2184 outrel.r_addend = relocation + rel->r_addend;
2188 sreloc = elf_section_data (input_section)->sreloc;
2189 if (sreloc == NULL)
2190 abort ();
2192 loc = sreloc->contents;
2193 loc += sreloc->reloc_count++ * sizeof (Elf64_External_Rela);
2194 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2196 /* If this reloc is against an external symbol, we do
2197 not want to fiddle with the addend. Otherwise, we
2198 need to include the symbol value so that it becomes
2199 an addend for the dynamic reloc. */
2200 if (! relocate)
2201 continue;
2204 break;
2206 case R_X86_64_TLSGD:
2207 case R_X86_64_GOTTPOFF:
2208 r_type = elf64_x86_64_tls_transition (info, r_type, h == NULL);
2209 tls_type = GOT_UNKNOWN;
2210 if (h == NULL && local_got_offsets)
2211 tls_type = elf64_x86_64_local_got_tls_type (input_bfd) [r_symndx];
2212 else if (h != NULL)
2214 tls_type = elf64_x86_64_hash_entry (h)->tls_type;
2215 if (!info->shared && h->dynindx == -1 && tls_type == GOT_TLS_IE)
2216 r_type = R_X86_64_TPOFF32;
2218 if (r_type == R_X86_64_TLSGD)
2220 if (tls_type == GOT_TLS_IE)
2221 r_type = R_X86_64_GOTTPOFF;
2224 if (r_type == R_X86_64_TPOFF32)
2226 BFD_ASSERT (! unresolved_reloc);
2227 if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSGD)
2229 unsigned int i;
2230 static unsigned char tlsgd[8]
2231 = { 0x66, 0x48, 0x8d, 0x3d, 0x66, 0x66, 0x48, 0xe8 };
2233 /* GD->LE transition.
2234 .byte 0x66; leaq foo@tlsgd(%rip), %rdi
2235 .word 0x6666; rex64; call __tls_get_addr@plt
2236 Change it into:
2237 movq %fs:0, %rax
2238 leaq foo@tpoff(%rax), %rax */
2239 BFD_ASSERT (rel->r_offset >= 4);
2240 for (i = 0; i < 4; i++)
2241 BFD_ASSERT (bfd_get_8 (input_bfd,
2242 contents + rel->r_offset - 4 + i)
2243 == tlsgd[i]);
2244 BFD_ASSERT (rel->r_offset + 12 <= input_section->size);
2245 for (i = 0; i < 4; i++)
2246 BFD_ASSERT (bfd_get_8 (input_bfd,
2247 contents + rel->r_offset + 4 + i)
2248 == tlsgd[i+4]);
2249 BFD_ASSERT (rel + 1 < relend);
2250 BFD_ASSERT (ELF64_R_TYPE (rel[1].r_info) == R_X86_64_PLT32);
2251 memcpy (contents + rel->r_offset - 4,
2252 "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0",
2253 16);
2254 bfd_put_32 (output_bfd, tpoff (info, relocation),
2255 contents + rel->r_offset + 8);
2256 /* Skip R_X86_64_PLT32. */
2257 rel++;
2258 continue;
2260 else
2262 unsigned int val, type, reg;
2264 /* IE->LE transition:
2265 Originally it can be one of:
2266 movq foo@gottpoff(%rip), %reg
2267 addq foo@gottpoff(%rip), %reg
2268 We change it into:
2269 movq $foo, %reg
2270 leaq foo(%reg), %reg
2271 addq $foo, %reg. */
2272 BFD_ASSERT (rel->r_offset >= 3);
2273 val = bfd_get_8 (input_bfd, contents + rel->r_offset - 3);
2274 BFD_ASSERT (val == 0x48 || val == 0x4c);
2275 type = bfd_get_8 (input_bfd, contents + rel->r_offset - 2);
2276 BFD_ASSERT (type == 0x8b || type == 0x03);
2277 reg = bfd_get_8 (input_bfd, contents + rel->r_offset - 1);
2278 BFD_ASSERT ((reg & 0xc7) == 5);
2279 reg >>= 3;
2280 BFD_ASSERT (rel->r_offset + 4 <= input_section->size);
2281 if (type == 0x8b)
2283 /* movq */
2284 if (val == 0x4c)
2285 bfd_put_8 (output_bfd, 0x49,
2286 contents + rel->r_offset - 3);
2287 bfd_put_8 (output_bfd, 0xc7,
2288 contents + rel->r_offset - 2);
2289 bfd_put_8 (output_bfd, 0xc0 | reg,
2290 contents + rel->r_offset - 1);
2292 else if (reg == 4)
2294 /* addq -> addq - addressing with %rsp/%r12 is
2295 special */
2296 if (val == 0x4c)
2297 bfd_put_8 (output_bfd, 0x49,
2298 contents + rel->r_offset - 3);
2299 bfd_put_8 (output_bfd, 0x81,
2300 contents + rel->r_offset - 2);
2301 bfd_put_8 (output_bfd, 0xc0 | reg,
2302 contents + rel->r_offset - 1);
2304 else
2306 /* addq -> leaq */
