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[binutils.git] / bfd / elf64-x86-64.c
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1 /* X86-64 specific support for 64-bit ELF
2 Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
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 3 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,
21 MA 02110-1301, USA. */
23 #include "sysdep.h"
24 #include "bfd.h"
25 #include "bfdlink.h"
26 #include "libbfd.h"
27 #include "elf-bfd.h"
29 #include "elf/x86-64.h"
31 /* In case we're on a 32-bit machine, construct a 64-bit "-1" value. */
32 #define MINUS_ONE (~ (bfd_vma) 0)
34 /* The relocation "howto" table. Order of fields:
35 type, rightshift, size, bitsize, pc_relative, bitpos, complain_on_overflow,
36 special_function, name, partial_inplace, src_mask, dst_mask, pcrel_offset. */
37 static reloc_howto_type x86_64_elf_howto_table[] =
39 HOWTO(R_X86_64_NONE, 0, 0, 0, FALSE, 0, complain_overflow_dont,
40 bfd_elf_generic_reloc, "R_X86_64_NONE", FALSE, 0x00000000, 0x00000000,
41 FALSE),
42 HOWTO(R_X86_64_64, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
43 bfd_elf_generic_reloc, "R_X86_64_64", FALSE, MINUS_ONE, MINUS_ONE,
44 FALSE),
45 HOWTO(R_X86_64_PC32, 0, 2, 32, TRUE, 0, complain_overflow_signed,
46 bfd_elf_generic_reloc, "R_X86_64_PC32", FALSE, 0xffffffff, 0xffffffff,
47 TRUE),
48 HOWTO(R_X86_64_GOT32, 0, 2, 32, FALSE, 0, complain_overflow_signed,
49 bfd_elf_generic_reloc, "R_X86_64_GOT32", FALSE, 0xffffffff, 0xffffffff,
50 FALSE),
51 HOWTO(R_X86_64_PLT32, 0, 2, 32, TRUE, 0, complain_overflow_signed,
52 bfd_elf_generic_reloc, "R_X86_64_PLT32", FALSE, 0xffffffff, 0xffffffff,
53 TRUE),
54 HOWTO(R_X86_64_COPY, 0, 2, 32, FALSE, 0, complain_overflow_bitfield,
55 bfd_elf_generic_reloc, "R_X86_64_COPY", FALSE, 0xffffffff, 0xffffffff,
56 FALSE),
57 HOWTO(R_X86_64_GLOB_DAT, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
58 bfd_elf_generic_reloc, "R_X86_64_GLOB_DAT", FALSE, MINUS_ONE,
59 MINUS_ONE, FALSE),
60 HOWTO(R_X86_64_JUMP_SLOT, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
61 bfd_elf_generic_reloc, "R_X86_64_JUMP_SLOT", FALSE, MINUS_ONE,
62 MINUS_ONE, FALSE),
63 HOWTO(R_X86_64_RELATIVE, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
64 bfd_elf_generic_reloc, "R_X86_64_RELATIVE", FALSE, MINUS_ONE,
65 MINUS_ONE, FALSE),
66 HOWTO(R_X86_64_GOTPCREL, 0, 2, 32, TRUE, 0, complain_overflow_signed,
67 bfd_elf_generic_reloc, "R_X86_64_GOTPCREL", FALSE, 0xffffffff,
68 0xffffffff, TRUE),
69 HOWTO(R_X86_64_32, 0, 2, 32, FALSE, 0, complain_overflow_unsigned,
70 bfd_elf_generic_reloc, "R_X86_64_32", FALSE, 0xffffffff, 0xffffffff,
71 FALSE),
72 HOWTO(R_X86_64_32S, 0, 2, 32, FALSE, 0, complain_overflow_signed,
73 bfd_elf_generic_reloc, "R_X86_64_32S", FALSE, 0xffffffff, 0xffffffff,
74 FALSE),
75 HOWTO(R_X86_64_16, 0, 1, 16, FALSE, 0, complain_overflow_bitfield,
76 bfd_elf_generic_reloc, "R_X86_64_16", FALSE, 0xffff, 0xffff, FALSE),
77 HOWTO(R_X86_64_PC16,0, 1, 16, TRUE, 0, complain_overflow_bitfield,
78 bfd_elf_generic_reloc, "R_X86_64_PC16", FALSE, 0xffff, 0xffff, TRUE),
79 HOWTO(R_X86_64_8, 0, 0, 8, FALSE, 0, complain_overflow_bitfield,
80 bfd_elf_generic_reloc, "R_X86_64_8", FALSE, 0xff, 0xff, FALSE),
81 HOWTO(R_X86_64_PC8, 0, 0, 8, TRUE, 0, complain_overflow_signed,
82 bfd_elf_generic_reloc, "R_X86_64_PC8", FALSE, 0xff, 0xff, TRUE),
83 HOWTO(R_X86_64_DTPMOD64, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
84 bfd_elf_generic_reloc, "R_X86_64_DTPMOD64", FALSE, MINUS_ONE,
85 MINUS_ONE, FALSE),
86 HOWTO(R_X86_64_DTPOFF64, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
87 bfd_elf_generic_reloc, "R_X86_64_DTPOFF64", FALSE, MINUS_ONE,
88 MINUS_ONE, FALSE),
89 HOWTO(R_X86_64_TPOFF64, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
90 bfd_elf_generic_reloc, "R_X86_64_TPOFF64", FALSE, MINUS_ONE,
91 MINUS_ONE, FALSE),
92 HOWTO(R_X86_64_TLSGD, 0, 2, 32, TRUE, 0, complain_overflow_signed,
93 bfd_elf_generic_reloc, "R_X86_64_TLSGD", FALSE, 0xffffffff,
94 0xffffffff, TRUE),
95 HOWTO(R_X86_64_TLSLD, 0, 2, 32, TRUE, 0, complain_overflow_signed,
96 bfd_elf_generic_reloc, "R_X86_64_TLSLD", FALSE, 0xffffffff,
97 0xffffffff, TRUE),
98 HOWTO(R_X86_64_DTPOFF32, 0, 2, 32, FALSE, 0, complain_overflow_signed,
99 bfd_elf_generic_reloc, "R_X86_64_DTPOFF32", FALSE, 0xffffffff,
100 0xffffffff, FALSE),
101 HOWTO(R_X86_64_GOTTPOFF, 0, 2, 32, TRUE, 0, complain_overflow_signed,
102 bfd_elf_generic_reloc, "R_X86_64_GOTTPOFF", FALSE, 0xffffffff,
103 0xffffffff, TRUE),
104 HOWTO(R_X86_64_TPOFF32, 0, 2, 32, FALSE, 0, complain_overflow_signed,
105 bfd_elf_generic_reloc, "R_X86_64_TPOFF32", FALSE, 0xffffffff,
106 0xffffffff, FALSE),
107 HOWTO(R_X86_64_PC64, 0, 4, 64, TRUE, 0, complain_overflow_bitfield,
108 bfd_elf_generic_reloc, "R_X86_64_PC64", FALSE, MINUS_ONE, MINUS_ONE,
109 TRUE),
110 HOWTO(R_X86_64_GOTOFF64, 0, 4, 64, FALSE, 0, complain_overflow_bitfield,
111 bfd_elf_generic_reloc, "R_X86_64_GOTOFF64",
112 FALSE, MINUS_ONE, MINUS_ONE, FALSE),
113 HOWTO(R_X86_64_GOTPC32, 0, 2, 32, TRUE, 0, complain_overflow_signed,
114 bfd_elf_generic_reloc, "R_X86_64_GOTPC32",
115 FALSE, 0xffffffff, 0xffffffff, TRUE),
116 HOWTO(R_X86_64_GOT64, 0, 4, 64, FALSE, 0, complain_overflow_signed,
117 bfd_elf_generic_reloc, "R_X86_64_GOT64", FALSE, MINUS_ONE, MINUS_ONE,
118 FALSE),
119 HOWTO(R_X86_64_GOTPCREL64, 0, 4, 64, TRUE, 0, complain_overflow_signed,
120 bfd_elf_generic_reloc, "R_X86_64_GOTPCREL64", FALSE, MINUS_ONE,
121 MINUS_ONE, TRUE),
122 HOWTO(R_X86_64_GOTPC64, 0, 4, 64, TRUE, 0, complain_overflow_signed,
123 bfd_elf_generic_reloc, "R_X86_64_GOTPC64",
124 FALSE, MINUS_ONE, MINUS_ONE, TRUE),
125 HOWTO(R_X86_64_GOTPLT64, 0, 4, 64, FALSE, 0, complain_overflow_signed,
126 bfd_elf_generic_reloc, "R_X86_64_GOTPLT64", FALSE, MINUS_ONE,
127 MINUS_ONE, FALSE),
128 HOWTO(R_X86_64_PLTOFF64, 0, 4, 64, FALSE, 0, complain_overflow_signed,
129 bfd_elf_generic_reloc, "R_X86_64_PLTOFF64", FALSE, MINUS_ONE,
130 MINUS_ONE, FALSE),
131 EMPTY_HOWTO (32),
132 EMPTY_HOWTO (33),
133 HOWTO(R_X86_64_GOTPC32_TLSDESC, 0, 2, 32, TRUE, 0,
134 complain_overflow_bitfield, bfd_elf_generic_reloc,
135 "R_X86_64_GOTPC32_TLSDESC",
136 FALSE, 0xffffffff, 0xffffffff, TRUE),
137 HOWTO(R_X86_64_TLSDESC_CALL, 0, 0, 0, FALSE, 0,
138 complain_overflow_dont, bfd_elf_generic_reloc,
139 "R_X86_64_TLSDESC_CALL",
140 FALSE, 0, 0, FALSE),
141 HOWTO(R_X86_64_TLSDESC, 0, 4, 64, FALSE, 0,
142 complain_overflow_bitfield, bfd_elf_generic_reloc,
143 "R_X86_64_TLSDESC",
144 FALSE, MINUS_ONE, MINUS_ONE, FALSE),
146 /* We have a gap in the reloc numbers here.
