bfd/
[binutils.git] / bfd / elf64-x86-64.c
blobb6c973f6dbc8bff6acabd1fc49b8cc4c6f9bd0c9
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, rightshift, size, bitsize, pc_relative, bitpos, complain_on_overflow,
35 special_function, name, partial_inplace, src_mask, dst_mask, 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 HOWTO(R_X86_64_GOT64, 0, 4, 64, FALSE, 0, complain_overflow_signed,
116 bfd_elf_generic_reloc, "R_X86_64_GOT64", FALSE, MINUS_ONE, MINUS_ONE,
117 FALSE),
118 HOWTO(R_X86_64_GOTPCREL64, 0, 4, 64, TRUE, 0, complain_overflow_signed,
119 bfd_elf_generic_reloc, "R_X86_64_GOTPCREL64", FALSE, MINUS_ONE,
120 MINUS_ONE, TRUE),
121 HOWTO(R_X86_64_GOTPC64, 0, 4, 64, TRUE, 0, complain_overflow_signed,
122 bfd_elf_generic_reloc, "R_X86_64_GOTPC64",
123 FALSE, MINUS_ONE, MINUS_ONE, TRUE),
124 HOWTO(R_X86_64_GOTPLT64, 0, 4, 64, FALSE, 0, complain_overflow_signed,
125 bfd_elf_generic_reloc, "R_X86_64_GOTPLT64", FALSE, MINUS_ONE,
126 MINUS_ONE, FALSE),
127 HOWTO(R_X86_64_PLTOFF64, 0, 4, 64, FALSE, 0, complain_overflow_signed,
128 bfd_elf_generic_reloc, "R_X86_64_PLTOFF64", FALSE, MINUS_ONE,
129 MINUS_ONE, FALSE),
130 EMPTY_HOWTO (32),
131 EMPTY_HOWTO (33),
132 HOWTO(R_X86_64_GOTPC32_TLSDESC, 0, 2, 32, TRUE, 0,
133 complain_overflow_bitfield, bfd_elf_generic_reloc,
134 "R_X86_64_GOTPC32_TLSDESC",
135 FALSE, 0xffffffff, 0xffffffff, TRUE),
136 HOWTO(R_X86_64_TLSDESC_CALL, 0, 0, 0, FALSE, 0,
137 complain_overflow_dont, bfd_elf_generic_reloc,
138 "R_X86_64_TLSDESC_CALL",
139 FALSE, 0, 0, FALSE),
140 HOWTO(R_X86_64_TLSDESC, 0, 4, 64, FALSE, 0,
141 complain_overflow_bitfield, bfd_elf_generic_reloc,
142 "R_X86_64_TLSDESC",
143 FALSE, MINUS_ONE, MINUS_ONE, FALSE),
145 /* We have a gap in the reloc numbers here.
146 R_X86_64_standard counts the number up to this point, and
147 R_X86_64_vt_offset is the value to subtract from a reloc type of
148 R_X86_64_GNU_VT* to form an index into this table. */
149 #define R_X86_64_standard (R_X86_64_TLSDESC + 1)
150 #define R_X86_64_vt_offset (R_X86_64_GNU_VTINHERIT - R_X86_64_standard)
152 /* GNU extension to record C++ vtable hierarchy. */
153 HOWTO (R_X86_64_GNU_VTINHERIT, 0, 4, 0, FALSE, 0, complain_overflow_dont,
154 NULL, "R_X86_64_GNU_VTINHERIT", FALSE, 0, 0, FALSE),
156 /* GNU extension to record C++ vtable member usage. */
157 HOWTO (R_X86_64_GNU_VTENTRY, 0, 4, 0, FALSE, 0, complain_overflow_dont,
158 _bfd_elf_rel_vtable_reloc_fn, "R_X86_64_GNU_VTENTRY", FALSE, 0, 0,
159 FALSE)
162 /* Map BFD relocs to the x86_64 elf relocs. */
163 struct elf_reloc_map
165 bfd_reloc_code_real_type bfd_reloc_val;
166 unsigned char elf_reloc_val;
169 static const struct elf_reloc_map x86_64_reloc_map[] =
171 { BFD_RELOC_NONE, R_X86_64_NONE, },
172 { BFD_RELOC_64, R_X86_64_64, },
173 { BFD_RELOC_32_PCREL, R_X86_64_PC32, },
174 { BFD_RELOC_X86_64_GOT32, R_X86_64_GOT32,},
175 { BFD_RELOC_X86_64_PLT32, R_X86_64_PLT32,},
176 { BFD_RELOC_X86_64_COPY, R_X86_64_COPY, },
177 { BFD_RELOC_X86_64_GLOB_DAT, R_X86_64_GLOB_DAT, },
178 { BFD_RELOC_X86_64_JUMP_SLOT, R_X86_64_JUMP_SLOT, },
179 { BFD_RELOC_X86_64_RELATIVE, R_X86_64_RELATIVE, },
180 { BFD_RELOC_X86_64_GOTPCREL, R_X86_64_GOTPCREL, },
181 { BFD_RELOC_32, R_X86_64_32, },
182 { BFD_RELOC_X86_64_32S, R_X86_64_32S, },
183 { BFD_RELOC_16, R_X86_64_16, },
184 { BFD_RELOC_16_PCREL, R_X86_64_PC16, },
185 { BFD_RELOC_8, R_X86_64_8, },
186 { BFD_RELOC_8_PCREL, R_X86_64_PC8, },
187 { BFD_RELOC_X86_64_DTPMOD64, R_X86_64_DTPMOD64, },
188 { BFD_RELOC_X86_64_DTPOFF64, R_X86_64_DTPOFF64, },
189 { BFD_RELOC_X86_64_TPOFF64, R_X86_64_TPOFF64, },
190 { BFD_RELOC_X86_64_TLSGD, R_X86_64_TLSGD, },
191 { BFD_RELOC_X86_64_TLSLD, R_X86_64_TLSLD, },
192 { BFD_RELOC_X86_64_DTPOFF32, R_X86_64_DTPOFF32, },
193 { BFD_RELOC_X86_64_GOTTPOFF, R_X86_64_GOTTPOFF, },
194 { BFD_RELOC_X86_64_TPOFF32, R_X86_64_TPOFF32, },
195 { BFD_RELOC_64_PCREL, R_X86_64_PC64, },
196 { BFD_RELOC_X86_64_GOTOFF64, R_X86_64_GOTOFF64, },
197 { BFD_RELOC_X86_64_GOTPC32, R_X86_64_GOTPC32, },
198 { BFD_RELOC_X86_64_GOT64, R_X86_64_GOT64, },
199 { BFD_RELOC_X86_64_GOTPCREL64,R_X86_64_GOTPCREL64, },
200 { BFD_RELOC_X86_64_GOTPC64, R_X86_64_GOTPC64, },
201 { BFD_RELOC_X86_64_GOTPLT64, R_X86_64_GOTPLT64, },
202 { BFD_RELOC_X86_64_PLTOFF64, R_X86_64_PLTOFF64, },
203 { BFD_RELOC_X86_64_GOTPC32_TLSDESC, R_X86_64_GOTPC32_TLSDESC, },
204 { BFD_RELOC_X86_64_TLSDESC_CALL, R_X86_64_TLSDESC_CALL, },
205 { BFD_RELOC_X86_64_TLSDESC, R_X86_64_TLSDESC, },
206 { BFD_RELOC_VTABLE_INHERIT, R_X86_64_GNU_VTINHERIT, },
207 { BFD_RELOC_VTABLE_ENTRY, R_X86_64_GNU_VTENTRY, },
210 static reloc_howto_type *
211 elf64_x86_64_rtype_to_howto (bfd *abfd, unsigned r_type)
213 unsigned i;
215 if (r_type < (unsigned int) R_X86_64_GNU_VTINHERIT
216 || r_type >= (unsigned int) R_X86_64_max)
218 if (r_type >= (unsigned int) R_X86_64_standard)
220 (*_bfd_error_handler) (_("%B: invalid relocation type %d"),
221 abfd, (int) r_type);
222 r_type = R_X86_64_NONE;
224 i = r_type;
226 else
227 i = r_type - (unsigned int) R_X86_64_vt_offset;
228 BFD_ASSERT (x86_64_elf_howto_table[i].type == r_type);
229 return &x86_64_elf_howto_table[i];
232 /* Given a BFD reloc type, return a HOWTO structure. */
233 static reloc_howto_type *
234 elf64_x86_64_reloc_type_lookup (bfd *abfd,
235 bfd_reloc_code_real_type code)
237 unsigned int i;
239 for (i = 0; i < sizeof (x86_64_reloc_map) / sizeof (struct elf_reloc_map);
240 i++)
242 if (x86_64_reloc_map[i].bfd_reloc_val == code)
243 return elf64_x86_64_rtype_to_howto (abfd,
244 x86_64_reloc_map[i].elf_reloc_val);
246 return 0;
249 /* Given an x86_64 ELF reloc type, fill in an arelent structure. */
251 static void
252 elf64_x86_64_info_to_howto (bfd *abfd ATTRIBUTE_UNUSED, arelent *cache_ptr,
253 Elf_Internal_Rela *dst)
255 unsigned r_type;
257 r_type = ELF64_R_TYPE (dst->r_info);
258 cache_ptr->howto = elf64_x86_64_rtype_to_howto (abfd, r_type);
259 BFD_ASSERT (r_type == cache_ptr->howto->type);
262 /* Support for core dump NOTE sections. */
263 static bfd_boolean
264 elf64_x86_64_grok_prstatus (bfd *abfd, Elf_Internal_Note *note)
266 int offset;
267 size_t size;
269 switch (note->descsz)
271 default:
272 return FALSE;
274 case 336: /* sizeof(istruct elf_prstatus) on Linux/x86_64 */
275 /* pr_cursig */
276 elf_tdata (abfd)->core_signal
277 = bfd_get_16 (abfd, note->descdata + 12);
279 /* pr_pid */
280 elf_tdata (abfd)->core_pid
281 = bfd_get_32 (abfd, note->descdata + 32);
283 /* pr_reg */
284 offset = 112;
285 size = 216;
287 break;
290 /* Make a ".reg/999" section. */
291 return _bfd_elfcore_make_pseudosection (abfd, ".reg",
292 size, note->descpos + offset);
295 static bfd_boolean
296 elf64_x86_64_grok_psinfo (bfd *abfd, Elf_Internal_Note *note)
298 switch (note->descsz)
300 default:
301 return FALSE;
303 case 136: /* sizeof(struct elf_prpsinfo) on Linux/x86_64 */
304 elf_tdata (abfd)->core_program
305 = _bfd_elfcore_strndup (abfd, note->descdata + 40, 16);
306 elf_tdata (abfd)->core_command
307 = _bfd_elfcore_strndup (abfd, note->descdata + 56, 80);
310 /* Note that for some reason, a spurious space is tacked
311 onto the end of the args in some (at least one anyway)
312 implementations, so strip it off if it exists. */
315 char *command = elf_tdata (abfd)->core_command;
316 int n = strlen (command);
318 if (0 < n && command[n - 1] == ' ')
319 command[n - 1] = '\0';
322 return TRUE;
325 /* Functions for the x86-64 ELF linker. */
327 /* The name of the dynamic interpreter. This is put in the .interp
328 section. */
330 #define ELF_DYNAMIC_INTERPRETER "/lib/ld64.so.1"
332 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
333 copying dynamic variables from a shared lib into an app's dynbss
334 section, and instead use a dynamic relocation to point into the
335 shared lib. */
336 #define ELIMINATE_COPY_RELOCS 1
338 /* The size in bytes of an entry in the global offset table. */
340 #define GOT_ENTRY_SIZE 8
342 /* The size in bytes of an entry in the procedure linkage table. */
344 #define PLT_ENTRY_SIZE 16
346 /* The first entry in a procedure linkage table looks like this. See the
347 SVR4 ABI i386 supplement and the x86-64 ABI to see how this works. */
349 static const bfd_byte elf64_x86_64_plt0_entry[PLT_ENTRY_SIZE] =
351 0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */
352 0xff, 0x25, 16, 0, 0, 0, /* jmpq *GOT+16(%rip) */
353 0x0f, 0x1f, 0x40, 0x00 /* nopl 0(%rax) */
356 /* Subsequent entries in a procedure linkage table look like this. */
358 static const bfd_byte elf64_x86_64_plt_entry[PLT_ENTRY_SIZE] =
360 0xff, 0x25, /* jmpq *name@GOTPC(%rip) */
361 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */
362 0x68, /* pushq immediate */
363 0, 0, 0, 0, /* replaced with index into relocation table. */
364 0xe9, /* jmp relative */
365 0, 0, 0, 0 /* replaced with offset to start of .plt0. */
368 /* The x86-64 linker needs to keep track of the number of relocs that
369 it decides to copy as dynamic relocs in check_relocs for each symbol.