2307 if (val == 0x4c)
2308 bfd_put_8 (output_bfd, 0x4d,
2309 contents + rel->r_offset - 3);
2310 bfd_put_8 (output_bfd, 0x8d,
2311 contents + rel->r_offset - 2);
2312 bfd_put_8 (output_bfd, 0x80 | reg | (reg << 3),
2313 contents + rel->r_offset - 1);
2315 bfd_put_32 (output_bfd, tpoff (info, relocation),
2316 contents + rel->r_offset);
2317 continue;
2321 if (htab->sgot == NULL)
2322 abort ();
2324 if (h != NULL)
2325 off = h->got.offset;
2326 else
2328 if (local_got_offsets == NULL)
2329 abort ();
2331 off = local_got_offsets[r_symndx];
2334 if ((off & 1) != 0)
2335 off &= ~1;
2336 else
2338 Elf_Internal_Rela outrel;
2339 bfd_byte *loc;
2340 int dr_type, indx;
2342 if (htab->srelgot == NULL)
2343 abort ();
2345 outrel.r_offset = (htab->sgot->output_section->vma
2346 + htab->sgot->output_offset + off);
2348 indx = h && h->dynindx != -1 ? h->dynindx : 0;
2349 if (r_type == R_X86_64_TLSGD)
2350 dr_type = R_X86_64_DTPMOD64;
2351 else
2352 dr_type = R_X86_64_TPOFF64;
2354 bfd_put_64 (output_bfd, 0, htab->sgot->contents + off);
2355 outrel.r_addend = 0;
2356 if (dr_type == R_X86_64_TPOFF64 && indx == 0)
2357 outrel.r_addend = relocation - dtpoff_base (info);
2358 outrel.r_info = ELF64_R_INFO (indx, dr_type);
2360 loc = htab->srelgot->contents;
2361 loc += htab->srelgot->reloc_count++ * sizeof (Elf64_External_Rela);
2362 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2364 if (r_type == R_X86_64_TLSGD)
2366 if (indx == 0)
2368 BFD_ASSERT (! unresolved_reloc);
2369 bfd_put_64 (output_bfd,
2370 relocation - dtpoff_base (info),
2371 htab->sgot->contents + off + GOT_ENTRY_SIZE);
2373 else
2375 bfd_put_64 (output_bfd, 0,
2376 htab->sgot->contents + off + GOT_ENTRY_SIZE);
2377 outrel.r_info = ELF64_R_INFO (indx,
2378 R_X86_64_DTPOFF64);
2379 outrel.r_offset += GOT_ENTRY_SIZE;
2380 htab->srelgot->reloc_count++;
2381 loc += sizeof (Elf64_External_Rela);
2382 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2386 if (h != NULL)
2387 h->got.offset |= 1;
2388 else
2389 local_got_offsets[r_symndx] |= 1;
2392 if (off >= (bfd_vma) -2)
2393 abort ();
2394 if (r_type == ELF64_R_TYPE (rel->r_info))
2396 relocation = htab->sgot->output_section->vma
2397 + htab->sgot->output_offset + off;
2398 unresolved_reloc = FALSE;
2400 else
2402 unsigned int i;
2403 static unsigned char tlsgd[8]
2404 = { 0x66, 0x48, 0x8d, 0x3d, 0x66, 0x66, 0x48, 0xe8 };
2406 /* GD->IE transition.
2407 .byte 0x66; leaq foo@tlsgd(%rip), %rdi
2408 .word 0x6666; rex64; call __tls_get_addr@plt
2409 Change it into:
2410 movq %fs:0, %rax
2411 addq foo@gottpoff(%rip), %rax */
2412 BFD_ASSERT (rel->r_offset >= 4);
2413 for (i = 0; i < 4; i++)
2414 BFD_ASSERT (bfd_get_8 (input_bfd,
2415 contents + rel->r_offset - 4 + i)
2416 == tlsgd[i]);
2417 BFD_ASSERT (rel->r_offset + 12 <= input_section->size);
2418 for (i = 0; i < 4; i++)
2419 BFD_ASSERT (bfd_get_8 (input_bfd,
2420 contents + rel->r_offset + 4 + i)
2421 == tlsgd[i+4]);
2422 BFD_ASSERT (rel + 1 < relend);
2423 BFD_ASSERT (ELF64_R_TYPE (rel[1].r_info) == R_X86_64_PLT32);
2424 memcpy (contents + rel->r_offset - 4,
2425 "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0",
2426 16);
2428 relocation = (htab->sgot->output_section->vma
2429 + htab->sgot->output_offset + off
2430 - rel->r_offset
2431 - input_section->output_section->vma
2432 - input_section->output_offset
2433 - 12);
2434 bfd_put_32 (output_bfd, relocation,
2435 contents + rel->r_offset + 8);
2436 /* Skip R_X86_64_PLT32. */
2437 rel++;
2438 continue;
2440 break;
2442 case R_X86_64_TLSLD:
2443 if (! info->shared)
2445 /* LD->LE transition:
2446 Ensure it is:
2447 leaq foo@tlsld(%rip), %rdi; call __tls_get_addr@plt.
