Merge to branch:
[binutils.git] / bfd / elf64-x86-64.c
bloba35400e2db017dc2a438d6281411a1078210a816
1 /* X86-64 specific support for 64-bit ELF
2 Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006
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),
115 EMPTY_HOWTO (27),
116 EMPTY_HOWTO (28),
117 EMPTY_HOWTO (29),
118 EMPTY_HOWTO (30),
119 EMPTY_HOWTO (31),
120 EMPTY_HOWTO (32),
121 EMPTY_HOWTO (33),
122 HOWTO(R_X86_64_GOTPC32_TLSDESC, 0, 2, 32, TRUE, 0,
123 complain_overflow_bitfield, bfd_elf_generic_reloc,
124 "R_X86_64_GOTPC32_TLSDESC",
125 FALSE, 0xffffffff, 0xffffffff, TRUE),
126 HOWTO(R_X86_64_TLSDESC_CALL, 0, 0, 0, FALSE, 0,
127 complain_overflow_dont, bfd_elf_generic_reloc,
128 "R_X86_64_TLSDESC_CALL",
129 FALSE, 0, 0, FALSE),
130 HOWTO(R_X86_64_TLSDESC, 0, 4, 64, FALSE, 0,
131 complain_overflow_bitfield, bfd_elf_generic_reloc,
132 "R_X86_64_TLSDESC",
133 FALSE, MINUS_ONE, MINUS_ONE, FALSE),
135 /* We have a gap in the reloc numbers here.
136 R_X86_64_standard counts the number up to this point, and
137 R_X86_64_vt_offset is the value to subtract from a reloc type of
138 R_X86_64_GNU_VT* to form an index into this table. */
139 #define R_X86_64_standard (R_X86_64_TLSDESC + 1)
140 #define R_X86_64_vt_offset (R_X86_64_GNU_VTINHERIT - R_X86_64_standard)
142 /* GNU extension to record C++ vtable hierarchy. */
143 HOWTO (R_X86_64_GNU_VTINHERIT, 0, 4, 0, FALSE, 0, complain_overflow_dont,
144 NULL, "R_X86_64_GNU_VTINHERIT", FALSE, 0, 0, FALSE),
146 /* GNU extension to record C++ vtable member usage. */
147 HOWTO (R_X86_64_GNU_VTENTRY, 0, 4, 0, FALSE, 0, complain_overflow_dont,
148 _bfd_elf_rel_vtable_reloc_fn, "R_X86_64_GNU_VTENTRY", FALSE, 0, 0,
149 FALSE)
152 /* Map BFD relocs to the x86_64 elf relocs. */
153 struct elf_reloc_map
155 bfd_reloc_code_real_type bfd_reloc_val;
156 unsigned char elf_reloc_val;
159 static const struct elf_reloc_map x86_64_reloc_map[] =
161 { BFD_RELOC_NONE, R_X86_64_NONE, },
162 { BFD_RELOC_64, R_X86_64_64, },
163 { BFD_RELOC_32_PCREL, R_X86_64_PC32, },
164 { BFD_RELOC_X86_64_GOT32, R_X86_64_GOT32,},
165 { BFD_RELOC_X86_64_PLT32, R_X86_64_PLT32,},
166 { BFD_RELOC_X86_64_COPY, R_X86_64_COPY, },
167 { BFD_RELOC_X86_64_GLOB_DAT, R_X86_64_GLOB_DAT, },
168 { BFD_RELOC_X86_64_JUMP_SLOT, R_X86_64_JUMP_SLOT, },
169 { BFD_RELOC_X86_64_RELATIVE, R_X86_64_RELATIVE, },
170 { BFD_RELOC_X86_64_GOTPCREL, R_X86_64_GOTPCREL, },
171 { BFD_RELOC_32, R_X86_64_32, },
172 { BFD_RELOC_X86_64_32S, R_X86_64_32S, },
173 { BFD_RELOC_16, R_X86_64_16, },
174 { BFD_RELOC_16_PCREL, R_X86_64_PC16, },
175 { BFD_RELOC_8, R_X86_64_8, },
176 { BFD_RELOC_8_PCREL, R_X86_64_PC8, },
177 { BFD_RELOC_X86_64_DTPMOD64, R_X86_64_DTPMOD64, },
178 { BFD_RELOC_X86_64_DTPOFF64, R_X86_64_DTPOFF64, },
179 { BFD_RELOC_X86_64_TPOFF64, R_X86_64_TPOFF64, },
180 { BFD_RELOC_X86_64_TLSGD, R_X86_64_TLSGD, },
181 { BFD_RELOC_X86_64_TLSLD, R_X86_64_TLSLD, },
182 { BFD_RELOC_X86_64_DTPOFF32, R_X86_64_DTPOFF32, },
183 { BFD_RELOC_X86_64_GOTTPOFF, R_X86_64_GOTTPOFF, },
184 { BFD_RELOC_X86_64_TPOFF32, R_X86_64_TPOFF32, },
185 { BFD_RELOC_64_PCREL, R_X86_64_PC64, },
186 { BFD_RELOC_X86_64_GOTOFF64, R_X86_64_GOTOFF64, },
187 { BFD_RELOC_X86_64_GOTPC32, R_X86_64_GOTPC32, },
188 { BFD_RELOC_X86_64_GOTPC32_TLSDESC, R_X86_64_GOTPC32_TLSDESC, },
189 { BFD_RELOC_X86_64_TLSDESC_CALL, R_X86_64_TLSDESC_CALL, },
190 { BFD_RELOC_X86_64_TLSDESC, R_X86_64_TLSDESC, },
191 { BFD_RELOC_VTABLE_INHERIT, R_X86_64_GNU_VTINHERIT, },
192 { BFD_RELOC_VTABLE_ENTRY, R_X86_64_GNU_VTENTRY, },
195 static reloc_howto_type *
196 elf64_x86_64_rtype_to_howto (bfd *abfd, unsigned r_type)
198 unsigned i;
200 if (r_type < (unsigned int) R_X86_64_GNU_VTINHERIT
201 || r_type >= (unsigned int) R_X86_64_max)
203 if (r_type >= (unsigned int) R_X86_64_standard)
205 (*_bfd_error_handler) (_("%B: invalid relocation type %d"),
206 abfd, (int) r_type);
207 r_type = R_X86_64_NONE;
209 i = r_type;
211 else
212 i = r_type - (unsigned int) R_X86_64_vt_offset;
213 BFD_ASSERT (x86_64_elf_howto_table[i].type == r_type);
214 return &x86_64_elf_howto_table[i];
217 /* Given a BFD reloc type, return a HOWTO structure. */
218 static reloc_howto_type *
219 elf64_x86_64_reloc_type_lookup (bfd *abfd,
220 bfd_reloc_code_real_type code)
222 unsigned int i;
224 for (i = 0; i < sizeof (x86_64_reloc_map) / sizeof (struct elf_reloc_map);
225 i++)
227 if (x86_64_reloc_map[i].bfd_reloc_val == code)
228 return elf64_x86_64_rtype_to_howto (abfd,
229 x86_64_reloc_map[i].elf_reloc_val);
231 return 0;
234 /* Given an x86_64 ELF reloc type, fill in an arelent structure. */
236 static void
237 elf64_x86_64_info_to_howto (bfd *abfd ATTRIBUTE_UNUSED, arelent *cache_ptr,
238 Elf_Internal_Rela *dst)
240 unsigned r_type;
242 r_type = ELF64_R_TYPE (dst->r_info);
243 cache_ptr->howto = elf64_x86_64_rtype_to_howto (abfd, r_type);
244 BFD_ASSERT (r_type == cache_ptr->howto->type);
247 /* Support for core dump NOTE sections. */
248 static bfd_boolean
249 elf64_x86_64_grok_prstatus (bfd *abfd, Elf_Internal_Note *note)
251 int offset;
252 size_t size;
254 switch (note->descsz)
256 default:
257 return FALSE;
259 case 336: /* sizeof(istruct elf_prstatus) on Linux/x86_64 */
260 /* pr_cursig */
261 elf_tdata (abfd)->core_signal
262 = bfd_get_16 (abfd, note->descdata + 12);
264 /* pr_pid */
265 elf_tdata (abfd)->core_pid
266 = bfd_get_32 (abfd, note->descdata + 32);
268 /* pr_reg */
269 offset = 112;
270 size = 216;
272 break;
275 /* Make a ".reg/999" section. */
276 return _bfd_elfcore_make_pseudosection (abfd, ".reg",
277 size, note->descpos + offset);
280 static bfd_boolean
281 elf64_x86_64_grok_psinfo (bfd *abfd, Elf_Internal_Note *note)
283 switch (note->descsz)
285 default:
286 return FALSE;
288 case 136: /* sizeof(struct elf_prpsinfo) on Linux/x86_64 */
289 elf_tdata (abfd)->core_program
290 = _bfd_elfcore_strndup (abfd, note->descdata + 40, 16);
291 elf_tdata (abfd)->core_command
292 = _bfd_elfcore_strndup (abfd, note->descdata + 56, 80);
295 /* Note that for some reason, a spurious space is tacked
296 onto the end of the args in some (at least one anyway)
297 implementations, so strip it off if it exists. */
300 char *command = elf_tdata (abfd)->core_command;
301 int n = strlen (command);
303 if (0 < n && command[n - 1] == ' ')
304 command[n - 1] = '\0';
307 return TRUE;
310 /* Functions for the x86-64 ELF linker. */
312 /* The name of the dynamic interpreter. This is put in the .interp
313 section. */
315 #define ELF_DYNAMIC_INTERPRETER "/lib/ld64.so.1"
317 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
318 copying dynamic variables from a shared lib into an app's dynbss
319 section, and instead use a dynamic relocation to point into the
320 shared lib. */
321 #define ELIMINATE_COPY_RELOCS 1
323 /* The size in bytes of an entry in the global offset table. */
325 #define GOT_ENTRY_SIZE 8
327 /* The size in bytes of an entry in the procedure linkage table. */
329 #define PLT_ENTRY_SIZE 16
331 /* The first entry in a procedure linkage table looks like this. See the
332 SVR4 ABI i386 supplement and the x86-64 ABI to see how this works. */
334 static const bfd_byte elf64_x86_64_plt0_entry[PLT_ENTRY_SIZE] =
336 0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */
337 0xff, 0x25, 16, 0, 0, 0, /* jmpq *GOT+16(%rip) */
338 0x90, 0x90, 0x90, 0x90 /* pad out to 16 bytes with nops. */
341 /* Subsequent entries in a procedure linkage table look like this. */
343 static const bfd_byte elf64_x86_64_plt_entry[PLT_ENTRY_SIZE] =
345 0xff, 0x25, /* jmpq *name@GOTPC(%rip) */
346 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */
347 0x68, /* pushq immediate */
348 0, 0, 0, 0, /* replaced with index into relocation table. */
349 0xe9, /* jmp relative */
350 0, 0, 0, 0 /* replaced with offset to start of .plt0. */
353 /* The x86-64 linker needs to keep track of the number of relocs that
354 it decides to copy as dynamic relocs in check_relocs for each symbol.