147 R_X86_64_standard counts the number up to this point, and
148 R_X86_64_vt_offset is the value to subtract from a reloc type of
149 R_X86_64_GNU_VT* to form an index into this table. */
150 #define R_X86_64_standard (R_X86_64_TLSDESC + 1)
151 #define R_X86_64_vt_offset (R_X86_64_GNU_VTINHERIT - R_X86_64_standard)
153 /* GNU extension to record C++ vtable hierarchy. */
154 HOWTO (R_X86_64_GNU_VTINHERIT, 0, 4, 0, FALSE, 0, complain_overflow_dont,
155 NULL, "R_X86_64_GNU_VTINHERIT", FALSE, 0, 0, FALSE),
157 /* GNU extension to record C++ vtable member usage. */
158 HOWTO (R_X86_64_GNU_VTENTRY, 0, 4, 0, FALSE, 0, complain_overflow_dont,
159 _bfd_elf_rel_vtable_reloc_fn, "R_X86_64_GNU_VTENTRY", FALSE, 0, 0,
160 FALSE)
163 /* Map BFD relocs to the x86_64 elf relocs. */
164 struct elf_reloc_map
166 bfd_reloc_code_real_type bfd_reloc_val;
167 unsigned char elf_reloc_val;
170 static const struct elf_reloc_map x86_64_reloc_map[] =
172 { BFD_RELOC_NONE, R_X86_64_NONE, },
173 { BFD_RELOC_64, R_X86_64_64, },
174 { BFD_RELOC_32_PCREL, R_X86_64_PC32, },
175 { BFD_RELOC_X86_64_GOT32, R_X86_64_GOT32,},
176 { BFD_RELOC_X86_64_PLT32, R_X86_64_PLT32,},
177 { BFD_RELOC_X86_64_COPY, R_X86_64_COPY, },
178 { BFD_RELOC_X86_64_GLOB_DAT, R_X86_64_GLOB_DAT, },
179 { BFD_RELOC_X86_64_JUMP_SLOT, R_X86_64_JUMP_SLOT, },
180 { BFD_RELOC_X86_64_RELATIVE, R_X86_64_RELATIVE, },
181 { BFD_RELOC_X86_64_GOTPCREL, R_X86_64_GOTPCREL, },
182 { BFD_RELOC_32, R_X86_64_32, },
183 { BFD_RELOC_X86_64_32S, R_X86_64_32S, },
184 { BFD_RELOC_16, R_X86_64_16, },
185 { BFD_RELOC_16_PCREL, R_X86_64_PC16, },
186 { BFD_RELOC_8, R_X86_64_8, },
187 { BFD_RELOC_8_PCREL, R_X86_64_PC8, },
188 { BFD_RELOC_X86_64_DTPMOD64, R_X86_64_DTPMOD64, },
189 { BFD_RELOC_X86_64_DTPOFF64, R_X86_64_DTPOFF64, },
190 { BFD_RELOC_X86_64_TPOFF64, R_X86_64_TPOFF64, },
191 { BFD_RELOC_X86_64_TLSGD, R_X86_64_TLSGD, },
192 { BFD_RELOC_X86_64_TLSLD, R_X86_64_TLSLD, },
193 { BFD_RELOC_X86_64_DTPOFF32, R_X86_64_DTPOFF32, },
194 { BFD_RELOC_X86_64_GOTTPOFF, R_X86_64_GOTTPOFF, },
195 { BFD_RELOC_X86_64_TPOFF32, R_X86_64_TPOFF32, },
196 { BFD_RELOC_64_PCREL, R_X86_64_PC64, },
197 { BFD_RELOC_X86_64_GOTOFF64, R_X86_64_GOTOFF64, },
198 { BFD_RELOC_X86_64_GOTPC32, R_X86_64_GOTPC32, },
199 { BFD_RELOC_X86_64_GOT64, R_X86_64_GOT64, },
200 { BFD_RELOC_X86_64_GOTPCREL64,R_X86_64_GOTPCREL64, },
201 { BFD_RELOC_X86_64_GOTPC64, R_X86_64_GOTPC64, },
202 { BFD_RELOC_X86_64_GOTPLT64, R_X86_64_GOTPLT64, },
203 { BFD_RELOC_X86_64_PLTOFF64, R_X86_64_PLTOFF64, },
204 { BFD_RELOC_X86_64_GOTPC32_TLSDESC, R_X86_64_GOTPC32_TLSDESC, },
205 { BFD_RELOC_X86_64_TLSDESC_CALL, R_X86_64_TLSDESC_CALL, },
206 { BFD_RELOC_X86_64_TLSDESC, R_X86_64_TLSDESC, },
207 { BFD_RELOC_VTABLE_INHERIT, R_X86_64_GNU_VTINHERIT, },
208 { BFD_RELOC_VTABLE_ENTRY, R_X86_64_GNU_VTENTRY, },
211 static reloc_howto_type *
212 elf64_x86_64_rtype_to_howto (bfd *abfd, unsigned r_type)
214 unsigned i;
216 if (r_type < (unsigned int) R_X86_64_GNU_VTINHERIT
217 || r_type >= (unsigned int) R_X86_64_max)
219 if (r_type >= (unsigned int) R_X86_64_standard)
221 (*_bfd_error_handler) (_("%B: invalid relocation type %d"),
222 abfd, (int) r_type);
223 r_type = R_X86_64_NONE;
225 i = r_type;
227 else
228 i = r_type - (unsigned int) R_X86_64_vt_offset;
229 BFD_ASSERT (x86_64_elf_howto_table[i].type == r_type);
230 return &x86_64_elf_howto_table[i];
233 /* Given a BFD reloc type, return a HOWTO structure. */
234 static reloc_howto_type *
235 elf64_x86_64_reloc_type_lookup (bfd *abfd,
236 bfd_reloc_code_real_type code)
238 unsigned int i;
240 for (i = 0; i < sizeof (x86_64_reloc_map) / sizeof (struct elf_reloc_map);
241 i++)
243 if (x86_64_reloc_map[i].bfd_reloc_val == code)
244 return elf64_x86_64_rtype_to_howto (abfd,
245 x86_64_reloc_map[i].elf_reloc_val);
247 return 0;
250 static reloc_howto_type *
251 elf64_x86_64_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
252 const char *r_name)
254 unsigned int i;
256 for (i = 0;
257 i < (sizeof (x86_64_elf_howto_table)
258 / sizeof (x86_64_elf_howto_table[0]));
259 i++)
260 if (x86_64_elf_howto_table[i].name != NULL
261 && strcasecmp (x86_64_elf_howto_table[i].name, r_name) == 0)
262 return &x86_64_elf_howto_table[i];
264 return NULL;
267 /* Given an x86_64 ELF reloc type, fill in an arelent structure. */
269 static void
270 elf64_x86_64_info_to_howto (bfd *abfd ATTRIBUTE_UNUSED, arelent *cache_ptr,
271 Elf_Internal_Rela *dst)
273 unsigned r_type;
275 r_type = ELF64_R_TYPE (dst->r_info);
276 cache_ptr->howto = elf64_x86_64_rtype_to_howto (abfd, r_type);
277 BFD_ASSERT (r_type == cache_ptr->howto->type);
280 /* Support for core dump NOTE sections. */
281 static bfd_boolean
282 elf64_x86_64_grok_prstatus (bfd *abfd, Elf_Internal_Note *note)
284 int offset;
285 size_t size;
287 switch (note->descsz)
289 default:
290 return FALSE;
292 case 336: /* sizeof(istruct elf_prstatus) on Linux/x86_64 */
293 /* pr_cursig */
294 elf_tdata (abfd)->core_signal
295 = bfd_get_16 (abfd, note->descdata + 12);
297 /* pr_pid */
298 elf_tdata (abfd)->core_pid
299 = bfd_get_32 (abfd, note->descdata + 32);
301 /* pr_reg */
302 offset = 112;
303 size = 216;
305 break;
308 /* Make a ".reg/999" section. */
309 return _bfd_elfcore_make_pseudosection (abfd, ".reg",
310 size, note->descpos + offset);
313 static bfd_boolean
314 elf64_x86_64_grok_psinfo (bfd *abfd, Elf_Internal_Note *note)
316 switch (note->descsz)
318 default:
319 return FALSE;
321 case 136: /* sizeof(struct elf_prpsinfo) on Linux/x86_64 */
322 elf_tdata (abfd)->core_program
323 = _bfd_elfcore_strndup (abfd, note->descdata + 40, 16);
324 elf_tdata (abfd)->core_command
325 = _bfd_elfcore_strndup (abfd, note->descdata + 56, 80);
328 /* Note that for some reason, a spurious space is tacked
329 onto the end of the args in some (at least one anyway)
330 implementations, so strip it off if it exists. */
333 char *command = elf_tdata (abfd)->core_command;
334 int n = strlen (command);
336 if (0 < n && command[n - 1] == ' ')
337 command[n - 1] = '\0';
340 return TRUE;
343 /* Functions for the x86-64 ELF linker. */
345 /* The name of the dynamic interpreter. This is put in the .interp
346 section. */
348 #define ELF_DYNAMIC_INTERPRETER "/lib/ld64.so.1"
350 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
351 copying dynamic variables from a shared lib into an app's dynbss
352 section, and instead use a dynamic relocation to point into the
353 shared lib. */
354 #define ELIMINATE_COPY_RELOCS 1
356 /* The size in bytes of an entry in the global offset table. */
358 #define GOT_ENTRY_SIZE 8
360 /* The size in bytes of an entry in the procedure linkage table. */
362 #define PLT_ENTRY_SIZE 16
364 /* The first entry in a procedure linkage table looks like this. See the
365 SVR4 ABI i386 supplement and the x86-64 ABI to see how this works. */
367 static const bfd_byte elf64_x86_64_plt0_entry[PLT_ENTRY_SIZE] =
369 0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */
370 0xff, 0x25, 16, 0, 0, 0, /* jmpq *GOT+16(%rip) */
371 0x0f, 0x1f, 0x40, 0x00 /* nopl 0(%rax) */
374 /* Subsequent entries in a procedure linkage table look like this. */
376 static const bfd_byte elf64_x86_64_plt_entry[PLT_ENTRY_SIZE] =
378 0xff, 0x25, /* jmpq *name@GOTPC(%rip) */
379 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */
380 0x68, /* pushq immediate */
381 0, 0, 0, 0, /* replaced with index into relocation table. */
382 0xe9, /* jmp relative */
383 0, 0, 0, 0 /* replaced with offset to start of .plt0. */
386 /* The x86-64 linker needs to keep track of the number of relocs that
387 it decides to copy as dynamic relocs in check_relocs for each symbol.