2448 We change it into:
2449 .word 0x6666; .byte 0x66; movl %fs:0, %rax. */
2450 BFD_ASSERT (rel->r_offset >= 3);
2451 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset - 3)
2452 == 0x48);
2453 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset - 2)
2454 == 0x8d);
2455 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset - 1)
2456 == 0x3d);
2457 BFD_ASSERT (rel->r_offset + 9 <= input_section->size);
2458 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset + 4)
2459 == 0xe8);
2460 BFD_ASSERT (rel + 1 < relend);
2461 BFD_ASSERT (ELF64_R_TYPE (rel[1].r_info) == R_X86_64_PLT32);
2462 memcpy (contents + rel->r_offset - 3,
2463 "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0", 12);
2464 /* Skip R_X86_64_PLT32. */
2465 rel++;
2466 continue;
2469 if (htab->sgot == NULL)
2470 abort ();
2472 off = htab->tls_ld_got.offset;
2473 if (off & 1)
2474 off &= ~1;
2475 else
2477 Elf_Internal_Rela outrel;
2478 bfd_byte *loc;
2480 if (htab->srelgot == NULL)
2481 abort ();
2483 outrel.r_offset = (htab->sgot->output_section->vma
2484 + htab->sgot->output_offset + off);
2486 bfd_put_64 (output_bfd, 0,
2487 htab->sgot->contents + off);
2488 bfd_put_64 (output_bfd, 0,
2489 htab->sgot->contents + off + GOT_ENTRY_SIZE);
2490 outrel.r_info = ELF64_R_INFO (0, R_X86_64_DTPMOD64);
2491 outrel.r_addend = 0;
2492 loc = htab->srelgot->contents;
2493 loc += htab->srelgot->reloc_count++ * sizeof (Elf64_External_Rela);
2494 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2495 htab->tls_ld_got.offset |= 1;
2497 relocation = htab->sgot->output_section->vma
2498 + htab->sgot->output_offset + off;
2499 unresolved_reloc = FALSE;
2500 break;
2502 case R_X86_64_DTPOFF32:
2503 if (info->shared || (input_section->flags & SEC_CODE) == 0)
2504 relocation -= dtpoff_base (info);
2505 else
2506 relocation = tpoff (info, relocation);
2507 break;
2509 case R_X86_64_TPOFF32:
2510 BFD_ASSERT (! info->shared);
2511 relocation = tpoff (info, relocation);
2512 break;
2514 default:
2515 break;
2518 /* Dynamic relocs are not propagated for SEC_DEBUGGING sections
2519 because such sections are not SEC_ALLOC and thus ld.so will
2520 not process them. */
2521 if (unresolved_reloc
2522 && !((input_section->flags & SEC_DEBUGGING) != 0
2523 && h->def_dynamic))
2524 (*_bfd_error_handler)
2525 (_("%B(%A+0x%lx): unresolvable %s relocation against symbol `%s'"),
2526 input_bfd,
2527 input_section,
2528 (long) rel->r_offset,
2529 howto->name,
2530 h->root.root.string);
2532 r = _bfd_final_link_relocate (howto, input_bfd, input_section,
2533 contents, rel->r_offset,
2534 relocation, rel->r_addend);
2536 if (r != bfd_reloc_ok)
2538 const char *name;
2540 if (h != NULL)
2541 name = h->root.root.string;
2542 else
2544 name = bfd_elf_string_from_elf_section (input_bfd,
2545 symtab_hdr->sh_link,
2546 sym->st_name);
2547 if (name == NULL)
2548 return FALSE;
2549 if (*name == '\0')
2550 name = bfd_section_name (input_bfd, sec);
2553 if (r == bfd_reloc_overflow)
2555 if (h != NULL
2556 && h->root.type == bfd_link_hash_undefweak
2557 && howto->pc_relative)
2558 /* Ignore reloc overflow on branches to undefweak syms. */
2559 continue;
2561 if (! ((*info->callbacks->reloc_overflow)
2562 (info, (h ? &h->root : NULL), name, howto->name,
2563 (bfd_vma) 0, input_bfd, input_section,
2564 rel->r_offset)))
2565 return FALSE;
2567 else
2569 (*_bfd_error_handler)
2570 (_("%B(%A+0x%lx): reloc against `%s': error %d"),
2571 input_bfd, input_section,
2572 (long) rel->r_offset, name, (int) r);
2573 return FALSE;
2578 return TRUE;
2581 /* Finish up dynamic symbol handling. We set the contents of various
2582 dynamic sections here. */
2584 static bfd_boolean
2585 elf64_x86_64_finish_dynamic_symbol (bfd *output_bfd,
2586 struct bfd_link_info *info,
2587 struct elf_link_hash_entry *h,
2588 Elf_Internal_Sym *sym)
2590 struct elf64_x86_64_link_hash_table *htab;
2592 htab = elf64_x86_64_hash_table (info);