355 This is so that it can later discard them if they are found to be
356 unnecessary. We store the information in a field extending the
357 regular ELF linker hash table. */
359 struct elf64_x86_64_dyn_relocs
361 /* Next section. */
362 struct elf64_x86_64_dyn_relocs *next;
364 /* The input section of the reloc. */
365 asection *sec;
367 /* Total number of relocs copied for the input section. */
368 bfd_size_type count;
370 /* Number of pc-relative relocs copied for the input section. */
371 bfd_size_type pc_count;
374 /* x86-64 ELF linker hash entry. */
376 struct elf64_x86_64_link_hash_entry
378 struct elf_link_hash_entry elf;
380 /* Track dynamic relocs copied for this symbol. */
381 struct elf64_x86_64_dyn_relocs *dyn_relocs;
383 #define GOT_UNKNOWN 0
384 #define GOT_NORMAL 1
385 #define GOT_TLS_GD 2
386 #define GOT_TLS_IE 3
387 #define GOT_TLS_GDESC 4
388 #define GOT_TLS_GD_BOTH_P(type) \
389 ((type) == (GOT_TLS_GD | GOT_TLS_GDESC))
390 #define GOT_TLS_GD_P(type) \
391 ((type) == GOT_TLS_GD || GOT_TLS_GD_BOTH_P (type))
392 #define GOT_TLS_GDESC_P(type) \
393 ((type) == GOT_TLS_GDESC || GOT_TLS_GD_BOTH_P (type))
394 #define GOT_TLS_GD_ANY_P(type) \
395 (GOT_TLS_GD_P (type) || GOT_TLS_GDESC_P (type))
396 unsigned char tls_type;
398 /* Offset of the GOTPLT entry reserved for the TLS descriptor,
399 starting at the end of the jump table. */
400 bfd_vma tlsdesc_got;
403 #define elf64_x86_64_hash_entry(ent) \
404 ((struct elf64_x86_64_link_hash_entry *)(ent))
406 struct elf64_x86_64_obj_tdata
408 struct elf_obj_tdata root;
410 /* tls_type for each local got entry. */
411 char *local_got_tls_type;
413 /* GOTPLT entries for TLS descriptors. */
414 bfd_vma *local_tlsdesc_gotent;
417 #define elf64_x86_64_tdata(abfd) \
418 ((struct elf64_x86_64_obj_tdata *) (abfd)->tdata.any)
420 #define elf64_x86_64_local_got_tls_type(abfd) \
421 (elf64_x86_64_tdata (abfd)->local_got_tls_type)
423 #define elf64_x86_64_local_tlsdesc_gotent(abfd) \
424 (elf64_x86_64_tdata (abfd)->local_tlsdesc_gotent)
426 /* x86-64 ELF linker hash table. */
428 struct elf64_x86_64_link_hash_table
430 struct elf_link_hash_table elf;
432 /* Short-cuts to get to dynamic linker sections. */
433 asection *sgot;
434 asection *sgotplt;
435 asection *srelgot;
436 asection *splt;
437 asection *srelplt;
438 asection *sdynbss;
439 asection *srelbss;
441 /* The offset into splt of the PLT entry for the TLS descriptor
442 resolver. Special values are 0, if not necessary (or not found
443 to be necessary yet), and -1 if needed but not determined
444 yet. */
445 bfd_vma tlsdesc_plt;
446 /* The offset into sgot of the GOT entry used by the PLT entry
447 above. */
448 bfd_vma tlsdesc_got;
450 union {
451 bfd_signed_vma refcount;
452 bfd_vma offset;
453 } tls_ld_got;
455 /* The amount of space used by the jump slots in the GOT. */
456 bfd_vma sgotplt_jump_table_size;
458 /* Small local sym to section mapping cache. */
459 struct sym_sec_cache sym_sec;
462 /* Get the x86-64 ELF linker hash table from a link_info structure. */
464 #define elf64_x86_64_hash_table(p) \
465 ((struct elf64_x86_64_link_hash_table *) ((p)->hash))
467 #define elf64_x86_64_compute_jump_table_size(htab) \
468 ((htab)->srelplt->reloc_count * GOT_ENTRY_SIZE)
470 /* Create an entry in an x86-64 ELF linker hash table. */
472 static struct bfd_hash_entry *
473 link_hash_newfunc (struct bfd_hash_entry *entry, struct bfd_hash_table *table,
474 const char *string)
476 /* Allocate the structure if it has not already been allocated by a
477 subclass. */
478 if (entry == NULL)
480 entry = bfd_hash_allocate (table,
481 sizeof (struct elf64_x86_64_link_hash_entry));
482 if (entry == NULL)
483 return entry;
486 /* Call the allocation method of the superclass. */
487 entry = _bfd_elf_link_hash_newfunc (entry, table, string);
488 if (entry != NULL)
490 struct elf64_x86_64_link_hash_entry *eh;
492 eh = (struct elf64_x86_64_link_hash_entry *) entry;
493 eh->dyn_relocs = NULL;
494 eh->tls_type = GOT_UNKNOWN;
495 eh->tlsdesc_got = (bfd_vma) -1;
498 return entry;
501 /* Create an X86-64 ELF linker hash table. */
503 static struct bfd_link_hash_table *
504 elf64_x86_64_link_hash_table_create (bfd *abfd)
506 struct elf64_x86_64_link_hash_table *ret;
507 bfd_size_type amt = sizeof (struct elf64_x86_64_link_hash_table);
509 ret = (struct elf64_x86_64_link_hash_table *) bfd_malloc (amt);
510 if (ret == NULL)
511 return NULL;
513 if (! _bfd_elf_link_hash_table_init (&ret->elf, abfd, link_hash_newfunc))
515 free (ret);
516 return NULL;
519 ret->sgot = NULL;
520 ret->sgotplt = NULL;
521 ret->srelgot = NULL;
522 ret->splt = NULL;
523 ret->srelplt = NULL;
524 ret->sdynbss = NULL;
525 ret->srelbss = NULL;
526 ret->sym_sec.abfd = NULL;
527 ret->tlsdesc_plt = 0;
528 ret->tlsdesc_got = 0;
529 ret->tls_ld_got.refcount = 0;
530 ret->sgotplt_jump_table_size = 0;
532 return &ret->elf.root;
535 /* Create .got, .gotplt, and .rela.got sections in DYNOBJ, and set up
536 shortcuts to them in our hash table. */
538 static bfd_boolean
539 create_got_section (bfd *dynobj, struct bfd_link_info *info)
541 struct elf64_x86_64_link_hash_table *htab;
543 if (! _bfd_elf_create_got_section (dynobj, info))
544 return FALSE;
546 htab = elf64_x86_64_hash_table (info);
547 htab->sgot = bfd_get_section_by_name (dynobj, ".got");
548 htab->sgotplt = bfd_get_section_by_name (dynobj, ".got.plt");
549 if (!htab->sgot || !htab->sgotplt)
550 abort ();
552 htab->srelgot = bfd_make_section_with_flags (dynobj, ".rela.got",
553 (SEC_ALLOC | SEC_LOAD
554 | SEC_HAS_CONTENTS
555 | SEC_IN_MEMORY
556 | SEC_LINKER_CREATED
557 | SEC_READONLY));
558 if (htab->srelgot == NULL
559 || ! bfd_set_section_alignment (dynobj, htab->srelgot, 3))
560 return FALSE;
561 return TRUE;
564 /* Create .plt, .rela.plt, .got, .got.plt, .rela.got, .dynbss, and
565 .rela.bss sections in DYNOBJ, and set up shortcuts to them in our
566 hash table. */
568 static bfd_boolean
569 elf64_x86_64_create_dynamic_sections (bfd *dynobj, struct bfd_link_info *info)
571 struct elf64_x86_64_link_hash_table *htab;
573 htab = elf64_x86_64_hash_table (info);
574 if (!htab->sgot && !create_got_section (dynobj, info))
575 return FALSE;
577 if (!_bfd_elf_create_dynamic_sections (dynobj, info))
578 return FALSE;
580 htab->splt = bfd_get_section_by_name (dynobj, ".plt");
581 htab->srelplt = bfd_get_section_by_name (dynobj, ".rela.plt");
582 htab->sdynbss = bfd_get_section_by_name (dynobj, ".dynbss");
583 if (!info->shared)
584 htab->srelbss = bfd_get_section_by_name (dynobj, ".rela.bss");
586 if (!htab->splt || !htab->srelplt || !htab->sdynbss
587 || (!info->shared && !htab->srelbss))
588 abort ();
590 return TRUE;
593 /* Copy the extra info we tack onto an elf_link_hash_entry. */
595 static void
596 elf64_x86_64_copy_indirect_symbol (struct bfd_link_info *info,
597 struct elf_link_hash_entry *dir,
598 struct elf_link_hash_entry *ind)
600 struct elf64_x86_64_link_hash_entry *edir, *eind;
602 edir = (struct elf64_x86_64_link_hash_entry *) dir;
603 eind = (struct elf64_x86_64_link_hash_entry *) ind;
605 if (eind->dyn_relocs != NULL)
607 if (edir->dyn_relocs != NULL)
609 struct elf64_x86_64_dyn_relocs **pp;
610 struct elf64_x86_64_dyn_relocs *p;
612 /* Add reloc counts against the indirect sym to the direct sym
613 list. Merge any entries against the same section. */
614 for (pp = &eind->dyn_relocs; (p = *pp) != NULL; )
616 struct elf64_x86_64_dyn_relocs *q;
618 for (q = edir->dyn_relocs; q != NULL; q = q->next)
619 if (q->sec == p->sec)
621 q->pc_count += p->pc_count;
622 q->count += p->count;
623 *pp = p->next;
624 break;
626 if (q == NULL)
627 pp = &p->next;
629 *pp = edir->dyn_relocs;
632 edir->dyn_relocs = eind->dyn_relocs;
633 eind->dyn_relocs = NULL;
636 if (ind->root.type == bfd_link_hash_indirect
637 && dir->got.refcount <= 0)
639 edir->tls_type = eind->tls_type;
640 eind->tls_type = GOT_UNKNOWN;
643 if (ELIMINATE_COPY_RELOCS
644 && ind->root.type != bfd_link_hash_indirect
645 && dir->dynamic_adjusted)
647 /* If called to transfer flags for a weakdef during processing
648 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
649 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
650 dir->ref_dynamic |= ind->ref_dynamic;
651 dir->ref_regular |= ind->ref_regular;
652 dir->ref_regular_nonweak |= ind->ref_regular_nonweak;
653 dir->needs_plt |= ind->needs_plt;
654 dir->pointer_equality_needed |= ind->pointer_equality_needed;
656 else
657 _bfd_elf_link_hash_copy_indirect (info, dir, ind);
660 static bfd_boolean
661 elf64_x86_64_mkobject (bfd *abfd)
663 bfd_size_type amt = sizeof (struct elf64_x86_64_obj_tdata);
664 abfd->tdata.any = bfd_zalloc (abfd, amt);
665 if (abfd->tdata.any == NULL)
666 return FALSE;
667 return TRUE;
670 static bfd_boolean
671 elf64_x86_64_elf_object_p (bfd *abfd)
673 /* Set the right machine number for an x86-64 elf64 file. */
674 bfd_default_set_arch_mach (abfd, bfd_arch_i386, bfd_mach_x86_64);
675 return TRUE;
678 static int
679 elf64_x86_64_tls_transition (struct bfd_link_info *info, int r_type, int is_local)
681 if (info->shared)
682 return r_type;
684 switch (r_type)
686 case R_X86_64_TLSGD:
687 case R_X86_64_GOTPC32_TLSDESC:
688 case R_X86_64_TLSDESC_CALL:
689 case R_X86_64_GOTTPOFF:
690 if (is_local)
691 return R_X86_64_TPOFF32;
692 return R_X86_64_GOTTPOFF;
693 case R_X86_64_TLSLD:
694 return R_X86_64_TPOFF32;
697 return r_type;
700 /* Look through the relocs for a section during the first phase, and
701 calculate needed space in the global offset table, procedure
702 linkage table, and dynamic reloc sections. */
704 static bfd_boolean
705 elf64_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, asection *sec,
706 const Elf_Internal_Rela *relocs)
708 struct elf64_x86_64_link_hash_table *htab;
709 Elf_Internal_Shdr *symtab_hdr;
710 struct elf_link_hash_entry **sym_hashes;
711 const Elf_Internal_Rela *rel;
712 const Elf_Internal_Rela *rel_end;
713 asection *sreloc;
715 if (info->relocatable)
716 return TRUE;
718 htab = elf64_x86_64_hash_table (info);
719 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
720 sym_hashes = elf_sym_hashes (abfd);
722 sreloc = NULL;
724 rel_end = relocs + sec->reloc_count;
725 for (rel = relocs; rel < rel_end; rel++)
727 unsigned int r_type;
728 unsigned long r_symndx;
729 struct elf_link_hash_entry *h;
731 r_symndx = ELF64_R_SYM (rel->r_info);
732 r_type = ELF64_R_TYPE (rel->r_info);
734 if (r_symndx >= NUM_SHDR_ENTRIES (symtab_hdr))
736 (*_bfd_error_handler) (_("%B: bad symbol index: %d"),
737 abfd, r_symndx);
738 return FALSE;
741 if (r_symndx < symtab_hdr->sh_info)
742 h = NULL;
743 else
745 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
746 while (h->root.type == bfd_link_hash_indirect
747 || h->root.type == bfd_link_hash_warning)
748 h = (struct elf_link_hash_entry *) h->root.u.i.link;
751 r_type = elf64_x86_64_tls_transition (info, r_type, h == NULL);
752 switch (r_type)
754 case R_X86_64_TLSLD:
755 htab->tls_ld_got.refcount += 1;
756 goto create_got;
758 case R_X86_64_TPOFF32:
759 if (info->shared)
761 (*_bfd_error_handler)
762 (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
763 abfd,
764 x86_64_elf_howto_table[r_type].name,
765 (h) ? h->root.root.string : "a local symbol");
766 bfd_set_error (bfd_error_bad_value);
767 return FALSE;
769 break;
771 case R_X86_64_GOTTPOFF:
772 if (info->shared)
773 info->flags |= DF_STATIC_TLS;
774 /* Fall through */
776 case R_X86_64_GOT32:
777 case R_X86_64_GOTPCREL:
778 case R_X86_64_TLSGD:
779 case R_X86_64_GOTPC32_TLSDESC:
780 case R_X86_64_TLSDESC_CALL:
781 /* This symbol requires a global offset table entry. */
783 int tls_type, old_tls_type;
785 switch (r_type)
787 default: tls_type = GOT_NORMAL; break;
788 case R_X86_64_TLSGD: tls_type = GOT_TLS_GD; break;
789 case R_X86_64_GOTTPOFF: tls_type = GOT_TLS_IE; break;
790 case R_X86_64_GOTPC32_TLSDESC:
791 case R_X86_64_TLSDESC_CALL:
792 tls_type = GOT_TLS_GDESC; break;
795 if (h != NULL)
797 h->got.refcount += 1;
798 old_tls_type = elf64_x86_64_hash_entry (h)->tls_type;
800 else
802 bfd_signed_vma *local_got_refcounts;
804 /* This is a global offset table entry for a local symbol. */
805 local_got_refcounts = elf_local_got_refcounts (abfd);
806 if (local_got_refcounts == NULL)
808 bfd_size_type size;
810 size = symtab_hdr->sh_info;
811 size *= sizeof (bfd_signed_vma)
812 + sizeof (bfd_vma) + sizeof (char);
813 local_got_refcounts = ((bfd_signed_vma *)
814 bfd_zalloc (abfd, size));
815 if (local_got_refcounts == NULL)
816 return FALSE;
817 elf_local_got_refcounts (abfd) = local_got_refcounts;
818 elf64_x86_64_local_tlsdesc_gotent (abfd)
819 = (bfd_vma *) (local_got_refcounts + symtab_hdr->sh_info);
820 elf64_x86_64_local_got_tls_type (abfd)
821 = (char *) (local_got_refcounts + 2 * symtab_hdr->sh_info);
823 local_got_refcounts[r_symndx] += 1;
824 old_tls_type
825 = elf64_x86_64_local_got_tls_type (abfd) [r_symndx];
828 /* If a TLS symbol is accessed using IE at least once,
829 there is no point to use dynamic model for it. */
830 if (old_tls_type != tls_type && old_tls_type != GOT_UNKNOWN
831 && (! GOT_TLS_GD_ANY_P (old_tls_type)
832 || tls_type != GOT_TLS_IE))
834 if (old_tls_type == GOT_TLS_IE && GOT_TLS_GD_ANY_P (tls_type))
835 tls_type = old_tls_type;
836 else if (GOT_TLS_GD_ANY_P (old_tls_type)
837 && GOT_TLS_GD_ANY_P (tls_type))
838 tls_type |= old_tls_type;
839 else
841 (*_bfd_error_handler)
842 (_("%B: %s' accessed both as normal and thread local symbol"),
843 abfd, h ? h->root.root.string : "<local>");
844 return FALSE;
848 if (old_tls_type != tls_type)
850 if (h != NULL)
851 elf64_x86_64_hash_entry (h)->tls_type = tls_type;
852 else
853 elf64_x86_64_local_got_tls_type (abfd) [r_symndx] = tls_type;
856 /* Fall through */
858 case R_X86_64_GOTOFF64:
859 case R_X86_64_GOTPC32:
860 create_got:
861 if (htab->sgot == NULL)
863 if (htab->elf.dynobj == NULL)
864 htab->elf.dynobj = abfd;
865 if (!create_got_section (htab->elf.dynobj, info))
866 return FALSE;
868 break;
870 case R_X86_64_PLT32:
871 /* This symbol requires a procedure linkage table entry. We
872 actually build the entry in adjust_dynamic_symbol,
873 because this might be a case of linking PIC code which is
874 never referenced by a dynamic object, in which case we
875 don't need to generate a procedure linkage table entry
876 after all. */
878 /* If this is a local symbol, we resolve it directly without
879 creating a procedure linkage table entry. */
880 if (h == NULL)
881 continue;
883 h->needs_plt = 1;
884 h->plt.refcount += 1;
885 break;
887 case R_X86_64_8:
888 case R_X86_64_16:
889 case R_X86_64_32:
890 case R_X86_64_32S:
891 /* Let's help debug shared library creation. These relocs
892 cannot be used in shared libs. Don't error out for
893 sections we don't care about, such as debug sections or
894 non-constant sections. */
895 if (info->shared
896 && (sec->flags & SEC_ALLOC) != 0
897 && (sec->flags & SEC_READONLY) != 0)
899 (*_bfd_error_handler)
900 (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
901 abfd,
902 x86_64_elf_howto_table[r_type].name,
903 (h) ? h->root.root.string : "a local symbol");
904 bfd_set_error (bfd_error_bad_value);
905 return FALSE;
907 /* Fall through. */
909 case R_X86_64_PC8:
910 case R_X86_64_PC16:
911 case R_X86_64_PC32:
912 case R_X86_64_PC64:
913 case R_X86_64_64:
914 if (h != NULL && !info->shared)
916 /* If this reloc is in a read-only section, we might
917 need a copy reloc. We can't check reliably at this
918 stage whether the section is read-only, as input
919 sections have not yet been mapped to output sections.
920 Tentatively set the flag for now, and correct in
921 adjust_dynamic_symbol. */
922 h->non_got_ref = 1;
924 /* We may need a .plt entry if the function this reloc
925 refers to is in a shared lib. */
926 h->plt.refcount += 1;
927 if (r_type != R_X86_64_PC32 && r_type != R_X86_64_PC64)
928 h->pointer_equality_needed = 1;
931 /* If we are creating a shared library, and this is a reloc
932 against a global symbol, or a non PC relative reloc
933 against a local symbol, then we need to copy the reloc
934 into the shared library. However, if we are linking with
935 -Bsymbolic, we do not need to copy a reloc against a
936 global symbol which is defined in an object we are
937 including in the link (i.e., DEF_REGULAR is set). At
938 this point we have not seen all the input files, so it is
939 possible that DEF_REGULAR is not set now but will be set
940 later (it is never cleared). In case of a weak definition,
941 DEF_REGULAR may be cleared later by a strong definition in
942 a shared library. We account for that possibility below by
943 storing information in the relocs_copied field of the hash
944 table entry. A similar situation occurs when creating
945 shared libraries and symbol visibility changes render the
946 symbol local.