370 This is so that it can later discard them if they are found to be
371 unnecessary. We store the information in a field extending the
372 regular ELF linker hash table. */
374 struct elf64_x86_64_dyn_relocs
376 /* Next section. */
377 struct elf64_x86_64_dyn_relocs *next;
379 /* The input section of the reloc. */
380 asection *sec;
382 /* Total number of relocs copied for the input section. */
383 bfd_size_type count;
385 /* Number of pc-relative relocs copied for the input section. */
386 bfd_size_type pc_count;
389 /* x86-64 ELF linker hash entry. */
391 struct elf64_x86_64_link_hash_entry
393 struct elf_link_hash_entry elf;
395 /* Track dynamic relocs copied for this symbol. */
396 struct elf64_x86_64_dyn_relocs *dyn_relocs;
398 #define GOT_UNKNOWN 0
399 #define GOT_NORMAL 1
400 #define GOT_TLS_GD 2
401 #define GOT_TLS_IE 3
402 #define GOT_TLS_GDESC 4
403 #define GOT_TLS_GD_BOTH_P(type) \
404 ((type) == (GOT_TLS_GD | GOT_TLS_GDESC))
405 #define GOT_TLS_GD_P(type) \
406 ((type) == GOT_TLS_GD || GOT_TLS_GD_BOTH_P (type))
407 #define GOT_TLS_GDESC_P(type) \
408 ((type) == GOT_TLS_GDESC || GOT_TLS_GD_BOTH_P (type))
409 #define GOT_TLS_GD_ANY_P(type) \
410 (GOT_TLS_GD_P (type) || GOT_TLS_GDESC_P (type))
411 unsigned char tls_type;
413 /* Offset of the GOTPLT entry reserved for the TLS descriptor,
414 starting at the end of the jump table. */
415 bfd_vma tlsdesc_got;
418 #define elf64_x86_64_hash_entry(ent) \
419 ((struct elf64_x86_64_link_hash_entry *)(ent))
421 struct elf64_x86_64_obj_tdata
423 struct elf_obj_tdata root;
425 /* tls_type for each local got entry. */
426 char *local_got_tls_type;
428 /* GOTPLT entries for TLS descriptors. */
429 bfd_vma *local_tlsdesc_gotent;
432 #define elf64_x86_64_tdata(abfd) \
433 ((struct elf64_x86_64_obj_tdata *) (abfd)->tdata.any)
435 #define elf64_x86_64_local_got_tls_type(abfd) \
436 (elf64_x86_64_tdata (abfd)->local_got_tls_type)
438 #define elf64_x86_64_local_tlsdesc_gotent(abfd) \
439 (elf64_x86_64_tdata (abfd)->local_tlsdesc_gotent)
441 /* x86-64 ELF linker hash table. */
443 struct elf64_x86_64_link_hash_table
445 struct elf_link_hash_table elf;
447 /* Short-cuts to get to dynamic linker sections. */
448 asection *sgot;
449 asection *sgotplt;
450 asection *srelgot;
451 asection *splt;
452 asection *srelplt;
453 asection *sdynbss;
454 asection *srelbss;
456 /* The offset into splt of the PLT entry for the TLS descriptor
457 resolver. Special values are 0, if not necessary (or not found
458 to be necessary yet), and -1 if needed but not determined
459 yet. */
460 bfd_vma tlsdesc_plt;
461 /* The offset into sgot of the GOT entry used by the PLT entry
462 above. */
463 bfd_vma tlsdesc_got;
465 union {
466 bfd_signed_vma refcount;
467 bfd_vma offset;
468 } tls_ld_got;
470 /* The amount of space used by the jump slots in the GOT. */
471 bfd_vma sgotplt_jump_table_size;
473 /* Small local sym to section mapping cache. */
474 struct sym_sec_cache sym_sec;
477 /* Get the x86-64 ELF linker hash table from a link_info structure. */
479 #define elf64_x86_64_hash_table(p) \
480 ((struct elf64_x86_64_link_hash_table *) ((p)->hash))
482 #define elf64_x86_64_compute_jump_table_size(htab) \
483 ((htab)->srelplt->reloc_count * GOT_ENTRY_SIZE)
485 /* Create an entry in an x86-64 ELF linker hash table. */
487 static struct bfd_hash_entry *
488 link_hash_newfunc (struct bfd_hash_entry *entry, struct bfd_hash_table *table,
489 const char *string)
491 /* Allocate the structure if it has not already been allocated by a
492 subclass. */
493 if (entry == NULL)
495 entry = bfd_hash_allocate (table,
496 sizeof (struct elf64_x86_64_link_hash_entry));
497 if (entry == NULL)
498 return entry;
501 /* Call the allocation method of the superclass. */
502 entry = _bfd_elf_link_hash_newfunc (entry, table, string);
503 if (entry != NULL)
505 struct elf64_x86_64_link_hash_entry *eh;
507 eh = (struct elf64_x86_64_link_hash_entry *) entry;
508 eh->dyn_relocs = NULL;
509 eh->tls_type = GOT_UNKNOWN;
510 eh->tlsdesc_got = (bfd_vma) -1;
513 return entry;
516 /* Create an X86-64 ELF linker hash table. */
518 static struct bfd_link_hash_table *
519 elf64_x86_64_link_hash_table_create (bfd *abfd)
521 struct elf64_x86_64_link_hash_table *ret;
522 bfd_size_type amt = sizeof (struct elf64_x86_64_link_hash_table);
524 ret = (struct elf64_x86_64_link_hash_table *) bfd_malloc (amt);
525 if (ret == NULL)
526 return NULL;
528 if (!_bfd_elf_link_hash_table_init (&ret->elf, abfd, link_hash_newfunc,
529 sizeof (struct elf64_x86_64_link_hash_entry)))
531 free (ret);
532 return NULL;
535 ret->sgot = NULL;
536 ret->sgotplt = NULL;
537 ret->srelgot = NULL;
538 ret->splt = NULL;
539 ret->srelplt = NULL;
540 ret->sdynbss = NULL;
541 ret->srelbss = NULL;
542 ret->sym_sec.abfd = NULL;
543 ret->tlsdesc_plt = 0;
544 ret->tlsdesc_got = 0;
545 ret->tls_ld_got.refcount = 0;
546 ret->sgotplt_jump_table_size = 0;
548 return &ret->elf.root;
551 /* Create .got, .gotplt, and .rela.got sections in DYNOBJ, and set up
552 shortcuts to them in our hash table. */
554 static bfd_boolean
555 create_got_section (bfd *dynobj, struct bfd_link_info *info)
557 struct elf64_x86_64_link_hash_table *htab;
559 if (! _bfd_elf_create_got_section (dynobj, info))
560 return FALSE;
562 htab = elf64_x86_64_hash_table (info);
563 htab->sgot = bfd_get_section_by_name (dynobj, ".got");
564 htab->sgotplt = bfd_get_section_by_name (dynobj, ".got.plt");
565 if (!htab->sgot || !htab->sgotplt)
566 abort ();
568 htab->srelgot = bfd_make_section_with_flags (dynobj, ".rela.got",
569 (SEC_ALLOC | SEC_LOAD
570 | SEC_HAS_CONTENTS
571 | SEC_IN_MEMORY
572 | SEC_LINKER_CREATED
573 | SEC_READONLY));
574 if (htab->srelgot == NULL
575 || ! bfd_set_section_alignment (dynobj, htab->srelgot, 3))
576 return FALSE;
577 return TRUE;
580 /* Create .plt, .rela.plt, .got, .got.plt, .rela.got, .dynbss, and
581 .rela.bss sections in DYNOBJ, and set up shortcuts to them in our
582 hash table. */
584 static bfd_boolean
585 elf64_x86_64_create_dynamic_sections (bfd *dynobj, struct bfd_link_info *info)
587 struct elf64_x86_64_link_hash_table *htab;
589 htab = elf64_x86_64_hash_table (info);
590 if (!htab->sgot && !create_got_section (dynobj, info))
591 return FALSE;
593 if (!_bfd_elf_create_dynamic_sections (dynobj, info))
594 return FALSE;
596 htab->splt = bfd_get_section_by_name (dynobj, ".plt");
597 htab->srelplt = bfd_get_section_by_name (dynobj, ".rela.plt");
598 htab->sdynbss = bfd_get_section_by_name (dynobj, ".dynbss");
599 if (!info->shared)
600 htab->srelbss = bfd_get_section_by_name (dynobj, ".rela.bss");
602 if (!htab->splt || !htab->srelplt || !htab->sdynbss
603 || (!info->shared && !htab->srelbss))
604 abort ();
606 return TRUE;
609 /* Copy the extra info we tack onto an elf_link_hash_entry. */
611 static void
612 elf64_x86_64_copy_indirect_symbol (struct bfd_link_info *info,
613 struct elf_link_hash_entry *dir,
614 struct elf_link_hash_entry *ind)
616 struct elf64_x86_64_link_hash_entry *edir, *eind;
618 edir = (struct elf64_x86_64_link_hash_entry *) dir;
619 eind = (struct elf64_x86_64_link_hash_entry *) ind;
621 if (eind->dyn_relocs != NULL)
623 if (edir->dyn_relocs != NULL)
625 struct elf64_x86_64_dyn_relocs **pp;
626 struct elf64_x86_64_dyn_relocs *p;
628 /* Add reloc counts against the indirect sym to the direct sym
629 list. Merge any entries against the same section. */
630 for (pp = &eind->dyn_relocs; (p = *pp) != NULL; )
632 struct elf64_x86_64_dyn_relocs *q;
634 for (q = edir->dyn_relocs; q != NULL; q = q->next)
635 if (q->sec == p->sec)
637 q->pc_count += p->pc_count;
638 q->count += p->count;
639 *pp = p->next;
640 break;
642 if (q == NULL)
643 pp = &p->next;
645 *pp = edir->dyn_relocs;
648 edir->dyn_relocs = eind->dyn_relocs;
649 eind->dyn_relocs = NULL;
652 if (ind->root.type == bfd_link_hash_indirect
653 && dir->got.refcount <= 0)
655 edir->tls_type = eind->tls_type;
656 eind->tls_type = GOT_UNKNOWN;
659 if (ELIMINATE_COPY_RELOCS
660 && ind->root.type != bfd_link_hash_indirect
661 && dir->dynamic_adjusted)
663 /* If called to transfer flags for a weakdef during processing
664 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
665 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
666 dir->ref_dynamic |= ind->ref_dynamic;
667 dir->ref_regular |= ind->ref_regular;
668 dir->ref_regular_nonweak |= ind->ref_regular_nonweak;
669 dir->needs_plt |= ind->needs_plt;
670 dir->pointer_equality_needed |= ind->pointer_equality_needed;
672 else
673 _bfd_elf_link_hash_copy_indirect (info, dir, ind);
676 static bfd_boolean
677 elf64_x86_64_mkobject (bfd *abfd)
679 if (abfd->tdata.any == NULL)
681 bfd_size_type amt = sizeof (struct elf64_x86_64_obj_tdata);
682 abfd->tdata.any = bfd_zalloc (abfd, amt);
683 if (abfd->tdata.any == NULL)
684 return FALSE;
686 return bfd_elf_mkobject (abfd);
689 static bfd_boolean
690 elf64_x86_64_elf_object_p (bfd *abfd)
692 /* Set the right machine number for an x86-64 elf64 file. */
693 bfd_default_set_arch_mach (abfd, bfd_arch_i386, bfd_mach_x86_64);
694 return TRUE;
697 static int
698 elf64_x86_64_tls_transition (struct bfd_link_info *info, int r_type, int is_local)
700 if (info->shared)
701 return r_type;
703 switch (r_type)
705 case R_X86_64_TLSGD:
706 case R_X86_64_GOTPC32_TLSDESC:
707 case R_X86_64_TLSDESC_CALL:
708 case R_X86_64_GOTTPOFF:
709 if (is_local)
710 return R_X86_64_TPOFF32;
711 return R_X86_64_GOTTPOFF;
712 case R_X86_64_TLSLD:
713 return R_X86_64_TPOFF32;
716 return r_type;
719 /* Look through the relocs for a section during the first phase, and
720 calculate needed space in the global offset table, procedure
721 linkage table, and dynamic reloc sections. */
723 static bfd_boolean
724 elf64_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, asection *sec,
725 const Elf_Internal_Rela *relocs)
727 struct elf64_x86_64_link_hash_table *htab;
728 Elf_Internal_Shdr *symtab_hdr;
729 struct elf_link_hash_entry **sym_hashes;
730 const Elf_Internal_Rela *rel;
731 const Elf_Internal_Rela *rel_end;
732 asection *sreloc;
734 if (info->relocatable)
735 return TRUE;
737 htab = elf64_x86_64_hash_table (info);
738 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
739 sym_hashes = elf_sym_hashes (abfd);
741 sreloc = NULL;
743 rel_end = relocs + sec->reloc_count;
744 for (rel = relocs; rel < rel_end; rel++)
746 unsigned int r_type;
747 unsigned long r_symndx;
748 struct elf_link_hash_entry *h;
750 r_symndx = ELF64_R_SYM (rel->r_info);
751 r_type = ELF64_R_TYPE (rel->r_info);
753 if (r_symndx >= NUM_SHDR_ENTRIES (symtab_hdr))
755 (*_bfd_error_handler) (_("%B: bad symbol index: %d"),
756 abfd, r_symndx);
757 return FALSE;
760 if (r_symndx < symtab_hdr->sh_info)
761 h = NULL;
762 else
764 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
765 while (h->root.type == bfd_link_hash_indirect
766 || h->root.type == bfd_link_hash_warning)
767 h = (struct elf_link_hash_entry *) h->root.u.i.link;
770 r_type = elf64_x86_64_tls_transition (info, r_type, h == NULL);
771 switch (r_type)
773 case R_X86_64_TLSLD:
774 htab->tls_ld_got.refcount += 1;
775 goto create_got;
777 case R_X86_64_TPOFF32:
778 if (info->shared)
780 (*_bfd_error_handler)
781 (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
782 abfd,
783 x86_64_elf_howto_table[r_type].name,
784 (h) ? h->root.root.string : "a local symbol");
785 bfd_set_error (bfd_error_bad_value);
786 return FALSE;
788 break;
790 case R_X86_64_GOTTPOFF:
791 if (info->shared)
792 info->flags |= DF_STATIC_TLS;
793 /* Fall through */
795 case R_X86_64_GOT32:
796 case R_X86_64_GOTPCREL:
797 case R_X86_64_TLSGD:
798 case R_X86_64_GOT64:
799 case R_X86_64_GOTPCREL64:
800 case R_X86_64_GOTPLT64:
801 case R_X86_64_GOTPC32_TLSDESC:
802 case R_X86_64_TLSDESC_CALL:
803 /* This symbol requires a global offset table entry. */
805 int tls_type, old_tls_type;
807 switch (r_type)
809 default: tls_type = GOT_NORMAL; break;
810 case R_X86_64_TLSGD: tls_type = GOT_TLS_GD; break;
811 case R_X86_64_GOTTPOFF: tls_type = GOT_TLS_IE; break;
812 case R_X86_64_GOTPC32_TLSDESC:
813 case R_X86_64_TLSDESC_CALL:
814 tls_type = GOT_TLS_GDESC; break;
817 if (h != NULL)
819 if (r_type == R_X86_64_GOTPLT64)
821 /* This relocation indicates that we also need
822 a PLT entry, as this is a function. We don't need
823 a PLT entry for local symbols. */
824 h->needs_plt = 1;
825 h->plt.refcount += 1;
827 h->got.refcount += 1;
828 old_tls_type = elf64_x86_64_hash_entry (h)->tls_type;
830 else
832 bfd_signed_vma *local_got_refcounts;
834 /* This is a global offset table entry for a local symbol. */
835 local_got_refcounts = elf_local_got_refcounts (abfd);
836 if (local_got_refcounts == NULL)
838 bfd_size_type size;
840 size = symtab_hdr->sh_info;
841 size *= sizeof (bfd_signed_vma)
842 + sizeof (bfd_vma) + sizeof (char);
843 local_got_refcounts = ((bfd_signed_vma *)
844 bfd_zalloc (abfd, size));
845 if (local_got_refcounts == NULL)
846 return FALSE;
847 elf_local_got_refcounts (abfd) = local_got_refcounts;
848 elf64_x86_64_local_tlsdesc_gotent (abfd)
849 = (bfd_vma *) (local_got_refcounts + symtab_hdr->sh_info);
850 elf64_x86_64_local_got_tls_type (abfd)
851 = (char *) (local_got_refcounts + 2 * symtab_hdr->sh_info);
853 local_got_refcounts[r_symndx] += 1;
854 old_tls_type
855 = elf64_x86_64_local_got_tls_type (abfd) [r_symndx];
858 /* If a TLS symbol is accessed using IE at least once,
859 there is no point to use dynamic model for it. */
860 if (old_tls_type != tls_type && old_tls_type != GOT_UNKNOWN
861 && (! GOT_TLS_GD_ANY_P (old_tls_type)
862 || tls_type != GOT_TLS_IE))
864 if (old_tls_type == GOT_TLS_IE && GOT_TLS_GD_ANY_P (tls_type))
865 tls_type = old_tls_type;
866 else if (GOT_TLS_GD_ANY_P (old_tls_type)
867 && GOT_TLS_GD_ANY_P (tls_type))
868 tls_type |= old_tls_type;
869 else
871 (*_bfd_error_handler)
872 (_("%B: %s' accessed both as normal and thread local symbol"),
873 abfd, h ? h->root.root.string : "<local>");
874 return FALSE;
878 if (old_tls_type != tls_type)
880 if (h != NULL)
881 elf64_x86_64_hash_entry (h)->tls_type = tls_type;
882 else
883 elf64_x86_64_local_got_tls_type (abfd) [r_symndx] = tls_type;
886 /* Fall through */
888 case R_X86_64_GOTOFF64:
889 case R_X86_64_GOTPC32:
890 case R_X86_64_GOTPC64:
891 create_got:
892 if (htab->sgot == NULL)
894 if (htab->elf.dynobj == NULL)
895 htab->elf.dynobj = abfd;
896 if (!create_got_section (htab->elf.dynobj, info))
897 return FALSE;
899 break;
901 case R_X86_64_PLT32:
902 /* This symbol requires a procedure linkage table entry. We
903 actually build the entry in adjust_dynamic_symbol,
904 because this might be a case of linking PIC code which is
905 never referenced by a dynamic object, in which case we
906 don't need to generate a procedure linkage table entry
907 after all. */
909 /* If this is a local symbol, we resolve it directly without
910 creating a procedure linkage table entry. */
911 if (h == NULL)
912 continue;
914 h->needs_plt = 1;
915 h->plt.refcount += 1;
916 break;
918 case R_X86_64_PLTOFF64:
919 /* This tries to form the 'address' of a function relative
920 to GOT. For global symbols we need a PLT entry. */
921 if (h != NULL)
923 h->needs_plt = 1;
924 h->plt.refcount += 1;
926 goto create_got;
928 case R_X86_64_8:
929 case R_X86_64_16:
930 case R_X86_64_32:
931 case R_X86_64_32S:
932 /* Let's help debug shared library creation. These relocs
933 cannot be used in shared libs. Don't error out for
934 sections we don't care about, such as debug sections or
935 non-constant sections. */
936 if (info->shared
937 && (sec->flags & SEC_ALLOC) != 0
938 && (sec->flags & SEC_READONLY) != 0)
940 (*_bfd_error_handler)
941 (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
942 abfd,
943 x86_64_elf_howto_table[r_type].name,
944 (h) ? h->root.root.string : "a local symbol");
945 bfd_set_error (bfd_error_bad_value);
946 return FALSE;
948 /* Fall through. */
950 case R_X86_64_PC8:
951 case R_X86_64_PC16:
952 case R_X86_64_PC32:
953 case R_X86_64_PC64:
954 case R_X86_64_64:
955 if (h != NULL && !info->shared)
957 /* If this reloc is in a read-only section, we might
958 need a copy reloc. We can't check reliably at this
959 stage whether the section is read-only, as input
960 sections have not yet been mapped to output sections.