388 This is so that it can later discard them if they are found to be
389 unnecessary. We store the information in a field extending the
390 regular ELF linker hash table. */
392 struct elf64_x86_64_dyn_relocs
394 /* Next section. */
395 struct elf64_x86_64_dyn_relocs *next;
397 /* The input section of the reloc. */
398 asection *sec;
400 /* Total number of relocs copied for the input section. */
401 bfd_size_type count;
403 /* Number of pc-relative relocs copied for the input section. */
404 bfd_size_type pc_count;
407 /* x86-64 ELF linker hash entry. */
409 struct elf64_x86_64_link_hash_entry
411 struct elf_link_hash_entry elf;
413 /* Track dynamic relocs copied for this symbol. */
414 struct elf64_x86_64_dyn_relocs *dyn_relocs;
416 #define GOT_UNKNOWN 0
417 #define GOT_NORMAL 1
418 #define GOT_TLS_GD 2
419 #define GOT_TLS_IE 3
420 #define GOT_TLS_GDESC 4
421 #define GOT_TLS_GD_BOTH_P(type) \
422 ((type) == (GOT_TLS_GD | GOT_TLS_GDESC))
423 #define GOT_TLS_GD_P(type) \
424 ((type) == GOT_TLS_GD || GOT_TLS_GD_BOTH_P (type))
425 #define GOT_TLS_GDESC_P(type) \
426 ((type) == GOT_TLS_GDESC || GOT_TLS_GD_BOTH_P (type))
427 #define GOT_TLS_GD_ANY_P(type) \
428 (GOT_TLS_GD_P (type) || GOT_TLS_GDESC_P (type))
429 unsigned char tls_type;
431 /* Offset of the GOTPLT entry reserved for the TLS descriptor,
432 starting at the end of the jump table. */
433 bfd_vma tlsdesc_got;
436 #define elf64_x86_64_hash_entry(ent) \
437 ((struct elf64_x86_64_link_hash_entry *)(ent))
439 struct elf64_x86_64_obj_tdata
441 struct elf_obj_tdata root;
443 /* tls_type for each local got entry. */
444 char *local_got_tls_type;
446 /* GOTPLT entries for TLS descriptors. */
447 bfd_vma *local_tlsdesc_gotent;
450 #define elf64_x86_64_tdata(abfd) \
451 ((struct elf64_x86_64_obj_tdata *) (abfd)->tdata.any)
453 #define elf64_x86_64_local_got_tls_type(abfd) \
454 (elf64_x86_64_tdata (abfd)->local_got_tls_type)
456 #define elf64_x86_64_local_tlsdesc_gotent(abfd) \
457 (elf64_x86_64_tdata (abfd)->local_tlsdesc_gotent)
459 /* x86-64 ELF linker hash table. */
461 struct elf64_x86_64_link_hash_table
463 struct elf_link_hash_table elf;
465 /* Short-cuts to get to dynamic linker sections. */
466 asection *sgot;
467 asection *sgotplt;
468 asection *srelgot;
469 asection *splt;
470 asection *srelplt;
471 asection *sdynbss;
472 asection *srelbss;
474 /* The offset into splt of the PLT entry for the TLS descriptor
475 resolver. Special values are 0, if not necessary (or not found
476 to be necessary yet), and -1 if needed but not determined
477 yet. */
478 bfd_vma tlsdesc_plt;
479 /* The offset into sgot of the GOT entry used by the PLT entry
480 above. */
481 bfd_vma tlsdesc_got;
483 union {
484 bfd_signed_vma refcount;
485 bfd_vma offset;
486 } tls_ld_got;
488 /* The amount of space used by the jump slots in the GOT. */
489 bfd_vma sgotplt_jump_table_size;
491 /* Small local sym to section mapping cache. */
492 struct sym_sec_cache sym_sec;
495 /* Get the x86-64 ELF linker hash table from a link_info structure. */
497 #define elf64_x86_64_hash_table(p) \
498 ((struct elf64_x86_64_link_hash_table *) ((p)->hash))
500 #define elf64_x86_64_compute_jump_table_size(htab) \
501 ((htab)->srelplt->reloc_count * GOT_ENTRY_SIZE)
503 /* Create an entry in an x86-64 ELF linker hash table. */
505 static struct bfd_hash_entry *
506 link_hash_newfunc (struct bfd_hash_entry *entry, struct bfd_hash_table *table,
507 const char *string)
509 /* Allocate the structure if it has not already been allocated by a
510 subclass. */
511 if (entry == NULL)
513 entry = bfd_hash_allocate (table,
514 sizeof (struct elf64_x86_64_link_hash_entry));
515 if (entry == NULL)
516 return entry;
519 /* Call the allocation method of the superclass. */
520 entry = _bfd_elf_link_hash_newfunc (entry, table, string);
521 if (entry != NULL)
523 struct elf64_x86_64_link_hash_entry *eh;
525 eh = (struct elf64_x86_64_link_hash_entry *) entry;
526 eh->dyn_relocs = NULL;
527 eh->tls_type = GOT_UNKNOWN;
528 eh->tlsdesc_got = (bfd_vma) -1;
531 return entry;
534 /* Create an X86-64 ELF linker hash table. */
536 static struct bfd_link_hash_table *
537 elf64_x86_64_link_hash_table_create (bfd *abfd)
539 struct elf64_x86_64_link_hash_table *ret;
540 bfd_size_type amt = sizeof (struct elf64_x86_64_link_hash_table);
542 ret = (struct elf64_x86_64_link_hash_table *) bfd_malloc (amt);
543 if (ret == NULL)
544 return NULL;
546 if (!_bfd_elf_link_hash_table_init (&ret->elf, abfd, link_hash_newfunc,
547 sizeof (struct elf64_x86_64_link_hash_entry)))
549 free (ret);
550 return NULL;
553 ret->sgot = NULL;
554 ret->sgotplt = NULL;
555 ret->srelgot = NULL;
556 ret->splt = NULL;
557 ret->srelplt = NULL;
558 ret->sdynbss = NULL;
559 ret->srelbss = NULL;
560 ret->sym_sec.abfd = NULL;
561 ret->tlsdesc_plt = 0;
562 ret->tlsdesc_got = 0;
563 ret->tls_ld_got.refcount = 0;
564 ret->sgotplt_jump_table_size = 0;
566 return &ret->elf.root;
569 /* Create .got, .gotplt, and .rela.got sections in DYNOBJ, and set up
570 shortcuts to them in our hash table. */
572 static bfd_boolean
573 create_got_section (bfd *dynobj, struct bfd_link_info *info)
575 struct elf64_x86_64_link_hash_table *htab;
577 if (! _bfd_elf_create_got_section (dynobj, info))
578 return FALSE;
580 htab = elf64_x86_64_hash_table (info);
581 htab->sgot = bfd_get_section_by_name (dynobj, ".got");
582 htab->sgotplt = bfd_get_section_by_name (dynobj, ".got.plt");
583 if (!htab->sgot || !htab->sgotplt)
584 abort ();
586 htab->srelgot = bfd_make_section_with_flags (dynobj, ".rela.got",
587 (SEC_ALLOC | SEC_LOAD
588 | SEC_HAS_CONTENTS
589 | SEC_IN_MEMORY
590 | SEC_LINKER_CREATED
591 | SEC_READONLY));
592 if (htab->srelgot == NULL
593 || ! bfd_set_section_alignment (dynobj, htab->srelgot, 3))
594 return FALSE;
595 return TRUE;
598 /* Create .plt, .rela.plt, .got, .got.plt, .rela.got, .dynbss, and
599 .rela.bss sections in DYNOBJ, and set up shortcuts to them in our
600 hash table. */
602 static bfd_boolean
603 elf64_x86_64_create_dynamic_sections (bfd *dynobj, struct bfd_link_info *info)
605 struct elf64_x86_64_link_hash_table *htab;
607 htab = elf64_x86_64_hash_table (info);
608 if (!htab->sgot && !create_got_section (dynobj, info))
609 return FALSE;
611 if (!_bfd_elf_create_dynamic_sections (dynobj, info))
612 return FALSE;
614 htab->splt = bfd_get_section_by_name (dynobj, ".plt");
615 htab->srelplt = bfd_get_section_by_name (dynobj, ".rela.plt");
616 htab->sdynbss = bfd_get_section_by_name (dynobj, ".dynbss");
617 if (!info->shared)
618 htab->srelbss = bfd_get_section_by_name (dynobj, ".rela.bss");
620 if (!htab->splt || !htab->srelplt || !htab->sdynbss
621 || (!info->shared && !htab->srelbss))
622 abort ();
624 return TRUE;
627 /* Copy the extra info we tack onto an elf_link_hash_entry. */
629 static void
630 elf64_x86_64_copy_indirect_symbol (struct bfd_link_info *info,
631 struct elf_link_hash_entry *dir,
632 struct elf_link_hash_entry *ind)
634 struct elf64_x86_64_link_hash_entry *edir, *eind;
636 edir = (struct elf64_x86_64_link_hash_entry *) dir;
637 eind = (struct elf64_x86_64_link_hash_entry *) ind;
639 if (eind->dyn_relocs != NULL)
641 if (edir->dyn_relocs != NULL)
643 struct elf64_x86_64_dyn_relocs **pp;
644 struct elf64_x86_64_dyn_relocs *p;
646 /* Add reloc counts against the indirect sym to the direct sym
647 list. Merge any entries against the same section. */
648 for (pp = &eind->dyn_relocs; (p = *pp) != NULL; )
650 struct elf64_x86_64_dyn_relocs *q;
652 for (q = edir->dyn_relocs; q != NULL; q = q->next)
653 if (q->sec == p->sec)
655 q->pc_count += p->pc_count;
656 q->count += p->count;
657 *pp = p->next;
658 break;
660 if (q == NULL)
661 pp = &p->next;
663 *pp = edir->dyn_relocs;
666 edir->dyn_relocs = eind->dyn_relocs;
667 eind->dyn_relocs = NULL;
670 if (ind->root.type == bfd_link_hash_indirect
671 && dir->got.refcount <= 0)
673 edir->tls_type = eind->tls_type;
674 eind->tls_type = GOT_UNKNOWN;
677 if (ELIMINATE_COPY_RELOCS
678 && ind->root.type != bfd_link_hash_indirect
679 && dir->dynamic_adjusted)
681 /* If called to transfer flags for a weakdef during processing
682 of elf_adjust_dynamic_symbol, don't copy non_got_ref.