948 If on the other hand, we are creating an executable, we
949 may need to keep relocations for symbols satisfied by a
950 dynamic library if we manage to avoid copy relocs for the
951 symbol. */
952 if ((info->shared
953 && (sec->flags & SEC_ALLOC) != 0
954 && (((r_type != R_X86_64_PC8)
955 && (r_type != R_X86_64_PC16)
956 && (r_type != R_X86_64_PC32)
957 && (r_type != R_X86_64_PC64))
958 || (h != NULL
959 && (! info->symbolic
960 || h->root.type == bfd_link_hash_defweak
961 || !h->def_regular))))
962 || (ELIMINATE_COPY_RELOCS
963 && !info->shared
964 && (sec->flags & SEC_ALLOC) != 0
965 && h != NULL
966 && (h->root.type == bfd_link_hash_defweak
967 || !h->def_regular)))
969 struct elf64_x86_64_dyn_relocs *p;
970 struct elf64_x86_64_dyn_relocs **head;
972 /* We must copy these reloc types into the output file.
973 Create a reloc section in dynobj and make room for
974 this reloc. */
975 if (sreloc == NULL)
977 const char *name;
978 bfd *dynobj;
980 name = (bfd_elf_string_from_elf_section
981 (abfd,
982 elf_elfheader (abfd)->e_shstrndx,
983 elf_section_data (sec)->rel_hdr.sh_name));
984 if (name == NULL)
985 return FALSE;
987 if (strncmp (name, ".rela", 5) != 0
988 || strcmp (bfd_get_section_name (abfd, sec),
989 name + 5) != 0)
991 (*_bfd_error_handler)
992 (_("%B: bad relocation section name `%s\'"),
993 abfd, name);
996 if (htab->elf.dynobj == NULL)
997 htab->elf.dynobj = abfd;
999 dynobj = htab->elf.dynobj;
1001 sreloc = bfd_get_section_by_name (dynobj, name);
1002 if (sreloc == NULL)
1004 flagword flags;
1006 flags = (SEC_HAS_CONTENTS | SEC_READONLY
1007 | SEC_IN_MEMORY | SEC_LINKER_CREATED);
1008 if ((sec->flags & SEC_ALLOC) != 0)
1009 flags |= SEC_ALLOC | SEC_LOAD;
1010 sreloc = bfd_make_section_with_flags (dynobj,
1011 name,
1012 flags);
1013 if (sreloc == NULL
1014 || ! bfd_set_section_alignment (dynobj, sreloc, 3))
1015 return FALSE;
1017 elf_section_data (sec)->sreloc = sreloc;
1020 /* If this is a global symbol, we count the number of
1021 relocations we need for this symbol. */
1022 if (h != NULL)
1024 head = &((struct elf64_x86_64_link_hash_entry *) h)->dyn_relocs;
1026 else
1028 void **vpp;
1029 /* Track dynamic relocs needed for local syms too.
1030 We really need local syms available to do this
1031 easily. Oh well. */
1033 asection *s;
1034 s = bfd_section_from_r_symndx (abfd, &htab->sym_sec,
1035 sec, r_symndx);
1036 if (s == NULL)
1037 return FALSE;
1039 /* Beware of type punned pointers vs strict aliasing
1040 rules. */
1041 vpp = &(elf_section_data (s)->local_dynrel);
1042 head = (struct elf64_x86_64_dyn_relocs **)vpp;
1045 p = *head;
1046 if (p == NULL || p->sec != sec)
1048 bfd_size_type amt = sizeof *p;
1049 p = ((struct elf64_x86_64_dyn_relocs *)
1050 bfd_alloc (htab->elf.dynobj, amt));
1051 if (p == NULL)
1052 return FALSE;
1053 p->next = *head;
1054 *head = p;
1055 p->sec = sec;
1056 p->count = 0;
1057 p->pc_count = 0;
1060 p->count += 1;
1061 if (r_type == R_X86_64_PC8
1062 || r_type == R_X86_64_PC16
1063 || r_type == R_X86_64_PC32
1064 || r_type == R_X86_64_PC64)
1065 p->pc_count += 1;
1067 break;
1069 /* This relocation describes the C++ object vtable hierarchy.
1070 Reconstruct it for later use during GC. */
1071 case R_X86_64_GNU_VTINHERIT:
1072 if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
1073 return FALSE;
1074 break;
1076 /* This relocation describes which C++ vtable entries are actually
1077 used. Record for later use during GC. */
1078 case R_X86_64_GNU_VTENTRY:
1079 if (!bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend))
1080 return FALSE;
1081 break;
1083 default:
1084 break;
1088 return TRUE;
1091 /* Return the section that should be marked against GC for a given
1092 relocation. */
1094 static asection *
1095 elf64_x86_64_gc_mark_hook (asection *sec,
1096 struct bfd_link_info *info ATTRIBUTE_UNUSED,
1097 Elf_Internal_Rela *rel,
1098 struct elf_link_hash_entry *h,
1099 Elf_Internal_Sym *sym)
1101 if (h != NULL)
1103 switch (ELF64_R_TYPE (rel->r_info))
1105 case R_X86_64_GNU_VTINHERIT:
1106 case R_X86_64_GNU_VTENTRY:
1107 break;
1109 default:
1110 switch (h->root.type)
1112 case bfd_link_hash_defined:
1113 case bfd_link_hash_defweak:
1114 return h->root.u.def.section;
1116 case bfd_link_hash_common:
1117 return h->root.u.c.p->section;
1119 default:
1120 break;
1124 else
1125 return bfd_section_from_elf_index (sec->owner, sym->st_shndx);
1127 return NULL;
1130 /* Update the got entry reference counts for the section being removed. */
1132 static bfd_boolean
1133 elf64_x86_64_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info,
1134 asection *sec, const Elf_Internal_Rela *relocs)
1136 Elf_Internal_Shdr *symtab_hdr;
1137 struct elf_link_hash_entry **sym_hashes;
1138 bfd_signed_vma *local_got_refcounts;
1139 const Elf_Internal_Rela *rel, *relend;
1141 elf_section_data (sec)->local_dynrel = NULL;
1143 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
1144 sym_hashes = elf_sym_hashes (abfd);
1145 local_got_refcounts = elf_local_got_refcounts (abfd);
1147 relend = relocs + sec->reloc_count;
1148 for (rel = relocs; rel < relend; rel++)
1150 unsigned long r_symndx;
1151 unsigned int r_type;
1152 struct elf_link_hash_entry *h = NULL;
1154 r_symndx = ELF64_R_SYM (rel->r_info);
1155 if (r_symndx >= symtab_hdr->sh_info)
1157 struct elf64_x86_64_link_hash_entry *eh;
1158 struct elf64_x86_64_dyn_relocs **pp;
1159 struct elf64_x86_64_dyn_relocs *p;
1161 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
1162 while (h->root.type == bfd_link_hash_indirect
1163 || h->root.type == bfd_link_hash_warning)
1164 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1165 eh = (struct elf64_x86_64_link_hash_entry *) h;
1167 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; pp = &p->next)
1168 if (p->sec == sec)
1170 /* Everything must go for SEC. */
1171 *pp = p->next;
1172 break;
1176 r_type = ELF64_R_TYPE (rel->r_info);
1177 r_type = elf64_x86_64_tls_transition (info, r_type, h != NULL);
1178 switch (r_type)
1180 case R_X86_64_TLSLD:
1181 if (elf64_x86_64_hash_table (info)->tls_ld_got.refcount > 0)
1182 elf64_x86_64_hash_table (info)->tls_ld_got.refcount -= 1;
1183 break;
1185 case R_X86_64_TLSGD:
1186 case R_X86_64_GOTPC32_TLSDESC:
1187 case R_X86_64_TLSDESC_CALL:
1188 case R_X86_64_GOTTPOFF:
1189 case R_X86_64_GOT32:
1190 case R_X86_64_GOTPCREL:
1191 if (h != NULL)
1193 if (h->got.refcount > 0)
1194 h->got.refcount -= 1;
1196 else if (local_got_refcounts != NULL)
1198 if (local_got_refcounts[r_symndx] > 0)
1199 local_got_refcounts[r_symndx] -= 1;
1201 break;
1203 case R_X86_64_8:
1204 case R_X86_64_16:
1205 case R_X86_64_32:
1206 case R_X86_64_64:
1207 case R_X86_64_32S:
1208 case R_X86_64_PC8:
1209 case R_X86_64_PC16:
1210 case R_X86_64_PC32:
1211 case R_X86_64_PC64:
1212 if (info->shared)
1213 break;
1214 /* Fall thru */
1216 case R_X86_64_PLT32:
1217 if (h != NULL)
1219 if (h->plt.refcount > 0)
1220 h->plt.refcount -= 1;
1222 break;
1224 default:
1225 break;
1229 return TRUE;
1232 /* Adjust a symbol defined by a dynamic object and referenced by a
1233 regular object. The current definition is in some section of the
1234 dynamic object, but we're not including those sections. We have to
1235 change the definition to something the rest of the link can
1236 understand. */
1238 static bfd_boolean
1239 elf64_x86_64_adjust_dynamic_symbol (struct bfd_link_info *info,
1240 struct elf_link_hash_entry *h)
1242 struct elf64_x86_64_link_hash_table *htab;
1243 asection *s;
1244 unsigned int power_of_two;
1246 /* If this is a function, put it in the procedure linkage table. We
1247 will fill in the contents of the procedure linkage table later,
1248 when we know the address of the .got section. */
1249 if (h->type == STT_FUNC
1250 || h->needs_plt)
1252 if (h->plt.refcount <= 0
1253 || SYMBOL_CALLS_LOCAL (info, h)
1254 || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1255 && h->root.type == bfd_link_hash_undefweak))
1257 /* This case can occur if we saw a PLT32 reloc in an input
1258 file, but the symbol was never referred to by a dynamic
1259 object, or if all references were garbage collected. In
1260 such a case, we don't actually need to build a procedure
1261 linkage table, and we can just do a PC32 reloc instead. */
1262 h->plt.offset = (bfd_vma) -1;
1263 h->needs_plt = 0;
1266 return TRUE;
1268 else
1269 /* It's possible that we incorrectly decided a .plt reloc was
1270 needed for an R_X86_64_PC32 reloc to a non-function sym in
1271 check_relocs. We can't decide accurately between function and
1272 non-function syms in check-relocs; Objects loaded later in
1273 the link may change h->type. So fix it now. */
1274 h->plt.offset = (bfd_vma) -1;
1276 /* If this is a weak symbol, and there is a real definition, the
1277 processor independent code will have arranged for us to see the
1278 real definition first, and we can just use the same value. */
1279 if (h->u.weakdef != NULL)
1281 BFD_ASSERT (h->u.weakdef->root.type == bfd_link_hash_defined
1282 || h->u.weakdef->root.type == bfd_link_hash_defweak);
1283 h->root.u.def.section = h->u.weakdef->root.u.def.section;
1284 h->root.u.def.value = h->u.weakdef->root.u.def.value;
1285 if (ELIMINATE_COPY_RELOCS || info->nocopyreloc)
1286 h->non_got_ref = h->u.weakdef->non_got_ref;
1287 return TRUE;
1290 /* This is a reference to a symbol defined by a dynamic object which
1291 is not a function. */
1293 /* If we are creating a shared library, we must presume that the
1294 only references to the symbol are via the global offset table.
1295 For such cases we need not do anything here; the relocations will
1296 be handled correctly by relocate_section. */
1297 if (info->shared)
1298 return TRUE;
1300 /* If there are no references to this symbol that do not use the
1301 GOT, we don't need to generate a copy reloc. */
1302 if (!h->non_got_ref)
1303 return TRUE;
1305 /* If -z nocopyreloc was given, we won't generate them either. */
1306 if (info->nocopyreloc)
1308 h->non_got_ref = 0;
1309 return TRUE;
1312 if (ELIMINATE_COPY_RELOCS)
1314 struct elf64_x86_64_link_hash_entry * eh;
1315 struct elf64_x86_64_dyn_relocs *p;
1317 eh = (struct elf64_x86_64_link_hash_entry *) h;
1318 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1320 s = p->sec->output_section;
1321 if (s != NULL && (s->flags & SEC_READONLY) != 0)
1322 break;
1325 /* If we didn't find any dynamic relocs in read-only sections, then
1326 we'll be keeping the dynamic relocs and avoiding the copy reloc. */
1327 if (p == NULL)
1329 h->non_got_ref = 0;
1330 return TRUE;
1334 if (h->size == 0)
1336 (*_bfd_error_handler) (_("dynamic variable `%s' is zero size"),
1337 h->root.root.string);
1338 return TRUE;
1341 /* We must allocate the symbol in our .dynbss section, which will
1342 become part of the .bss section of the executable. There will be
1343 an entry for this symbol in the .dynsym section. The dynamic
1344 object will contain position independent code, so all references
1345 from the dynamic object to this symbol will go through the global
1346 offset table. The dynamic linker will use the .dynsym entry to
1347 determine the address it must put in the global offset table, so
1348 both the dynamic object and the regular object will refer to the
1349 same memory location for the variable. */
1351 htab = elf64_x86_64_hash_table (info);
1353 /* We must generate a R_X86_64_COPY reloc to tell the dynamic linker
1354 to copy the initial value out of the dynamic object and into the
1355 runtime process image. */
1356 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0)
1358 htab->srelbss->size += sizeof (Elf64_External_Rela);
1359 h->needs_copy = 1;
1362 /* We need to figure out the alignment required for this symbol. I
1363 have no idea how ELF linkers handle this. 16-bytes is the size
1364 of the largest type that requires hard alignment -- long double. */
1365 /* FIXME: This is VERY ugly. Should be fixed for all architectures using
1366 this construct. */
1367 power_of_two = bfd_log2 (h->size);
1368 if (power_of_two > 4)
1369 power_of_two = 4;
1371 /* Apply the required alignment. */
1372 s = htab->sdynbss;
1373 s->size = BFD_ALIGN (s->size, (bfd_size_type) (1 << power_of_two));
1374 if (power_of_two > bfd_get_section_alignment (htab->elf.dynobj, s))
1376 if (! bfd_set_section_alignment (htab->elf.dynobj, s, power_of_two))
1377 return FALSE;
1380 /* Define the symbol as being at this point in the section. */
1381 h->root.u.def.section = s;
1382 h->root.u.def.value = s->size;
1384 /* Increment the section size to make room for the symbol. */
1385 s->size += h->size;
1387 return TRUE;
1390 /* Allocate space in .plt, .got and associated reloc sections for
1391 dynamic relocs. */
1393 static bfd_boolean
1394 allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
1396 struct bfd_link_info *info;
1397 struct elf64_x86_64_link_hash_table *htab;
1398 struct elf64_x86_64_link_hash_entry *eh;
1399 struct elf64_x86_64_dyn_relocs *p;
1401 if (h->root.type == bfd_link_hash_indirect)
1402 return TRUE;
1404 if (h->root.type == bfd_link_hash_warning)
1405 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1407 info = (struct bfd_link_info *) inf;
1408 htab = elf64_x86_64_hash_table (info);
1410 if (htab->elf.dynamic_sections_created
1411 && h->plt.refcount > 0)
1413 /* Make sure this symbol is output as a dynamic symbol.