961 Tentatively set the flag for now, and correct in
962 adjust_dynamic_symbol. */
963 h->non_got_ref = 1;
965 /* We may need a .plt entry if the function this reloc
966 refers to is in a shared lib. */
967 h->plt.refcount += 1;
968 if (r_type != R_X86_64_PC32 && r_type != R_X86_64_PC64)
969 h->pointer_equality_needed = 1;
972 /* If we are creating a shared library, and this is a reloc
973 against a global symbol, or a non PC relative reloc
974 against a local symbol, then we need to copy the reloc
975 into the shared library. However, if we are linking with
976 -Bsymbolic, we do not need to copy a reloc against a
977 global symbol which is defined in an object we are
978 including in the link (i.e., DEF_REGULAR is set). At
979 this point we have not seen all the input files, so it is
980 possible that DEF_REGULAR is not set now but will be set
981 later (it is never cleared). In case of a weak definition,
982 DEF_REGULAR may be cleared later by a strong definition in
983 a shared library. We account for that possibility below by
984 storing information in the relocs_copied field of the hash
985 table entry. A similar situation occurs when creating
986 shared libraries and symbol visibility changes render the
987 symbol local.
989 If on the other hand, we are creating an executable, we
990 may need to keep relocations for symbols satisfied by a
991 dynamic library if we manage to avoid copy relocs for the
992 symbol. */
993 if ((info->shared
994 && (sec->flags & SEC_ALLOC) != 0
995 && (((r_type != R_X86_64_PC8)
996 && (r_type != R_X86_64_PC16)
997 && (r_type != R_X86_64_PC32)
998 && (r_type != R_X86_64_PC64))
999 || (h != NULL
1000 && (! SYMBOLIC_BIND (info, h)
1001 || h->root.type == bfd_link_hash_defweak
1002 || !h->def_regular))))
1003 || (ELIMINATE_COPY_RELOCS
1004 && !info->shared
1005 && (sec->flags & SEC_ALLOC) != 0
1006 && h != NULL
1007 && (h->root.type == bfd_link_hash_defweak
1008 || !h->def_regular)))
1010 struct elf64_x86_64_dyn_relocs *p;
1011 struct elf64_x86_64_dyn_relocs **head;
1013 /* We must copy these reloc types into the output file.
1014 Create a reloc section in dynobj and make room for
1015 this reloc. */
1016 if (sreloc == NULL)
1018 const char *name;
1019 bfd *dynobj;
1021 name = (bfd_elf_string_from_elf_section
1022 (abfd,
1023 elf_elfheader (abfd)->e_shstrndx,
1024 elf_section_data (sec)->rel_hdr.sh_name));
1025 if (name == NULL)
1026 return FALSE;
1028 if (! CONST_STRNEQ (name, ".rela")
1029 || strcmp (bfd_get_section_name (abfd, sec),
1030 name + 5) != 0)
1032 (*_bfd_error_handler)
1033 (_("%B: bad relocation section name `%s\'"),
1034 abfd, name);
1037 if (htab->elf.dynobj == NULL)
1038 htab->elf.dynobj = abfd;
1040 dynobj = htab->elf.dynobj;
1042 sreloc = bfd_get_section_by_name (dynobj, name);
1043 if (sreloc == NULL)
1045 flagword flags;
1047 flags = (SEC_HAS_CONTENTS | SEC_READONLY
1048 | SEC_IN_MEMORY | SEC_LINKER_CREATED);
1049 if ((sec->flags & SEC_ALLOC) != 0)
1050 flags |= SEC_ALLOC | SEC_LOAD;
1051 sreloc = bfd_make_section_with_flags (dynobj,
1052 name,
1053 flags);
1054 if (sreloc == NULL
1055 || ! bfd_set_section_alignment (dynobj, sreloc, 3))
1056 return FALSE;
1058 elf_section_data (sec)->sreloc = sreloc;
1061 /* If this is a global symbol, we count the number of
1062 relocations we need for this symbol. */
1063 if (h != NULL)
1065 head = &((struct elf64_x86_64_link_hash_entry *) h)->dyn_relocs;
1067 else
1069 void **vpp;
1070 /* Track dynamic relocs needed for local syms too.
1071 We really need local syms available to do this
1072 easily. Oh well. */
1074 asection *s;
1075 s = bfd_section_from_r_symndx (abfd, &htab->sym_sec,
1076 sec, r_symndx);
1077 if (s == NULL)
1078 return FALSE;
1080 /* Beware of type punned pointers vs strict aliasing
1081 rules. */
1082 vpp = &(elf_section_data (s)->local_dynrel);
1083 head = (struct elf64_x86_64_dyn_relocs **)vpp;
1086 p = *head;
1087 if (p == NULL || p->sec != sec)
1089 bfd_size_type amt = sizeof *p;
1090 p = ((struct elf64_x86_64_dyn_relocs *)
1091 bfd_alloc (htab->elf.dynobj, amt));
1092 if (p == NULL)
1093 return FALSE;
1094 p->next = *head;
1095 *head = p;
1096 p->sec = sec;
1097 p->count = 0;
1098 p->pc_count = 0;
1101 p->count += 1;
1102 if (r_type == R_X86_64_PC8
1103 || r_type == R_X86_64_PC16
1104 || r_type == R_X86_64_PC32
1105 || r_type == R_X86_64_PC64)
1106 p->pc_count += 1;
1108 break;
1110 /* This relocation describes the C++ object vtable hierarchy.
1111 Reconstruct it for later use during GC. */
1112 case R_X86_64_GNU_VTINHERIT:
1113 if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
1114 return FALSE;
1115 break;
1117 /* This relocation describes which C++ vtable entries are actually
1118 used. Record for later use during GC. */
1119 case R_X86_64_GNU_VTENTRY:
1120 if (!bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend))
1121 return FALSE;
1122 break;
1124 default:
1125 break;
1129 return TRUE;
1132 /* Return the section that should be marked against GC for a given
1133 relocation. */
1135 static asection *
1136 elf64_x86_64_gc_mark_hook (asection *sec,
1137 struct bfd_link_info *info,
1138 Elf_Internal_Rela *rel,
1139 struct elf_link_hash_entry *h,
1140 Elf_Internal_Sym *sym)
1142 if (h != NULL)
1143 switch (ELF64_R_TYPE (rel->r_info))
1145 case R_X86_64_GNU_VTINHERIT:
1146 case R_X86_64_GNU_VTENTRY:
1147 return NULL;
1150 return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
1153 /* Update the got entry reference counts for the section being removed. */
1155 static bfd_boolean
1156 elf64_x86_64_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info,
1157 asection *sec, const Elf_Internal_Rela *relocs)
1159 Elf_Internal_Shdr *symtab_hdr;
1160 struct elf_link_hash_entry **sym_hashes;
1161 bfd_signed_vma *local_got_refcounts;
1162 const Elf_Internal_Rela *rel, *relend;
1164 elf_section_data (sec)->local_dynrel = NULL;
1166 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
1167 sym_hashes = elf_sym_hashes (abfd);
1168 local_got_refcounts = elf_local_got_refcounts (abfd);
1170 relend = relocs + sec->reloc_count;
1171 for (rel = relocs; rel < relend; rel++)
1173 unsigned long r_symndx;
1174 unsigned int r_type;
1175 struct elf_link_hash_entry *h = NULL;
1177 r_symndx = ELF64_R_SYM (rel->r_info);
1178 if (r_symndx >= symtab_hdr->sh_info)
1180 struct elf64_x86_64_link_hash_entry *eh;
1181 struct elf64_x86_64_dyn_relocs **pp;
1182 struct elf64_x86_64_dyn_relocs *p;
1184 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
1185 while (h->root.type == bfd_link_hash_indirect
1186 || h->root.type == bfd_link_hash_warning)
1187 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1188 eh = (struct elf64_x86_64_link_hash_entry *) h;
1190 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; pp = &p->next)
1191 if (p->sec == sec)
1193 /* Everything must go for SEC. */
1194 *pp = p->next;
1195 break;
1199 r_type = ELF64_R_TYPE (rel->r_info);
1200 r_type = elf64_x86_64_tls_transition (info, r_type, h != NULL);
1201 switch (r_type)
1203 case R_X86_64_TLSLD:
1204 if (elf64_x86_64_hash_table (info)->tls_ld_got.refcount > 0)
1205 elf64_x86_64_hash_table (info)->tls_ld_got.refcount -= 1;
1206 break;
1208 case R_X86_64_TLSGD:
1209 case R_X86_64_GOTPC32_TLSDESC:
1210 case R_X86_64_TLSDESC_CALL:
1211 case R_X86_64_GOTTPOFF:
1212 case R_X86_64_GOT32:
1213 case R_X86_64_GOTPCREL:
1214 case R_X86_64_GOT64:
1215 case R_X86_64_GOTPCREL64:
1216 case R_X86_64_GOTPLT64:
1217 if (h != NULL)
1219 if (r_type == R_X86_64_GOTPLT64 && h->plt.refcount > 0)
1220 h->plt.refcount -= 1;
1221 if (h->got.refcount > 0)
1222 h->got.refcount -= 1;
1224 else if (local_got_refcounts != NULL)
1226 if (local_got_refcounts[r_symndx] > 0)
1227 local_got_refcounts[r_symndx] -= 1;
1229 break;
1231 case R_X86_64_8:
1232 case R_X86_64_16:
1233 case R_X86_64_32:
1234 case R_X86_64_64:
1235 case R_X86_64_32S:
1236 case R_X86_64_PC8:
1237 case R_X86_64_PC16:
1238 case R_X86_64_PC32:
1239 case R_X86_64_PC64:
1240 if (info->shared)
1241 break;
1242 /* Fall thru */
1244 case R_X86_64_PLT32:
1245 case R_X86_64_PLTOFF64:
1246 if (h != NULL)
1248 if (h->plt.refcount > 0)
1249 h->plt.refcount -= 1;
1251 break;
1253 default:
1254 break;
1258 return TRUE;
1261 /* Adjust a symbol defined by a dynamic object and referenced by a
1262 regular object. The current definition is in some section of the
1263 dynamic object, but we're not including those sections. We have to
1264 change the definition to something the rest of the link can
1265 understand. */
1267 static bfd_boolean
1268 elf64_x86_64_adjust_dynamic_symbol (struct bfd_link_info *info,
1269 struct elf_link_hash_entry *h)
1271 struct elf64_x86_64_link_hash_table *htab;
1272 asection *s;
1273 unsigned int power_of_two;
1275 /* If this is a function, put it in the procedure linkage table. We
1276 will fill in the contents of the procedure linkage table later,
1277 when we know the address of the .got section. */
1278 if (h->type == STT_FUNC
1279 || h->needs_plt)
1281 if (h->plt.refcount <= 0
1282 || SYMBOL_CALLS_LOCAL (info, h)
1283 || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1284 && h->root.type == bfd_link_hash_undefweak))
1286 /* This case can occur if we saw a PLT32 reloc in an input
1287 file, but the symbol was never referred to by a dynamic
1288 object, or if all references were garbage collected. In
1289 such a case, we don't actually need to build a procedure
1290 linkage table, and we can just do a PC32 reloc instead. */
1291 h->plt.offset = (bfd_vma) -1;
1292 h->needs_plt = 0;
1295 return TRUE;
1297 else
1298 /* It's possible that we incorrectly decided a .plt reloc was
1299 needed for an R_X86_64_PC32 reloc to a non-function sym in
1300 check_relocs. We can't decide accurately between function and
1301 non-function syms in check-relocs; Objects loaded later in
1302 the link may change h->type. So fix it now. */
1303 h->plt.offset = (bfd_vma) -1;
1305 /* If this is a weak symbol, and there is a real definition, the
1306 processor independent code will have arranged for us to see the
1307 real definition first, and we can just use the same value. */
1308 if (h->u.weakdef != NULL)
1310 BFD_ASSERT (h->u.weakdef->root.type == bfd_link_hash_defined
1311 || h->u.weakdef->root.type == bfd_link_hash_defweak);
1312 h->root.u.def.section = h->u.weakdef->root.u.def.section;
1313 h->root.u.def.value = h->u.weakdef->root.u.def.value;
1314 if (ELIMINATE_COPY_RELOCS || info->nocopyreloc)
1315 h->non_got_ref = h->u.weakdef->non_got_ref;
1316 return TRUE;
1319 /* This is a reference to a symbol defined by a dynamic object which
1320 is not a function. */
1322 /* If we are creating a shared library, we must presume that the
1323 only references to the symbol are via the global offset table.
1324 For such cases we need not do anything here; the relocations will
1325 be handled correctly by relocate_section. */
1326 if (info->shared)
1327 return TRUE;
1329 /* If there are no references to this symbol that do not use the
1330 GOT, we don't need to generate a copy reloc. */
1331 if (!h->non_got_ref)
1332 return TRUE;
1334 /* If -z nocopyreloc was given, we won't generate them either. */
1335 if (info->nocopyreloc)
1337 h->non_got_ref = 0;
1338 return TRUE;
1341 if (ELIMINATE_COPY_RELOCS)
1343 struct elf64_x86_64_link_hash_entry * eh;
1344 struct elf64_x86_64_dyn_relocs *p;
1346 eh = (struct elf64_x86_64_link_hash_entry *) h;
1347 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1349 s = p->sec->output_section;
1350 if (s != NULL && (s->flags & SEC_READONLY) != 0)
1351 break;
1354 /* If we didn't find any dynamic relocs in read-only sections, then
1355 we'll be keeping the dynamic relocs and avoiding the copy reloc. */
1356 if (p == NULL)
1358 h->non_got_ref = 0;
1359 return TRUE;
1363 if (h->size == 0)
1365 (*_bfd_error_handler) (_("dynamic variable `%s' is zero size"),
1366 h->root.root.string);
1367 return TRUE;
1370 /* We must allocate the symbol in our .dynbss section, which will
1371 become part of the .bss section of the executable. There will be
1372 an entry for this symbol in the .dynsym section. The dynamic
1373 object will contain position independent code, so all references
1374 from the dynamic object to this symbol will go through the global
1375 offset table. The dynamic linker will use the .dynsym entry to
1376 determine the address it must put in the global offset table, so
1377 both the dynamic object and the regular object will refer to the
1378 same memory location for the variable. */
1380 htab = elf64_x86_64_hash_table (info);
1382 /* We must generate a R_X86_64_COPY reloc to tell the dynamic linker
1383 to copy the initial value out of the dynamic object and into the
1384 runtime process image. */
1385 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0)
1387 htab->srelbss->size += sizeof (Elf64_External_Rela);
1388 h->needs_copy = 1;
1391 /* We need to figure out the alignment required for this symbol. I
1392 have no idea how ELF linkers handle this. 16-bytes is the size
1393 of the largest type that requires hard alignment -- long double. */
1394 /* FIXME: This is VERY ugly. Should be fixed for all architectures using
1395 this construct. */
1396 power_of_two = bfd_log2 (h->size);
1397 if (power_of_two > 4)
1398 power_of_two = 4;
1400 /* Apply the required alignment. */
1401 s = htab->sdynbss;
1402 s->size = BFD_ALIGN (s->size, (bfd_size_type) (1 << power_of_two));
1403 if (power_of_two > bfd_get_section_alignment (htab->elf.dynobj, s))
1405 if (! bfd_set_section_alignment (htab->elf.dynobj, s, power_of_two))
1406 return FALSE;
1409 /* Define the symbol as being at this point in the section. */
1410 h->root.u.def.section = s;
1411 h->root.u.def.value = s->size;
1413 /* Increment the section size to make room for the symbol. */
1414 s->size += h->size;
1416 return TRUE;
1419 /* Allocate space in .plt, .got and associated reloc sections for
1420 dynamic relocs. */
1422 static bfd_boolean
1423 allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
1425 struct bfd_link_info *info;
1426 struct elf64_x86_64_link_hash_table *htab;
1427 struct elf64_x86_64_link_hash_entry *eh;
1428 struct elf64_x86_64_dyn_relocs *p;
1430 if (h->root.type == bfd_link_hash_indirect)
1431 return TRUE;
1433 if (h->root.type == bfd_link_hash_warning)
1434 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1436 info = (struct bfd_link_info *) inf;
1437 htab = elf64_x86_64_hash_table (info);
1439 if (htab->elf.dynamic_sections_created
1440 && h->plt.refcount > 0)
1442 /* Make sure this symbol is output as a dynamic symbol.