2594 if (h->plt.offset != (bfd_vma) -1)
2596 bfd_vma plt_index;
2597 bfd_vma got_offset;
2598 Elf_Internal_Rela rela;
2599 bfd_byte *loc;
2601 /* This symbol has an entry in the procedure linkage table. Set
2602 it up. */
2603 if (h->dynindx == -1
2604 || htab->splt == NULL
2605 || htab->sgotplt == NULL
2606 || htab->srelplt == NULL)
2607 abort ();
2609 /* Get the index in the procedure linkage table which
2610 corresponds to this symbol. This is the index of this symbol
2611 in all the symbols for which we are making plt entries. The
2612 first entry in the procedure linkage table is reserved. */
2613 plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1;
2615 /* Get the offset into the .got table of the entry that
2616 corresponds to this function. Each .got entry is GOT_ENTRY_SIZE
2617 bytes. The first three are reserved for the dynamic linker. */
2618 got_offset = (plt_index + 3) * GOT_ENTRY_SIZE;
2620 /* Fill in the entry in the procedure linkage table. */
2621 memcpy (htab->splt->contents + h->plt.offset, elf64_x86_64_plt_entry,
2622 PLT_ENTRY_SIZE);
2624 /* Insert the relocation positions of the plt section. The magic
2625 numbers at the end of the statements are the positions of the
2626 relocations in the plt section. */
2627 /* Put offset for jmp *name@GOTPCREL(%rip), since the
2628 instruction uses 6 bytes, subtract this value. */
2629 bfd_put_32 (output_bfd,
2630 (htab->sgotplt->output_section->vma
2631 + htab->sgotplt->output_offset
2632 + got_offset
2633 - htab->splt->output_section->vma
2634 - htab->splt->output_offset
2635 - h->plt.offset
2636 - 6),
2637 htab->splt->contents + h->plt.offset + 2);
2638 /* Put relocation index. */
2639 bfd_put_32 (output_bfd, plt_index,
2640 htab->splt->contents + h->plt.offset + 7);
2641 /* Put offset for jmp .PLT0. */
2642 bfd_put_32 (output_bfd, - (h->plt.offset + PLT_ENTRY_SIZE),
2643 htab->splt->contents + h->plt.offset + 12);
2645 /* Fill in the entry in the global offset table, initially this
2646 points to the pushq instruction in the PLT which is at offset 6. */
2647 bfd_put_64 (output_bfd, (htab->splt->output_section->vma
2648 + htab->splt->output_offset
2649 + h->plt.offset + 6),
2650 htab->sgotplt->contents + got_offset);
2652 /* Fill in the entry in the .rela.plt section. */
2653 rela.r_offset = (htab->sgotplt->output_section->vma
2654 + htab->sgotplt->output_offset
2655 + got_offset);
2656 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_JUMP_SLOT);
2657 rela.r_addend = 0;
2658 loc = htab->srelplt->contents + plt_index * sizeof (Elf64_External_Rela);
2659 bfd_elf64_swap_reloca_out (output_bfd, &rela, loc);
2661 if (!h->def_regular)
2663 /* Mark the symbol as undefined, rather than as defined in
2664 the .plt section. Leave the value if there were any
2665 relocations where pointer equality matters (this is a clue
2666 for the dynamic linker, to make function pointer
2667 comparisons work between an application and shared
2668 library), otherwise set it to zero. If a function is only
2669 called from a binary, there is no need to slow down
2670 shared libraries because of that. */
2671 sym->st_shndx = SHN_UNDEF;
2672 if (!h->pointer_equality_needed)
2673 sym->st_value = 0;
2677 if (h->got.offset != (bfd_vma) -1
2678 && elf64_x86_64_hash_entry (h)->tls_type != GOT_TLS_GD
2679 && elf64_x86_64_hash_entry (h)->tls_type != GOT_TLS_IE)
2681 Elf_Internal_Rela rela;
2682 bfd_byte *loc;
2684 /* This symbol has an entry in the global offset table. Set it
2685 up. */
2686 if (htab->sgot == NULL || htab->srelgot == NULL)
2687 abort ();
2689 rela.r_offset = (htab->sgot->output_section->vma
2690 + htab->sgot->output_offset
2691 + (h->got.offset &~ (bfd_vma) 1));
2693 /* If this is a static link, or it is a -Bsymbolic link and the
2694 symbol is defined locally or was forced to be local because
2695 of a version file, we just want to emit a RELATIVE reloc.