1414 Undefined weak syms won't yet be marked as dynamic. */
1415 if (h->dynindx == -1
1416 && !h->forced_local)
1418 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1419 return FALSE;
1422 if (info->shared
1423 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
1425 asection *s = htab->splt;
1427 /* If this is the first .plt entry, make room for the special
1428 first entry. */
1429 if (s->size == 0)
1430 s->size += PLT_ENTRY_SIZE;
1432 h->plt.offset = s->size;
1434 /* If this symbol is not defined in a regular file, and we are
1435 not generating a shared library, then set the symbol to this
1436 location in the .plt. This is required to make function
1437 pointers compare as equal between the normal executable and
1438 the shared library. */
1439 if (! info->shared
1440 && !h->def_regular)
1442 h->root.u.def.section = s;
1443 h->root.u.def.value = h->plt.offset;
1446 /* Make room for this entry. */
1447 s->size += PLT_ENTRY_SIZE;
1449 /* We also need to make an entry in the .got.plt section, which
1450 will be placed in the .got section by the linker script. */
1451 htab->sgotplt->size += GOT_ENTRY_SIZE;
1453 /* We also need to make an entry in the .rela.plt section. */
1454 htab->srelplt->size += sizeof (Elf64_External_Rela);
1455 htab->srelplt->reloc_count++;
1457 else
1459 h->plt.offset = (bfd_vma) -1;
1460 h->needs_plt = 0;
1463 else
1465 h->plt.offset = (bfd_vma) -1;
1466 h->needs_plt = 0;
1469 eh = (struct elf64_x86_64_link_hash_entry *) h;
1470 eh->tlsdesc_got = (bfd_vma) -1;
1472 /* If R_X86_64_GOTTPOFF symbol is now local to the binary,
1473 make it a R_X86_64_TPOFF32 requiring no GOT entry. */
1474 if (h->got.refcount > 0
1475 && !info->shared
1476 && h->dynindx == -1
1477 && elf64_x86_64_hash_entry (h)->tls_type == GOT_TLS_IE)
1478 h->got.offset = (bfd_vma) -1;
1479 else if (h->got.refcount > 0)
1481 asection *s;
1482 bfd_boolean dyn;
1483 int tls_type = elf64_x86_64_hash_entry (h)->tls_type;
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 (GOT_TLS_GDESC_P (tls_type))
1496 eh->tlsdesc_got = htab->sgotplt->size
1497 - elf64_x86_64_compute_jump_table_size (htab);
1498 htab->sgotplt->size += 2 * GOT_ENTRY_SIZE;
1499 h->got.offset = (bfd_vma) -2;
1501 if (! GOT_TLS_GDESC_P (tls_type)
1502 || GOT_TLS_GD_P (tls_type))
1504 s = htab->sgot;
1505 h->got.offset = s->size;
1506 s->size += GOT_ENTRY_SIZE;
1507 if (GOT_TLS_GD_P (tls_type))
1508 s->size += GOT_ENTRY_SIZE;
1510 dyn = htab->elf.dynamic_sections_created;
1511 /* R_X86_64_TLSGD needs one dynamic relocation if local symbol
1512 and two if global.
1513 R_X86_64_GOTTPOFF needs one dynamic relocation. */
1514 if ((GOT_TLS_GD_P (tls_type) && h->dynindx == -1)
1515 || tls_type == GOT_TLS_IE)
1516 htab->srelgot->size += sizeof (Elf64_External_Rela);
1517 else if (GOT_TLS_GD_P (tls_type))
1518 htab->srelgot->size += 2 * sizeof (Elf64_External_Rela);
1519 else if (! GOT_TLS_GDESC_P (tls_type)
1520 && (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
1521 || h->root.type != bfd_link_hash_undefweak)
1522 && (info->shared
1523 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h)))
1524 htab->srelgot->size += sizeof (Elf64_External_Rela);
1525 if (GOT_TLS_GDESC_P (tls_type))
1527 htab->srelplt->size += sizeof (Elf64_External_Rela);
1528 htab->tlsdesc_plt = (bfd_vma) -1;
1531 else
1532 h->got.offset = (bfd_vma) -1;
1534 if (eh->dyn_relocs == NULL)
1535 return TRUE;
1537 /* In the shared -Bsymbolic case, discard space allocated for
1538 dynamic pc-relative relocs against symbols which turn out to be
1539 defined in regular objects. For the normal shared case, discard
1540 space for pc-relative relocs that have become local due to symbol
1541 visibility changes. */
1543 if (info->shared)
1545 /* Relocs that use pc_count are those that appear on a call
1546 insn, or certain REL relocs that can generated via assembly.
1547 We want calls to protected symbols to resolve directly to the
1548 function rather than going via the plt. If people want
1549 function pointer comparisons to work as expected then they
1550 should avoid writing weird assembly. */
1551 if (SYMBOL_CALLS_LOCAL (info, h))
1553 struct elf64_x86_64_dyn_relocs **pp;
1555 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
1557 p->count -= p->pc_count;
1558 p->pc_count = 0;
1559 if (p->count == 0)
1560 *pp = p->next;
1561 else
1562 pp = &p->next;
1566 /* Also discard relocs on undefined weak syms with non-default
1567 visibility. */
1568 if (eh->dyn_relocs != NULL
1569 && h->root.type == bfd_link_hash_undefweak)
1571 if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
1572 eh->dyn_relocs = NULL;
1574 /* Make sure undefined weak symbols are output as a dynamic
1575 symbol in PIEs. */
1576 else if (h->dynindx == -1
1577 && !h->forced_local)
1579 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1580 return FALSE;
1584 else if (ELIMINATE_COPY_RELOCS)
1586 /* For the non-shared case, discard space for relocs against
1587 symbols which turn out to need copy relocs or are not
1588 dynamic. */
1590 if (!h->non_got_ref
1591 && ((h->def_dynamic
1592 && !h->def_regular)
1593 || (htab->elf.dynamic_sections_created
1594 && (h->root.type == bfd_link_hash_undefweak
1595 || h->root.type == bfd_link_hash_undefined))))
1597 /* Make sure this symbol is output as a dynamic symbol.
1598 Undefined weak syms won't yet be marked as dynamic. */
1599 if (h->dynindx == -1
1600 && !h->forced_local)
1602 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1603 return FALSE;
1606 /* If that succeeded, we know we'll be keeping all the
1607 relocs. */
1608 if (h->dynindx != -1)
1609 goto keep;
1612 eh->dyn_relocs = NULL;
1614 keep: ;
1617 /* Finally, allocate space. */
1618 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1620 asection *sreloc = elf_section_data (p->sec)->sreloc;
1621 sreloc->size += p->count * sizeof (Elf64_External_Rela);
1624 return TRUE;
1627 /* Find any dynamic relocs that apply to read-only sections. */
1629 static bfd_boolean
1630 readonly_dynrelocs (struct elf_link_hash_entry *h, void * inf)
1632 struct elf64_x86_64_link_hash_entry *eh;
1633 struct elf64_x86_64_dyn_relocs *p;
1635 if (h->root.type == bfd_link_hash_warning)
1636 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1638 eh = (struct elf64_x86_64_link_hash_entry *) h;
1639 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1641 asection *s = p->sec->output_section;
1643 if (s != NULL && (s->flags & SEC_READONLY) != 0)
1645 struct bfd_link_info *info = (struct bfd_link_info *) inf;
1647 info->flags |= DF_TEXTREL;
1649 /* Not an error, just cut short the traversal. */
1650 return FALSE;
1653 return TRUE;
1656 /* Set the sizes of the dynamic sections. */
1658 static bfd_boolean
1659 elf64_x86_64_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED,
1660 struct bfd_link_info *info)
1662 struct elf64_x86_64_link_hash_table *htab;
1663 bfd *dynobj;
1664 asection *s;
1665 bfd_boolean relocs;
1666 bfd *ibfd;
1668 htab = elf64_x86_64_hash_table (info);
1669 dynobj = htab->elf.dynobj;
1670 if (dynobj == NULL)
1671 abort ();
1673 if (htab->elf.dynamic_sections_created)
1675 /* Set the contents of the .interp section to the interpreter. */
1676 if (info->executable)
1678 s = bfd_get_section_by_name (dynobj, ".interp");
1679 if (s == NULL)
1680 abort ();
1681 s->size = sizeof ELF_DYNAMIC_INTERPRETER;
1682 s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER;
1686 /* Set up .got offsets for local syms, and space for local dynamic
1687 relocs. */
1688 for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next)
1690 bfd_signed_vma *local_got;
1691 bfd_signed_vma *end_local_got;
1692 char *local_tls_type;
1693 bfd_vma *local_tlsdesc_gotent;
1694 bfd_size_type locsymcount;
1695 Elf_Internal_Shdr *symtab_hdr;
1696 asection *srel;
1698 if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour)
1699 continue;
1701 for (s = ibfd->sections; s != NULL; s = s->next)
1703 struct elf64_x86_64_dyn_relocs *p;
1705 for (p = (struct elf64_x86_64_dyn_relocs *)
1706 (elf_section_data (s)->local_dynrel);
1707 p != NULL;
1708 p = p->next)
1710 if (!bfd_is_abs_section (p->sec)
1711 && bfd_is_abs_section (p->sec->output_section))
1713 /* Input section has been discarded, either because
1714 it is a copy of a linkonce section or due to
1715 linker script /DISCARD/, so we'll be discarding
1716 the relocs too. */
1718 else if (p->count != 0)
1720 srel = elf_section_data (p->sec)->sreloc;
1721 srel->size += p->count * sizeof (Elf64_External_Rela);
1722 if ((p->sec->output_section->flags & SEC_READONLY) != 0)
1723 info->flags |= DF_TEXTREL;
1729 local_got = elf_local_got_refcounts (ibfd);
1730 if (!local_got)
1731 continue;
1733 symtab_hdr = &elf_tdata (ibfd)->symtab_hdr;
1734 locsymcount = symtab_hdr->sh_info;
1735 end_local_got = local_got + locsymcount;
1736 local_tls_type = elf64_x86_64_local_got_tls_type (ibfd);
1737 local_tlsdesc_gotent = elf64_x86_64_local_tlsdesc_gotent (ibfd);
1738 s = htab->sgot;
1739 srel = htab->srelgot;
1740 for (; local_got < end_local_got;
1741 ++local_got, ++local_tls_type, ++local_tlsdesc_gotent)
1743 *local_tlsdesc_gotent = (bfd_vma) -1;
1744 if (*local_got > 0)
1746 if (GOT_TLS_GDESC_P (*local_tls_type))
1748 *local_tlsdesc_gotent = htab->sgotplt->size
1749 - elf64_x86_64_compute_jump_table_size (htab);
1750 htab->sgotplt->size += 2 * GOT_ENTRY_SIZE;
1751 *local_got = (bfd_vma) -2;
1753 if (! GOT_TLS_GDESC_P (*local_tls_type)
1754 || GOT_TLS_GD_P (*local_tls_type))
1756 *local_got = s->size;
1757 s->size += GOT_ENTRY_SIZE;
1758 if (GOT_TLS_GD_P (*local_tls_type))
1759 s->size += GOT_ENTRY_SIZE;
1761 if (info->shared
1762 || GOT_TLS_GD_ANY_P (*local_tls_type)
1763 || *local_tls_type == GOT_TLS_IE)
1765 if (GOT_TLS_GDESC_P (*local_tls_type))
1767 htab->srelplt->size += sizeof (Elf64_External_Rela);
1768 htab->tlsdesc_plt = (bfd_vma) -1;
1770 if (! GOT_TLS_GDESC_P (*local_tls_type)
1771 || GOT_TLS_GD_P (*local_tls_type))
1772 srel->size += sizeof (Elf64_External_Rela);
1775 else
1776 *local_got = (bfd_vma) -1;
1780 if (htab->tls_ld_got.refcount > 0)
1782 /* Allocate 2 got entries and 1 dynamic reloc for R_X86_64_TLSLD
1783 relocs. */
1784 htab->tls_ld_got.offset = htab->sgot->size;
1785 htab->sgot->size += 2 * GOT_ENTRY_SIZE;
1786 htab->srelgot->size += sizeof (Elf64_External_Rela);
1788 else
1789 htab->tls_ld_got.offset = -1;
1791 /* Allocate global sym .plt and .got entries, and space for global
1792 sym dynamic relocs. */
1793 elf_link_hash_traverse (&htab->elf, allocate_dynrelocs, (PTR) info);
1795 /* For every jump slot reserved in the sgotplt, reloc_count is
1796 incremented. However, when we reserve space for TLS descriptors,
1797 it's not incremented, so in order to compute the space reserved
1798 for them, it suffices to multiply the reloc count by the jump
1799 slot size. */
1800 if (htab->srelplt)
1801 htab->sgotplt_jump_table_size
1802 = elf64_x86_64_compute_jump_table_size (htab);
1804 if (htab->tlsdesc_plt)
1806 /* If we're not using lazy TLS relocations, don't generate the
1807 PLT and GOT entries they require. */
1808 if ((info->flags & DF_BIND_NOW))
1809 htab->tlsdesc_plt = 0;
1810 else
1812 htab->tlsdesc_got = htab->sgot->size;
1813 htab->sgot->size += GOT_ENTRY_SIZE;
1814 /* Reserve room for the initial entry.
1815 FIXME: we could probably do away with it in this case. */
1816 if (htab->splt->size == 0)
1817 htab->splt->size += PLT_ENTRY_SIZE;
1818 htab->tlsdesc_plt = htab->splt->size;
1819 htab->splt->size += PLT_ENTRY_SIZE;
1823 /* We now have determined the sizes of the various dynamic sections.