1443 Undefined weak syms won't yet be marked as dynamic. */
1444 if (h->dynindx == -1
1445 && !h->forced_local)
1447 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1448 return FALSE;
1451 if (info->shared
1452 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
1454 asection *s = htab->splt;
1456 /* If this is the first .plt entry, make room for the special
1457 first entry. */
1458 if (s->size == 0)
1459 s->size += PLT_ENTRY_SIZE;
1461 h->plt.offset = s->size;
1463 /* If this symbol is not defined in a regular file, and we are
1464 not generating a shared library, then set the symbol to this
1465 location in the .plt. This is required to make function
1466 pointers compare as equal between the normal executable and
1467 the shared library. */
1468 if (! info->shared
1469 && !h->def_regular)
1471 h->root.u.def.section = s;
1472 h->root.u.def.value = h->plt.offset;
1475 /* Make room for this entry. */
1476 s->size += PLT_ENTRY_SIZE;
1478 /* We also need to make an entry in the .got.plt section, which
1479 will be placed in the .got section by the linker script. */
1480 htab->sgotplt->size += GOT_ENTRY_SIZE;
1482 /* We also need to make an entry in the .rela.plt section. */
1483 htab->srelplt->size += sizeof (Elf64_External_Rela);
1484 htab->srelplt->reloc_count++;
1486 else
1488 h->plt.offset = (bfd_vma) -1;
1489 h->needs_plt = 0;
1492 else
1494 h->plt.offset = (bfd_vma) -1;
1495 h->needs_plt = 0;
1498 eh = (struct elf64_x86_64_link_hash_entry *) h;
1499 eh->tlsdesc_got = (bfd_vma) -1;
1501 /* If R_X86_64_GOTTPOFF symbol is now local to the binary,
1502 make it a R_X86_64_TPOFF32 requiring no GOT entry. */
1503 if (h->got.refcount > 0
1504 && !info->shared
1505 && h->dynindx == -1
1506 && elf64_x86_64_hash_entry (h)->tls_type == GOT_TLS_IE)
1507 h->got.offset = (bfd_vma) -1;
1508 else if (h->got.refcount > 0)
1510 asection *s;
1511 bfd_boolean dyn;
1512 int tls_type = elf64_x86_64_hash_entry (h)->tls_type;
1514 /* Make sure this symbol is output as a dynamic symbol.
1515 Undefined weak syms won't yet be marked as dynamic. */
1516 if (h->dynindx == -1
1517 && !h->forced_local)
1519 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1520 return FALSE;
1523 if (GOT_TLS_GDESC_P (tls_type))
1525 eh->tlsdesc_got = htab->sgotplt->size
1526 - elf64_x86_64_compute_jump_table_size (htab);
1527 htab->sgotplt->size += 2 * GOT_ENTRY_SIZE;
1528 h->got.offset = (bfd_vma) -2;
1530 if (! GOT_TLS_GDESC_P (tls_type)
1531 || GOT_TLS_GD_P (tls_type))
1533 s = htab->sgot;
1534 h->got.offset = s->size;
1535 s->size += GOT_ENTRY_SIZE;
1536 if (GOT_TLS_GD_P (tls_type))
1537 s->size += GOT_ENTRY_SIZE;
1539 dyn = htab->elf.dynamic_sections_created;
1540 /* R_X86_64_TLSGD needs one dynamic relocation if local symbol
1541 and two if global.
1542 R_X86_64_GOTTPOFF needs one dynamic relocation. */
1543 if ((GOT_TLS_GD_P (tls_type) && h->dynindx == -1)
1544 || tls_type == GOT_TLS_IE)
1545 htab->srelgot->size += sizeof (Elf64_External_Rela);
1546 else if (GOT_TLS_GD_P (tls_type))
1547 htab->srelgot->size += 2 * sizeof (Elf64_External_Rela);
1548 else if (! GOT_TLS_GDESC_P (tls_type)
1549 && (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
1550 || h->root.type != bfd_link_hash_undefweak)
1551 && (info->shared
1552 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h)))
1553 htab->srelgot->size += sizeof (Elf64_External_Rela);
1554 if (GOT_TLS_GDESC_P (tls_type))
1556 htab->srelplt->size += sizeof (Elf64_External_Rela);
1557 htab->tlsdesc_plt = (bfd_vma) -1;
1560 else
1561 h->got.offset = (bfd_vma) -1;
1563 if (eh->dyn_relocs == NULL)
1564 return TRUE;
1566 /* In the shared -Bsymbolic case, discard space allocated for
1567 dynamic pc-relative relocs against symbols which turn out to be
1568 defined in regular objects. For the normal shared case, discard
1569 space for pc-relative relocs that have become local due to symbol
1570 visibility changes. */
1572 if (info->shared)
1574 /* Relocs that use pc_count are those that appear on a call
1575 insn, or certain REL relocs that can generated via assembly.
1576 We want calls to protected symbols to resolve directly to the
1577 function rather than going via the plt. If people want
1578 function pointer comparisons to work as expected then they
1579 should avoid writing weird assembly. */
1580 if (SYMBOL_CALLS_LOCAL (info, h))
1582 struct elf64_x86_64_dyn_relocs **pp;
1584 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
1586 p->count -= p->pc_count;
1587 p->pc_count = 0;
1588 if (p->count == 0)
1589 *pp = p->next;
1590 else
1591 pp = &p->next;
1595 /* Also discard relocs on undefined weak syms with non-default
1596 visibility. */
1597 if (eh->dyn_relocs != NULL
1598 && h->root.type == bfd_link_hash_undefweak)
1600 if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
1601 eh->dyn_relocs = NULL;
1603 /* Make sure undefined weak symbols are output as a dynamic
1604 symbol in PIEs. */
1605 else if (h->dynindx == -1
1606 && !h->forced_local)
1608 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1609 return FALSE;
1613 else if (ELIMINATE_COPY_RELOCS)
1615 /* For the non-shared case, discard space for relocs against
1616 symbols which turn out to need copy relocs or are not
1617 dynamic. */
1619 if (!h->non_got_ref
1620 && ((h->def_dynamic
1621 && !h->def_regular)
1622 || (htab->elf.dynamic_sections_created
1623 && (h->root.type == bfd_link_hash_undefweak
1624 || h->root.type == bfd_link_hash_undefined))))
1626 /* Make sure this symbol is output as a dynamic symbol.
1627 Undefined weak syms won't yet be marked as dynamic. */
1628 if (h->dynindx == -1
1629 && !h->forced_local)
1631 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1632 return FALSE;
1635 /* If that succeeded, we know we'll be keeping all the
1636 relocs. */
1637 if (h->dynindx != -1)
1638 goto keep;
1641 eh->dyn_relocs = NULL;
1643 keep: ;
1646 /* Finally, allocate space. */
1647 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1649 asection *sreloc = elf_section_data (p->sec)->sreloc;
1650 sreloc->size += p->count * sizeof (Elf64_External_Rela);
1653 return TRUE;
1656 /* Find any dynamic relocs that apply to read-only sections. */
1658 static bfd_boolean
1659 readonly_dynrelocs (struct elf_link_hash_entry *h, void * inf)
1661 struct elf64_x86_64_link_hash_entry *eh;
1662 struct elf64_x86_64_dyn_relocs *p;
1664 if (h->root.type == bfd_link_hash_warning)
1665 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1667 eh = (struct elf64_x86_64_link_hash_entry *) h;
1668 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1670 asection *s = p->sec->output_section;
1672 if (s != NULL && (s->flags & SEC_READONLY) != 0)
1674 struct bfd_link_info *info = (struct bfd_link_info *) inf;
1676 info->flags |= DF_TEXTREL;
1678 /* Not an error, just cut short the traversal. */
1679 return FALSE;
1682 return TRUE;
1685 /* Set the sizes of the dynamic sections. */
1687 static bfd_boolean
1688 elf64_x86_64_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED,
1689 struct bfd_link_info *info)
1691 struct elf64_x86_64_link_hash_table *htab;
1692 bfd *dynobj;
1693 asection *s;
1694 bfd_boolean relocs;
1695 bfd *ibfd;
1697 htab = elf64_x86_64_hash_table (info);
1698 dynobj = htab->elf.dynobj;
1699 if (dynobj == NULL)
1700 abort ();
1702 if (htab->elf.dynamic_sections_created)
1704 /* Set the contents of the .interp section to the interpreter. */
1705 if (info->executable)
1707 s = bfd_get_section_by_name (dynobj, ".interp");
1708 if (s == NULL)
1709 abort ();
1710 s->size = sizeof ELF_DYNAMIC_INTERPRETER;
1711 s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER;
1715 /* Set up .got offsets for local syms, and space for local dynamic
1716 relocs. */
1717 for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next)
1719 bfd_signed_vma *local_got;
1720 bfd_signed_vma *end_local_got;
1721 char *local_tls_type;
1722 bfd_vma *local_tlsdesc_gotent;
1723 bfd_size_type locsymcount;
1724 Elf_Internal_Shdr *symtab_hdr;
1725 asection *srel;
1727 if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour)
1728 continue;
1730 for (s = ibfd->sections; s != NULL; s = s->next)
1732 struct elf64_x86_64_dyn_relocs *p;
1734 for (p = (struct elf64_x86_64_dyn_relocs *)
1735 (elf_section_data (s)->local_dynrel);
1736 p != NULL;
1737 p = p->next)
1739 if (!bfd_is_abs_section (p->sec)
1740 && bfd_is_abs_section (p->sec->output_section))
1742 /* Input section has been discarded, either because
1743 it is a copy of a linkonce section or due to
1744 linker script /DISCARD/, so we'll be discarding
1745 the relocs too. */
1747 else if (p->count != 0)
1749 srel = elf_section_data (p->sec)->sreloc;
1750 srel->size += p->count * sizeof (Elf64_External_Rela);
1751 if ((p->sec->output_section->flags & SEC_READONLY) != 0)
1752 info->flags |= DF_TEXTREL;
1758 local_got = elf_local_got_refcounts (ibfd);
1759 if (!local_got)
1760 continue;
1762 symtab_hdr = &elf_tdata (ibfd)->symtab_hdr;
1763 locsymcount = symtab_hdr->sh_info;
1764 end_local_got = local_got + locsymcount;
1765 local_tls_type = elf64_x86_64_local_got_tls_type (ibfd);
1766 local_tlsdesc_gotent = elf64_x86_64_local_tlsdesc_gotent (ibfd);
1767 s = htab->sgot;
1768 srel = htab->srelgot;
1769 for (; local_got < end_local_got;
1770 ++local_got, ++local_tls_type, ++local_tlsdesc_gotent)
1772 *local_tlsdesc_gotent = (bfd_vma) -1;
1773 if (*local_got > 0)
1775 if (GOT_TLS_GDESC_P (*local_tls_type))
1777 *local_tlsdesc_gotent = htab->sgotplt->size
1778 - elf64_x86_64_compute_jump_table_size (htab);
1779 htab->sgotplt->size += 2 * GOT_ENTRY_SIZE;
1780 *local_got = (bfd_vma) -2;
1782 if (! GOT_TLS_GDESC_P (*local_tls_type)
1783 || GOT_TLS_GD_P (*local_tls_type))
1785 *local_got = s->size;
1786 s->size += GOT_ENTRY_SIZE;
1787 if (GOT_TLS_GD_P (*local_tls_type))
1788 s->size += GOT_ENTRY_SIZE;
1790 if (info->shared
1791 || GOT_TLS_GD_ANY_P (*local_tls_type)
1792 || *local_tls_type == GOT_TLS_IE)
1794 if (GOT_TLS_GDESC_P (*local_tls_type))
1796 htab->srelplt->size += sizeof (Elf64_External_Rela);
1797 htab->tlsdesc_plt = (bfd_vma) -1;
1799 if (! GOT_TLS_GDESC_P (*local_tls_type)
1800 || GOT_TLS_GD_P (*local_tls_type))
1801 srel->size += sizeof (Elf64_External_Rela);
1804 else
1805 *local_got = (bfd_vma) -1;
1809 if (htab->tls_ld_got.refcount > 0)
1811 /* Allocate 2 got entries and 1 dynamic reloc for R_X86_64_TLSLD
1812 relocs. */
1813 htab->tls_ld_got.offset = htab->sgot->size;
1814 htab->sgot->size += 2 * GOT_ENTRY_SIZE;
1815 htab->srelgot->size += sizeof (Elf64_External_Rela);
1817 else
1818 htab->tls_ld_got.offset = -1;
1820 /* Allocate global sym .plt and .got entries, and space for global
1821 sym dynamic relocs. */
1822 elf_link_hash_traverse (&htab->elf, allocate_dynrelocs, (PTR) info);
1824 /* For every jump slot reserved in the sgotplt, reloc_count is
1825 incremented. However, when we reserve space for TLS descriptors,
1826 it's not incremented, so in order to compute the space reserved
1827 for them, it suffices to multiply the reloc count by the jump
1828 slot size. */
1829 if (htab->srelplt)
1830 htab->sgotplt_jump_table_size
1831 = elf64_x86_64_compute_jump_table_size (htab);
1833 if (htab->tlsdesc_plt)
1835 /* If we're not using lazy TLS relocations, don't generate the
1836 PLT and GOT entries they require. */
1837 if ((info->flags & DF_BIND_NOW))
1838 htab->tlsdesc_plt = 0;
1839 else
1841 htab->tlsdesc_got = htab->sgot->size;
1842 htab->sgot->size += GOT_ENTRY_SIZE;
1843 /* Reserve room for the initial entry.
1844 FIXME: we could probably do away with it in this case. */
1845 if (htab->splt->size == 0)
1846 htab->splt->size += PLT_ENTRY_SIZE;
1847 htab->tlsdesc_plt = htab->splt->size;
1848 htab->splt->size += PLT_ENTRY_SIZE;
1852 /* We now have determined the sizes of the various dynamic sections.
1853 Allocate memory for them. */
1854 relocs = FALSE;
1855 for (s = dynobj->sections; s != NULL; s = s->next)
1857 if ((s->flags & SEC_LINKER_CREATED) == 0)
1858 continue;
1860 if (s == htab->splt
1861 || s == htab->sgot
1862 || s == htab->sgotplt
1863 || s == htab->sdynbss)
1865 /* Strip this section if we don't need it; see the
1866 comment below. */
1868 else if (CONST_STRNEQ (bfd_get_section_name (dynobj, s), ".rela"))
1870 if (s->size != 0 && s != htab->srelplt)
1871 relocs = TRUE;
1873 /* We use the reloc_count field as a counter if we need
1874 to copy relocs into the output file. */
1875 if (s != htab->srelplt)
1876 s->reloc_count = 0;
1878 else
1880 /* It's not one of our sections, so don't allocate space. */
1881 continue;
1884 if (s->size == 0)
1886 /* If we don't need this section, strip it from the
1887 output file. This is mostly to handle .rela.bss and
1888 .rela.plt. We must create both sections in
1889 create_dynamic_sections, because they must be created
1890 before the linker maps input sections to output
1891 sections. The linker does that before
1892 adjust_dynamic_symbol is called, and it is that
1893 function which decides whether anything needs to go
1894 into these sections. */
1896 s->flags |= SEC_EXCLUDE;
1897 continue;
1900 if ((s->flags & SEC_HAS_CONTENTS) == 0)
1901 continue;
1903 /* Allocate memory for the section contents. We use bfd_zalloc
1904 here in case unused entries are not reclaimed before the
1905 section's contents are written out. This should not happen,
1906 but this way if it does, we get a R_X86_64_NONE reloc instead
1907 of garbage. */
1908 s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->size);
1909 if (s->contents == NULL)
1910 return FALSE;
1913 if (htab->elf.dynamic_sections_created)
1915 /* Add some entries to the .dynamic section. We fill in the
1916 values later, in elf64_x86_64_finish_dynamic_sections, but we
1917 must add the entries now so that we get the correct size for
1918 the .dynamic section. The DT_DEBUG entry is filled in by the
1919 dynamic linker and used by the debugger. */
1920 #define add_dynamic_entry(TAG, VAL) \
1921 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
1923 if (info->executable)
1925 if (!add_dynamic_entry (DT_DEBUG, 0))
1926 return FALSE;
1929 if (htab->splt->size != 0)
1931 if (!add_dynamic_entry (DT_PLTGOT, 0)
1932 || !add_dynamic_entry (DT_PLTRELSZ, 0)
1933 || !add_dynamic_entry (DT_PLTREL, DT_RELA)
1934 || !add_dynamic_entry (DT_JMPREL, 0))
1935 return FALSE;
1937 if (htab->tlsdesc_plt
1938 && (!add_dynamic_entry (DT_TLSDESC_PLT, 0)
1939 || !add_dynamic_entry (DT_TLSDESC_GOT, 0)))
1940 return FALSE;
1943 if (relocs)
1945 if (!add_dynamic_entry (DT_RELA, 0)
1946 || !add_dynamic_entry (DT_RELASZ, 0)
1947 || !add_dynamic_entry (DT_RELAENT, sizeof (Elf64_External_Rela)))
1948 return FALSE;
1950 /* If any dynamic relocs apply to a read-only section,
1951 then we need a DT_TEXTREL entry. */
1952 if ((info->flags & DF_TEXTREL) == 0)
1953 elf_link_hash_traverse (&htab->elf, readonly_dynrelocs,
1954 (PTR) info);
1956 if ((info->flags & DF_TEXTREL) != 0)
1958 if (!add_dynamic_entry (DT_TEXTREL, 0))
1959 return FALSE;
1963 #undef add_dynamic_entry
1965 return TRUE;
1968 static bfd_boolean
1969 elf64_x86_64_always_size_sections (bfd *output_bfd,
1970 struct bfd_link_info *info)
1972 asection *tls_sec = elf_hash_table (info)->tls_sec;
1974 if (tls_sec)
1976 struct elf_link_hash_entry *tlsbase;
1978 tlsbase = elf_link_hash_lookup (elf_hash_table (info),
1979 "_TLS_MODULE_BASE_",
1980 FALSE, FALSE, FALSE);
1982 if (tlsbase && tlsbase->type == STT_TLS)
1984 struct bfd_link_hash_entry *bh = NULL;
1985 const struct elf_backend_data *bed
1986 = get_elf_backend_data (output_bfd);
1988 if (!(_bfd_generic_link_add_one_symbol
1989 (info, output_bfd, "_TLS_MODULE_BASE_", BSF_LOCAL,
1990 tls_sec, 0, NULL, FALSE,
1991 bed->collect, &bh)))
1992 return FALSE;
1993 tlsbase = (struct elf_link_hash_entry *)bh;
1994 tlsbase->def_regular = 1;
1995 tlsbase->other = STV_HIDDEN;
1996 (*bed->elf_backend_hide_symbol) (info, tlsbase, TRUE);
2000 return TRUE;
2003 /* Return the base VMA address which should be subtracted from real addresses
2004 when resolving @dtpoff relocation.