2696 The entry in the global offset table will already have been
2697 initialized in the relocate_section function. */
2698 if (info->shared
2699 && SYMBOL_REFERENCES_LOCAL (info, h))
2701 BFD_ASSERT((h->got.offset & 1) != 0);
2702 rela.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE);
2703 rela.r_addend = (h->root.u.def.value
2704 + h->root.u.def.section->output_section->vma
2705 + h->root.u.def.section->output_offset);
2707 else
2709 BFD_ASSERT((h->got.offset & 1) == 0);
2710 bfd_put_64 (output_bfd, (bfd_vma) 0,
2711 htab->sgot->contents + h->got.offset);
2712 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_GLOB_DAT);
2713 rela.r_addend = 0;
2716 loc = htab->srelgot->contents;
2717 loc += htab->srelgot->reloc_count++ * sizeof (Elf64_External_Rela);
2718 bfd_elf64_swap_reloca_out (output_bfd, &rela, loc);
2721 if (h->needs_copy)
2723 Elf_Internal_Rela rela;
2724 bfd_byte *loc;
2726 /* This symbol needs a copy reloc. Set it up. */
2728 if (h->dynindx == -1
2729 || (h->root.type != bfd_link_hash_defined
2730 && h->root.type != bfd_link_hash_defweak)
2731 || htab->srelbss == NULL)
2732 abort ();
2734 rela.r_offset = (h->root.u.def.value
2735 + h->root.u.def.section->output_section->vma
2736 + h->root.u.def.section->output_offset);
2737 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_COPY);
2738 rela.r_addend = 0;
2739 loc = htab->srelbss->contents;
2740 loc += htab->srelbss->reloc_count++ * sizeof (Elf64_External_Rela);
2741 bfd_elf64_swap_reloca_out (output_bfd, &rela, loc);
2744 /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */
2745 if (strcmp (h->root.root.string, "_DYNAMIC") == 0
2746 || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0)
2747 sym->st_shndx = SHN_ABS;
2749 return TRUE;
2752 /* Used to decide how to sort relocs in an optimal manner for the
2753 dynamic linker, before writing them out. */
2755 static enum elf_reloc_type_class
2756 elf64_x86_64_reloc_type_class (const Elf_Internal_Rela *rela)
2758 switch ((int) ELF64_R_TYPE (rela->r_info))
2760 case R_X86_64_RELATIVE:
2761 return reloc_class_relative;
2762 case R_X86_64_JUMP_SLOT:
2763 return reloc_class_plt;
2764 case R_X86_64_COPY:
2765 return reloc_class_copy;
2766 default:
2767 return reloc_class_normal;
2771 /* Finish up the dynamic sections. */
2773 static bfd_boolean
2774 elf64_x86_64_finish_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info)
2776 struct elf64_x86_64_link_hash_table *htab;
2777 bfd *dynobj;
2778 asection *sdyn;
2780 htab = elf64_x86_64_hash_table (info);
2781 dynobj = htab->elf.dynobj;
2782 sdyn = bfd_get_section_by_name (dynobj, ".dynamic");
2784 if (htab->elf.dynamic_sections_created)
2786 Elf64_External_Dyn *dyncon, *dynconend;
2788 if (sdyn == NULL || htab->sgot == NULL)
2789 abort ();
2791 dyncon = (Elf64_External_Dyn *) sdyn->contents;
2792 dynconend = (Elf64_External_Dyn *) (sdyn->contents + sdyn->size);
2793 for (; dyncon < dynconend; dyncon++)
2795 Elf_Internal_Dyn dyn;
2796 asection *s;
2798 bfd_elf64_swap_dyn_in (dynobj, dyncon, &dyn);
2800 switch (dyn.d_tag)
2802 default:
2803 continue;
2805 case DT_PLTGOT:
2806 s = htab->sgotplt;
2807 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
2808 break;
2810 case DT_JMPREL:
2811 dyn.d_un.d_ptr = htab->srelplt->output_section->vma;
2812 break;
2814 case DT_PLTRELSZ:
2815 s = htab->srelplt->output_section;
2816 dyn.d_un.d_val = s->size;
2817 break;
2819 case DT_RELASZ:
2820 /* The procedure linkage table relocs (DT_JMPREL) should
2821 not be included in the overall relocs (DT_RELA).