1824 Allocate memory for them. */
1825 relocs = FALSE;
1826 for (s = dynobj->sections; s != NULL; s = s->next)
1828 if ((s->flags & SEC_LINKER_CREATED) == 0)
1829 continue;
1831 if (s == htab->splt
1832 || s == htab->sgot
1833 || s == htab->sgotplt
1834 || s == htab->sdynbss)
1836 /* Strip this section if we don't need it; see the
1837 comment below. */
1839 else if (strncmp (bfd_get_section_name (dynobj, s), ".rela", 5) == 0)
1841 if (s->size != 0 && s != htab->srelplt)
1842 relocs = TRUE;
1844 /* We use the reloc_count field as a counter if we need
1845 to copy relocs into the output file. */
1846 if (s != htab->srelplt)
1847 s->reloc_count = 0;
1849 else
1851 /* It's not one of our sections, so don't allocate space. */
1852 continue;
1855 if (s->size == 0)
1857 /* If we don't need this section, strip it from the
1858 output file. This is mostly to handle .rela.bss and
1859 .rela.plt. We must create both sections in
1860 create_dynamic_sections, because they must be created
1861 before the linker maps input sections to output
1862 sections. The linker does that before
1863 adjust_dynamic_symbol is called, and it is that
1864 function which decides whether anything needs to go
1865 into these sections. */
1867 s->flags |= SEC_EXCLUDE;
1868 continue;
1871 if ((s->flags & SEC_HAS_CONTENTS) == 0)
1872 continue;
1874 /* Allocate memory for the section contents. We use bfd_zalloc
1875 here in case unused entries are not reclaimed before the
1876 section's contents are written out. This should not happen,
1877 but this way if it does, we get a R_X86_64_NONE reloc instead
1878 of garbage. */
1879 s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->size);
1880 if (s->contents == NULL)
1881 return FALSE;
1884 if (htab->elf.dynamic_sections_created)
1886 /* Add some entries to the .dynamic section. We fill in the
1887 values later, in elf64_x86_64_finish_dynamic_sections, but we
1888 must add the entries now so that we get the correct size for
1889 the .dynamic section. The DT_DEBUG entry is filled in by the
1890 dynamic linker and used by the debugger. */
1891 #define add_dynamic_entry(TAG, VAL) \
1892 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
1894 if (info->executable)
1896 if (!add_dynamic_entry (DT_DEBUG, 0))
1897 return FALSE;
1900 if (htab->splt->size != 0)
1902 if (!add_dynamic_entry (DT_PLTGOT, 0)
1903 || !add_dynamic_entry (DT_PLTRELSZ, 0)
1904 || !add_dynamic_entry (DT_PLTREL, DT_RELA)
1905 || !add_dynamic_entry (DT_JMPREL, 0))
1906 return FALSE;
1908 if (htab->tlsdesc_plt
1909 && (!add_dynamic_entry (DT_TLSDESC_PLT, 0)
1910 || !add_dynamic_entry (DT_TLSDESC_GOT, 0)))
1911 return FALSE;
1914 if (relocs)
1916 if (!add_dynamic_entry (DT_RELA, 0)
1917 || !add_dynamic_entry (DT_RELASZ, 0)
1918 || !add_dynamic_entry (DT_RELAENT, sizeof (Elf64_External_Rela)))
1919 return FALSE;
1921 /* If any dynamic relocs apply to a read-only section,
1922 then we need a DT_TEXTREL entry. */
1923 if ((info->flags & DF_TEXTREL) == 0)
1924 elf_link_hash_traverse (&htab->elf, readonly_dynrelocs,
1925 (PTR) info);
1927 if ((info->flags & DF_TEXTREL) != 0)
1929 if (!add_dynamic_entry (DT_TEXTREL, 0))
1930 return FALSE;
1934 #undef add_dynamic_entry
1936 return TRUE;
1939 static bfd_boolean
1940 elf64_x86_64_always_size_sections (bfd *output_bfd,
1941 struct bfd_link_info *info)
1943 asection *tls_sec = elf_hash_table (info)->tls_sec;
1945 if (tls_sec)
1947 struct elf_link_hash_entry *tlsbase;
1949 tlsbase = elf_link_hash_lookup (elf_hash_table (info),
1950 "_TLS_MODULE_BASE_",
1951 FALSE, FALSE, FALSE);
1953 if (tlsbase && tlsbase->type == STT_TLS)
1955 struct bfd_link_hash_entry *bh = NULL;
1956 const struct elf_backend_data *bed
1957 = get_elf_backend_data (output_bfd);
1959 if (!(_bfd_generic_link_add_one_symbol
1960 (info, output_bfd, "_TLS_MODULE_BASE_", BSF_LOCAL,
1961 tls_sec, 0, NULL, FALSE,
1962 bed->collect, &bh)))
1963 return FALSE;
1964 tlsbase = (struct elf_link_hash_entry *)bh;
1965 tlsbase->def_regular = 1;
1966 tlsbase->other = STV_HIDDEN;
1967 (*bed->elf_backend_hide_symbol) (info, tlsbase, TRUE);
1971 return TRUE;
1974 /* Return the base VMA address which should be subtracted from real addresses
1975 when resolving @dtpoff relocation.
1976 This is PT_TLS segment p_vaddr. */
1978 static bfd_vma
1979 dtpoff_base (struct bfd_link_info *info)
1981 /* If tls_sec is NULL, we should have signalled an error already. */
1982 if (elf_hash_table (info)->tls_sec == NULL)
1983 return 0;
1984 return elf_hash_table (info)->tls_sec->vma;
1987 /* Return the relocation value for @tpoff relocation
1988 if STT_TLS virtual address is ADDRESS. */
1990 static bfd_vma
1991 tpoff (struct bfd_link_info *info, bfd_vma address)
1993 struct elf_link_hash_table *htab = elf_hash_table (info);
1995 /* If tls_segment is NULL, we should have signalled an error already. */
1996 if (htab->tls_sec == NULL)
1997 return 0;
1998 return address - htab->tls_size - htab->tls_sec->vma;
2001 /* Is the instruction before OFFSET in CONTENTS a 32bit relative
2002 branch? */
2004 static bfd_boolean
2005 is_32bit_relative_branch (bfd_byte *contents, bfd_vma offset)
2007 /* Opcode Instruction
2008 0xe8 call
2009 0xe9 jump
2010 0x0f 0x8x conditional jump */
2011 return ((offset > 0
2012 && (contents [offset - 1] == 0xe8
2013 || contents [offset - 1] == 0xe9))
2014 || (offset > 1
2015 && contents [offset - 2] == 0x0f
2016 && (contents [offset - 1] & 0xf0) == 0x80));
2019 /* Relocate an x86_64 ELF section. */
2021 static bfd_boolean
2022 elf64_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
2023 bfd *input_bfd, asection *input_section,
2024 bfd_byte *contents, Elf_Internal_Rela *relocs,
2025 Elf_Internal_Sym *local_syms,
2026 asection **local_sections)
2028 struct elf64_x86_64_link_hash_table *htab;
2029 Elf_Internal_Shdr *symtab_hdr;
2030 struct elf_link_hash_entry **sym_hashes;
2031 bfd_vma *local_got_offsets;
2032 bfd_vma *local_tlsdesc_gotents;
2033 Elf_Internal_Rela *rel;
2034 Elf_Internal_Rela *relend;
2036 if (info->relocatable)
2037 return TRUE;
2039 htab = elf64_x86_64_hash_table (info);
2040 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
2041 sym_hashes = elf_sym_hashes (input_bfd);
2042 local_got_offsets = elf_local_got_offsets (input_bfd);
2043 local_tlsdesc_gotents = elf64_x86_64_local_tlsdesc_gotent (input_bfd);
2045 rel = relocs;
2046 relend = relocs + input_section->reloc_count;
2047 for (; rel < relend; rel++)
2049 unsigned int r_type;
2050 reloc_howto_type *howto;
2051 unsigned long r_symndx;
2052 struct elf_link_hash_entry *h;
2053 Elf_Internal_Sym *sym;
2054 asection *sec;
2055 bfd_vma off, offplt;
2056 bfd_vma relocation;
2057 bfd_boolean unresolved_reloc;
2058 bfd_reloc_status_type r;
2059 int tls_type;
2061 r_type = ELF64_R_TYPE (rel->r_info);
2062 if (r_type == (int) R_X86_64_GNU_VTINHERIT
2063 || r_type == (int) R_X86_64_GNU_VTENTRY)
2064 continue;
2066 if (r_type >= R_X86_64_max)
2068 bfd_set_error (bfd_error_bad_value);
2069 return FALSE;
2072 howto = x86_64_elf_howto_table + r_type;
2073 r_symndx = ELF64_R_SYM (rel->r_info);
2074 h = NULL;
2075 sym = NULL;
2076 sec = NULL;
2077 unresolved_reloc = FALSE;
2078 if (r_symndx < symtab_hdr->sh_info)
2080 sym = local_syms + r_symndx;
2081 sec = local_sections[r_symndx];
2083 relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
2085 else
2087 bfd_boolean warned;
2089 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
2090 r_symndx, symtab_hdr, sym_hashes,
2091 h, sec, relocation,
2092 unresolved_reloc, warned);
2094 /* When generating a shared object, the relocations handled here are
2095 copied into the output file to be resolved at run time. */
2096 switch (r_type)
2098 case R_X86_64_GOT32:
2099 /* Relocation is to the entry for this symbol in the global
2100 offset table. */
2101 case R_X86_64_GOTPCREL:
2102 /* Use global offset table as symbol value. */
2103 if (htab->sgot == NULL)
2104 abort ();
2106 if (h != NULL)
2108 bfd_boolean dyn;
2110 off = h->got.offset;
2111 dyn = htab->elf.dynamic_sections_created;
2113 if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info->shared, h)
2114 || (info->shared
2115 && SYMBOL_REFERENCES_LOCAL (info, h))
2116 || (ELF_ST_VISIBILITY (h->other)
2117 && h->root.type == bfd_link_hash_undefweak))
2119 /* This is actually a static link, or it is a -Bsymbolic
2120 link and the symbol is defined locally, or the symbol
2121 was forced to be local because of a version file. We
2122 must initialize this entry in the global offset table.
2123 Since the offset must always be a multiple of 8, we
2124 use the least significant bit to record whether we
2125 have initialized it already.
2127 When doing a dynamic link, we create a .rela.got
2128 relocation entry to initialize the value. This is
2129 done in the finish_dynamic_symbol routine. */
2130 if ((off & 1) != 0)
2131 off &= ~1;
2132 else
2134 bfd_put_64 (output_bfd, relocation,
2135 htab->sgot->contents + off);
2136 h->got.offset |= 1;
2139 else
2140 unresolved_reloc = FALSE;
2142 else
2144 if (local_got_offsets == NULL)
2145 abort ();
2147 off = local_got_offsets[r_symndx];
2149 /* The offset must always be a multiple of 8. We use
2150 the least significant bit to record whether we have
2151 already generated the necessary reloc. */
2152 if ((off & 1) != 0)
2153 off &= ~1;
2154 else
2156 bfd_put_64 (output_bfd, relocation,
2157 htab->sgot->contents + off);
2159 if (info->shared)
2161 asection *s;
2162 Elf_Internal_Rela outrel;
2163 bfd_byte *loc;
2165 /* We need to generate a R_X86_64_RELATIVE reloc
2166 for the dynamic linker. */
2167 s = htab->srelgot;
2168 if (s == NULL)
2169 abort ();
2171 outrel.r_offset = (htab->sgot->output_section->vma
2172 + htab->sgot->output_offset
2173 + off);
2174 outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE);
2175 outrel.r_addend = relocation;
2176 loc = s->contents;
2177 loc += s->reloc_count++ * sizeof (Elf64_External_Rela);
2178 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2181 local_got_offsets[r_symndx] |= 1;
2185 if (off >= (bfd_vma) -2)
2186 abort ();
2188 relocation = htab->sgot->output_section->vma
2189 + htab->sgot->output_offset + off;
2190 if (r_type != R_X86_64_GOTPCREL)
2191 relocation -= htab->sgotplt->output_section->vma
2192 - htab->sgotplt->output_offset;
2194 break;
2196 case R_X86_64_GOTOFF64:
2197 /* Relocation is relative to the start of the global offset
2198 table. */
2200 /* Check to make sure it isn't a protected function symbol
2201 for shared library since it may not be local when used
2202 as function address. */
2203 if (info->shared
2204 && h
2205 && h->def_regular
2206 && h->type == STT_FUNC
2207 && ELF_ST_VISIBILITY (h->other) == STV_PROTECTED)
2209 (*_bfd_error_handler)
2210 (_("%B: relocation R_X86_64_GOTOFF64 against protected function `%s' can not be used when making a shared object"),
2211 input_bfd, h->root.root.string);
2212 bfd_set_error (bfd_error_bad_value);
2213 return FALSE;
2216 /* Note that sgot is not involved in this
2217 calculation. We always want the start of .got.plt. If we
2218 defined _GLOBAL_OFFSET_TABLE_ in a different way, as is
2219 permitted by the ABI, we might have to change this
2220 calculation. */
2221 relocation -= htab->sgotplt->output_section->vma
2222 + htab->sgotplt->output_offset;
2223 break;
2225 case R_X86_64_GOTPC32:
2226 /* Use global offset table as symbol value. */
2227 relocation = htab->sgotplt->output_section->vma
2228 + htab->sgotplt->output_offset;
2229 unresolved_reloc = FALSE;
2230 break;
2232 case R_X86_64_PLT32:
2233 /* Relocation is to the entry for this symbol in the
2234 procedure linkage table. */
2236 /* Resolve a PLT32 reloc against a local symbol directly,
2237 without using the procedure linkage table. */
2238 if (h == NULL)
2239 break;
2241 if (h->plt.offset == (bfd_vma) -1
2242 || htab->splt == NULL)
2244 /* We didn't make a PLT entry for this symbol. This
2245 happens when statically linking PIC code, or when
2246 using -Bsymbolic. */
2247 break;
2250 relocation = (htab->splt->output_section->vma
2251 + htab->splt->output_offset
2252 + h->plt.offset);
2253 unresolved_reloc = FALSE;
2254 break;
2256 case R_X86_64_PC8:
2257 case R_X86_64_PC16:
2258 case R_X86_64_PC32:
2259 if (info->shared
2260 && !SYMBOL_REFERENCES_LOCAL (info, h)
2261 && (input_section->flags & SEC_ALLOC) != 0
2262 && (input_section->flags & SEC_READONLY) != 0
2263 && (!h->def_regular
2264 || r_type != R_X86_64_PC32
2265 || h->type != STT_FUNC
2266 || ELF_ST_VISIBILITY (h->other) != STV_PROTECTED
2267 || !is_32bit_relative_branch (contents,
2268 rel->r_offset)))
2270 if (h->def_regular
2271 && r_type == R_X86_64_PC32
2272 && h->type == STT_FUNC
2273 && ELF_ST_VISIBILITY (h->other) == STV_PROTECTED)
2274 (*_bfd_error_handler)
2275 (_("%B: relocation R_X86_64_PC32 against protected function `%s' can not be used when making a shared object"),
2276 input_bfd, h->root.root.string);
2277 else
2278 (*_bfd_error_handler)
2279 (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
2280 input_bfd, x86_64_elf_howto_table[r_type].name,
2281 h->root.root.string);
2282 bfd_set_error (bfd_error_bad_value);
2283 return FALSE;
2285 /* Fall through. */
2287 case R_X86_64_8:
2288 case R_X86_64_16:
2289 case R_X86_64_32:
2290 case R_X86_64_PC64:
2291 case R_X86_64_64:
2292 /* FIXME: The ABI says the linker should make sure the value is
2293 the same when it's zeroextended to 64 bit. */
2295 /* r_symndx will be zero only for relocs against symbols
2296 from removed linkonce sections, or sections discarded by
2297 a linker script. */
2298 if (r_symndx == 0
2299 || (input_section->flags & SEC_ALLOC) == 0)
2300 break;
2302 if ((info->shared
2303 && (h == NULL
2304 || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
2305 || h->root.type != bfd_link_hash_undefweak)
2306 && ((r_type != R_X86_64_PC8
2307 && r_type != R_X86_64_PC16
2308 && r_type != R_X86_64_PC32
2309 && r_type != R_X86_64_PC64)
2310 || !SYMBOL_CALLS_LOCAL (info, h)))
2311 || (ELIMINATE_COPY_RELOCS
2312 && !info->shared
2313 && h != NULL
2314 && h->dynindx != -1
2315 && !h->non_got_ref
2316 && ((h->def_dynamic
2317 && !h->def_regular)
2318 || h->root.type == bfd_link_hash_undefweak
2319 || h->root.type == bfd_link_hash_undefined)))
2321 Elf_Internal_Rela outrel;
2322 bfd_byte *loc;
2323 bfd_boolean skip, relocate;
2324 asection *sreloc;
2326 /* When generating a shared object, these relocations
2327 are copied into the output file to be resolved at run
2328 time. */
2329 skip = FALSE;
2330 relocate = FALSE;
2332 outrel.r_offset =
2333 _bfd_elf_section_offset (output_bfd, info, input_section,
2334 rel->r_offset);
2335 if (outrel.r_offset == (bfd_vma) -1)
2336 skip = TRUE;
2337 else if (outrel.r_offset == (bfd_vma) -2)
2338 skip = TRUE, relocate = TRUE;
2340 outrel.r_offset += (input_section->output_section->vma
2341 + input_section->output_offset);
2343 if (skip)
2344 memset (&outrel, 0, sizeof outrel);
2346 /* h->dynindx may be -1 if this symbol was marked to
2347 become local. */
2348 else if (h != NULL
2349 && h->dynindx != -1
2350 && (r_type == R_X86_64_PC8
2351 || r_type == R_X86_64_PC16
2352 || r_type == R_X86_64_PC32
2353 || r_type == R_X86_64_PC64
2354 || !info->shared
2355 || !info->symbolic
2356 || !h->def_regular))
2358 outrel.r_info = ELF64_R_INFO (h->dynindx, r_type);
2359 outrel.r_addend = rel->r_addend;
2361 else
2363 /* This symbol is local, or marked to become local. */
2364 if (r_type == R_X86_64_64)
2366 relocate = TRUE;
2367 outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE);
2368 outrel.r_addend = relocation + rel->r_addend;
2370 else
2372 long sindx;
2374 if (bfd_is_abs_section (sec))
2375 sindx = 0;
2376 else if (sec == NULL || sec->owner == NULL)
2378 bfd_set_error (bfd_error_bad_value);
2379 return FALSE;
2381 else
2383 asection *osec;
2385 osec = sec->output_section;
2386 sindx = elf_section_data (osec)->dynindx;
2387 BFD_ASSERT (sindx > 0);
2390 outrel.r_info = ELF64_R_INFO (sindx, r_type);
2391 outrel.r_addend = relocation + rel->r_addend;
2395 sreloc = elf_section_data (input_section)->sreloc;
2396 if (sreloc == NULL)
2397 abort ();
2399 loc = sreloc->contents;
2400 loc += sreloc->reloc_count++ * sizeof (Elf64_External_Rela);
2401 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2403 /* If this reloc is against an external symbol, we do
2404 not want to fiddle with the addend. Otherwise, we
2405 need to include the symbol value so that it becomes
2406 an addend for the dynamic reloc. */
2407 if (! relocate)
2408 continue;
2411 break;
2413 case R_X86_64_TLSGD:
2414 case R_X86_64_GOTPC32_TLSDESC:
2415 case R_X86_64_TLSDESC_CALL:
2416 case R_X86_64_GOTTPOFF:
2417 r_type = elf64_x86_64_tls_transition (info, r_type, h == NULL);
2418 tls_type = GOT_UNKNOWN;
2419 if (h == NULL && local_got_offsets)
2420 tls_type = elf64_x86_64_local_got_tls_type (input_bfd) [r_symndx];
2421 else if (h != NULL)
2423 tls_type = elf64_x86_64_hash_entry (h)->tls_type;
2424 if (!info->shared && h->dynindx == -1 && tls_type == GOT_TLS_IE)
2425 r_type = R_X86_64_TPOFF32;
2427 if (r_type == R_X86_64_TLSGD
2428 || r_type == R_X86_64_GOTPC32_TLSDESC
2429 || r_type == R_X86_64_TLSDESC_CALL)
2431 if (tls_type == GOT_TLS_IE)
2432 r_type = R_X86_64_GOTTPOFF;
2435 if (r_type == R_X86_64_TPOFF32)
2437 BFD_ASSERT (! unresolved_reloc);
2438 if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSGD)
2440 unsigned int i;
2441 static unsigned char tlsgd[8]
2442 = { 0x66, 0x48, 0x8d, 0x3d, 0x66, 0x66, 0x48, 0xe8 };
2444 /* GD->LE transition.