2005 This is PT_TLS segment p_vaddr. */
2007 static bfd_vma
2008 dtpoff_base (struct bfd_link_info *info)
2010 /* If tls_sec is NULL, we should have signalled an error already. */
2011 if (elf_hash_table (info)->tls_sec == NULL)
2012 return 0;
2013 return elf_hash_table (info)->tls_sec->vma;
2016 /* Return the relocation value for @tpoff relocation
2017 if STT_TLS virtual address is ADDRESS. */
2019 static bfd_vma
2020 tpoff (struct bfd_link_info *info, bfd_vma address)
2022 struct elf_link_hash_table *htab = elf_hash_table (info);
2024 /* If tls_segment is NULL, we should have signalled an error already. */
2025 if (htab->tls_sec == NULL)
2026 return 0;
2027 return address - htab->tls_size - htab->tls_sec->vma;
2030 /* Is the instruction before OFFSET in CONTENTS a 32bit relative
2031 branch? */
2033 static bfd_boolean
2034 is_32bit_relative_branch (bfd_byte *contents, bfd_vma offset)
2036 /* Opcode Instruction
2037 0xe8 call
2038 0xe9 jump
2039 0x0f 0x8x conditional jump */
2040 return ((offset > 0
2041 && (contents [offset - 1] == 0xe8
2042 || contents [offset - 1] == 0xe9))
2043 || (offset > 1
2044 && contents [offset - 2] == 0x0f
2045 && (contents [offset - 1] & 0xf0) == 0x80));
2048 /* Relocate an x86_64 ELF section. */
2050 static bfd_boolean
2051 elf64_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
2052 bfd *input_bfd, asection *input_section,
2053 bfd_byte *contents, Elf_Internal_Rela *relocs,
2054 Elf_Internal_Sym *local_syms,
2055 asection **local_sections)
2057 struct elf64_x86_64_link_hash_table *htab;
2058 Elf_Internal_Shdr *symtab_hdr;
2059 struct elf_link_hash_entry **sym_hashes;
2060 bfd_vma *local_got_offsets;
2061 bfd_vma *local_tlsdesc_gotents;
2062 Elf_Internal_Rela *rel;
2063 Elf_Internal_Rela *relend;
2065 if (info->relocatable)
2066 return TRUE;
2068 htab = elf64_x86_64_hash_table (info);
2069 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
2070 sym_hashes = elf_sym_hashes (input_bfd);
2071 local_got_offsets = elf_local_got_offsets (input_bfd);
2072 local_tlsdesc_gotents = elf64_x86_64_local_tlsdesc_gotent (input_bfd);
2074 rel = relocs;
2075 relend = relocs + input_section->reloc_count;
2076 for (; rel < relend; rel++)
2078 unsigned int r_type;
2079 reloc_howto_type *howto;
2080 unsigned long r_symndx;
2081 struct elf_link_hash_entry *h;
2082 Elf_Internal_Sym *sym;
2083 asection *sec;
2084 bfd_vma off, offplt;
2085 bfd_vma relocation;
2086 bfd_boolean unresolved_reloc;
2087 bfd_reloc_status_type r;
2088 int tls_type;
2090 r_type = ELF64_R_TYPE (rel->r_info);
2091 if (r_type == (int) R_X86_64_GNU_VTINHERIT
2092 || r_type == (int) R_X86_64_GNU_VTENTRY)
2093 continue;
2095 if (r_type >= R_X86_64_max)
2097 bfd_set_error (bfd_error_bad_value);
2098 return FALSE;
2101 howto = x86_64_elf_howto_table + r_type;
2102 r_symndx = ELF64_R_SYM (rel->r_info);
2103 h = NULL;
2104 sym = NULL;
2105 sec = NULL;
2106 unresolved_reloc = FALSE;
2107 if (r_symndx < symtab_hdr->sh_info)
2109 sym = local_syms + r_symndx;
2110 sec = local_sections[r_symndx];
2112 relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
2114 else
2116 bfd_boolean warned;
2118 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
2119 r_symndx, symtab_hdr, sym_hashes,
2120 h, sec, relocation,
2121 unresolved_reloc, warned);
2123 /* When generating a shared object, the relocations handled here are
2124 copied into the output file to be resolved at run time. */
2125 switch (r_type)
2127 asection *base_got;
2128 case R_X86_64_GOT32:
2129 case R_X86_64_GOT64:
2130 /* Relocation is to the entry for this symbol in the global
2131 offset table. */
2132 case R_X86_64_GOTPCREL:
2133 case R_X86_64_GOTPCREL64:
2134 /* Use global offset table entry as symbol value. */
2135 case R_X86_64_GOTPLT64:
2136 /* This is the same as GOT64 for relocation purposes, but
2137 indicates the existence of a PLT entry. The difficulty is,
2138 that we must calculate the GOT slot offset from the PLT
2139 offset, if this symbol got a PLT entry (it was global).
2140 Additionally if it's computed from the PLT entry, then that
2141 GOT offset is relative to .got.plt, not to .got. */
2142 base_got = htab->sgot;
2144 if (htab->sgot == NULL)
2145 abort ();
2147 if (h != NULL)
2149 bfd_boolean dyn;
2151 off = h->got.offset;
2152 if (h->needs_plt
2153 && h->plt.offset != (bfd_vma)-1
2154 && off == (bfd_vma)-1)
2156 /* We can't use h->got.offset here to save
2157 state, or even just remember the offset, as
2158 finish_dynamic_symbol would use that as offset into
2159 .got. */
2160 bfd_vma plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1;
2161 off = (plt_index + 3) * GOT_ENTRY_SIZE;
2162 base_got = htab->sgotplt;
2165 dyn = htab->elf.dynamic_sections_created;
2167 if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info->shared, h)
2168 || (info->shared
2169 && SYMBOL_REFERENCES_LOCAL (info, h))
2170 || (ELF_ST_VISIBILITY (h->other)
2171 && h->root.type == bfd_link_hash_undefweak))
2173 /* This is actually a static link, or it is a -Bsymbolic
2174 link and the symbol is defined locally, or the symbol
2175 was forced to be local because of a version file. We
2176 must initialize this entry in the global offset table.
2177 Since the offset must always be a multiple of 8, we
2178 use the least significant bit to record whether we
2179 have initialized it already.
2181 When doing a dynamic link, we create a .rela.got
2182 relocation entry to initialize the value. This is
2183 done in the finish_dynamic_symbol routine. */
2184 if ((off & 1) != 0)
2185 off &= ~1;
2186 else
2188 bfd_put_64 (output_bfd, relocation,
2189 base_got->contents + off);
2190 /* Note that this is harmless for the GOTPLT64 case,
2191 as -1 | 1 still is -1. */
2192 h->got.offset |= 1;
2195 else
2196 unresolved_reloc = FALSE;
2198 else
2200 if (local_got_offsets == NULL)
2201 abort ();
2203 off = local_got_offsets[r_symndx];
2205 /* The offset must always be a multiple of 8. We use
2206 the least significant bit to record whether we have
2207 already generated the necessary reloc. */
2208 if ((off & 1) != 0)
2209 off &= ~1;
2210 else
2212 bfd_put_64 (output_bfd, relocation,
2213 base_got->contents + off);
2215 if (info->shared)
2217 asection *s;
2218 Elf_Internal_Rela outrel;
2219 bfd_byte *loc;
2221 /* We need to generate a R_X86_64_RELATIVE reloc
2222 for the dynamic linker. */
2223 s = htab->srelgot;
2224 if (s == NULL)
2225 abort ();
2227 outrel.r_offset = (base_got->output_section->vma
2228 + base_got->output_offset
2229 + off);
2230 outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE);
2231 outrel.r_addend = relocation;
2232 loc = s->contents;
2233 loc += s->reloc_count++ * sizeof (Elf64_External_Rela);
2234 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2237 local_got_offsets[r_symndx] |= 1;
2241 if (off >= (bfd_vma) -2)
2242 abort ();
2244 relocation = base_got->output_section->vma
2245 + base_got->output_offset + off;
2246 if (r_type != R_X86_64_GOTPCREL && r_type != R_X86_64_GOTPCREL64)
2247 relocation -= htab->sgotplt->output_section->vma
2248 - htab->sgotplt->output_offset;
2250 break;
2252 case R_X86_64_GOTOFF64:
2253 /* Relocation is relative to the start of the global offset
2254 table. */
2256 /* Check to make sure it isn't a protected function symbol
2257 for shared library since it may not be local when used
2258 as function address. */
2259 if (info->shared
2260 && h
2261 && h->def_regular
2262 && h->type == STT_FUNC
2263 && ELF_ST_VISIBILITY (h->other) == STV_PROTECTED)
2265 (*_bfd_error_handler)
2266 (_("%B: relocation R_X86_64_GOTOFF64 against protected function `%s' can not be used when making a shared object"),
2267 input_bfd, h->root.root.string);
2268 bfd_set_error (bfd_error_bad_value);
2269 return FALSE;
2272 /* Note that sgot is not involved in this
2273 calculation. We always want the start of .got.plt. If we
2274 defined _GLOBAL_OFFSET_TABLE_ in a different way, as is
2275 permitted by the ABI, we might have to change this
2276 calculation. */
2277 relocation -= htab->sgotplt->output_section->vma
2278 + htab->sgotplt->output_offset;
2279 break;
2281 case R_X86_64_GOTPC32:
2282 case R_X86_64_GOTPC64:
2283 /* Use global offset table as symbol value. */
2284 relocation = htab->sgotplt->output_section->vma
2285 + htab->sgotplt->output_offset;
2286 unresolved_reloc = FALSE;
2287 break;
2289 case R_X86_64_PLTOFF64:
2290 /* Relocation is PLT entry relative to GOT. For local
2291 symbols it's the symbol itself relative to GOT. */
2292 if (h != NULL
2293 /* See PLT32 handling. */
2294 && h->plt.offset != (bfd_vma) -1
2295 && htab->splt != NULL)
2297 relocation = (htab->splt->output_section->vma
2298 + htab->splt->output_offset
2299 + h->plt.offset);
2300 unresolved_reloc = FALSE;
2303 relocation -= htab->sgotplt->output_section->vma
2304 + htab->sgotplt->output_offset;
2305 break;
2307 case R_X86_64_PLT32:
2308 /* Relocation is to the entry for this symbol in the
2309 procedure linkage table. */
2311 /* Resolve a PLT32 reloc against a local symbol directly,
2312 without using the procedure linkage table. */
2313 if (h == NULL)
2314 break;
2316 if (h->plt.offset == (bfd_vma) -1
2317 || htab->splt == NULL)
2319 /* We didn't make a PLT entry for this symbol. This
2320 happens when statically linking PIC code, or when
2321 using -Bsymbolic. */
2322 break;
2325 relocation = (htab->splt->output_section->vma
2326 + htab->splt->output_offset
2327 + h->plt.offset);
2328 unresolved_reloc = FALSE;
2329 break;
2331 case R_X86_64_PC8:
2332 case R_X86_64_PC16:
2333 case R_X86_64_PC32:
2334 if (info->shared
2335 && !SYMBOL_REFERENCES_LOCAL (info, h)
2336 && (input_section->flags & SEC_ALLOC) != 0
2337 && (input_section->flags & SEC_READONLY) != 0
2338 && (!h->def_regular
2339 || r_type != R_X86_64_PC32
2340 || h->type != STT_FUNC
2341 || ELF_ST_VISIBILITY (h->other) != STV_PROTECTED
2342 || !is_32bit_relative_branch (contents,
2343 rel->r_offset)))
2345 if (h->def_regular
2346 && r_type == R_X86_64_PC32
2347 && h->type == STT_FUNC
2348 && ELF_ST_VISIBILITY (h->other) == STV_PROTECTED)
2349 (*_bfd_error_handler)
2350 (_("%B: relocation R_X86_64_PC32 against protected function `%s' can not be used when making a shared object"),
2351 input_bfd, h->root.root.string);
2352 else
2353 (*_bfd_error_handler)
2354 (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
2355 input_bfd, x86_64_elf_howto_table[r_type].name,
2356 h->root.root.string);
2357 bfd_set_error (bfd_error_bad_value);
2358 return FALSE;
2360 /* Fall through. */
2362 case R_X86_64_8:
2363 case R_X86_64_16:
2364 case R_X86_64_32:
2365 case R_X86_64_PC64:
2366 case R_X86_64_64:
2367 /* FIXME: The ABI says the linker should make sure the value is
2368 the same when it's zeroextended to 64 bit. */
2370 /* r_symndx will be zero only for relocs against symbols
2371 from removed linkonce sections, or sections discarded by
2372 a linker script. */
2373 if (r_symndx == 0)
2375 _bfd_clear_contents (howto, input_bfd, contents + rel->r_offset);
2376 break;
2379 if ((input_section->flags & SEC_ALLOC) == 0)
2380 break;
2382 if ((info->shared
2383 && (h == NULL
2384 || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
2385 || h->root.type != bfd_link_hash_undefweak)
2386 && ((r_type != R_X86_64_PC8
2387 && r_type != R_X86_64_PC16
2388 && r_type != R_X86_64_PC32
2389 && r_type != R_X86_64_PC64)
2390 || !SYMBOL_CALLS_LOCAL (info, h)))
2391 || (ELIMINATE_COPY_RELOCS
2392 && !info->shared
2393 && h != NULL
2394 && h->dynindx != -1
2395 && !h->non_got_ref
2396 && ((h->def_dynamic
2397 && !h->def_regular)
2398 || h->root.type == bfd_link_hash_undefweak
2399 || h->root.type == bfd_link_hash_undefined)))
2401 Elf_Internal_Rela outrel;
2402 bfd_byte *loc;
2403 bfd_boolean skip, relocate;
2404 asection *sreloc;
2406 /* When generating a shared object, these relocations
2407 are copied into the output file to be resolved at run
2408 time. */
2409 skip = FALSE;
2410 relocate = FALSE;
2412 outrel.r_offset =
2413 _bfd_elf_section_offset (output_bfd, info, input_section,
2414 rel->r_offset);
2415 if (outrel.r_offset == (bfd_vma) -1)
2416 skip = TRUE;
2417 else if (outrel.r_offset == (bfd_vma) -2)
2418 skip = TRUE, relocate = TRUE;
2420 outrel.r_offset += (input_section->output_section->vma
2421 + input_section->output_offset);
2423 if (skip)
2424 memset (&outrel, 0, sizeof outrel);
2426 /* h->dynindx may be -1 if this symbol was marked to
2427 become local. */
2428 else if (h != NULL
2429 && h->dynindx != -1
2430 && (r_type == R_X86_64_PC8
2431 || r_type == R_X86_64_PC16
2432 || r_type == R_X86_64_PC32
2433 || r_type == R_X86_64_PC64
2434 || !info->shared
2435 || !SYMBOLIC_BIND (info, h)
2436 || !h->def_regular))
2438 outrel.r_info = ELF64_R_INFO (h->dynindx, r_type);
2439 outrel.r_addend = rel->r_addend;
2441 else
2443 /* This symbol is local, or marked to become local. */
2444 if (r_type == R_X86_64_64)
2446 relocate = TRUE;
2447 outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE);
2448 outrel.r_addend = relocation + rel->r_addend;
2450 else
2452 long sindx;
2454 if (bfd_is_abs_section (sec))
2455 sindx = 0;
2456 else if (sec == NULL || sec->owner == NULL)
2458 bfd_set_error (bfd_error_bad_value);
2459 return FALSE;
2461 else
2463 asection *osec;
2465 /* We are turning this relocation into one
2466 against a section symbol. It would be
2467 proper to subtract the symbol's value,
2468 osec->vma, from the emitted reloc addend,
2469 but ld.so expects buggy relocs. */
2470 osec = sec->output_section;
2471 sindx = elf_section_data (osec)->dynindx;
2472 if (sindx == 0)
2474 asection *oi = htab->elf.text_index_section;
2475 sindx = elf_section_data (oi)->dynindx;
2477 BFD_ASSERT (sindx != 0);
2480 outrel.r_info = ELF64_R_INFO (sindx, r_type);
2481 outrel.r_addend = relocation + rel->r_addend;
2485 sreloc = elf_section_data (input_section)->sreloc;
2486 if (sreloc == NULL)
2487 abort ();
2489 loc = sreloc->contents;
2490 loc += sreloc->reloc_count++ * sizeof (Elf64_External_Rela);
2491 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2493 /* If this reloc is against an external symbol, we do
2494 not want to fiddle with the addend. Otherwise, we
2495 need to include the symbol value so that it becomes
2496 an addend for the dynamic reloc. */
2497 if (! relocate)
2498 continue;
2501 break;
2503 case R_X86_64_TLSGD:
2504 case R_X86_64_GOTPC32_TLSDESC:
2505 case R_X86_64_TLSDESC_CALL:
2506 case R_X86_64_GOTTPOFF:
2507 r_type = elf64_x86_64_tls_transition (info, r_type, h == NULL);
2508 tls_type = GOT_UNKNOWN;
2509 if (h == NULL && local_got_offsets)
2510 tls_type = elf64_x86_64_local_got_tls_type (input_bfd) [r_symndx];
2511 else if (h != NULL)
2513 tls_type = elf64_x86_64_hash_entry (h)->tls_type;
2514 if (!info->shared && h->dynindx == -1 && tls_type == GOT_TLS_IE)
2515 r_type = R_X86_64_TPOFF32;
2517 if (r_type == R_X86_64_TLSGD
2518 || r_type == R_X86_64_GOTPC32_TLSDESC
2519 || r_type == R_X86_64_TLSDESC_CALL)
2521 if (tls_type == GOT_TLS_IE)
2522 r_type = R_X86_64_GOTTPOFF;
2525 if (r_type == R_X86_64_TPOFF32)
2527 BFD_ASSERT (! unresolved_reloc);
2528 if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSGD)
2530 unsigned int i;
2531 static unsigned char tlsgd[8]
2532 = { 0x66, 0x48, 0x8d, 0x3d, 0x66, 0x66, 0x48, 0xe8 };
2534 /* GD->LE transition.