683 We clear it ourselves for ELIMINATE_COPY_RELOCS. */
684 dir->ref_dynamic |= ind->ref_dynamic;
685 dir->ref_regular |= ind->ref_regular;
686 dir->ref_regular_nonweak |= ind->ref_regular_nonweak;
687 dir->needs_plt |= ind->needs_plt;
688 dir->pointer_equality_needed |= ind->pointer_equality_needed;
690 else
691 _bfd_elf_link_hash_copy_indirect (info, dir, ind);
694 static bfd_boolean
695 elf64_x86_64_mkobject (bfd *abfd)
697 if (abfd->tdata.any == NULL)
699 bfd_size_type amt = sizeof (struct elf64_x86_64_obj_tdata);
700 abfd->tdata.any = bfd_zalloc (abfd, amt);
701 if (abfd->tdata.any == NULL)
702 return FALSE;
704 return bfd_elf_mkobject (abfd);
707 static bfd_boolean
708 elf64_x86_64_elf_object_p (bfd *abfd)
710 /* Set the right machine number for an x86-64 elf64 file. */
711 bfd_default_set_arch_mach (abfd, bfd_arch_i386, bfd_mach_x86_64);
712 return TRUE;
715 static int
716 elf64_x86_64_tls_transition (struct bfd_link_info *info, int r_type, int is_local)
718 if (info->shared)
719 return r_type;
721 switch (r_type)
723 case R_X86_64_TLSGD:
724 case R_X86_64_GOTPC32_TLSDESC:
725 case R_X86_64_TLSDESC_CALL:
726 case R_X86_64_GOTTPOFF:
727 if (is_local)
728 return R_X86_64_TPOFF32;
729 return R_X86_64_GOTTPOFF;
730 case R_X86_64_TLSLD:
731 return R_X86_64_TPOFF32;
734 return r_type;
737 /* Look through the relocs for a section during the first phase, and
738 calculate needed space in the global offset table, procedure
739 linkage table, and dynamic reloc sections. */
741 static bfd_boolean
742 elf64_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, asection *sec,
743 const Elf_Internal_Rela *relocs)
745 struct elf64_x86_64_link_hash_table *htab;
746 Elf_Internal_Shdr *symtab_hdr;
747 struct elf_link_hash_entry **sym_hashes;
748 const Elf_Internal_Rela *rel;
749 const Elf_Internal_Rela *rel_end;
750 asection *sreloc;
752 if (info->relocatable)
753 return TRUE;
755 htab = elf64_x86_64_hash_table (info);
756 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
757 sym_hashes = elf_sym_hashes (abfd);
759 sreloc = NULL;
761 rel_end = relocs + sec->reloc_count;
762 for (rel = relocs; rel < rel_end; rel++)
764 unsigned int r_type;
765 unsigned long r_symndx;
766 struct elf_link_hash_entry *h;
768 r_symndx = ELF64_R_SYM (rel->r_info);
769 r_type = ELF64_R_TYPE (rel->r_info);
771 if (r_symndx >= NUM_SHDR_ENTRIES (symtab_hdr))
773 (*_bfd_error_handler) (_("%B: bad symbol index: %d"),
774 abfd, r_symndx);
775 return FALSE;
778 if (r_symndx < symtab_hdr->sh_info)
779 h = NULL;
780 else
782 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
783 while (h->root.type == bfd_link_hash_indirect
784 || h->root.type == bfd_link_hash_warning)
785 h = (struct elf_link_hash_entry *) h->root.u.i.link;
788 r_type = elf64_x86_64_tls_transition (info, r_type, h == NULL);
789 switch (r_type)
791 case R_X86_64_TLSLD:
792 htab->tls_ld_got.refcount += 1;
793 goto create_got;
795 case R_X86_64_TPOFF32:
796 if (info->shared)
798 (*_bfd_error_handler)
799 (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
800 abfd,
801 x86_64_elf_howto_table[r_type].name,
802 (h) ? h->root.root.string : "a local symbol");
803 bfd_set_error (bfd_error_bad_value);
804 return FALSE;
806 break;
808 case R_X86_64_GOTTPOFF:
809 if (info->shared)
810 info->flags |= DF_STATIC_TLS;
811 /* Fall through */
813 case R_X86_64_GOT32:
814 case R_X86_64_GOTPCREL:
815 case R_X86_64_TLSGD:
816 case R_X86_64_GOT64:
817 case R_X86_64_GOTPCREL64:
818 case R_X86_64_GOTPLT64:
819 case R_X86_64_GOTPC32_TLSDESC:
820 case R_X86_64_TLSDESC_CALL:
821 /* This symbol requires a global offset table entry. */
823 int tls_type, old_tls_type;
825 switch (r_type)
827 default: tls_type = GOT_NORMAL; break;
828 case R_X86_64_TLSGD: tls_type = GOT_TLS_GD; break;
829 case R_X86_64_GOTTPOFF: tls_type = GOT_TLS_IE; break;
830 case R_X86_64_GOTPC32_TLSDESC:
831 case R_X86_64_TLSDESC_CALL:
832 tls_type = GOT_TLS_GDESC; break;
835 if (h != NULL)
837 if (r_type == R_X86_64_GOTPLT64)
839 /* This relocation indicates that we also need
840 a PLT entry, as this is a function. We don't need
841 a PLT entry for local symbols. */
842 h->needs_plt = 1;
843 h->plt.refcount += 1;
845 h->got.refcount += 1;
846 old_tls_type = elf64_x86_64_hash_entry (h)->tls_type;
848 else
850 bfd_signed_vma *local_got_refcounts;
852 /* This is a global offset table entry for a local symbol. */
853 local_got_refcounts = elf_local_got_refcounts (abfd);
854 if (local_got_refcounts == NULL)
856 bfd_size_type size;
858 size = symtab_hdr->sh_info;
859 size *= sizeof (bfd_signed_vma)
860 + sizeof (bfd_vma) + sizeof (char);
861 local_got_refcounts = ((bfd_signed_vma *)
862 bfd_zalloc (abfd, size));
863 if (local_got_refcounts == NULL)
864 return FALSE;
865 elf_local_got_refcounts (abfd) = local_got_refcounts;
866 elf64_x86_64_local_tlsdesc_gotent (abfd)
867 = (bfd_vma *) (local_got_refcounts + symtab_hdr->sh_info);
868 elf64_x86_64_local_got_tls_type (abfd)
869 = (char *) (local_got_refcounts + 2 * symtab_hdr->sh_info);
871 local_got_refcounts[r_symndx] += 1;
872 old_tls_type
873 = elf64_x86_64_local_got_tls_type (abfd) [r_symndx];
876 /* If a TLS symbol is accessed using IE at least once,
877 there is no point to use dynamic model for it. */
878 if (old_tls_type != tls_type && old_tls_type != GOT_UNKNOWN
879 && (! GOT_TLS_GD_ANY_P (old_tls_type)
880 || tls_type != GOT_TLS_IE))
882 if (old_tls_type == GOT_TLS_IE && GOT_TLS_GD_ANY_P (tls_type))
883 tls_type = old_tls_type;
884 else if (GOT_TLS_GD_ANY_P (old_tls_type)
885 && GOT_TLS_GD_ANY_P (tls_type))
886 tls_type |= old_tls_type;
887 else
889 (*_bfd_error_handler)
890 (_("%B: %s' accessed both as normal and thread local symbol"),
891 abfd, h ? h->root.root.string : "<local>");
892 return FALSE;
896 if (old_tls_type != tls_type)
898 if (h != NULL)
899 elf64_x86_64_hash_entry (h)->tls_type = tls_type;
900 else
901 elf64_x86_64_local_got_tls_type (abfd) [r_symndx] = tls_type;
904 /* Fall through */
906 case R_X86_64_GOTOFF64:
907 case R_X86_64_GOTPC32:
908 case R_X86_64_GOTPC64:
909 create_got:
910 if (htab->sgot == NULL)
912 if (htab->elf.dynobj == NULL)
913 htab->elf.dynobj = abfd;
914 if (!create_got_section (htab->elf.dynobj, info))
915 return FALSE;
917 break;
919 case R_X86_64_PLT32:
920 /* This symbol requires a procedure linkage table entry. We
921 actually build the entry in adjust_dynamic_symbol,
922 because this might be a case of linking PIC code which is
923 never referenced by a dynamic object, in which case we
924 don't need to generate a procedure linkage table entry
925 after all. */
927 /* If this is a local symbol, we resolve it directly without
928 creating a procedure linkage table entry. */
929 if (h == NULL)
930 continue;
932 h->needs_plt = 1;
933 h->plt.refcount += 1;
934 break;
936 case R_X86_64_PLTOFF64:
937 /* This tries to form the 'address' of a function relative
938 to GOT. For global symbols we need a PLT entry. */
939 if (h != NULL)
941 h->needs_plt = 1;
942 h->plt.refcount += 1;
944 goto create_got;
946 case R_X86_64_8:
947 case R_X86_64_16:
948 case R_X86_64_32:
949 case R_X86_64_32S:
950 /* Let's help debug shared library creation. These relocs
951 cannot be used in shared libs. Don't error out for
952 sections we don't care about, such as debug sections or
953 non-constant sections. */
954 if (info->shared
955 && (sec->flags & SEC_ALLOC) != 0
956 && (sec->flags & SEC_READONLY) != 0)
958 (*_bfd_error_handler)
959 (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
960 abfd,
961 x86_64_elf_howto_table[r_type].name,
962 (h) ? h->root.root.string : "a local symbol");
963 bfd_set_error (bfd_error_bad_value);
964 return FALSE;
966 /* Fall through. */
968 case R_X86_64_PC8:
969 case R_X86_64_PC16:
970 case R_X86_64_PC32:
971 case R_X86_64_PC64:
972 case R_X86_64_64:
973 if (h != NULL && !info->shared)
975 /* If this reloc is in a read-only section, we might
976 need a copy reloc. We can't check reliably at this
977 stage whether the section is read-only, as input
978 sections have not yet been mapped to output sections.
979 Tentatively set the flag for now, and correct in
980 adjust_dynamic_symbol. */
981 h->non_got_ref = 1;
983 /* We may need a .plt entry if the function this reloc
984 refers to is in a shared lib. */
985 h->plt.refcount += 1;
986 if (r_type != R_X86_64_PC32 && r_type != R_X86_64_PC64)
987 h->pointer_equality_needed = 1;
990 /* If we are creating a shared library, and this is a reloc
991 against a global symbol, or a non PC relative reloc
992 against a local symbol, then we need to copy the reloc
993 into the shared library. However, if we are linking with
994 -Bsymbolic, we do not need to copy a reloc against a
995 global symbol which is defined in an object we are
996 including in the link (i.e., DEF_REGULAR is set). At
997 this point we have not seen all the input files, so it is
998 possible that DEF_REGULAR is not set now but will be set
999 later (it is never cleared). In case of a weak definition,
1000 DEF_REGULAR may be cleared later by a strong definition in
1001 a shared library. We account for that possibility below by
1002 storing information in the relocs_copied field of the hash
1003 table entry. A similar situation occurs when creating
1004 shared libraries and symbol visibility changes render the
1005 symbol local.
1007 If on the other hand, we are creating an executable, we
1008 may need to keep relocations for symbols satisfied by a
1009 dynamic library if we manage to avoid copy relocs for the
1010 symbol. */
1011 if ((info->shared
1012 && (sec->flags & SEC_ALLOC) != 0
1013 && (((r_type != R_X86_64_PC8)
1014 && (r_type != R_X86_64_PC16)
1015 && (r_type != R_X86_64_PC32)
1016 && (r_type != R_X86_64_PC64))
1017 || (h != NULL
1018 && (! SYMBOLIC_BIND (info, h)
1019 || h->root.type == bfd_link_hash_defweak
1020 || !h->def_regular))))
1021 || (ELIMINATE_COPY_RELOCS
1022 && !info->shared
1023 && (sec->flags & SEC_ALLOC) != 0
1024 && h != NULL
1025 && (h->root.type == bfd_link_hash_defweak
1026 || !h->def_regular)))
1028 struct elf64_x86_64_dyn_relocs *p;
1029 struct elf64_x86_64_dyn_relocs **head;
1031 /* We must copy these reloc types into the output file.