2445 .byte 0x66; leaq foo@tlsgd(%rip), %rdi
2446 .word 0x6666; rex64; call __tls_get_addr@plt
2447 Change it into:
2448 movq %fs:0, %rax
2449 leaq foo@tpoff(%rax), %rax */
2450 BFD_ASSERT (rel->r_offset >= 4);
2451 for (i = 0; i < 4; i++)
2452 BFD_ASSERT (bfd_get_8 (input_bfd,
2453 contents + rel->r_offset - 4 + i)
2454 == tlsgd[i]);
2455 BFD_ASSERT (rel->r_offset + 12 <= input_section->size);
2456 for (i = 0; i < 4; i++)
2457 BFD_ASSERT (bfd_get_8 (input_bfd,
2458 contents + rel->r_offset + 4 + i)
2459 == tlsgd[i+4]);
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 - 4,
2463 "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0",
2464 16);
2465 bfd_put_32 (output_bfd, tpoff (info, relocation),
2466 contents + rel->r_offset + 8);
2467 /* Skip R_X86_64_PLT32. */
2468 rel++;
2469 continue;
2471 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_GOTPC32_TLSDESC)
2473 /* GDesc -> LE transition.
2474 It's originally something like:
2475 leaq x@tlsdesc(%rip), %rax
2477 Change it to:
2478 movl $x@tpoff, %rax
2480 Registers other than %rax may be set up here. */
2482 unsigned int val, type, type2;
2483 bfd_vma roff;
2485 /* First, make sure it's a leaq adding rip to a
2486 32-bit offset into any register, although it's
2487 probably almost always going to be rax. */
2488 roff = rel->r_offset;
2489 BFD_ASSERT (roff >= 3);
2490 type = bfd_get_8 (input_bfd, contents + roff - 3);
2491 BFD_ASSERT ((type & 0xfb) == 0x48);
2492 type2 = bfd_get_8 (input_bfd, contents + roff - 2);
2493 BFD_ASSERT (type2 == 0x8d);
2494 val = bfd_get_8 (input_bfd, contents + roff - 1);
2495 BFD_ASSERT ((val & 0xc7) == 0x05);
2496 BFD_ASSERT (roff + 4 <= input_section->size);
2498 /* Now modify the instruction as appropriate. */
2499 bfd_put_8 (output_bfd, 0x48 | ((type >> 2) & 1),
2500 contents + roff - 3);
2501 bfd_put_8 (output_bfd, 0xc7, contents + roff - 2);
2502 bfd_put_8 (output_bfd, 0xc0 | ((val >> 3) & 7),
2503 contents + roff - 1);
2504 bfd_put_32 (output_bfd, tpoff (info, relocation),
2505 contents + roff);
2506 continue;
2508 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSDESC_CALL)
2510 /* GDesc -> LE transition.
2511 It's originally:
2512 call *(%rax)
2513 Turn it into:
2514 nop; nop. */
2516 unsigned int val, type;
2517 bfd_vma roff;
2519 /* First, make sure it's a call *(%rax). */
2520 roff = rel->r_offset;
2521 BFD_ASSERT (roff + 2 <= input_section->size);
2522 type = bfd_get_8 (input_bfd, contents + roff);
2523 BFD_ASSERT (type == 0xff);
2524 val = bfd_get_8 (input_bfd, contents + roff + 1);
2525 BFD_ASSERT (val == 0x10);
2527 /* Now modify the instruction as appropriate. */
2528 bfd_put_8 (output_bfd, 0x90, contents + roff);
2529 bfd_put_8 (output_bfd, 0x90, contents + roff + 1);
2530 continue;
2532 else
2534 unsigned int val, type, reg;
2536 /* IE->LE transition:
2537 Originally it can be one of:
2538 movq foo@gottpoff(%rip), %reg
2539 addq foo@gottpoff(%rip), %reg
2540 We change it into:
2541 movq $foo, %reg
2542 leaq foo(%reg), %reg
2543 addq $foo, %reg. */
2544 BFD_ASSERT (rel->r_offset >= 3);
2545 val = bfd_get_8 (input_bfd, contents + rel->r_offset - 3);
2546 BFD_ASSERT (val == 0x48 || val == 0x4c);
2547 type = bfd_get_8 (input_bfd, contents + rel->r_offset - 2);
2548 BFD_ASSERT (type == 0x8b || type == 0x03);
2549 reg = bfd_get_8 (input_bfd, contents + rel->r_offset - 1);
2550 BFD_ASSERT ((reg & 0xc7) == 5);
2551 reg >>= 3;
2552 BFD_ASSERT (rel->r_offset + 4 <= input_section->size);
2553 if (type == 0x8b)
2555 /* movq */
2556 if (val == 0x4c)
2557 bfd_put_8 (output_bfd, 0x49,
2558 contents + rel->r_offset - 3);
2559 bfd_put_8 (output_bfd, 0xc7,
2560 contents + rel->r_offset - 2);
2561 bfd_put_8 (output_bfd, 0xc0 | reg,
2562 contents + rel->r_offset - 1);
2564 else if (reg == 4)
2566 /* addq -> addq - addressing with %rsp/%r12 is
2567 special */
2568 if (val == 0x4c)
2569 bfd_put_8 (output_bfd, 0x49,
2570 contents + rel->r_offset - 3);
2571 bfd_put_8 (output_bfd, 0x81,
2572 contents + rel->r_offset - 2);
2573 bfd_put_8 (output_bfd, 0xc0 | reg,
2574 contents + rel->r_offset - 1);
2576 else
2578 /* addq -> leaq */
2579 if (val == 0x4c)
2580 bfd_put_8 (output_bfd, 0x4d,
2581 contents + rel->r_offset - 3);
2582 bfd_put_8 (output_bfd, 0x8d,
2583 contents + rel->r_offset - 2);
2584 bfd_put_8 (output_bfd, 0x80 | reg | (reg << 3),
2585 contents + rel->r_offset - 1);
2587 bfd_put_32 (output_bfd, tpoff (info, relocation),
2588 contents + rel->r_offset);
2589 continue;
2593 if (htab->sgot == NULL)
2594 abort ();
2596 if (h != NULL)
2598 off = h->got.offset;
2599 offplt = elf64_x86_64_hash_entry (h)->tlsdesc_got;
2601 else
2603 if (local_got_offsets == NULL)
2604 abort ();
2606 off = local_got_offsets[r_symndx];
2607 offplt = local_tlsdesc_gotents[r_symndx];
2610 if ((off & 1) != 0)
2611 off &= ~1;
2612 else
2614 Elf_Internal_Rela outrel;
2615 bfd_byte *loc;
2616 int dr_type, indx;
2617 asection *sreloc;
2619 if (htab->srelgot == NULL)
2620 abort ();
2622 indx = h && h->dynindx != -1 ? h->dynindx : 0;
2624 if (GOT_TLS_GDESC_P (tls_type))
2626 outrel.r_info = ELF64_R_INFO (indx, R_X86_64_TLSDESC);
2627 BFD_ASSERT (htab->sgotplt_jump_table_size + offplt
2628 + 2 * GOT_ENTRY_SIZE <= htab->sgotplt->size);
2629 outrel.r_offset = (htab->sgotplt->output_section->vma
2630 + htab->sgotplt->output_offset
2631 + offplt
2632 + htab->sgotplt_jump_table_size);
2633 sreloc = htab->srelplt;
2634 loc = sreloc->contents;
2635 loc += sreloc->reloc_count++
2636 * sizeof (Elf64_External_Rela);
2637 BFD_ASSERT (loc + sizeof (Elf64_External_Rela)
2638 <= sreloc->contents + sreloc->size);
2639 if (indx == 0)
2640 outrel.r_addend = relocation - dtpoff_base (info);
2641 else
2642 outrel.r_addend = 0;
2643 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2646 sreloc = htab->srelgot;
2648 outrel.r_offset = (htab->sgot->output_section->vma
2649 + htab->sgot->output_offset + off);
2651 if (GOT_TLS_GD_P (tls_type))
2652 dr_type = R_X86_64_DTPMOD64;
2653 else if (GOT_TLS_GDESC_P (tls_type))
2654 goto dr_done;
2655 else
2656 dr_type = R_X86_64_TPOFF64;
2658 bfd_put_64 (output_bfd, 0, htab->sgot->contents + off);
2659 outrel.r_addend = 0;
2660 if ((dr_type == R_X86_64_TPOFF64
2661 || dr_type == R_X86_64_TLSDESC) && indx == 0)
2662 outrel.r_addend = relocation - dtpoff_base (info);
2663 outrel.r_info = ELF64_R_INFO (indx, dr_type);
2665 loc = sreloc->contents;
2666 loc += sreloc->reloc_count++ * sizeof (Elf64_External_Rela);
2667 BFD_ASSERT (loc + sizeof (Elf64_External_Rela)
2668 <= sreloc->contents + sreloc->size);
2669 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2671 if (GOT_TLS_GD_P (tls_type))
2673 if (indx == 0)
2675 BFD_ASSERT (! unresolved_reloc);
2676 bfd_put_64 (output_bfd,
2677 relocation - dtpoff_base (info),
2678 htab->sgot->contents + off + GOT_ENTRY_SIZE);
2680 else
2682 bfd_put_64 (output_bfd, 0,
2683 htab->sgot->contents + off + GOT_ENTRY_SIZE);
2684 outrel.r_info = ELF64_R_INFO (indx,
2685 R_X86_64_DTPOFF64);
2686 outrel.r_offset += GOT_ENTRY_SIZE;
2687 sreloc->reloc_count++;
2688 loc += sizeof (Elf64_External_Rela);
2689 BFD_ASSERT (loc + sizeof (Elf64_External_Rela)
2690 <= sreloc->contents + sreloc->size);
2691 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2695 dr_done:
2696 if (h != NULL)
2697 h->got.offset |= 1;
2698 else
2699 local_got_offsets[r_symndx] |= 1;
2702 if (off >= (bfd_vma) -2
2703 && ! GOT_TLS_GDESC_P (tls_type))
2704 abort ();
2705 if (r_type == ELF64_R_TYPE (rel->r_info))
2707 if (r_type == R_X86_64_GOTPC32_TLSDESC
2708 || r_type == R_X86_64_TLSDESC_CALL)
2709 relocation = htab->sgotplt->output_section->vma
2710 + htab->sgotplt->output_offset
2711 + offplt + htab->sgotplt_jump_table_size;
2712 else
2713 relocation = htab->sgot->output_section->vma
2714 + htab->sgot->output_offset + off;
2715 unresolved_reloc = FALSE;
2717 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSGD)
2719 unsigned int i;
2720 static unsigned char tlsgd[8]
2721 = { 0x66, 0x48, 0x8d, 0x3d, 0x66, 0x66, 0x48, 0xe8 };
2723 /* GD->IE transition.
2724 .byte 0x66; leaq foo@tlsgd(%rip), %rdi
2725 .word 0x6666; rex64; call __tls_get_addr@plt
2726 Change it into:
2727 movq %fs:0, %rax
2728 addq foo@gottpoff(%rip), %rax */
2729 BFD_ASSERT (rel->r_offset >= 4);
2730 for (i = 0; i < 4; i++)
2731 BFD_ASSERT (bfd_get_8 (input_bfd,
2732 contents + rel->r_offset - 4 + i)
2733 == tlsgd[i]);
2734 BFD_ASSERT (rel->r_offset + 12 <= input_section->size);
2735 for (i = 0; i < 4; i++)
2736 BFD_ASSERT (bfd_get_8 (input_bfd,
2737 contents + rel->r_offset + 4 + i)
2738 == tlsgd[i+4]);
2739 BFD_ASSERT (rel + 1 < relend);
2740 BFD_ASSERT (ELF64_R_TYPE (rel[1].r_info) == R_X86_64_PLT32);
2741 memcpy (contents + rel->r_offset - 4,
2742 "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0",
2743 16);
2745 relocation = (htab->sgot->output_section->vma
2746 + htab->sgot->output_offset + off
2747 - rel->r_offset
2748 - input_section->output_section->vma
2749 - input_section->output_offset
2750 - 12);
2751 bfd_put_32 (output_bfd, relocation,
2752 contents + rel->r_offset + 8);
2753 /* Skip R_X86_64_PLT32. */
2754 rel++;
2755 continue;
2757 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_GOTPC32_TLSDESC)
2759 /* GDesc -> IE transition.