2535 .byte 0x66; leaq foo@tlsgd(%rip), %rdi
2536 .word 0x6666; rex64; call __tls_get_addr@plt
2537 Change it into:
2538 movq %fs:0, %rax
2539 leaq foo@tpoff(%rax), %rax */
2540 BFD_ASSERT (rel->r_offset >= 4);
2541 for (i = 0; i < 4; i++)
2542 BFD_ASSERT (bfd_get_8 (input_bfd,
2543 contents + rel->r_offset - 4 + i)
2544 == tlsgd[i]);
2545 BFD_ASSERT (rel->r_offset + 12 <= input_section->size);
2546 for (i = 0; i < 4; i++)
2547 BFD_ASSERT (bfd_get_8 (input_bfd,
2548 contents + rel->r_offset + 4 + i)
2549 == tlsgd[i+4]);
2550 BFD_ASSERT (rel + 1 < relend);
2551 BFD_ASSERT (ELF64_R_TYPE (rel[1].r_info) == R_X86_64_PLT32);
2552 memcpy (contents + rel->r_offset - 4,
2553 "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0",
2554 16);
2555 bfd_put_32 (output_bfd, tpoff (info, relocation),
2556 contents + rel->r_offset + 8);
2557 /* Skip R_X86_64_PLT32. */
2558 rel++;
2559 continue;
2561 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_GOTPC32_TLSDESC)
2563 /* GDesc -> LE transition.
2564 It's originally something like:
2565 leaq x@tlsdesc(%rip), %rax
2567 Change it to:
2568 movl $x@tpoff, %rax
2570 Registers other than %rax may be set up here. */
2572 unsigned int val, type, type2;
2573 bfd_vma roff;
2575 /* First, make sure it's a leaq adding rip to a
2576 32-bit offset into any register, although it's
2577 probably almost always going to be rax. */
2578 roff = rel->r_offset;
2579 BFD_ASSERT (roff >= 3);
2580 type = bfd_get_8 (input_bfd, contents + roff - 3);
2581 BFD_ASSERT ((type & 0xfb) == 0x48);
2582 type2 = bfd_get_8 (input_bfd, contents + roff - 2);
2583 BFD_ASSERT (type2 == 0x8d);
2584 val = bfd_get_8 (input_bfd, contents + roff - 1);
2585 BFD_ASSERT ((val & 0xc7) == 0x05);
2586 BFD_ASSERT (roff + 4 <= input_section->size);
2588 /* Now modify the instruction as appropriate. */
2589 bfd_put_8 (output_bfd, 0x48 | ((type >> 2) & 1),
2590 contents + roff - 3);
2591 bfd_put_8 (output_bfd, 0xc7, contents + roff - 2);
2592 bfd_put_8 (output_bfd, 0xc0 | ((val >> 3) & 7),
2593 contents + roff - 1);
2594 bfd_put_32 (output_bfd, tpoff (info, relocation),
2595 contents + roff);
2596 continue;
2598 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSDESC_CALL)
2600 /* GDesc -> LE transition.
2601 It's originally:
2602 call *(%rax)
2603 Turn it into:
2604 nop; nop. */
2606 unsigned int val, type;
2607 bfd_vma roff;
2609 /* First, make sure it's a call *(%rax). */
2610 roff = rel->r_offset;
2611 BFD_ASSERT (roff + 2 <= input_section->size);
2612 type = bfd_get_8 (input_bfd, contents + roff);
2613 BFD_ASSERT (type == 0xff);
2614 val = bfd_get_8 (input_bfd, contents + roff + 1);
2615 BFD_ASSERT (val == 0x10);
2617 /* Now modify the instruction as appropriate. Use
2618 xchg %ax,%ax instead of 2 nops. */
2619 bfd_put_8 (output_bfd, 0x66, contents + roff);
2620 bfd_put_8 (output_bfd, 0x90, contents + roff + 1);
2621 continue;
2623 else
2625 unsigned int val, type, reg;
2627 /* IE->LE transition:
2628 Originally it can be one of:
2629 movq foo@gottpoff(%rip), %reg
2630 addq foo@gottpoff(%rip), %reg
2631 We change it into:
2632 movq $foo, %reg
2633 leaq foo(%reg), %reg
2634 addq $foo, %reg. */
2635 BFD_ASSERT (rel->r_offset >= 3);
2636 val = bfd_get_8 (input_bfd, contents + rel->r_offset - 3);
2637 BFD_ASSERT (val == 0x48 || val == 0x4c);
2638 type = bfd_get_8 (input_bfd, contents + rel->r_offset - 2);
2639 BFD_ASSERT (type == 0x8b || type == 0x03);
2640 reg = bfd_get_8 (input_bfd, contents + rel->r_offset - 1);
2641 BFD_ASSERT ((reg & 0xc7) == 5);
2642 reg >>= 3;
2643 BFD_ASSERT (rel->r_offset + 4 <= input_section->size);
2644 if (type == 0x8b)
2646 /* movq */
2647 if (val == 0x4c)
2648 bfd_put_8 (output_bfd, 0x49,
2649 contents + rel->r_offset - 3);
2650 bfd_put_8 (output_bfd, 0xc7,
2651 contents + rel->r_offset - 2);
2652 bfd_put_8 (output_bfd, 0xc0 | reg,
2653 contents + rel->r_offset - 1);
2655 else if (reg == 4)
2657 /* addq -> addq - addressing with %rsp/%r12 is
2658 special */
2659 if (val == 0x4c)
2660 bfd_put_8 (output_bfd, 0x49,
2661 contents + rel->r_offset - 3);
2662 bfd_put_8 (output_bfd, 0x81,
2663 contents + rel->r_offset - 2);
2664 bfd_put_8 (output_bfd, 0xc0 | reg,
2665 contents + rel->r_offset - 1);
2667 else
2669 /* addq -> leaq */
2670 if (val == 0x4c)
2671 bfd_put_8 (output_bfd, 0x4d,
2672 contents + rel->r_offset - 3);
2673 bfd_put_8 (output_bfd, 0x8d,
2674 contents + rel->r_offset - 2);
2675 bfd_put_8 (output_bfd, 0x80 | reg | (reg << 3),
2676 contents + rel->r_offset - 1);
2678 bfd_put_32 (output_bfd, tpoff (info, relocation),
2679 contents + rel->r_offset);
2680 continue;
2684 if (htab->sgot == NULL)
2685 abort ();
2687 if (h != NULL)
2689 off = h->got.offset;
2690 offplt = elf64_x86_64_hash_entry (h)->tlsdesc_got;
2692 else
2694 if (local_got_offsets == NULL)
2695 abort ();
2697 off = local_got_offsets[r_symndx];
2698 offplt = local_tlsdesc_gotents[r_symndx];
2701 if ((off & 1) != 0)
2702 off &= ~1;
2703 else
2705 Elf_Internal_Rela outrel;
2706 bfd_byte *loc;
2707 int dr_type, indx;
2708 asection *sreloc;
2710 if (htab->srelgot == NULL)
2711 abort ();
2713 indx = h && h->dynindx != -1 ? h->dynindx : 0;
2715 if (GOT_TLS_GDESC_P (tls_type))
2717 outrel.r_info = ELF64_R_INFO (indx, R_X86_64_TLSDESC);
2718 BFD_ASSERT (htab->sgotplt_jump_table_size + offplt
2719 + 2 * GOT_ENTRY_SIZE <= htab->sgotplt->size);
2720 outrel.r_offset = (htab->sgotplt->output_section->vma
2721 + htab->sgotplt->output_offset
2722 + offplt
2723 + htab->sgotplt_jump_table_size);
2724 sreloc = htab->srelplt;
2725 loc = sreloc->contents;
2726 loc += sreloc->reloc_count++
2727 * sizeof (Elf64_External_Rela);
2728 BFD_ASSERT (loc + sizeof (Elf64_External_Rela)
2729 <= sreloc->contents + sreloc->size);
2730 if (indx == 0)
2731 outrel.r_addend = relocation - dtpoff_base (info);
2732 else
2733 outrel.r_addend = 0;
2734 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2737 sreloc = htab->srelgot;
2739 outrel.r_offset = (htab->sgot->output_section->vma
2740 + htab->sgot->output_offset + off);
2742 if (GOT_TLS_GD_P (tls_type))
2743 dr_type = R_X86_64_DTPMOD64;
2744 else if (GOT_TLS_GDESC_P (tls_type))
2745 goto dr_done;
2746 else
2747 dr_type = R_X86_64_TPOFF64;
2749 bfd_put_64 (output_bfd, 0, htab->sgot->contents + off);
2750 outrel.r_addend = 0;
2751 if ((dr_type == R_X86_64_TPOFF64
2752 || dr_type == R_X86_64_TLSDESC) && indx == 0)
2753 outrel.r_addend = relocation - dtpoff_base (info);
2754 outrel.r_info = ELF64_R_INFO (indx, dr_type);
2756 loc = sreloc->contents;
2757 loc += sreloc->reloc_count++ * sizeof (Elf64_External_Rela);
2758 BFD_ASSERT (loc + sizeof (Elf64_External_Rela)
2759 <= sreloc->contents + sreloc->size);
2760 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2762 if (GOT_TLS_GD_P (tls_type))
2764 if (indx == 0)
2766 BFD_ASSERT (! unresolved_reloc);
2767 bfd_put_64 (output_bfd,
2768 relocation - dtpoff_base (info),
2769 htab->sgot->contents + off + GOT_ENTRY_SIZE);
2771 else
2773 bfd_put_64 (output_bfd, 0,
2774 htab->sgot->contents + off + GOT_ENTRY_SIZE);
2775 outrel.r_info = ELF64_R_INFO (indx,
2776 R_X86_64_DTPOFF64);
2777 outrel.r_offset += GOT_ENTRY_SIZE;
2778 sreloc->reloc_count++;
2779 loc += sizeof (Elf64_External_Rela);
2780 BFD_ASSERT (loc + sizeof (Elf64_External_Rela)
2781 <= sreloc->contents + sreloc->size);
2782 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2786 dr_done:
2787 if (h != NULL)
2788 h->got.offset |= 1;
2789 else
2790 local_got_offsets[r_symndx] |= 1;
2793 if (off >= (bfd_vma) -2
2794 && ! GOT_TLS_GDESC_P (tls_type))
2795 abort ();
2796 if (r_type == ELF64_R_TYPE (rel->r_info))
2798 if (r_type == R_X86_64_GOTPC32_TLSDESC
2799 || r_type == R_X86_64_TLSDESC_CALL)
2800 relocation = htab->sgotplt->output_section->vma
2801 + htab->sgotplt->output_offset
2802 + offplt + htab->sgotplt_jump_table_size;
2803 else
2804 relocation = htab->sgot->output_section->vma
2805 + htab->sgot->output_offset + off;
2806 unresolved_reloc = FALSE;
2808 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSGD)
2810 unsigned int i;
2811 static unsigned char tlsgd[8]
2812 = { 0x66, 0x48, 0x8d, 0x3d, 0x66, 0x66, 0x48, 0xe8 };
2814 /* GD->IE transition.
2815 .byte 0x66; leaq foo@tlsgd(%rip), %rdi
2816 .word 0x6666; rex64; call __tls_get_addr@plt
2817 Change it into:
2818 movq %fs:0, %rax
2819 addq foo@gottpoff(%rip), %rax */
2820 BFD_ASSERT (rel->r_offset >= 4);
2821 for (i = 0; i < 4; i++)
2822 BFD_ASSERT (bfd_get_8 (input_bfd,
2823 contents + rel->r_offset - 4 + i)
2824 == tlsgd[i]);
2825 BFD_ASSERT (rel->r_offset + 12 <= input_section->size);
2826 for (i = 0; i < 4; i++)
2827 BFD_ASSERT (bfd_get_8 (input_bfd,
2828 contents + rel->r_offset + 4 + i)
2829 == tlsgd[i+4]);
2830 BFD_ASSERT (rel + 1 < relend);
2831 BFD_ASSERT (ELF64_R_TYPE (rel[1].r_info) == R_X86_64_PLT32);
2832 memcpy (contents + rel->r_offset - 4,
2833 "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0",
2834 16);
2836 relocation = (htab->sgot->output_section->vma
2837 + htab->sgot->output_offset + off
2838 - rel->r_offset
2839 - input_section->output_section->vma
2840 - input_section->output_offset
2841 - 12);
2842 bfd_put_32 (output_bfd, relocation,
2843 contents + rel->r_offset + 8);
2844 /* Skip R_X86_64_PLT32. */
2845 rel++;
2846 continue;
2848 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_GOTPC32_TLSDESC)
2850 /* GDesc -> IE transition.