1032 Create a reloc section in dynobj and make room for
1033 this reloc. */
1034 if (sreloc == NULL)
1036 const char *name;
1037 bfd *dynobj;
1039 name = (bfd_elf_string_from_elf_section
1040 (abfd,
1041 elf_elfheader (abfd)->e_shstrndx,
1042 elf_section_data (sec)->rel_hdr.sh_name));
1043 if (name == NULL)
1044 return FALSE;
1046 if (! CONST_STRNEQ (name, ".rela")
1047 || strcmp (bfd_get_section_name (abfd, sec),
1048 name + 5) != 0)
1050 (*_bfd_error_handler)
1051 (_("%B: bad relocation section name `%s\'"),
1052 abfd, name);
1055 if (htab->elf.dynobj == NULL)
1056 htab->elf.dynobj = abfd;
1058 dynobj = htab->elf.dynobj;
1060 sreloc = bfd_get_section_by_name (dynobj, name);
1061 if (sreloc == NULL)
1063 flagword flags;
1065 flags = (SEC_HAS_CONTENTS | SEC_READONLY
1066 | SEC_IN_MEMORY | SEC_LINKER_CREATED);
1067 if ((sec->flags & SEC_ALLOC) != 0)
1068 flags |= SEC_ALLOC | SEC_LOAD;
1069 sreloc = bfd_make_section_with_flags (dynobj,
1070 name,
1071 flags);
1072 if (sreloc == NULL
1073 || ! bfd_set_section_alignment (dynobj, sreloc, 3))
1074 return FALSE;
1076 elf_section_data (sec)->sreloc = sreloc;
1079 /* If this is a global symbol, we count the number of
1080 relocations we need for this symbol. */
1081 if (h != NULL)
1083 head = &((struct elf64_x86_64_link_hash_entry *) h)->dyn_relocs;
1085 else
1087 void **vpp;
1088 /* Track dynamic relocs needed for local syms too.
1089 We really need local syms available to do this
1090 easily. Oh well. */
1092 asection *s;
1093 s = bfd_section_from_r_symndx (abfd, &htab->sym_sec,
1094 sec, r_symndx);
1095 if (s == NULL)
1096 return FALSE;
1098 /* Beware of type punned pointers vs strict aliasing
1099 rules. */
1100 vpp = &(elf_section_data (s)->local_dynrel);
1101 head = (struct elf64_x86_64_dyn_relocs **)vpp;
1104 p = *head;
1105 if (p == NULL || p->sec != sec)
1107 bfd_size_type amt = sizeof *p;
1108 p = ((struct elf64_x86_64_dyn_relocs *)
1109 bfd_alloc (htab->elf.dynobj, amt));
1110 if (p == NULL)
1111 return FALSE;
1112 p->next = *head;
1113 *head = p;
1114 p->sec = sec;
1115 p->count = 0;
1116 p->pc_count = 0;
1119 p->count += 1;
1120 if (r_type == R_X86_64_PC8
1121 || r_type == R_X86_64_PC16
1122 || r_type == R_X86_64_PC32
1123 || r_type == R_X86_64_PC64)
1124 p->pc_count += 1;
1126 break;
1128 /* This relocation describes the C++ object vtable hierarchy.
1129 Reconstruct it for later use during GC. */
1130 case R_X86_64_GNU_VTINHERIT:
1131 if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
1132 return FALSE;
1133 break;
1135 /* This relocation describes which C++ vtable entries are actually
1136 used. Record for later use during GC. */
1137 case R_X86_64_GNU_VTENTRY:
1138 if (!bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend))
1139 return FALSE;
1140 break;
1142 default:
1143 break;
1147 return TRUE;
1150 /* Return the section that should be marked against GC for a given
1151 relocation. */
1153 static asection *
1154 elf64_x86_64_gc_mark_hook (asection *sec,
1155 struct bfd_link_info *info,
1156 Elf_Internal_Rela *rel,
1157 struct elf_link_hash_entry *h,
1158 Elf_Internal_Sym *sym)
1160 if (h != NULL)
1161 switch (ELF64_R_TYPE (rel->r_info))
1163 case R_X86_64_GNU_VTINHERIT:
1164 case R_X86_64_GNU_VTENTRY:
1165 return NULL;
1168 return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
1171 /* Update the got entry reference counts for the section being removed. */
1173 static bfd_boolean
1174 elf64_x86_64_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info,
1175 asection *sec, const Elf_Internal_Rela *relocs)
1177 Elf_Internal_Shdr *symtab_hdr;
1178 struct elf_link_hash_entry **sym_hashes;
1179 bfd_signed_vma *local_got_refcounts;
1180 const Elf_Internal_Rela *rel, *relend;
1182 elf_section_data (sec)->local_dynrel = NULL;
1184 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
1185 sym_hashes = elf_sym_hashes (abfd);
1186 local_got_refcounts = elf_local_got_refcounts (abfd);
1188 relend = relocs + sec->reloc_count;
1189 for (rel = relocs; rel < relend; rel++)
1191 unsigned long r_symndx;
1192 unsigned int r_type;
1193 struct elf_link_hash_entry *h = NULL;
1195 r_symndx = ELF64_R_SYM (rel->r_info);
1196 if (r_symndx >= symtab_hdr->sh_info)
1198 struct elf64_x86_64_link_hash_entry *eh;
1199 struct elf64_x86_64_dyn_relocs **pp;
1200 struct elf64_x86_64_dyn_relocs *p;
1202 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
1203 while (h->root.type == bfd_link_hash_indirect
1204 || h->root.type == bfd_link_hash_warning)
1205 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1206 eh = (struct elf64_x86_64_link_hash_entry *) h;
1208 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; pp = &p->next)
1209 if (p->sec == sec)
1211 /* Everything must go for SEC. */
1212 *pp = p->next;
1213 break;
1217 r_type = ELF64_R_TYPE (rel->r_info);
1218 r_type = elf64_x86_64_tls_transition (info, r_type, h != NULL);
1219 switch (r_type)
1221 case R_X86_64_TLSLD:
1222 if (elf64_x86_64_hash_table (info)->tls_ld_got.refcount > 0)
1223 elf64_x86_64_hash_table (info)->tls_ld_got.refcount -= 1;
1224 break;
1226 case R_X86_64_TLSGD:
1227 case R_X86_64_GOTPC32_TLSDESC:
1228 case R_X86_64_TLSDESC_CALL:
1229 case R_X86_64_GOTTPOFF:
1230 case R_X86_64_GOT32:
1231 case R_X86_64_GOTPCREL:
1232 case R_X86_64_GOT64:
1233 case R_X86_64_GOTPCREL64:
1234 case R_X86_64_GOTPLT64:
1235 if (h != NULL)
1237 if (r_type == R_X86_64_GOTPLT64 && h->plt.refcount > 0)
1238 h->plt.refcount -= 1;
1239 if (h->got.refcount > 0)
1240 h->got.refcount -= 1;
1242 else if (local_got_refcounts != NULL)
1244 if (local_got_refcounts[r_symndx] > 0)
1245 local_got_refcounts[r_symndx] -= 1;
1247 break;
1249 case R_X86_64_8:
1250 case R_X86_64_16:
1251 case R_X86_64_32:
1252 case R_X86_64_64:
1253 case R_X86_64_32S:
1254 case R_X86_64_PC8:
1255 case R_X86_64_PC16:
1256 case R_X86_64_PC32:
1257 case R_X86_64_PC64:
1258 if (info->shared)
1259 break;
1260 /* Fall thru */
1262 case R_X86_64_PLT32:
1263 case R_X86_64_PLTOFF64:
1264 if (h != NULL)
1266 if (h->plt.refcount > 0)
1267 h->plt.refcount -= 1;
1269 break;
1271 default:
1272 break;
1276 return TRUE;
1279 /* Adjust a symbol defined by a dynamic object and referenced by a
1280 regular object. The current definition is in some section of the
1281 dynamic object, but we're not including those sections. We have to
1282 change the definition to something the rest of the link can
1283 understand. */
1285 static bfd_boolean
1286 elf64_x86_64_adjust_dynamic_symbol (struct bfd_link_info *info,
1287 struct elf_link_hash_entry *h)
1289 struct elf64_x86_64_link_hash_table *htab;
1290 asection *s;
1292 /* If this is a function, put it in the procedure linkage table. We
1293 will fill in the contents of the procedure linkage table later,
1294 when we know the address of the .got section. */
1295 if (h->type == STT_FUNC
1296 || h->needs_plt)
1298 if (h->plt.refcount <= 0
1299 || SYMBOL_CALLS_LOCAL (info, h)
1300 || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
1301 && h->root.type == bfd_link_hash_undefweak))
1303 /* This case can occur if we saw a PLT32 reloc in an input
1304 file, but the symbol was never referred to by a dynamic
1305 object, or if all references were garbage collected. In
1306 such a case, we don't actually need to build a procedure
1307 linkage table, and we can just do a PC32 reloc instead. */
1308 h->plt.offset = (bfd_vma) -1;
1309 h->needs_plt = 0;
1312 return TRUE;
1314 else
1315 /* It's possible that we incorrectly decided a .plt reloc was
1316 needed for an R_X86_64_PC32 reloc to a non-function sym in
1317 check_relocs. We can't decide accurately between function and
1318 non-function syms in check-relocs; Objects loaded later in
1319 the link may change h->type. So fix it now. */
1320 h->plt.offset = (bfd_vma) -1;
1322 /* If this is a weak symbol, and there is a real definition, the
1323 processor independent code will have arranged for us to see the
1324 real definition first, and we can just use the same value. */
1325 if (h->u.weakdef != NULL)
1327 BFD_ASSERT (h->u.weakdef->root.type == bfd_link_hash_defined
1328 || h->u.weakdef->root.type == bfd_link_hash_defweak);
1329 h->root.u.def.section = h->u.weakdef->root.u.def.section;
1330 h->root.u.def.value = h->u.weakdef->root.u.def.value;
1331 if (ELIMINATE_COPY_RELOCS || info->nocopyreloc)
1332 h->non_got_ref = h->u.weakdef->non_got_ref;
1333 return TRUE;
1336 /* This is a reference to a symbol defined by a dynamic object which
1337 is not a function. */
1339 /* If we are creating a shared library, we must presume that the
1340 only references to the symbol are via the global offset table.