2760 It's originally something like:
2761 leaq x@tlsdesc(%rip), %rax
2763 Change it to:
2764 movq x@gottpoff(%rip), %rax # before nop; nop
2766 Registers other than %rax may be set up here. */
2768 unsigned int val, type, type2;
2769 bfd_vma roff;
2771 /* First, make sure it's a leaq adding rip to a 32-bit
2772 offset into any register, although it's probably
2773 almost always going to be rax. */
2774 roff = rel->r_offset;
2775 BFD_ASSERT (roff >= 3);
2776 type = bfd_get_8 (input_bfd, contents + roff - 3);
2777 BFD_ASSERT ((type & 0xfb) == 0x48);
2778 type2 = bfd_get_8 (input_bfd, contents + roff - 2);
2779 BFD_ASSERT (type2 == 0x8d);
2780 val = bfd_get_8 (input_bfd, contents + roff - 1);
2781 BFD_ASSERT ((val & 0xc7) == 0x05);
2782 BFD_ASSERT (roff + 4 <= input_section->size);
2784 /* Now modify the instruction as appropriate. */
2785 /* To turn a leaq into a movq in the form we use it, it
2786 suffices to change the second byte from 0x8d to
2787 0x8b. */
2788 bfd_put_8 (output_bfd, 0x8b, contents + roff - 2);
2790 bfd_put_32 (output_bfd,
2791 htab->sgot->output_section->vma
2792 + htab->sgot->output_offset + off
2793 - rel->r_offset
2794 - input_section->output_section->vma
2795 - input_section->output_offset
2796 - 4,
2797 contents + roff);
2798 continue;
2800 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSDESC_CALL)
2802 /* GDesc -> IE transition.
2803 It's originally:
2804 call *(%rax)
2806 Change it to:
2807 nop; nop. */
2809 unsigned int val, type;
2810 bfd_vma roff;
2812 /* First, make sure it's a call *(%eax). */
2813 roff = rel->r_offset;
2814 BFD_ASSERT (roff + 2 <= input_section->size);
2815 type = bfd_get_8 (input_bfd, contents + roff);
2816 BFD_ASSERT (type == 0xff);
2817 val = bfd_get_8 (input_bfd, contents + roff + 1);
2818 BFD_ASSERT (val == 0x10);
2820 /* Now modify the instruction as appropriate. */
2821 bfd_put_8 (output_bfd, 0x90, contents + roff);
2822 bfd_put_8 (output_bfd, 0x90, contents + roff + 1);
2824 continue;
2826 else
2827 BFD_ASSERT (FALSE);
2828 break;
2830 case R_X86_64_TLSLD:
2831 if (! info->shared)
2833 /* LD->LE transition:
2834 Ensure it is:
2835 leaq foo@tlsld(%rip), %rdi; call __tls_get_addr@plt.
2836 We change it into:
2837 .word 0x6666; .byte 0x66; movl %fs:0, %rax. */
2838 BFD_ASSERT (rel->r_offset >= 3);
2839 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset - 3)
2840 == 0x48);
2841 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset - 2)
2842 == 0x8d);
2843 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset - 1)
2844 == 0x3d);
2845 BFD_ASSERT (rel->r_offset + 9 <= input_section->size);
2846 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset + 4)
2847 == 0xe8);
2848 BFD_ASSERT (rel + 1 < relend);
2849 BFD_ASSERT (ELF64_R_TYPE (rel[1].r_info) == R_X86_64_PLT32);
2850 memcpy (contents + rel->r_offset - 3,
2851 "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0", 12);
2852 /* Skip R_X86_64_PLT32. */
2853 rel++;
2854 continue;
2857 if (htab->sgot == NULL)
2858 abort ();
2860 off = htab->tls_ld_got.offset;
2861 if (off & 1)
2862 off &= ~1;
2863 else
2865 Elf_Internal_Rela outrel;
2866 bfd_byte *loc;
2868 if (htab->srelgot == NULL)
2869 abort ();
2871 outrel.r_offset = (htab->sgot->output_section->vma
2872 + htab->sgot->output_offset + off);
2874 bfd_put_64 (output_bfd, 0,
2875 htab->sgot->contents + off);
2876 bfd_put_64 (output_bfd, 0,
2877 htab->sgot->contents + off + GOT_ENTRY_SIZE);
2878 outrel.r_info = ELF64_R_INFO (0, R_X86_64_DTPMOD64);
2879 outrel.r_addend = 0;
2880 loc = htab->srelgot->contents;
2881 loc += htab->srelgot->reloc_count++ * sizeof (Elf64_External_Rela);
2882 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2883 htab->tls_ld_got.offset |= 1;
2885 relocation = htab->sgot->output_section->vma
2886 + htab->sgot->output_offset + off;
2887 unresolved_reloc = FALSE;
2888 break;
2890 case R_X86_64_DTPOFF32:
2891 if (info->shared || (input_section->flags & SEC_CODE) == 0)
2892 relocation -= dtpoff_base (info);
2893 else
2894 relocation = tpoff (info, relocation);
2895 break;
2897 case R_X86_64_TPOFF32:
2898 BFD_ASSERT (! info->shared);
2899 relocation = tpoff (info, relocation);
2900 break;
2902 default:
2903 break;
2906 /* Dynamic relocs are not propagated for SEC_DEBUGGING sections
2907 because such sections are not SEC_ALLOC and thus ld.so will
2908 not process them. */
2909 if (unresolved_reloc
2910 && !((input_section->flags & SEC_DEBUGGING) != 0
2911 && h->def_dynamic))
2912 (*_bfd_error_handler)
2913 (_("%B(%A+0x%lx): unresolvable %s relocation against symbol `%s'"),
2914 input_bfd,
2915 input_section,
2916 (long) rel->r_offset,
2917 howto->name,
2918 h->root.root.string);
2920 r = _bfd_final_link_relocate (howto, input_bfd, input_section,
2921 contents, rel->r_offset,
2922 relocation, rel->r_addend);
2924 if (r != bfd_reloc_ok)
2926 const char *name;
2928 if (h != NULL)
2929 name = h->root.root.string;
2930 else
2932 name = bfd_elf_string_from_elf_section (input_bfd,
2933 symtab_hdr->sh_link,
2934 sym->st_name);
2935 if (name == NULL)
2936 return FALSE;
2937 if (*name == '\0')
2938 name = bfd_section_name (input_bfd, sec);
2941 if (r == bfd_reloc_overflow)
2943 if (h != NULL
2944 && h->root.type == bfd_link_hash_undefweak
2945 && howto->pc_relative)
2946 /* Ignore reloc overflow on branches to undefweak syms. */
2947 continue;
2949 if (! ((*info->callbacks->reloc_overflow)
2950 (info, (h ? &h->root : NULL), name, howto->name,
2951 (bfd_vma) 0, input_bfd, input_section,
2952 rel->r_offset)))
2953 return FALSE;
2955 else
2957 (*_bfd_error_handler)
2958 (_("%B(%A+0x%lx): reloc against `%s': error %d"),
2959 input_bfd, input_section,
2960 (long) rel->r_offset, name, (int) r);
2961 return FALSE;
2966 return TRUE;
2969 /* Finish up dynamic symbol handling. We set the contents of various
2970 dynamic sections here. */
2972 static bfd_boolean
2973 elf64_x86_64_finish_dynamic_symbol (bfd *output_bfd,
2974 struct bfd_link_info *info,
2975 struct elf_link_hash_entry *h,
2976 Elf_Internal_Sym *sym)
2978 struct elf64_x86_64_link_hash_table *htab;
2980 htab = elf64_x86_64_hash_table (info);
2982 if (h->plt.offset != (bfd_vma) -1)
2984 bfd_vma plt_index;
2985 bfd_vma got_offset;
2986 Elf_Internal_Rela rela;
2987 bfd_byte *loc;
2989 /* This symbol has an entry in the procedure linkage table. Set
2990 it up. */
2991 if (h->dynindx == -1
2992 || htab->splt == NULL
2993 || htab->sgotplt == NULL
2994 || htab->srelplt == NULL)
2995 abort ();
2997 /* Get the index in the procedure linkage table which
2998 corresponds to this symbol. This is the index of this symbol
2999 in all the symbols for which we are making plt entries. The
3000 first entry in the procedure linkage table is reserved. */
3001 plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1;
3003 /* Get the offset into the .got table of the entry that
3004 corresponds to this function. Each .got entry is GOT_ENTRY_SIZE
3005 bytes. The first three are reserved for the dynamic linker. */
3006 got_offset = (plt_index + 3) * GOT_ENTRY_SIZE;
3008 /* Fill in the entry in the procedure linkage table. */
3009 memcpy (htab->splt->contents + h->plt.offset, elf64_x86_64_plt_entry,
3010 PLT_ENTRY_SIZE);
3012 /* Insert the relocation positions of the plt section. The magic
3013 numbers at the end of the statements are the positions of the
3014 relocations in the plt section. */
3015 /* Put offset for jmp *name@GOTPCREL(%rip), since the
3016 instruction uses 6 bytes, subtract this value. */
3017 bfd_put_32 (output_bfd,
3018 (htab->sgotplt->output_section->vma
3019 + htab->sgotplt->output_offset
3020 + got_offset
3021 - htab->splt->output_section->vma
3022 - htab->splt->output_offset
3023 - h->plt.offset
3024 - 6),
3025 htab->splt->contents + h->plt.offset + 2);
3026 /* Put relocation index. */
3027 bfd_put_32 (output_bfd, plt_index,
3028 htab->splt->contents + h->plt.offset + 7);
3029 /* Put offset for jmp .PLT0. */
3030 bfd_put_32 (output_bfd, - (h->plt.offset + PLT_ENTRY_SIZE),
3031 htab->splt->contents + h->plt.offset + 12);
3033 /* Fill in the entry in the global offset table, initially this
3034 points to the pushq instruction in the PLT which is at offset 6. */
3035 bfd_put_64 (output_bfd, (htab->splt->output_section->vma
3036 + htab->splt->output_offset
3037 + h->plt.offset + 6),
3038 htab->sgotplt->contents + got_offset);
3040 /* Fill in the entry in the .rela.plt section. */
3041 rela.r_offset = (htab->sgotplt->output_section->vma
3042 + htab->sgotplt->output_offset
3043 + got_offset);
3044 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_JUMP_SLOT);
3045 rela.r_addend = 0;
3046 loc = htab->srelplt->contents + plt_index * sizeof (Elf64_External_Rela);
3047 bfd_elf64_swap_reloca_out (output_bfd, &rela, loc);
3049 if (!h->def_regular)
3051 /* Mark the symbol as undefined, rather than as defined in
3052 the .plt section. Leave the value if there were any
3053 relocations where pointer equality matters (this is a clue
3054 for the dynamic linker, to make function pointer
3055 comparisons work between an application and shared
3056 library), otherwise set it to zero. If a function is only
3057 called from a binary, there is no need to slow down
3058 shared libraries because of that. */
3059 sym->st_shndx = SHN_UNDEF;
3060 if (!h->pointer_equality_needed)
3061 sym->st_value = 0;
3065 if (h->got.offset != (bfd_vma) -1
3066 && ! GOT_TLS_GD_ANY_P (elf64_x86_64_hash_entry (h)->tls_type)
3067 && elf64_x86_64_hash_entry (h)->tls_type != GOT_TLS_IE)
3069 Elf_Internal_Rela rela;
3070 bfd_byte *loc;
3072 /* This symbol has an entry in the global offset table. Set it
3073 up. */
3074 if (htab->sgot == NULL || htab->srelgot == NULL)
3075 abort ();
3077 rela.r_offset = (htab->sgot->output_section->vma
3078 + htab->sgot->output_offset
3079 + (h->got.offset &~ (bfd_vma) 1));
3081 /* If this is a static link, or it is a -Bsymbolic link and the
3082 symbol is defined locally or was forced to be local because
3083 of a version file, we just want to emit a RELATIVE reloc.
3084 The entry in the global offset table will already have been
3085 initialized in the relocate_section function. */
3086 if (info->shared
3087 && SYMBOL_REFERENCES_LOCAL (info, h))
3089 BFD_ASSERT((h->got.offset & 1) != 0);
3090 rela.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE);
3091 rela.r_addend = (h->root.u.def.value
3092 + h->root.u.def.section->output_section->vma
3093 + h->root.u.def.section->output_offset);
3095 else
3097 BFD_ASSERT((h->got.offset & 1) == 0);
3098 bfd_put_64 (output_bfd, (bfd_vma) 0,
3099 htab->sgot->contents + h->got.offset);
3100 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_GLOB_DAT);
3101 rela.r_addend = 0;
3104 loc = htab->srelgot->contents;
3105 loc += htab->srelgot->reloc_count++ * sizeof (Elf64_External_Rela);
3106 bfd_elf64_swap_reloca_out (output_bfd, &rela, loc);
3109 if (h->needs_copy)
3111 Elf_Internal_Rela rela;
3112 bfd_byte *loc;
3114 /* This symbol needs a copy reloc. Set it up. */
3116 if (h->dynindx == -1
3117 || (h->root.type != bfd_link_hash_defined
3118 && h->root.type != bfd_link_hash_defweak)
3119 || htab->srelbss == NULL)
3120 abort ();
3122 rela.r_offset = (h->root.u.def.value
3123 + h->root.u.def.section->output_section->vma
3124 + h->root.u.def.section->output_offset);
3125 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_COPY);
3126 rela.r_addend = 0;
3127 loc = htab->srelbss->contents;
3128 loc += htab->srelbss->reloc_count++ * sizeof (Elf64_External_Rela);
3129 bfd_elf64_swap_reloca_out (output_bfd, &rela, loc);
3132 /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */
3133 if (strcmp (h->root.root.string, "_DYNAMIC") == 0
3134 || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0)
3135 sym->st_shndx = SHN_ABS;
3137 return TRUE;
3140 /* Used to decide how to sort relocs in an optimal manner for the
3141 dynamic linker, before writing them out. */
3143 static enum elf_reloc_type_class
3144 elf64_x86_64_reloc_type_class (const Elf_Internal_Rela *rela)
3146 switch ((int) ELF64_R_TYPE (rela->r_info))
3148 case R_X86_64_RELATIVE:
3149 return reloc_class_relative;
3150 case R_X86_64_JUMP_SLOT:
3151 return reloc_class_plt;
3152 case R_X86_64_COPY:
3153 return reloc_class_copy;
3154 default:
3155 return reloc_class_normal;
3159 /* Finish up the dynamic sections. */
3161 static bfd_boolean
3162 elf64_x86_64_finish_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info)
3164 struct elf64_x86_64_link_hash_table *htab;
3165 bfd *dynobj;
3166 asection *sdyn;
3168 htab = elf64_x86_64_hash_table (info);
3169 dynobj = htab->elf.dynobj;
3170 sdyn = bfd_get_section_by_name (dynobj, ".dynamic");
3172 if (htab->elf.dynamic_sections_created)
3174 Elf64_External_Dyn *dyncon, *dynconend;
3176 if (sdyn == NULL || htab->sgot == NULL)
3177 abort ();
3179 dyncon = (Elf64_External_Dyn *) sdyn->contents;
3180 dynconend = (Elf64_External_Dyn *) (sdyn->contents + sdyn->size);
3181 for (; dyncon < dynconend; dyncon++)
3183 Elf_Internal_Dyn dyn;
3184 asection *s;
3186 bfd_elf64_swap_dyn_in (dynobj, dyncon, &dyn);
3188 switch (dyn.d_tag)
3190 default:
3191 continue;
3193 case DT_PLTGOT:
3194 s = htab->sgotplt;
3195 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
3196 break;
3198 case DT_JMPREL:
3199 dyn.d_un.d_ptr = htab->srelplt->output_section->vma;
3200 break;
3202 case DT_PLTRELSZ:
3203 s = htab->srelplt->output_section;
3204 dyn.d_un.d_val = s->size;
3205 break;
3207 case DT_RELASZ:
3208 /* The procedure linkage table relocs (DT_JMPREL) should
3209 not be included in the overall relocs (DT_RELA).