2851 It's originally something like:
2852 leaq x@tlsdesc(%rip), %rax
2854 Change it to:
2855 movq x@gottpoff(%rip), %rax # before nop; nop
2857 Registers other than %rax may be set up here. */
2859 unsigned int val, type, type2;
2860 bfd_vma roff;
2862 /* First, make sure it's a leaq adding rip to a 32-bit
2863 offset into any register, although it's probably
2864 almost always going to be rax. */
2865 roff = rel->r_offset;
2866 BFD_ASSERT (roff >= 3);
2867 type = bfd_get_8 (input_bfd, contents + roff - 3);
2868 BFD_ASSERT ((type & 0xfb) == 0x48);
2869 type2 = bfd_get_8 (input_bfd, contents + roff - 2);
2870 BFD_ASSERT (type2 == 0x8d);
2871 val = bfd_get_8 (input_bfd, contents + roff - 1);
2872 BFD_ASSERT ((val & 0xc7) == 0x05);
2873 BFD_ASSERT (roff + 4 <= input_section->size);
2875 /* Now modify the instruction as appropriate. */
2876 /* To turn a leaq into a movq in the form we use it, it
2877 suffices to change the second byte from 0x8d to
2878 0x8b. */
2879 bfd_put_8 (output_bfd, 0x8b, contents + roff - 2);
2881 bfd_put_32 (output_bfd,
2882 htab->sgot->output_section->vma
2883 + htab->sgot->output_offset + off
2884 - rel->r_offset
2885 - input_section->output_section->vma
2886 - input_section->output_offset
2887 - 4,
2888 contents + roff);
2889 continue;
2891 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSDESC_CALL)
2893 /* GDesc -> IE transition.
2894 It's originally:
2895 call *(%rax)
2897 Change it to:
2898 nop; nop. */
2900 unsigned int val, type;
2901 bfd_vma roff;
2903 /* First, make sure it's a call *(%eax). */
2904 roff = rel->r_offset;
2905 BFD_ASSERT (roff + 2 <= input_section->size);
2906 type = bfd_get_8 (input_bfd, contents + roff);
2907 BFD_ASSERT (type == 0xff);
2908 val = bfd_get_8 (input_bfd, contents + roff + 1);
2909 BFD_ASSERT (val == 0x10);
2911 /* Now modify the instruction as appropriate. Use
2912 xchg %ax,%ax instead of 2 nops. */
2913 bfd_put_8 (output_bfd, 0x66, contents + roff);
2914 bfd_put_8 (output_bfd, 0x90, contents + roff + 1);
2916 continue;
2918 else
2919 BFD_ASSERT (FALSE);
2920 break;
2922 case R_X86_64_TLSLD:
2923 if (! info->shared)
2925 /* LD->LE transition:
2926 Ensure it is:
2927 leaq foo@tlsld(%rip), %rdi; call __tls_get_addr@plt.
2928 We change it into:
2929 .word 0x6666; .byte 0x66; movl %fs:0, %rax. */
2930 BFD_ASSERT (rel->r_offset >= 3);
2931 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset - 3)
2932 == 0x48);
2933 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset - 2)
2934 == 0x8d);
2935 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset - 1)
2936 == 0x3d);
2937 BFD_ASSERT (rel->r_offset + 9 <= input_section->size);
2938 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset + 4)
2939 == 0xe8);
2940 BFD_ASSERT (rel + 1 < relend);
2941 BFD_ASSERT (ELF64_R_TYPE (rel[1].r_info) == R_X86_64_PLT32);
2942 memcpy (contents + rel->r_offset - 3,
2943 "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0", 12);
2944 /* Skip R_X86_64_PLT32. */
2945 rel++;
2946 continue;
2949 if (htab->sgot == NULL)
2950 abort ();
2952 off = htab->tls_ld_got.offset;
2953 if (off & 1)
2954 off &= ~1;
2955 else
2957 Elf_Internal_Rela outrel;
2958 bfd_byte *loc;
2960 if (htab->srelgot == NULL)
2961 abort ();
2963 outrel.r_offset = (htab->sgot->output_section->vma
2964 + htab->sgot->output_offset + off);
2966 bfd_put_64 (output_bfd, 0,
2967 htab->sgot->contents + off);
2968 bfd_put_64 (output_bfd, 0,
2969 htab->sgot->contents + off + GOT_ENTRY_SIZE);
2970 outrel.r_info = ELF64_R_INFO (0, R_X86_64_DTPMOD64);
2971 outrel.r_addend = 0;
2972 loc = htab->srelgot->contents;
2973 loc += htab->srelgot->reloc_count++ * sizeof (Elf64_External_Rela);
2974 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2975 htab->tls_ld_got.offset |= 1;
2977 relocation = htab->sgot->output_section->vma
2978 + htab->sgot->output_offset + off;
2979 unresolved_reloc = FALSE;
2980 break;
2982 case R_X86_64_DTPOFF32:
2983 if (info->shared || (input_section->flags & SEC_CODE) == 0)
2984 relocation -= dtpoff_base (info);
2985 else
2986 relocation = tpoff (info, relocation);
2987 break;
2989 case R_X86_64_TPOFF32:
2990 BFD_ASSERT (! info->shared);
2991 relocation = tpoff (info, relocation);
2992 break;
2994 default:
2995 break;
2998 /* Dynamic relocs are not propagated for SEC_DEBUGGING sections
2999 because such sections are not SEC_ALLOC and thus ld.so will
3000 not process them. */
3001 if (unresolved_reloc
3002 && !((input_section->flags & SEC_DEBUGGING) != 0
3003 && h->def_dynamic))
3004 (*_bfd_error_handler)
3005 (_("%B(%A+0x%lx): unresolvable %s relocation against symbol `%s'"),
3006 input_bfd,
3007 input_section,
3008 (long) rel->r_offset,
3009 howto->name,
3010 h->root.root.string);
3012 r = _bfd_final_link_relocate (howto, input_bfd, input_section,
3013 contents, rel->r_offset,
3014 relocation, rel->r_addend);
3016 if (r != bfd_reloc_ok)
3018 const char *name;
3020 if (h != NULL)
3021 name = h->root.root.string;
3022 else
3024 name = bfd_elf_string_from_elf_section (input_bfd,
3025 symtab_hdr->sh_link,
3026 sym->st_name);
3027 if (name == NULL)
3028 return FALSE;
3029 if (*name == '\0')
3030 name = bfd_section_name (input_bfd, sec);
3033 if (r == bfd_reloc_overflow)
3035 if (! ((*info->callbacks->reloc_overflow)
3036 (info, (h ? &h->root : NULL), name, howto->name,
3037 (bfd_vma) 0, input_bfd, input_section,
3038 rel->r_offset)))
3039 return FALSE;
3041 else
3043 (*_bfd_error_handler)
3044 (_("%B(%A+0x%lx): reloc against `%s': error %d"),
3045 input_bfd, input_section,
3046 (long) rel->r_offset, name, (int) r);
3047 return FALSE;
3052 return TRUE;
3055 /* Finish up dynamic symbol handling. We set the contents of various
3056 dynamic sections here. */
3058 static bfd_boolean
3059 elf64_x86_64_finish_dynamic_symbol (bfd *output_bfd,
3060 struct bfd_link_info *info,
3061 struct elf_link_hash_entry *h,
3062 Elf_Internal_Sym *sym)
3064 struct elf64_x86_64_link_hash_table *htab;
3066 htab = elf64_x86_64_hash_table (info);
3068 if (h->plt.offset != (bfd_vma) -1)
3070 bfd_vma plt_index;
3071 bfd_vma got_offset;
3072 Elf_Internal_Rela rela;
3073 bfd_byte *loc;
3075 /* This symbol has an entry in the procedure linkage table. Set
3076 it up. */
3077 if (h->dynindx == -1
3078 || htab->splt == NULL
3079 || htab->sgotplt == NULL
3080 || htab->srelplt == NULL)
3081 abort ();
3083 /* Get the index in the procedure linkage table which
3084 corresponds to this symbol. This is the index of this symbol
3085 in all the symbols for which we are making plt entries. The
3086 first entry in the procedure linkage table is reserved. */
3087 plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1;
3089 /* Get the offset into the .got table of the entry that
3090 corresponds to this function. Each .got entry is GOT_ENTRY_SIZE
3091 bytes. The first three are reserved for the dynamic linker. */
3092 got_offset = (plt_index + 3) * GOT_ENTRY_SIZE;
3094 /* Fill in the entry in the procedure linkage table. */
3095 memcpy (htab->splt->contents + h->plt.offset, elf64_x86_64_plt_entry,
3096 PLT_ENTRY_SIZE);
3098 /* Insert the relocation positions of the plt section. The magic
3099 numbers at the end of the statements are the positions of the
3100 relocations in the plt section. */
3101 /* Put offset for jmp *name@GOTPCREL(%rip), since the
3102 instruction uses 6 bytes, subtract this value. */
3103 bfd_put_32 (output_bfd,
3104 (htab->sgotplt->output_section->vma
3105 + htab->sgotplt->output_offset
3106 + got_offset
3107 - htab->splt->output_section->vma
3108 - htab->splt->output_offset
3109 - h->plt.offset
3110 - 6),
3111 htab->splt->contents + h->plt.offset + 2);
3112 /* Put relocation index. */
3113 bfd_put_32 (output_bfd, plt_index,
3114 htab->splt->contents + h->plt.offset + 7);
3115 /* Put offset for jmp .PLT0. */
3116 bfd_put_32 (output_bfd, - (h->plt.offset + PLT_ENTRY_SIZE),
3117 htab->splt->contents + h->plt.offset + 12);
3119 /* Fill in the entry in the global offset table, initially this
3120 points to the pushq instruction in the PLT which is at offset 6. */
3121 bfd_put_64 (output_bfd, (htab->splt->output_section->vma
3122 + htab->splt->output_offset
3123 + h->plt.offset + 6),
3124 htab->sgotplt->contents + got_offset);
3126 /* Fill in the entry in the .rela.plt section. */
3127 rela.r_offset = (htab->sgotplt->output_section->vma
3128 + htab->sgotplt->output_offset
3129 + got_offset);
3130 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_JUMP_SLOT);
3131 rela.r_addend = 0;
3132 loc = htab->srelplt->contents + plt_index * sizeof (Elf64_External_Rela);
3133 bfd_elf64_swap_reloca_out (output_bfd, &rela, loc);
3135 if (!h->def_regular)
3137 /* Mark the symbol as undefined, rather than as defined in
3138 the .plt section. Leave the value if there were any
3139 relocations where pointer equality matters (this is a clue
3140 for the dynamic linker, to make function pointer
3141 comparisons work between an application and shared
3142 library), otherwise set it to zero. If a function is only
3143 called from a binary, there is no need to slow down
3144 shared libraries because of that. */
3145 sym->st_shndx = SHN_UNDEF;
3146 if (!h->pointer_equality_needed)
3147 sym->st_value = 0;
3151 if (h->got.offset != (bfd_vma) -1
3152 && ! GOT_TLS_GD_ANY_P (elf64_x86_64_hash_entry (h)->tls_type)
3153 && elf64_x86_64_hash_entry (h)->tls_type != GOT_TLS_IE)
3155 Elf_Internal_Rela rela;
3156 bfd_byte *loc;
3158 /* This symbol has an entry in the global offset table. Set it
3159 up. */
3160 if (htab->sgot == NULL || htab->srelgot == NULL)
3161 abort ();
3163 rela.r_offset = (htab->sgot->output_section->vma
3164 + htab->sgot->output_offset
3165 + (h->got.offset &~ (bfd_vma) 1));
3167 /* If this is a static link, or it is a -Bsymbolic link and the
3168 symbol is defined locally or was forced to be local because
3169 of a version file, we just want to emit a RELATIVE reloc.
3170 The entry in the global offset table will already have been
3171 initialized in the relocate_section function. */
3172 if (info->shared
3173 && SYMBOL_REFERENCES_LOCAL (info, h))
3175 BFD_ASSERT((h->got.offset & 1) != 0);
3176 rela.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE);
3177 rela.r_addend = (h->root.u.def.value
3178 + h->root.u.def.section->output_section->vma
3179 + h->root.u.def.section->output_offset);
3181 else
3183 BFD_ASSERT((h->got.offset & 1) == 0);
3184 bfd_put_64 (output_bfd, (bfd_vma) 0,
3185 htab->sgot->contents + h->got.offset);
3186 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_GLOB_DAT);
3187 rela.r_addend = 0;
3190 loc = htab->srelgot->contents;
3191 loc += htab->srelgot->reloc_count++ * sizeof (Elf64_External_Rela);
3192 bfd_elf64_swap_reloca_out (output_bfd, &rela, loc);
3195 if (h->needs_copy)
3197 Elf_Internal_Rela rela;
3198 bfd_byte *loc;
3200 /* This symbol needs a copy reloc. Set it up. */
3202 if (h->dynindx == -1
3203 || (h->root.type != bfd_link_hash_defined
3204 && h->root.type != bfd_link_hash_defweak)
3205 || htab->srelbss == NULL)
3206 abort ();
3208 rela.r_offset = (h->root.u.def.value
3209 + h->root.u.def.section->output_section->vma
3210 + h->root.u.def.section->output_offset);
3211 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_COPY);
3212 rela.r_addend = 0;
3213 loc = htab->srelbss->contents;
3214 loc += htab->srelbss->reloc_count++ * sizeof (Elf64_External_Rela);
3215 bfd_elf64_swap_reloca_out (output_bfd, &rela, loc);
3218 /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */
3219 if (strcmp (h->root.root.string, "_DYNAMIC") == 0
3220 || h == htab->elf.hgot)
3221 sym->st_shndx = SHN_ABS;
3223 return TRUE;
3226 /* Used to decide how to sort relocs in an optimal manner for the
3227 dynamic linker, before writing them out. */
3229 static enum elf_reloc_type_class
3230 elf64_x86_64_reloc_type_class (const Elf_Internal_Rela *rela)
3232 switch ((int) ELF64_R_TYPE (rela->r_info))
3234 case R_X86_64_RELATIVE:
3235 return reloc_class_relative;
3236 case R_X86_64_JUMP_SLOT:
3237 return reloc_class_plt;
3238 case R_X86_64_COPY:
3239 return reloc_class_copy;
3240 default:
3241 return reloc_class_normal;
3245 /* Finish up the dynamic sections. */
3247 static bfd_boolean
3248 elf64_x86_64_finish_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info)
3250 struct elf64_x86_64_link_hash_table *htab;
3251 bfd *dynobj;
3252 asection *sdyn;
3254 htab = elf64_x86_64_hash_table (info);
3255 dynobj = htab->elf.dynobj;
3256 sdyn = bfd_get_section_by_name (dynobj, ".dynamic");
3258 if (htab->elf.dynamic_sections_created)
3260 Elf64_External_Dyn *dyncon, *dynconend;
3262 if (sdyn == NULL || htab->sgot == NULL)
3263 abort ();
3265 dyncon = (Elf64_External_Dyn *) sdyn->contents;
3266 dynconend = (Elf64_External_Dyn *) (sdyn->contents + sdyn->size);
3267 for (; dyncon < dynconend; dyncon++)
3269 Elf_Internal_Dyn dyn;
3270 asection *s;
3272 bfd_elf64_swap_dyn_in (dynobj, dyncon, &dyn);
3274 switch (dyn.d_tag)
3276 default:
3277 continue;
3279 case DT_PLTGOT:
3280 s = htab->sgotplt;
3281 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
3282 break;
3284 case DT_JMPREL:
3285 dyn.d_un.d_ptr = htab->srelplt->output_section->vma;
3286 break;
3288 case DT_PLTRELSZ:
3289 s = htab->srelplt->output_section;
3290 dyn.d_un.d_val = s->size;
3291 break;
3293 case DT_RELASZ:
3294 /* The procedure linkage table relocs (DT_JMPREL) should
3295 not be included in the overall relocs (DT_RELA).