1341 For such cases we need not do anything here; the relocations will
1342 be handled correctly by relocate_section. */
1343 if (info->shared)
1344 return TRUE;
1346 /* If there are no references to this symbol that do not use the
1347 GOT, we don't need to generate a copy reloc. */
1348 if (!h->non_got_ref)
1349 return TRUE;
1351 /* If -z nocopyreloc was given, we won't generate them either. */
1352 if (info->nocopyreloc)
1354 h->non_got_ref = 0;
1355 return TRUE;
1358 if (ELIMINATE_COPY_RELOCS)
1360 struct elf64_x86_64_link_hash_entry * eh;
1361 struct elf64_x86_64_dyn_relocs *p;
1363 eh = (struct elf64_x86_64_link_hash_entry *) h;
1364 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1366 s = p->sec->output_section;
1367 if (s != NULL && (s->flags & SEC_READONLY) != 0)
1368 break;
1371 /* If we didn't find any dynamic relocs in read-only sections, then
1372 we'll be keeping the dynamic relocs and avoiding the copy reloc. */
1373 if (p == NULL)
1375 h->non_got_ref = 0;
1376 return TRUE;
1380 if (h->size == 0)
1382 (*_bfd_error_handler) (_("dynamic variable `%s' is zero size"),
1383 h->root.root.string);
1384 return TRUE;
1387 /* We must allocate the symbol in our .dynbss section, which will
1388 become part of the .bss section of the executable. There will be
1389 an entry for this symbol in the .dynsym section. The dynamic
1390 object will contain position independent code, so all references
1391 from the dynamic object to this symbol will go through the global
1392 offset table. The dynamic linker will use the .dynsym entry to
1393 determine the address it must put in the global offset table, so
1394 both the dynamic object and the regular object will refer to the
1395 same memory location for the variable. */
1397 htab = elf64_x86_64_hash_table (info);
1399 /* We must generate a R_X86_64_COPY reloc to tell the dynamic linker
1400 to copy the initial value out of the dynamic object and into the
1401 runtime process image. */
1402 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0)
1404 htab->srelbss->size += sizeof (Elf64_External_Rela);
1405 h->needs_copy = 1;
1408 s = htab->sdynbss;
1410 return _bfd_elf_adjust_dynamic_copy (h, s);
1413 /* Allocate space in .plt, .got and associated reloc sections for
1414 dynamic relocs. */
1416 static bfd_boolean
1417 allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
1419 struct bfd_link_info *info;
1420 struct elf64_x86_64_link_hash_table *htab;
1421 struct elf64_x86_64_link_hash_entry *eh;
1422 struct elf64_x86_64_dyn_relocs *p;
1424 if (h->root.type == bfd_link_hash_indirect)
1425 return TRUE;
1427 if (h->root.type == bfd_link_hash_warning)
1428 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1430 info = (struct bfd_link_info *) inf;
1431 htab = elf64_x86_64_hash_table (info);
1433 if (htab->elf.dynamic_sections_created
1434 && h->plt.refcount > 0)
1436 /* Make sure this symbol is output as a dynamic symbol.
1437 Undefined weak syms won't yet be marked as dynamic. */
1438 if (h->dynindx == -1
1439 && !h->forced_local)
1441 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1442 return FALSE;
1445 if (info->shared
1446 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
1448 asection *s = htab->splt;
1450 /* If this is the first .plt entry, make room for the special
1451 first entry. */
1452 if (s->size == 0)
1453 s->size += PLT_ENTRY_SIZE;
1455 h->plt.offset = s->size;
1457 /* If this symbol is not defined in a regular file, and we are
1458 not generating a shared library, then set the symbol to this
1459 location in the .plt. This is required to make function
1460 pointers compare as equal between the normal executable and
1461 the shared library. */
1462 if (! info->shared
1463 && !h->def_regular)
1465 h->root.u.def.section = s;
1466 h->root.u.def.value = h->plt.offset;
1469 /* Make room for this entry. */
1470 s->size += PLT_ENTRY_SIZE;
1472 /* We also need to make an entry in the .got.plt section, which
1473 will be placed in the .got section by the linker script. */
1474 htab->sgotplt->size += GOT_ENTRY_SIZE;
1476 /* We also need to make an entry in the .rela.plt section. */
1477 htab->srelplt->size += sizeof (Elf64_External_Rela);
1478 htab->srelplt->reloc_count++;
1480 else
1482 h->plt.offset = (bfd_vma) -1;
1483 h->needs_plt = 0;
1486 else
1488 h->plt.offset = (bfd_vma) -1;
1489 h->needs_plt = 0;
1492 eh = (struct elf64_x86_64_link_hash_entry *) h;
1493 eh->tlsdesc_got = (bfd_vma) -1;
1495 /* If R_X86_64_GOTTPOFF symbol is now local to the binary,
1496 make it a R_X86_64_TPOFF32 requiring no GOT entry. */
1497 if (h->got.refcount > 0
1498 && !info->shared
1499 && h->dynindx == -1
1500 && elf64_x86_64_hash_entry (h)->tls_type == GOT_TLS_IE)
1501 h->got.offset = (bfd_vma) -1;
1502 else if (h->got.refcount > 0)
1504 asection *s;
1505 bfd_boolean dyn;
1506 int tls_type = elf64_x86_64_hash_entry (h)->tls_type;
1508 /* Make sure this symbol is output as a dynamic symbol.
1509 Undefined weak syms won't yet be marked as dynamic. */
1510 if (h->dynindx == -1
1511 && !h->forced_local)
1513 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1514 return FALSE;
1517 if (GOT_TLS_GDESC_P (tls_type))
1519 eh->tlsdesc_got = htab->sgotplt->size
1520 - elf64_x86_64_compute_jump_table_size (htab);
1521 htab->sgotplt->size += 2 * GOT_ENTRY_SIZE;
1522 h->got.offset = (bfd_vma) -2;
1524 if (! GOT_TLS_GDESC_P (tls_type)
1525 || GOT_TLS_GD_P (tls_type))
1527 s = htab->sgot;
1528 h->got.offset = s->size;
1529 s->size += GOT_ENTRY_SIZE;
1530 if (GOT_TLS_GD_P (tls_type))
1531 s->size += GOT_ENTRY_SIZE;
1533 dyn = htab->elf.dynamic_sections_created;
1534 /* R_X86_64_TLSGD needs one dynamic relocation if local symbol
1535 and two if global.
1536 R_X86_64_GOTTPOFF needs one dynamic relocation. */
1537 if ((GOT_TLS_GD_P (tls_type) && h->dynindx == -1)
1538 || tls_type == GOT_TLS_IE)
1539 htab->srelgot->size += sizeof (Elf64_External_Rela);
1540 else if (GOT_TLS_GD_P (tls_type))
1541 htab->srelgot->size += 2 * sizeof (Elf64_External_Rela);
1542 else if (! GOT_TLS_GDESC_P (tls_type)
1543 && (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
1544 || h->root.type != bfd_link_hash_undefweak)
1545 && (info->shared
1546 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h)))
1547 htab->srelgot->size += sizeof (Elf64_External_Rela);
1548 if (GOT_TLS_GDESC_P (tls_type))
1550 htab->srelplt->size += sizeof (Elf64_External_Rela);
1551 htab->tlsdesc_plt = (bfd_vma) -1;
1554 else
1555 h->got.offset = (bfd_vma) -1;
1557 if (eh->dyn_relocs == NULL)
1558 return TRUE;
1560 /* In the shared -Bsymbolic case, discard space allocated for
1561 dynamic pc-relative relocs against symbols which turn out to be
1562 defined in regular objects. For the normal shared case, discard
1563 space for pc-relative relocs that have become local due to symbol
1564 visibility changes. */
1566 if (info->shared)
1568 /* Relocs that use pc_count are those that appear on a call
1569 insn, or certain REL relocs that can generated via assembly.
1570 We want calls to protected symbols to resolve directly to the
1571 function rather than going via the plt. If people want
1572 function pointer comparisons to work as expected then they
1573 should avoid writing weird assembly. */
1574 if (SYMBOL_CALLS_LOCAL (info, h))
1576 struct elf64_x86_64_dyn_relocs **pp;
1578 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
1580 p->count -= p->pc_count;
1581 p->pc_count = 0;
1582 if (p->count == 0)
1583 *pp = p->next;
1584 else
1585 pp = &p->next;
1589 /* Also discard relocs on undefined weak syms with non-default
1590 visibility. */
1591 if (eh->dyn_relocs != NULL
1592 && h->root.type == bfd_link_hash_undefweak)
1594 if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
1595 eh->dyn_relocs = NULL;
1597 /* Make sure undefined weak symbols are output as a dynamic
1598 symbol in PIEs. */
1599 else if (h->dynindx == -1
1600 && !h->forced_local)
1602 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1603 return FALSE;
1607 else if (ELIMINATE_COPY_RELOCS)
1609 /* For the non-shared case, discard space for relocs against
1610 symbols which turn out to need copy relocs or are not
1611 dynamic. */
1613 if (!h->non_got_ref
1614 && ((h->def_dynamic
1615 && !h->def_regular)
1616 || (htab->elf.dynamic_sections_created
1617 && (h->root.type == bfd_link_hash_undefweak
1618 || h->root.type == bfd_link_hash_undefined))))
1620 /* Make sure this symbol is output as a dynamic symbol.