3210 Therefore, we override the DT_RELASZ entry here to
3211 make it not include the JMPREL relocs. Since the
3212 linker script arranges for .rela.plt to follow all
3213 other relocation sections, we don't have to worry
3214 about changing the DT_RELA entry. */
3215 if (htab->srelplt != NULL)
3217 s = htab->srelplt->output_section;
3218 dyn.d_un.d_val -= s->size;
3220 break;
3222 case DT_TLSDESC_PLT:
3223 s = htab->splt;
3224 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset
3225 + htab->tlsdesc_plt;
3226 break;
3228 case DT_TLSDESC_GOT:
3229 s = htab->sgot;
3230 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset
3231 + htab->tlsdesc_got;
3232 break;
3235 bfd_elf64_swap_dyn_out (output_bfd, &dyn, dyncon);
3238 /* Fill in the special first entry in the procedure linkage table. */
3239 if (htab->splt && htab->splt->size > 0)
3241 /* Fill in the first entry in the procedure linkage table. */
3242 memcpy (htab->splt->contents, elf64_x86_64_plt0_entry,
3243 PLT_ENTRY_SIZE);
3244 /* Add offset for pushq GOT+8(%rip), since the instruction
3245 uses 6 bytes subtract this value. */
3246 bfd_put_32 (output_bfd,
3247 (htab->sgotplt->output_section->vma
3248 + htab->sgotplt->output_offset
3250 - htab->splt->output_section->vma
3251 - htab->splt->output_offset
3252 - 6),
3253 htab->splt->contents + 2);
3254 /* Add offset for jmp *GOT+16(%rip). The 12 is the offset to
3255 the end of the instruction. */
3256 bfd_put_32 (output_bfd,
3257 (htab->sgotplt->output_section->vma
3258 + htab->sgotplt->output_offset
3259 + 16
3260 - htab->splt->output_section->vma
3261 - htab->splt->output_offset
3262 - 12),
3263 htab->splt->contents + 8);
3265 elf_section_data (htab->splt->output_section)->this_hdr.sh_entsize =
3266 PLT_ENTRY_SIZE;
3268 if (htab->tlsdesc_plt)
3270 bfd_put_64 (output_bfd, (bfd_vma) 0,
3271 htab->sgot->contents + htab->tlsdesc_got);
3273 memcpy (htab->splt->contents + htab->tlsdesc_plt,
3274 elf64_x86_64_plt0_entry,
3275 PLT_ENTRY_SIZE);
3277 /* Add offset for pushq GOT+8(%rip), since the
3278 instruction uses 6 bytes subtract this value. */
3279 bfd_put_32 (output_bfd,
3280 (htab->sgotplt->output_section->vma
3281 + htab->sgotplt->output_offset
3283 - htab->splt->output_section->vma
3284 - htab->splt->output_offset
3285 - htab->tlsdesc_plt
3286 - 6),
3287 htab->splt->contents + htab->tlsdesc_plt + 2);
3288 /* Add offset for jmp *GOT+TDG(%rip), where TGD stands for
3289 htab->tlsdesc_got. The 12 is the offset to the end of
3290 the instruction. */
3291 bfd_put_32 (output_bfd,
3292 (htab->sgot->output_section->vma
3293 + htab->sgot->output_offset
3294 + htab->tlsdesc_got
3295 - htab->splt->output_section->vma
3296 - htab->splt->output_offset
3297 - htab->tlsdesc_plt
3298 - 12),
3299 htab->splt->contents + htab->tlsdesc_plt + 8);
3304 if (htab->sgotplt)
3306 /* Fill in the first three entries in the global offset table. */
3307 if (htab->sgotplt->size > 0)
3309 /* Set the first entry in the global offset table to the address of
3310 the dynamic section. */
3311 if (sdyn == NULL)
3312 bfd_put_64 (output_bfd, (bfd_vma) 0, htab->sgotplt->contents);
3313 else
3314 bfd_put_64 (output_bfd,
3315 sdyn->output_section->vma + sdyn->output_offset,
3316 htab->sgotplt->contents);
3317 /* Write GOT[1] and GOT[2], needed for the dynamic linker. */
3318 bfd_put_64 (output_bfd, (bfd_vma) 0, htab->sgotplt->contents + GOT_ENTRY_SIZE);
3319 bfd_put_64 (output_bfd, (bfd_vma) 0, htab->sgotplt->contents + GOT_ENTRY_SIZE*2);
3322 elf_section_data (htab->sgotplt->output_section)->this_hdr.sh_entsize =
3323 GOT_ENTRY_SIZE;
3326 if (htab->sgot && htab->sgot->size > 0)
3327 elf_section_data (htab->sgot->output_section)->this_hdr.sh_entsize
3328 = GOT_ENTRY_SIZE;
3330 return TRUE;
3333 /* Return address for Ith PLT stub in section PLT, for relocation REL
3334 or (bfd_vma) -1 if it should not be included. */
3336 static bfd_vma
3337 elf64_x86_64_plt_sym_val (bfd_vma i, const asection *plt,
3338 const arelent *rel ATTRIBUTE_UNUSED)
3340 return plt->vma + (i + 1) * PLT_ENTRY_SIZE;
3343 /* Handle an x86-64 specific section when reading an object file. This
3344 is called when elfcode.h finds a section with an unknown type. */
3346 static bfd_boolean
3347 elf64_x86_64_section_from_shdr (bfd *abfd,
3348 Elf_Internal_Shdr *hdr,
3349 const char *name,
3350 int shindex)
3352 if (hdr->sh_type != SHT_X86_64_UNWIND)
3353 return FALSE;
3355 if (! _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex))
3356 return FALSE;
3358 return TRUE;
3361 /* Hook called by the linker routine which adds symbols from an object
3362 file. We use it to put SHN_X86_64_LCOMMON items in .lbss, instead
3363 of .bss. */
3365 static bfd_boolean
3366 elf64_x86_64_add_symbol_hook (bfd *abfd,
3367 struct bfd_link_info *info ATTRIBUTE_UNUSED,
3368 Elf_Internal_Sym *sym,
3369 const char **namep ATTRIBUTE_UNUSED,
3370 flagword *flagsp ATTRIBUTE_UNUSED,
3371 asection **secp, bfd_vma *valp)
3373 asection *lcomm;
3375 switch (sym->st_shndx)
3377 case SHN_X86_64_LCOMMON:
3378 lcomm = bfd_get_section_by_name (abfd, "LARGE_COMMON");
3379 if (lcomm == NULL)
3381 lcomm = bfd_make_section_with_flags (abfd,
3382 "LARGE_COMMON",
3383 (SEC_ALLOC
3384 | SEC_IS_COMMON
3385 | SEC_LINKER_CREATED));
3386 if (lcomm == NULL)
3387 return FALSE;
3388 elf_section_flags (lcomm) |= SHF_X86_64_LARGE;
3390 *secp = lcomm;
3391 *valp = sym->st_size;
3392 break;
3394 return TRUE;
3398 /* Given a BFD section, try to locate the corresponding ELF section
3399 index. */
3401 static bfd_boolean
3402 elf64_x86_64_elf_section_from_bfd_section (bfd *abfd ATTRIBUTE_UNUSED,
3403 asection *sec, int *index)
3405 if (sec == &_bfd_elf_large_com_section)
3407 *index = SHN_X86_64_LCOMMON;
3408 return TRUE;
3410 return FALSE;
3413 /* Process a symbol. */
3415 static void
3416 elf64_x86_64_symbol_processing (bfd *abfd ATTRIBUTE_UNUSED,
3417 asymbol *asym)
3419 elf_symbol_type *elfsym = (elf_symbol_type *) asym;
3421 switch (elfsym->internal_elf_sym.st_shndx)
3423 case SHN_X86_64_LCOMMON:
3424 asym->section = &_bfd_elf_large_com_section;
3425 asym->value = elfsym->internal_elf_sym.st_size;
3426 /* Common symbol doesn't set BSF_GLOBAL. */
3427 asym->flags &= ~BSF_GLOBAL;
3428 break;
3432 static bfd_boolean
3433 elf64_x86_64_common_definition (Elf_Internal_Sym *sym)
3435 return (sym->st_shndx == SHN_COMMON
3436 || sym->st_shndx == SHN_X86_64_LCOMMON);
3439 static unsigned int
3440 elf64_x86_64_common_section_index (asection *sec)
3442 if ((elf_section_flags (sec) & SHF_X86_64_LARGE) == 0)
3443 return SHN_COMMON;
3444 else
3445 return SHN_X86_64_LCOMMON;
3448 static asection *
3449 elf64_x86_64_common_section (asection *sec)
3451 if ((elf_section_flags (sec) & SHF_X86_64_LARGE) == 0)
3452 return bfd_com_section_ptr;
3453 else
3454 return &_bfd_elf_large_com_section;
3457 static bfd_boolean
3458 elf64_x86_64_merge_symbol (struct bfd_link_info *info ATTRIBUTE_UNUSED,
3459 struct elf_link_hash_entry **sym_hash ATTRIBUTE_UNUSED,
3460 struct elf_link_hash_entry *h,
3461 Elf_Internal_Sym *sym,
3462 asection **psec,
3463 bfd_vma *pvalue ATTRIBUTE_UNUSED,
3464 unsigned int *pold_alignment ATTRIBUTE_UNUSED,
3465 bfd_boolean *skip ATTRIBUTE_UNUSED,
3466 bfd_boolean *override ATTRIBUTE_UNUSED,
3467 bfd_boolean *type_change_ok ATTRIBUTE_UNUSED,
3468 bfd_boolean *size_change_ok ATTRIBUTE_UNUSED,
3469 bfd_boolean *newdef ATTRIBUTE_UNUSED,
3470 bfd_boolean *newdyn,
3471 bfd_boolean *newdyncommon ATTRIBUTE_UNUSED,
3472 bfd_boolean *newweak ATTRIBUTE_UNUSED,
3473 bfd *abfd ATTRIBUTE_UNUSED,
3474 asection **sec,
3475 bfd_boolean *olddef ATTRIBUTE_UNUSED,
3476 bfd_boolean *olddyn,
3477 bfd_boolean *olddyncommon ATTRIBUTE_UNUSED,
3478 bfd_boolean *oldweak ATTRIBUTE_UNUSED,
3479 bfd *oldbfd,
3480 asection **oldsec)
3482 /* A normal common symbol and a large common symbol result in a
3483 normal common symbol. We turn the large common symbol into a
3484 normal one. */
3485 if (!*olddyn
3486 && h->root.type == bfd_link_hash_common
3487 && !*newdyn
3488 && bfd_is_com_section (*sec)
3489 && *oldsec != *sec)
3491 if (sym->st_shndx == SHN_COMMON
3492 && (elf_section_flags (*oldsec) & SHF_X86_64_LARGE) != 0)
3494 h->root.u.c.p->section
3495 = bfd_make_section_old_way (oldbfd, "COMMON");
3496 h->root.u.c.p->section->flags = SEC_ALLOC;
3498 else if (sym->st_shndx == SHN_X86_64_LCOMMON
3499 && (elf_section_flags (*oldsec) & SHF_X86_64_LARGE) == 0)
3500 *psec = *sec = bfd_com_section_ptr;
3503 return TRUE;
3506 static int
3507 elf64_x86_64_additional_program_headers (bfd *abfd)
3509 asection *s;
3510 int count = 0;
3512 /* Check to see if we need a large readonly segment. */
3513 s = bfd_get_section_by_name (abfd, ".lrodata");
3514 if (s && (s->flags & SEC_LOAD))
3515 count++;
3517 /* Check to see if we need a large data segment. Since .lbss sections
3518 is placed right after the .bss section, there should be no need for
3519 a large data segment just because of .lbss. */
3520 s = bfd_get_section_by_name (abfd, ".ldata");
3521 if (s && (s->flags & SEC_LOAD))
3522 count++;
3524 return count;
3527 static const struct bfd_elf_special_section
3528 elf64_x86_64_special_sections[]=
3530 { ".gnu.linkonce.lb", 16, -2, SHT_NOBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE},
3531 { ".gnu.linkonce.lr", 16, -2, SHT_PROGBITS, SHF_ALLOC + SHF_X86_64_LARGE},
3532 { ".gnu.linkonce.lt", 16, -2, SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR + SHF_X86_64_LARGE},
3533 { ".lbss", 5, -2, SHT_NOBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE},
3534 { ".ldata", 6, -2, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE},
3535 { ".lrodata", 8, -2, SHT_PROGBITS, SHF_ALLOC + SHF_X86_64_LARGE},
3536 { NULL, 0, 0, 0, 0 }
3539 #define TARGET_LITTLE_SYM bfd_elf64_x86_64_vec
3540 #define TARGET_LITTLE_NAME "elf64-x86-64"
3541 #define ELF_ARCH bfd_arch_i386
3542 #define ELF_MACHINE_CODE EM_X86_64
3543 #define ELF_MAXPAGESIZE 0x100000
3545 #define elf_backend_can_gc_sections 1
3546 #define elf_backend_can_refcount 1
3547 #define elf_backend_want_got_plt 1
3548 #define elf_backend_plt_readonly 1
3549 #define elf_backend_want_plt_sym 0
3550 #define elf_backend_got_header_size (GOT_ENTRY_SIZE*3)
3551 #define elf_backend_rela_normal 1
3553 #define elf_info_to_howto elf64_x86_64_info_to_howto
3555 #define bfd_elf64_bfd_link_hash_table_create \
3556 elf64_x86_64_link_hash_table_create
3557 #define bfd_elf64_bfd_reloc_type_lookup elf64_x86_64_reloc_type_lookup
3559 #define elf_backend_adjust_dynamic_symbol elf64_x86_64_adjust_dynamic_symbol
3560 #define elf_backend_check_relocs elf64_x86_64_check_relocs
3561 #define elf_backend_copy_indirect_symbol elf64_x86_64_copy_indirect_symbol
3562 #define elf_backend_create_dynamic_sections elf64_x86_64_create_dynamic_sections
3563 #define elf_backend_finish_dynamic_sections elf64_x86_64_finish_dynamic_sections
3564 #define elf_backend_finish_dynamic_symbol elf64_x86_64_finish_dynamic_symbol
3565 #define elf_backend_gc_mark_hook elf64_x86_64_gc_mark_hook
3566 #define elf_backend_gc_sweep_hook elf64_x86_64_gc_sweep_hook
3567 #define elf_backend_grok_prstatus elf64_x86_64_grok_prstatus
3568 #define elf_backend_grok_psinfo elf64_x86_64_grok_psinfo
3569 #define elf_backend_reloc_type_class elf64_x86_64_reloc_type_class
3570 #define elf_backend_relocate_section elf64_x86_64_relocate_section
3571 #define elf_backend_size_dynamic_sections elf64_x86_64_size_dynamic_sections
3572 #define elf_backend_always_size_sections elf64_x86_64_always_size_sections
3573 #define elf_backend_plt_sym_val elf64_x86_64_plt_sym_val
3574 #define elf_backend_object_p elf64_x86_64_elf_object_p
3575 #define bfd_elf64_mkobject elf64_x86_64_mkobject
3577 #define elf_backend_section_from_shdr \
3578 elf64_x86_64_section_from_shdr
3580 #define elf_backend_section_from_bfd_section \
3581 elf64_x86_64_elf_section_from_bfd_section
3582 #define elf_backend_add_symbol_hook \
3583 elf64_x86_64_add_symbol_hook
3584 #define elf_backend_symbol_processing \
3585 elf64_x86_64_symbol_processing
3586 #define elf_backend_common_section_index \
3587 elf64_x86_64_common_section_index
3588 #define elf_backend_common_section \
3589 elf64_x86_64_common_section
3590 #define elf_backend_common_definition \
3591 elf64_x86_64_common_definition
3592 #define elf_backend_merge_symbol \
3593 elf64_x86_64_merge_symbol
3594 #define elf_backend_special_sections \
3595 elf64_x86_64_special_sections
3596 #define elf_backend_additional_program_headers \
3597 elf64_x86_64_additional_program_headers
3599 #include "elf64-target.h"