2822 Therefore, we override the DT_RELASZ entry here to
2823 make it not include the JMPREL relocs. Since the
2824 linker script arranges for .rela.plt to follow all
2825 other relocation sections, we don't have to worry
2826 about changing the DT_RELA entry. */
2827 if (htab->srelplt != NULL)
2829 s = htab->srelplt->output_section;
2830 dyn.d_un.d_val -= s->size;
2832 break;
2835 bfd_elf64_swap_dyn_out (output_bfd, &dyn, dyncon);
2838 /* Fill in the special first entry in the procedure linkage table. */
2839 if (htab->splt && htab->splt->size > 0)
2841 /* Fill in the first entry in the procedure linkage table. */
2842 memcpy (htab->splt->contents, elf64_x86_64_plt0_entry,
2843 PLT_ENTRY_SIZE);
2844 /* Add offset for pushq GOT+8(%rip), since the instruction
2845 uses 6 bytes subtract this value. */
2846 bfd_put_32 (output_bfd,
2847 (htab->sgotplt->output_section->vma
2848 + htab->sgotplt->output_offset
2850 - htab->splt->output_section->vma
2851 - htab->splt->output_offset
2852 - 6),
2853 htab->splt->contents + 2);
2854 /* Add offset for jmp *GOT+16(%rip). The 12 is the offset to
2855 the end of the instruction. */
2856 bfd_put_32 (output_bfd,
2857 (htab->sgotplt->output_section->vma
2858 + htab->sgotplt->output_offset
2859 + 16
2860 - htab->splt->output_section->vma
2861 - htab->splt->output_offset
2862 - 12),
2863 htab->splt->contents + 8);
2865 elf_section_data (htab->splt->output_section)->this_hdr.sh_entsize =
2866 PLT_ENTRY_SIZE;
2870 if (htab->sgotplt)
2872 /* Fill in the first three entries in the global offset table. */
2873 if (htab->sgotplt->size > 0)
2875 /* Set the first entry in the global offset table to the address of
2876 the dynamic section. */
2877 if (sdyn == NULL)
2878 bfd_put_64 (output_bfd, (bfd_vma) 0, htab->sgotplt->contents);
2879 else
2880 bfd_put_64 (output_bfd,
2881 sdyn->output_section->vma + sdyn->output_offset,
2882 htab->sgotplt->contents);
2883 /* Write GOT[1] and GOT[2], needed for the dynamic linker. */
2884 bfd_put_64 (output_bfd, (bfd_vma) 0, htab->sgotplt->contents + GOT_ENTRY_SIZE);
2885 bfd_put_64 (output_bfd, (bfd_vma) 0, htab->sgotplt->contents + GOT_ENTRY_SIZE*2);
2888 elf_section_data (htab->sgotplt->output_section)->this_hdr.sh_entsize =
2889 GOT_ENTRY_SIZE;
2892 if (htab->sgot && htab->sgot->size > 0)
2893 elf_section_data (htab->sgot->output_section)->this_hdr.sh_entsize
2894 = GOT_ENTRY_SIZE;
2896 return TRUE;
2899 /* Return address for Ith PLT stub in section PLT, for relocation REL
2900 or (bfd_vma) -1 if it should not be included. */
2902 static bfd_vma
2903 elf64_x86_64_plt_sym_val (bfd_vma i, const asection *plt,
2904 const arelent *rel ATTRIBUTE_UNUSED)
2906 return plt->vma + (i + 1) * PLT_ENTRY_SIZE;
2909 /* Handle an x86-64 specific section when reading an object file. This
2910 is called when elfcode.h finds a section with an unknown type. */
2912 static bfd_boolean
2913 elf64_x86_64_section_from_shdr (bfd *abfd,
2914 Elf_Internal_Shdr *hdr,
2915 const char *name,
2916 int shindex)
2918 if (hdr->sh_type != SHT_X86_64_UNWIND)
2919 return FALSE;
2921 if (! _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex))
2922 return FALSE;
2924 return TRUE;
2927 /* Hook called by the linker routine which adds symbols from an object
2928 file. We use it to put SHN_X86_64_LCOMMON items in .lbss, instead
2929 of .bss. */
2931 static bfd_boolean
2932 elf64_x86_64_add_symbol_hook (bfd *abfd,
2933 struct bfd_link_info *info ATTRIBUTE_UNUSED,
2934 Elf_Internal_Sym *sym,
2935 const char **namep ATTRIBUTE_UNUSED,
2936 flagword *flagsp ATTRIBUTE_UNUSED,
2937 asection **secp, bfd_vma *valp)
2939 asection *lcomm;
2941 switch (sym->st_shndx)
2943 case SHN_X86_64_LCOMMON:
2944 lcomm = bfd_get_section_by_name (abfd, "LARGE_COMMON");
2945 if (lcomm == NULL)
2947 lcomm = bfd_make_section_with_flags (abfd,
2948 "LARGE_COMMON",
2949 (SEC_ALLOC
2950 | SEC_IS_COMMON
2951 | SEC_LINKER_CREATED));
2952 if (lcomm == NULL)
2953 return FALSE;
2954 elf_section_flags (lcomm) |= SHF_X86_64_LARGE;
2956 *secp = lcomm;
2957 *valp = sym->st_size;
2958 break;
2960 return TRUE;
2964 /* Given a BFD section, try to locate the corresponding ELF section
2965 index. */
2967 static bfd_boolean
2968 elf64_x86_64_elf_section_from_bfd_section (bfd *abfd ATTRIBUTE_UNUSED,
2969 asection *sec, int *index)
2971 if (sec == &_bfd_elf_large_com_section)
2973 *index = SHN_X86_64_LCOMMON;
2974 return TRUE;
2976 return FALSE;
2979 /* Process a symbol. */
2981 static void
2982 elf64_x86_64_symbol_processing (bfd *abfd ATTRIBUTE_UNUSED,
2983 asymbol *asym)
2985 elf_symbol_type *elfsym = (elf_symbol_type *) asym;
2987 switch (elfsym->internal_elf_sym.st_shndx)
2989 case SHN_X86_64_LCOMMON:
2990 asym->section = &_bfd_elf_large_com_section;
2991 asym->value = elfsym->internal_elf_sym.st_size;
2992 /* Common symbol doesn't set BSF_GLOBAL. */
2993 asym->flags &= ~BSF_GLOBAL;
2994 break;
2998 static bfd_boolean
2999 elf64_x86_64_common_definition (Elf_Internal_Sym *sym)
3001 return (sym->st_shndx == SHN_COMMON
3002 || sym->st_shndx == SHN_X86_64_LCOMMON);
3005 static unsigned int
3006 elf64_x86_64_common_section_index (asection *sec)
3008 if ((elf_section_flags (sec) & SHF_X86_64_LARGE) == 0)
3009 return SHN_COMMON;
3010 else
3011 return SHN_X86_64_LCOMMON;
3014 static asection *
3015 elf64_x86_64_common_section (asection *sec)
3017 if ((elf_section_flags (sec) & SHF_X86_64_LARGE) == 0)
3018 return bfd_com_section_ptr;
3019 else
3020 return &_bfd_elf_large_com_section;
3023 static bfd_boolean
3024 elf64_x86_64_merge_symbol (struct bfd_link_info *info ATTRIBUTE_UNUSED,
3025 struct elf_link_hash_entry **sym_hash ATTRIBUTE_UNUSED,
3026 struct elf_link_hash_entry *h,
3027 Elf_Internal_Sym *sym,
3028 asection **psec,
3029 bfd_vma *pvalue ATTRIBUTE_UNUSED,
3030 unsigned int *pold_alignment ATTRIBUTE_UNUSED,
3031 bfd_boolean *skip ATTRIBUTE_UNUSED,
3032 bfd_boolean *override ATTRIBUTE_UNUSED,
3033 bfd_boolean *type_change_ok ATTRIBUTE_UNUSED,
3034 bfd_boolean *size_change_ok ATTRIBUTE_UNUSED,
3035 bfd_boolean *newdef ATTRIBUTE_UNUSED,
3036 bfd_boolean *newdyn,
3037 bfd_boolean *newdyncommon ATTRIBUTE_UNUSED,
3038 bfd_boolean *newweak ATTRIBUTE_UNUSED,
3039 bfd *abfd ATTRIBUTE_UNUSED,
3040 asection **sec,
3041 bfd_boolean *olddef ATTRIBUTE_UNUSED,
3042 bfd_boolean *olddyn,
3043 bfd_boolean *olddyncommon ATTRIBUTE_UNUSED,
3044 bfd_boolean *oldweak ATTRIBUTE_UNUSED,
3045 bfd *oldbfd,
3046 asection **oldsec)
3048 /* A normal common symbol and a large common symbol result in a
3049 normal common symbol. We turn the large common symbol into a
3050 normal one. */
3051 if (!*olddyn
3052 && h->root.type == bfd_link_hash_common
3053 && !*newdyn
3054 && bfd_is_com_section (*sec)
3055 && *oldsec != *sec)
3057 if (sym->st_shndx == SHN_COMMON
3058 && (elf_section_flags (*oldsec) & SHF_X86_64_LARGE) != 0)
3060 h->root.u.c.p->section
3061 = bfd_make_section_old_way (oldbfd, "COMMON");
3062 h->root.u.c.p->section->flags = SEC_ALLOC;
3064 else if (sym->st_shndx == SHN_X86_64_LCOMMON
3065 && (elf_section_flags (*oldsec) & SHF_X86_64_LARGE) == 0)
3066 *psec = *sec = bfd_com_section_ptr;
3069 return TRUE;
3072 static int
3073 elf64_x86_64_additional_program_headers (bfd *abfd)
3075 asection *s;
3076 int count = 0;
3078 /* Check to see if we need a large readonly segment. */
3079 s = bfd_get_section_by_name (abfd, ".lrodata");
3080 if (s && (s->flags & SEC_LOAD))
3081 count++;