1621 Undefined weak syms won't yet be marked as dynamic. */
1622 if (h->dynindx == -1
1623 && !h->forced_local)
1625 if (! bfd_elf_link_record_dynamic_symbol (info, h))
1626 return FALSE;
1629 /* If that succeeded, we know we'll be keeping all the
1630 relocs. */
1631 if (h->dynindx != -1)
1632 goto keep;
1635 eh->dyn_relocs = NULL;
1637 keep: ;
1640 /* Finally, allocate space. */
1641 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1643 asection *sreloc = elf_section_data (p->sec)->sreloc;
1644 sreloc->size += p->count * sizeof (Elf64_External_Rela);
1647 return TRUE;
1650 /* Find any dynamic relocs that apply to read-only sections. */
1652 static bfd_boolean
1653 readonly_dynrelocs (struct elf_link_hash_entry *h, void * inf)
1655 struct elf64_x86_64_link_hash_entry *eh;
1656 struct elf64_x86_64_dyn_relocs *p;
1658 if (h->root.type == bfd_link_hash_warning)
1659 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1661 eh = (struct elf64_x86_64_link_hash_entry *) h;
1662 for (p = eh->dyn_relocs; p != NULL; p = p->next)
1664 asection *s = p->sec->output_section;
1666 if (s != NULL && (s->flags & SEC_READONLY) != 0)
1668 struct bfd_link_info *info = (struct bfd_link_info *) inf;
1670 info->flags |= DF_TEXTREL;
1672 /* Not an error, just cut short the traversal. */
1673 return FALSE;
1676 return TRUE;
1679 /* Set the sizes of the dynamic sections. */
1681 static bfd_boolean
1682 elf64_x86_64_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED,
1683 struct bfd_link_info *info)
1685 struct elf64_x86_64_link_hash_table *htab;
1686 bfd *dynobj;
1687 asection *s;
1688 bfd_boolean relocs;
1689 bfd *ibfd;
1691 htab = elf64_x86_64_hash_table (info);
1692 dynobj = htab->elf.dynobj;
1693 if (dynobj == NULL)
1694 abort ();
1696 if (htab->elf.dynamic_sections_created)
1698 /* Set the contents of the .interp section to the interpreter. */
1699 if (info->executable)
1701 s = bfd_get_section_by_name (dynobj, ".interp");
1702 if (s == NULL)
1703 abort ();
1704 s->size = sizeof ELF_DYNAMIC_INTERPRETER;
1705 s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER;
1709 /* Set up .got offsets for local syms, and space for local dynamic
1710 relocs. */
1711 for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next)
1713 bfd_signed_vma *local_got;
1714 bfd_signed_vma *end_local_got;
1715 char *local_tls_type;
1716 bfd_vma *local_tlsdesc_gotent;
1717 bfd_size_type locsymcount;
1718 Elf_Internal_Shdr *symtab_hdr;
1719 asection *srel;
1721 if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour)
1722 continue;
1724 for (s = ibfd->sections; s != NULL; s = s->next)
1726 struct elf64_x86_64_dyn_relocs *p;
1728 for (p = (struct elf64_x86_64_dyn_relocs *)
1729 (elf_section_data (s)->local_dynrel);
1730 p != NULL;
1731 p = p->next)
1733 if (!bfd_is_abs_section (p->sec)
1734 && bfd_is_abs_section (p->sec->output_section))
1736 /* Input section has been discarded, either because
1737 it is a copy of a linkonce section or due to
1738 linker script /DISCARD/, so we'll be discarding
1739 the relocs too. */
1741 else if (p->count != 0)
1743 srel = elf_section_data (p->sec)->sreloc;
1744 srel->size += p->count * sizeof (Elf64_External_Rela);
1745 if ((p->sec->output_section->flags & SEC_READONLY) != 0)
1746 info->flags |= DF_TEXTREL;
1752 local_got = elf_local_got_refcounts (ibfd);
1753 if (!local_got)
1754 continue;
1756 symtab_hdr = &elf_tdata (ibfd)->symtab_hdr;
1757 locsymcount = symtab_hdr->sh_info;
1758 end_local_got = local_got + locsymcount;
1759 local_tls_type = elf64_x86_64_local_got_tls_type (ibfd);
1760 local_tlsdesc_gotent = elf64_x86_64_local_tlsdesc_gotent (ibfd);
1761 s = htab->sgot;
1762 srel = htab->srelgot;
1763 for (; local_got < end_local_got;
1764 ++local_got, ++local_tls_type, ++local_tlsdesc_gotent)
1766 *local_tlsdesc_gotent = (bfd_vma) -1;
1767 if (*local_got > 0)
1769 if (GOT_TLS_GDESC_P (*local_tls_type))
1771 *local_tlsdesc_gotent = htab->sgotplt->size
1772 - elf64_x86_64_compute_jump_table_size (htab);
1773 htab->sgotplt->size += 2 * GOT_ENTRY_SIZE;
1774 *local_got = (bfd_vma) -2;
1776 if (! GOT_TLS_GDESC_P (*local_tls_type)
1777 || GOT_TLS_GD_P (*local_tls_type))
1779 *local_got = s->size;
1780 s->size += GOT_ENTRY_SIZE;
1781 if (GOT_TLS_GD_P (*local_tls_type))
1782 s->size += GOT_ENTRY_SIZE;
1784 if (info->shared
1785 || GOT_TLS_GD_ANY_P (*local_tls_type)
1786 || *local_tls_type == GOT_TLS_IE)
1788 if (GOT_TLS_GDESC_P (*local_tls_type))
1790 htab->srelplt->size += sizeof (Elf64_External_Rela);
1791 htab->tlsdesc_plt = (bfd_vma) -1;
1793 if (! GOT_TLS_GDESC_P (*local_tls_type)
1794 || GOT_TLS_GD_P (*local_tls_type))
1795 srel->size += sizeof (Elf64_External_Rela);
1798 else
1799 *local_got = (bfd_vma) -1;
1803 if (htab->tls_ld_got.refcount > 0)
1805 /* Allocate 2 got entries and 1 dynamic reloc for R_X86_64_TLSLD
1806 relocs. */
1807 htab->tls_ld_got.offset = htab->sgot->size;
1808 htab->sgot->size += 2 * GOT_ENTRY_SIZE;
1809 htab->srelgot->size += sizeof (Elf64_External_Rela);
1811 else
1812 htab->tls_ld_got.offset = -1;
1814 /* Allocate global sym .plt and .got entries, and space for global
1815 sym dynamic relocs. */
1816 elf_link_hash_traverse (&htab->elf, allocate_dynrelocs, (PTR) info);
1818 /* For every jump slot reserved in the sgotplt, reloc_count is
1819 incremented. However, when we reserve space for TLS descriptors,
1820 it's not incremented, so in order to compute the space reserved
1821 for them, it suffices to multiply the reloc count by the jump
1822 slot size. */
1823 if (htab->srelplt)
1824 htab->sgotplt_jump_table_size
1825 = elf64_x86_64_compute_jump_table_size (htab);
1827 if (htab->tlsdesc_plt)
1829 /* If we're not using lazy TLS relocations, don't generate the
1830 PLT and GOT entries they require. */
1831 if ((info->flags & DF_BIND_NOW))
1832 htab->tlsdesc_plt = 0;
1833 else
1835 htab->tlsdesc_got = htab->sgot->size;
1836 htab->sgot->size += GOT_ENTRY_SIZE;
1837 /* Reserve room for the initial entry.
1838 FIXME: we could probably do away with it in this case. */
1839 if (htab->splt->size == 0)
1840 htab->splt->size += PLT_ENTRY_SIZE;
1841 htab->tlsdesc_plt = htab->splt->size;
1842 htab->splt->size += PLT_ENTRY_SIZE;
1846 /* We now have determined the sizes of the various dynamic sections.
1847 Allocate memory for them. */
1848 relocs = FALSE;
1849 for (s = dynobj->sections; s != NULL; s = s->next)
1851 if ((s->flags & SEC_LINKER_CREATED) == 0)
1852 continue;
1854 if (s == htab->splt
1855 || s == htab->sgot
1856 || s == htab->sgotplt
1857 || s == htab->sdynbss)
1859 /* Strip this section if we don't need it; see the
1860 comment below. */
1862 else if (CONST_STRNEQ (bfd_get_section_name (dynobj, s), ".rela"))
1864 if (s->size != 0 && s != htab->srelplt)
1865 relocs = TRUE;
1867 /* We use the reloc_count field as a counter if we need
1868 to copy relocs into the output file. */
1869 if (s != htab->srelplt)
1870 s->reloc_count = 0;
1872 else
1874 /* It's not one of our sections, so don't allocate space. */
1875 continue;
1878 if (s->size == 0)
1880 /* If we don't need this section, strip it from the
1881 output file. This is mostly to handle .rela.bss and
1882 .rela.plt. We must create both sections in
1883 create_dynamic_sections, because they must be created
1884 before the linker maps input sections to output
1885 sections. The linker does that before
1886 adjust_dynamic_symbol is called, and it is that
1887 function which decides whether anything needs to go
1888 into these sections. */
1890 s->flags |= SEC_EXCLUDE;
1891 continue;
1894 if ((s->flags & SEC_HAS_CONTENTS) == 0)
1895 continue;
1897 /* Allocate memory for the section contents. We use bfd_zalloc
1898 here in case unused entries are not reclaimed before the
1899 section's contents are written out. This should not happen,
1900 but this way if it does, we get a R_X86_64_NONE reloc instead
1901 of garbage. */
1902 s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->size);
1903 if (s->contents == NULL)
1904 return FALSE;
1907 if (htab->elf.dynamic_sections_created)
1909 /* Add some entries to the .dynamic section. We fill in the
1910 values later, in elf64_x86_64_finish_dynamic_sections, but we
1911 must add the entries now so that we get the correct size for
1912 the .dynamic section. The DT_DEBUG entry is filled in by the
1913 dynamic linker and used by the debugger. */
1914 #define add_dynamic_entry(TAG, VAL) \
1915 _bfd_elf_add_dynamic_entry (info, TAG, VAL)
1917 if (info->executable)
1919 if (!add_dynamic_entry (DT_DEBUG, 0))
1920 return FALSE;
1923 if (htab->splt->size != 0)
1925 if (!add_dynamic_entry (DT_PLTGOT, 0)
1926 || !add_dynamic_entry (DT_PLTRELSZ, 0)
1927 || !add_dynamic_entry (DT_PLTREL, DT_RELA)
1928 || !add_dynamic_entry (DT_JMPREL, 0))
1929 return FALSE;
1931 if (htab->tlsdesc_plt
1932 && (!add_dynamic_entry (DT_TLSDESC_PLT, 0)
1933 || !add_dynamic_entry (DT_TLSDESC_GOT, 0)))
1934 return FALSE;
1937 if (relocs)
1939 if (!add_dynamic_entry (DT_RELA, 0)
1940 || !add_dynamic_entry (DT_RELASZ, 0)
1941 || !add_dynamic_entry (DT_RELAENT, sizeof (Elf64_External_Rela)))
1942 return FALSE;
1944 /* If any dynamic relocs apply to a read-only section,
1945 then we need a DT_TEXTREL entry. */
1946 if ((info->flags & DF_TEXTREL) == 0)
1947 elf_link_hash_traverse (&htab->elf, readonly_dynrelocs,
1948 (PTR) info);
1950 if ((info->flags & DF_TEXTREL) != 0)
1952 if (!add_dynamic_entry (DT_TEXTREL, 0))
1953 return FALSE;
1957 #undef add_dynamic_entry
1959 return TRUE;
1962 static bfd_boolean
1963 elf64_x86_64_always_size_sections (bfd *output_bfd,
1964 struct bfd_link_info *info)
1966 asection *tls_sec = elf_hash_table (info)->tls_sec;
1968 if (tls_sec)
1970 struct elf_link_hash_entry *tlsbase;
1972 tlsbase = elf_link_hash_lookup (elf_hash_table (info),
1973 "_TLS_MODULE_BASE_",
1974 FALSE, FALSE, FALSE);
1976 if (tlsbase && tlsbase->type == STT_TLS)
1978 struct bfd_link_hash_entry *bh = NULL;
1979 const struct elf_backend_data *bed
1980 = get_elf_backend_data (output_bfd);
1982 if (!(_bfd_generic_link_add_one_symbol
1983 (info, output_bfd, "_TLS_MODULE_BASE_", BSF_LOCAL,
1984 tls_sec, 0, NULL, FALSE,
1985 bed->collect, &bh)))
1986 return FALSE;
1987 tlsbase = (struct elf_link_hash_entry *)bh;
1988 tlsbase->def_regular = 1;
1989 tlsbase->other = STV_HIDDEN;
1990 (*bed->elf_backend_hide_symbol) (info, tlsbase, TRUE);
1994 return TRUE;
1997 /* Return the base VMA address which should be subtracted from real addresses
1998 when resolving @dtpoff relocation.