3296 Therefore, we override the DT_RELASZ entry here to
3297 make it not include the JMPREL relocs. Since the
3298 linker script arranges for .rela.plt to follow all
3299 other relocation sections, we don't have to worry
3300 about changing the DT_RELA entry. */
3301 if (htab->srelplt != NULL)
3303 s = htab->srelplt->output_section;
3304 dyn.d_un.d_val -= s->size;
3306 break;
3308 case DT_TLSDESC_PLT:
3309 s = htab->splt;
3310 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset
3311 + htab->tlsdesc_plt;
3312 break;
3314 case DT_TLSDESC_GOT:
3315 s = htab->sgot;
3316 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset
3317 + htab->tlsdesc_got;
3318 break;
3321 bfd_elf64_swap_dyn_out (output_bfd, &dyn, dyncon);
3324 /* Fill in the special first entry in the procedure linkage table. */
3325 if (htab->splt && htab->splt->size > 0)
3327 /* Fill in the first entry in the procedure linkage table. */
3328 memcpy (htab->splt->contents, elf64_x86_64_plt0_entry,
3329 PLT_ENTRY_SIZE);
3330 /* Add offset for pushq GOT+8(%rip), since the instruction
3331 uses 6 bytes subtract this value. */
3332 bfd_put_32 (output_bfd,
3333 (htab->sgotplt->output_section->vma
3334 + htab->sgotplt->output_offset
3336 - htab->splt->output_section->vma
3337 - htab->splt->output_offset
3338 - 6),
3339 htab->splt->contents + 2);
3340 /* Add offset for jmp *GOT+16(%rip). The 12 is the offset to
3341 the end of the instruction. */
3342 bfd_put_32 (output_bfd,
3343 (htab->sgotplt->output_section->vma
3344 + htab->sgotplt->output_offset
3345 + 16
3346 - htab->splt->output_section->vma
3347 - htab->splt->output_offset
3348 - 12),
3349 htab->splt->contents + 8);
3351 elf_section_data (htab->splt->output_section)->this_hdr.sh_entsize =
3352 PLT_ENTRY_SIZE;
3354 if (htab->tlsdesc_plt)
3356 bfd_put_64 (output_bfd, (bfd_vma) 0,
3357 htab->sgot->contents + htab->tlsdesc_got);
3359 memcpy (htab->splt->contents + htab->tlsdesc_plt,
3360 elf64_x86_64_plt0_entry,
3361 PLT_ENTRY_SIZE);
3363 /* Add offset for pushq GOT+8(%rip), since the
3364 instruction uses 6 bytes subtract this value. */
3365 bfd_put_32 (output_bfd,
3366 (htab->sgotplt->output_section->vma
3367 + htab->sgotplt->output_offset
3369 - htab->splt->output_section->vma
3370 - htab->splt->output_offset
3371 - htab->tlsdesc_plt
3372 - 6),
3373 htab->splt->contents + htab->tlsdesc_plt + 2);
3374 /* Add offset for jmp *GOT+TDG(%rip), where TGD stands for
3375 htab->tlsdesc_got. The 12 is the offset to the end of
3376 the instruction. */
3377 bfd_put_32 (output_bfd,
3378 (htab->sgot->output_section->vma
3379 + htab->sgot->output_offset
3380 + htab->tlsdesc_got
3381 - htab->splt->output_section->vma
3382 - htab->splt->output_offset
3383 - htab->tlsdesc_plt
3384 - 12),
3385 htab->splt->contents + htab->tlsdesc_plt + 8);
3390 if (htab->sgotplt)
3392 /* Fill in the first three entries in the global offset table. */
3393 if (htab->sgotplt->size > 0)
3395 /* Set the first entry in the global offset table to the address of
3396 the dynamic section. */
3397 if (sdyn == NULL)
3398 bfd_put_64 (output_bfd, (bfd_vma) 0, htab->sgotplt->contents);
3399 else
3400 bfd_put_64 (output_bfd,
3401 sdyn->output_section->vma + sdyn->output_offset,
3402 htab->sgotplt->contents);
3403 /* Write GOT[1] and GOT[2], needed for the dynamic linker. */
3404 bfd_put_64 (output_bfd, (bfd_vma) 0, htab->sgotplt->contents + GOT_ENTRY_SIZE);
3405 bfd_put_64 (output_bfd, (bfd_vma) 0, htab->sgotplt->contents + GOT_ENTRY_SIZE*2);
3408 elf_section_data (htab->sgotplt->output_section)->this_hdr.sh_entsize =
3409 GOT_ENTRY_SIZE;
3412 if (htab->sgot && htab->sgot->size > 0)
3413 elf_section_data (htab->sgot->output_section)->this_hdr.sh_entsize
3414 = GOT_ENTRY_SIZE;
3416 return TRUE;
3419 /* Return address for Ith PLT stub in section PLT, for relocation REL
3420 or (bfd_vma) -1 if it should not be included. */
3422 static bfd_vma
3423 elf64_x86_64_plt_sym_val (bfd_vma i, const asection *plt,
3424 const arelent *rel ATTRIBUTE_UNUSED)
3426 return plt->vma + (i + 1) * PLT_ENTRY_SIZE;
3429 /* Handle an x86-64 specific section when reading an object file. This
3430 is called when elfcode.h finds a section with an unknown type. */
3432 static bfd_boolean
3433 elf64_x86_64_section_from_shdr (bfd *abfd,
3434 Elf_Internal_Shdr *hdr,
3435 const char *name,
3436 int shindex)
3438 if (hdr->sh_type != SHT_X86_64_UNWIND)
3439 return FALSE;
3441 if (! _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex))
3442 return FALSE;
3444 return TRUE;
3447 /* Hook called by the linker routine which adds symbols from an object
3448 file. We use it to put SHN_X86_64_LCOMMON items in .lbss, instead
3449 of .bss. */
3451 static bfd_boolean
3452 elf64_x86_64_add_symbol_hook (bfd *abfd,
3453 struct bfd_link_info *info ATTRIBUTE_UNUSED,
3454 Elf_Internal_Sym *sym,
3455 const char **namep ATTRIBUTE_UNUSED,
3456 flagword *flagsp ATTRIBUTE_UNUSED,
3457 asection **secp, bfd_vma *valp)
3459 asection *lcomm;
3461 switch (sym->st_shndx)
3463 case SHN_X86_64_LCOMMON:
3464 lcomm = bfd_get_section_by_name (abfd, "LARGE_COMMON");
3465 if (lcomm == NULL)
3467 lcomm = bfd_make_section_with_flags (abfd,
3468 "LARGE_COMMON",
3469 (SEC_ALLOC
3470 | SEC_IS_COMMON
3471 | SEC_LINKER_CREATED));
3472 if (lcomm == NULL)
3473 return FALSE;
3474 elf_section_flags (lcomm) |= SHF_X86_64_LARGE;
3476 *secp = lcomm;
3477 *valp = sym->st_size;
3478 break;
3480 return TRUE;
3484 /* Given a BFD section, try to locate the corresponding ELF section
3485 index. */
3487 static bfd_boolean
3488 elf64_x86_64_elf_section_from_bfd_section (bfd *abfd ATTRIBUTE_UNUSED,
3489 asection *sec, int *index)
3491 if (sec == &_bfd_elf_large_com_section)
3493 *index = SHN_X86_64_LCOMMON;
3494 return TRUE;
3496 return FALSE;
3499 /* Process a symbol. */
3501 static void
3502 elf64_x86_64_symbol_processing (bfd *abfd ATTRIBUTE_UNUSED,
3503 asymbol *asym)
3505 elf_symbol_type *elfsym = (elf_symbol_type *) asym;
3507 switch (elfsym->internal_elf_sym.st_shndx)
3509 case SHN_X86_64_LCOMMON:
3510 asym->section = &_bfd_elf_large_com_section;
3511 asym->value = elfsym->internal_elf_sym.st_size;
3512 /* Common symbol doesn't set BSF_GLOBAL. */
3513 asym->flags &= ~BSF_GLOBAL;
3514 break;
3518 static bfd_boolean
3519 elf64_x86_64_common_definition (Elf_Internal_Sym *sym)
3521 return (sym->st_shndx == SHN_COMMON
3522 || sym->st_shndx == SHN_X86_64_LCOMMON);
3525 static unsigned int
3526 elf64_x86_64_common_section_index (asection *sec)
3528 if ((elf_section_flags (sec) & SHF_X86_64_LARGE) == 0)
3529 return SHN_COMMON;
3530 else
3531 return SHN_X86_64_LCOMMON;
3534 static asection *
3535 elf64_x86_64_common_section (asection *sec)
3537 if ((elf_section_flags (sec) & SHF_X86_64_LARGE) == 0)
3538 return bfd_com_section_ptr;
3539 else
3540 return &_bfd_elf_large_com_section;
3543 static bfd_boolean
3544 elf64_x86_64_merge_symbol (struct bfd_link_info *info ATTRIBUTE_UNUSED,
3545 struct elf_link_hash_entry **sym_hash ATTRIBUTE_UNUSED,
3546 struct elf_link_hash_entry *h,
3547 Elf_Internal_Sym *sym,
3548 asection **psec,
3549 bfd_vma *pvalue ATTRIBUTE_UNUSED,
3550 unsigned int *pold_alignment ATTRIBUTE_UNUSED,
3551 bfd_boolean *skip ATTRIBUTE_UNUSED,
3552 bfd_boolean *override ATTRIBUTE_UNUSED,
3553 bfd_boolean *type_change_ok ATTRIBUTE_UNUSED,
3554 bfd_boolean *size_change_ok ATTRIBUTE_UNUSED,
3555 bfd_boolean *newdef ATTRIBUTE_UNUSED,
3556 bfd_boolean *newdyn,
3557 bfd_boolean *newdyncommon ATTRIBUTE_UNUSED,
3558 bfd_boolean *newweak ATTRIBUTE_UNUSED,
3559 bfd *abfd ATTRIBUTE_UNUSED,
3560 asection **sec,
3561 bfd_boolean *olddef ATTRIBUTE_UNUSED,
3562 bfd_boolean *olddyn,
3563 bfd_boolean *olddyncommon ATTRIBUTE_UNUSED,
3564 bfd_boolean *oldweak ATTRIBUTE_UNUSED,
3565 bfd *oldbfd,
3566 asection **oldsec)
3568 /* A normal common symbol and a large common symbol result in a
3569 normal common symbol. We turn the large common symbol into a
3570 normal one. */
3571 if (!*olddyn
3572 && h->root.type == bfd_link_hash_common
3573 && !*newdyn
3574 && bfd_is_com_section (*sec)
3575 && *oldsec != *sec)
3577 if (sym->st_shndx == SHN_COMMON
3578 && (elf_section_flags (*oldsec) & SHF_X86_64_LARGE) != 0)
3580 h->root.u.c.p->section
3581 = bfd_make_section_old_way (oldbfd, "COMMON");
3582 h->root.u.c.p->section->flags = SEC_ALLOC;
3584 else if (sym->st_shndx == SHN_X86_64_LCOMMON
3585 && (elf_section_flags (*oldsec) & SHF_X86_64_LARGE) == 0)
3586 *psec = *sec = bfd_com_section_ptr;
3589 return TRUE;
3592 static int
3593 elf64_x86_64_additional_program_headers (bfd *abfd,
3594 struct bfd_link_info *info ATTRIBUTE_UNUSED)
3596 asection *s;
3597 int count = 0;
3599 /* Check to see if we need a large readonly segment. */
3600 s = bfd_get_section_by_name (abfd, ".lrodata");
3601 if (s && (s->flags & SEC_LOAD))
3602 count++;
3604 /* Check to see if we need a large data segment. Since .lbss sections
3605 is placed right after the .bss section, there should be no need for
3606 a large data segment just because of .lbss. */
3607 s = bfd_get_section_by_name (abfd, ".ldata");
3608 if (s && (s->flags & SEC_LOAD))
3609 count++;
3611 return count;
3614 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
3616 static bfd_boolean
3617 elf64_x86_64_hash_symbol (struct elf_link_hash_entry *h)
3619 if (h->plt.offset != (bfd_vma) -1
3620 && !h->def_regular
3621 && !h->pointer_equality_needed)
3622 return FALSE;
3624 return _bfd_elf_hash_symbol (h);
3627 static const struct bfd_elf_special_section
3628 elf64_x86_64_special_sections[]=
3630 { STRING_COMMA_LEN (".gnu.linkonce.lb"), -2, SHT_NOBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE},
3631 { STRING_COMMA_LEN (".gnu.linkonce.lr"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_X86_64_LARGE},
3632 { STRING_COMMA_LEN (".gnu.linkonce.lt"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR + SHF_X86_64_LARGE},
3633 { STRING_COMMA_LEN (".lbss"), -2, SHT_NOBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE},
3634 { STRING_COMMA_LEN (".ldata"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE},
3635 { STRING_COMMA_LEN (".lrodata"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_X86_64_LARGE},
3636 { NULL, 0, 0, 0, 0 }
3639 #define TARGET_LITTLE_SYM bfd_elf64_x86_64_vec
3640 #define TARGET_LITTLE_NAME "elf64-x86-64"
3641 #define ELF_ARCH bfd_arch_i386
3642 #define ELF_MACHINE_CODE EM_X86_64
3643 #define ELF_MAXPAGESIZE 0x200000
3644 #define ELF_MINPAGESIZE 0x1000
3645 #define ELF_COMMONPAGESIZE 0x1000
3647 #define elf_backend_can_gc_sections 1
3648 #define elf_backend_can_refcount 1
3649 #define elf_backend_want_got_plt 1
3650 #define elf_backend_plt_readonly 1
3651 #define elf_backend_want_plt_sym 0
3652 #define elf_backend_got_header_size (GOT_ENTRY_SIZE*3)
3653 #define elf_backend_rela_normal 1
3655 #define elf_info_to_howto elf64_x86_64_info_to_howto
3657 #define bfd_elf64_bfd_link_hash_table_create \
3658 elf64_x86_64_link_hash_table_create
3659 #define bfd_elf64_bfd_reloc_type_lookup elf64_x86_64_reloc_type_lookup
3661 #define elf_backend_adjust_dynamic_symbol elf64_x86_64_adjust_dynamic_symbol
3662 #define elf_backend_check_relocs elf64_x86_64_check_relocs
3663 #define elf_backend_copy_indirect_symbol elf64_x86_64_copy_indirect_symbol
3664 #define elf_backend_create_dynamic_sections elf64_x86_64_create_dynamic_sections
3665 #define elf_backend_finish_dynamic_sections elf64_x86_64_finish_dynamic_sections
3666 #define elf_backend_finish_dynamic_symbol elf64_x86_64_finish_dynamic_symbol
3667 #define elf_backend_gc_mark_hook elf64_x86_64_gc_mark_hook
3668 #define elf_backend_gc_sweep_hook elf64_x86_64_gc_sweep_hook
3669 #define elf_backend_grok_prstatus elf64_x86_64_grok_prstatus
3670 #define elf_backend_grok_psinfo elf64_x86_64_grok_psinfo
3671 #define elf_backend_reloc_type_class elf64_x86_64_reloc_type_class
3672 #define elf_backend_relocate_section elf64_x86_64_relocate_section
3673 #define elf_backend_size_dynamic_sections elf64_x86_64_size_dynamic_sections
3674 #define elf_backend_always_size_sections elf64_x86_64_always_size_sections
3675 #define elf_backend_init_index_section _bfd_elf_init_1_index_section
3676 #define elf_backend_plt_sym_val elf64_x86_64_plt_sym_val
3677 #define elf_backend_object_p elf64_x86_64_elf_object_p
3678 #define bfd_elf64_mkobject elf64_x86_64_mkobject
3680 #define elf_backend_section_from_shdr \
3681 elf64_x86_64_section_from_shdr
3683 #define elf_backend_section_from_bfd_section \
3684 elf64_x86_64_elf_section_from_bfd_section
3685 #define elf_backend_add_symbol_hook \
3686 elf64_x86_64_add_symbol_hook
3687 #define elf_backend_symbol_processing \
3688 elf64_x86_64_symbol_processing
3689 #define elf_backend_common_section_index \
3690 elf64_x86_64_common_section_index
3691 #define elf_backend_common_section \
3692 elf64_x86_64_common_section
3693 #define elf_backend_common_definition \
3694 elf64_x86_64_common_definition
3695 #define elf_backend_merge_symbol \
3696 elf64_x86_64_merge_symbol
3697 #define elf_backend_special_sections \
3698 elf64_x86_64_special_sections
3699 #define elf_backend_additional_program_headers \
3700 elf64_x86_64_additional_program_headers
3701 #define elf_backend_hash_symbol \
3702 elf64_x86_64_hash_symbol
3704 #include "elf64-target.h"
3706 /* FreeBSD support. */
3708 #undef TARGET_LITTLE_SYM
3709 #define TARGET_LITTLE_SYM bfd_elf64_x86_64_freebsd_vec
3710 #undef TARGET_LITTLE_NAME
3711 #define TARGET_LITTLE_NAME "elf64-x86-64-freebsd"
3713 /* The kernel recognizes executables as valid only if they carry a
3714 "FreeBSD" label in the ELF header. So we put this label on all
3715 executables and (for simplicity) also all other object files. */
3717 static void
3718 elf64_x86_64_fbsd_post_process_headers (bfd * abfd,
3719 struct bfd_link_info * link_info ATTRIBUTE_UNUSED)
3721 Elf_Internal_Ehdr * i_ehdrp; /* ELF file header, internal form. */
3723 i_ehdrp = elf_elfheader (abfd);
3725 /* Put an ABI label supported by FreeBSD >= 4.1. */
3726 i_ehdrp->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
3729 #undef elf_backend_post_process_headers
3730 #define elf_backend_post_process_headers elf64_x86_64_fbsd_post_process_headers
3732 #undef elf64_bed
3733 #define elf64_bed elf64_x86_64_fbsd_bed
3735 #include "elf64-target.h"