3083 /* Check to see if we need a large data segment. Since .lbss sections
3084 is placed right after the .bss section, there should be no need for
3085 a large data segment just because of .lbss. */
3086 s = bfd_get_section_by_name (abfd, ".ldata");
3087 if (s && (s->flags & SEC_LOAD))
3088 count++;
3090 return count;
3093 static const struct bfd_elf_special_section
3094 elf64_x86_64_special_sections[]=
3096 { ".gnu.linkonce.lb", 16, -2, SHT_NOBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE},
3097 { ".gnu.linkonce.lr", 16, -2, SHT_PROGBITS, SHF_ALLOC + SHF_X86_64_LARGE},
3098 { ".gnu.linkonce.lt", 16, -2, SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR + SHF_X86_64_LARGE},
3099 { ".lbss", 5, -2, SHT_NOBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE},
3100 { ".ldata", 6, -2, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE},
3101 { ".lrodata", 8, -2, SHT_PROGBITS, SHF_ALLOC + SHF_X86_64_LARGE},
3102 { NULL, 0, 0, 0, 0 }
3105 #define TARGET_LITTLE_SYM bfd_elf64_x86_64_vec
3106 #define TARGET_LITTLE_NAME "elf64-x86-64"
3107 #define ELF_ARCH bfd_arch_i386
3108 #define ELF_MACHINE_CODE EM_X86_64
3109 #define ELF_MAXPAGESIZE 0x100000
3111 #define elf_backend_can_gc_sections 1
3112 #define elf_backend_can_refcount 1
3113 #define elf_backend_want_got_plt 1
3114 #define elf_backend_plt_readonly 1
3115 #define elf_backend_want_plt_sym 0
3116 #define elf_backend_got_header_size (GOT_ENTRY_SIZE*3)
3117 #define elf_backend_rela_normal 1
3119 #define elf_info_to_howto elf64_x86_64_info_to_howto
3121 #define bfd_elf64_bfd_link_hash_table_create \
3122 elf64_x86_64_link_hash_table_create
3123 #define bfd_elf64_bfd_reloc_type_lookup elf64_x86_64_reloc_type_lookup
3125 #define elf_backend_adjust_dynamic_symbol elf64_x86_64_adjust_dynamic_symbol
3126 #define elf_backend_check_relocs elf64_x86_64_check_relocs
3127 #define elf_backend_copy_indirect_symbol elf64_x86_64_copy_indirect_symbol
3128 #define elf_backend_create_dynamic_sections elf64_x86_64_create_dynamic_sections
3129 #define elf_backend_finish_dynamic_sections elf64_x86_64_finish_dynamic_sections
3130 #define elf_backend_finish_dynamic_symbol elf64_x86_64_finish_dynamic_symbol
3131 #define elf_backend_gc_mark_hook elf64_x86_64_gc_mark_hook
3132 #define elf_backend_gc_sweep_hook elf64_x86_64_gc_sweep_hook
3133 #define elf_backend_grok_prstatus elf64_x86_64_grok_prstatus
3134 #define elf_backend_grok_psinfo elf64_x86_64_grok_psinfo
3135 #define elf_backend_reloc_type_class elf64_x86_64_reloc_type_class
3136 #define elf_backend_relocate_section elf64_x86_64_relocate_section
3137 #define elf_backend_size_dynamic_sections elf64_x86_64_size_dynamic_sections
3138 #define elf_backend_plt_sym_val elf64_x86_64_plt_sym_val
3139 #define elf_backend_object_p elf64_x86_64_elf_object_p
3140 #define bfd_elf64_mkobject elf64_x86_64_mkobject
3142 #define elf_backend_section_from_shdr \
3143 elf64_x86_64_section_from_shdr
3145 #define elf_backend_section_from_bfd_section \
3146 elf64_x86_64_elf_section_from_bfd_section
3147 #define elf_backend_add_symbol_hook \
3148 elf64_x86_64_add_symbol_hook
3149 #define elf_backend_symbol_processing \
3150 elf64_x86_64_symbol_processing
3151 #define elf_backend_common_section_index \
3152 elf64_x86_64_common_section_index
3153 #define elf_backend_common_section \
3154 elf64_x86_64_common_section
3155 #define elf_backend_common_definition \
3156 elf64_x86_64_common_definition
3157 #define elf_backend_merge_symbol \
3158 elf64_x86_64_merge_symbol
3159 #define elf_backend_special_sections \
3160 elf64_x86_64_special_sections
3161 #define elf_backend_additional_program_headers \
3162 elf64_x86_64_additional_program_headers
3164 #include "elf64-target.h"