1999 This is PT_TLS segment p_vaddr. */
2001 static bfd_vma
2002 dtpoff_base (struct bfd_link_info *info)
2004 /* If tls_sec is NULL, we should have signalled an error already. */
2005 if (elf_hash_table (info)->tls_sec == NULL)
2006 return 0;
2007 return elf_hash_table (info)->tls_sec->vma;
2010 /* Return the relocation value for @tpoff relocation
2011 if STT_TLS virtual address is ADDRESS. */
2013 static bfd_vma
2014 tpoff (struct bfd_link_info *info, bfd_vma address)
2016 struct elf_link_hash_table *htab = elf_hash_table (info);
2018 /* If tls_segment is NULL, we should have signalled an error already. */
2019 if (htab->tls_sec == NULL)
2020 return 0;
2021 return address - htab->tls_size - htab->tls_sec->vma;
2024 /* Is the instruction before OFFSET in CONTENTS a 32bit relative
2025 branch? */
2027 static bfd_boolean
2028 is_32bit_relative_branch (bfd_byte *contents, bfd_vma offset)
2030 /* Opcode Instruction
2031 0xe8 call
2032 0xe9 jump
2033 0x0f 0x8x conditional jump */
2034 return ((offset > 0
2035 && (contents [offset - 1] == 0xe8
2036 || contents [offset - 1] == 0xe9))
2037 || (offset > 1
2038 && contents [offset - 2] == 0x0f
2039 && (contents [offset - 1] & 0xf0) == 0x80));
2042 /* Relocate an x86_64 ELF section. */
2044 static bfd_boolean
2045 elf64_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
2046 bfd *input_bfd, asection *input_section,
2047 bfd_byte *contents, Elf_Internal_Rela *relocs,
2048 Elf_Internal_Sym *local_syms,
2049 asection **local_sections)
2051 struct elf64_x86_64_link_hash_table *htab;
2052 Elf_Internal_Shdr *symtab_hdr;
2053 struct elf_link_hash_entry **sym_hashes;
2054 bfd_vma *local_got_offsets;
2055 bfd_vma *local_tlsdesc_gotents;
2056 Elf_Internal_Rela *rel;
2057 Elf_Internal_Rela *relend;
2059 htab = elf64_x86_64_hash_table (info);
2060 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
2061 sym_hashes = elf_sym_hashes (input_bfd);
2062 local_got_offsets = elf_local_got_offsets (input_bfd);
2063 local_tlsdesc_gotents = elf64_x86_64_local_tlsdesc_gotent (input_bfd);
2065 rel = relocs;
2066 relend = relocs + input_section->reloc_count;
2067 for (; rel < relend; rel++)
2069 unsigned int r_type;
2070 reloc_howto_type *howto;
2071 unsigned long r_symndx;
2072 struct elf_link_hash_entry *h;
2073 Elf_Internal_Sym *sym;
2074 asection *sec;
2075 bfd_vma off, offplt;
2076 bfd_vma relocation;
2077 bfd_boolean unresolved_reloc;
2078 bfd_reloc_status_type r;
2079 int tls_type;
2081 r_type = ELF64_R_TYPE (rel->r_info);
2082 if (r_type == (int) R_X86_64_GNU_VTINHERIT
2083 || r_type == (int) R_X86_64_GNU_VTENTRY)
2084 continue;
2086 if (r_type >= R_X86_64_max)
2088 bfd_set_error (bfd_error_bad_value);
2089 return FALSE;
2092 howto = x86_64_elf_howto_table + r_type;
2093 r_symndx = ELF64_R_SYM (rel->r_info);
2094 h = NULL;
2095 sym = NULL;
2096 sec = NULL;
2097 unresolved_reloc = FALSE;
2098 if (r_symndx < symtab_hdr->sh_info)
2100 sym = local_syms + r_symndx;
2101 sec = local_sections[r_symndx];
2103 relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
2105 else
2107 bfd_boolean warned;
2109 RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
2110 r_symndx, symtab_hdr, sym_hashes,
2111 h, sec, relocation,
2112 unresolved_reloc, warned);
2115 if (sec != NULL && elf_discarded_section (sec))
2117 /* For relocs against symbols from removed linkonce sections,
2118 or sections discarded by a linker script, we just want the
2119 section contents zeroed. Avoid any special processing. */
2120 _bfd_clear_contents (howto, input_bfd, contents + rel->r_offset);
2121 rel->r_info = 0;
2122 rel->r_addend = 0;
2123 continue;
2126 if (info->relocatable)
2127 continue;
2129 /* When generating a shared object, the relocations handled here are
2130 copied into the output file to be resolved at run time. */
2131 switch (r_type)
2133 asection *base_got;
2134 case R_X86_64_GOT32:
2135 case R_X86_64_GOT64:
2136 /* Relocation is to the entry for this symbol in the global
2137 offset table. */
2138 case R_X86_64_GOTPCREL:
2139 case R_X86_64_GOTPCREL64:
2140 /* Use global offset table entry as symbol value. */
2141 case R_X86_64_GOTPLT64:
2142 /* This is the same as GOT64 for relocation purposes, but
2143 indicates the existence of a PLT entry. The difficulty is,
2144 that we must calculate the GOT slot offset from the PLT
2145 offset, if this symbol got a PLT entry (it was global).
2146 Additionally if it's computed from the PLT entry, then that
2147 GOT offset is relative to .got.plt, not to .got. */
2148 base_got = htab->sgot;
2150 if (htab->sgot == NULL)
2151 abort ();
2153 if (h != NULL)
2155 bfd_boolean dyn;
2157 off = h->got.offset;
2158 if (h->needs_plt
2159 && h->plt.offset != (bfd_vma)-1
2160 && off == (bfd_vma)-1)
2162 /* We can't use h->got.offset here to save
2163 state, or even just remember the offset, as
2164 finish_dynamic_symbol would use that as offset into
2165 .got. */
2166 bfd_vma plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1;
2167 off = (plt_index + 3) * GOT_ENTRY_SIZE;
2168 base_got = htab->sgotplt;
2171 dyn = htab->elf.dynamic_sections_created;
2173 if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info->shared, h)
2174 || (info->shared
2175 && SYMBOL_REFERENCES_LOCAL (info, h))
2176 || (ELF_ST_VISIBILITY (h->other)
2177 && h->root.type == bfd_link_hash_undefweak))
2179 /* This is actually a static link, or it is a -Bsymbolic
2180 link and the symbol is defined locally, or the symbol
2181 was forced to be local because of a version file. We
2182 must initialize this entry in the global offset table.
2183 Since the offset must always be a multiple of 8, we
2184 use the least significant bit to record whether we
2185 have initialized it already.
2187 When doing a dynamic link, we create a .rela.got
2188 relocation entry to initialize the value. This is
2189 done in the finish_dynamic_symbol routine. */
2190 if ((off & 1) != 0)
2191 off &= ~1;
2192 else
2194 bfd_put_64 (output_bfd, relocation,
2195 base_got->contents + off);
2196 /* Note that this is harmless for the GOTPLT64 case,
2197 as -1 | 1 still is -1. */
2198 h->got.offset |= 1;
2201 else
2202 unresolved_reloc = FALSE;
2204 else
2206 if (local_got_offsets == NULL)
2207 abort ();
2209 off = local_got_offsets[r_symndx];
2211 /* The offset must always be a multiple of 8. We use
2212 the least significant bit to record whether we have
2213 already generated the necessary reloc. */
2214 if ((off & 1) != 0)
2215 off &= ~1;
2216 else
2218 bfd_put_64 (output_bfd, relocation,
2219 base_got->contents + off);
2221 if (info->shared)
2223 asection *s;
2224 Elf_Internal_Rela outrel;
2225 bfd_byte *loc;
2227 /* We need to generate a R_X86_64_RELATIVE reloc
2228 for the dynamic linker. */
2229 s = htab->srelgot;
2230 if (s == NULL)
2231 abort ();
2233 outrel.r_offset = (base_got->output_section->vma
2234 + base_got->output_offset
2235 + off);
2236 outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE);
2237 outrel.r_addend = relocation;
2238 loc = s->contents;
2239 loc += s->reloc_count++ * sizeof (Elf64_External_Rela);
2240 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2243 local_got_offsets[r_symndx] |= 1;
2247 if (off >= (bfd_vma) -2)
2248 abort ();
2250 relocation = base_got->output_section->vma
2251 + base_got->output_offset + off;
2252 if (r_type != R_X86_64_GOTPCREL && r_type != R_X86_64_GOTPCREL64)
2253 relocation -= htab->sgotplt->output_section->vma
2254 - htab->sgotplt->output_offset;
2256 break;
2258 case R_X86_64_GOTOFF64:
2259 /* Relocation is relative to the start of the global offset
2260 table. */
2262 /* Check to make sure it isn't a protected function symbol
2263 for shared library since it may not be local when used
2264 as function address. */
2265 if (info->shared
2266 && h
2267 && h->def_regular
2268 && h->type == STT_FUNC
2269 && ELF_ST_VISIBILITY (h->other) == STV_PROTECTED)
2271 (*_bfd_error_handler)
2272 (_("%B: relocation R_X86_64_GOTOFF64 against protected function `%s' can not be used when making a shared object"),
2273 input_bfd, h->root.root.string);
2274 bfd_set_error (bfd_error_bad_value);
2275 return FALSE;
2278 /* Note that sgot is not involved in this
2279 calculation. We always want the start of .got.plt. If we
2280 defined _GLOBAL_OFFSET_TABLE_ in a different way, as is
2281 permitted by the ABI, we might have to change this
2282 calculation. */
2283 relocation -= htab->sgotplt->output_section->vma
2284 + htab->sgotplt->output_offset;
2285 break;
2287 case R_X86_64_GOTPC32:
2288 case R_X86_64_GOTPC64:
2289 /* Use global offset table as symbol value. */
2290 relocation = htab->sgotplt->output_section->vma
2291 + htab->sgotplt->output_offset;
2292 unresolved_reloc = FALSE;
2293 break;
2295 case R_X86_64_PLTOFF64:
2296 /* Relocation is PLT entry relative to GOT. For local
2297 symbols it's the symbol itself relative to GOT. */
2298 if (h != NULL
2299 /* See PLT32 handling. */
2300 && h->plt.offset != (bfd_vma) -1
2301 && htab->splt != NULL)
2303 relocation = (htab->splt->output_section->vma
2304 + htab->splt->output_offset
2305 + h->plt.offset);
2306 unresolved_reloc = FALSE;
2309 relocation -= htab->sgotplt->output_section->vma
2310 + htab->sgotplt->output_offset;
2311 break;
2313 case R_X86_64_PLT32:
2314 /* Relocation is to the entry for this symbol in the
2315 procedure linkage table. */
2317 /* Resolve a PLT32 reloc against a local symbol directly,
2318 without using the procedure linkage table. */
2319 if (h == NULL)
2320 break;
2322 if (h->plt.offset == (bfd_vma) -1
2323 || htab->splt == NULL)
2325 /* We didn't make a PLT entry for this symbol. This
2326 happens when statically linking PIC code, or when
2327 using -Bsymbolic. */
2328 break;
2331 relocation = (htab->splt->output_section->vma
2332 + htab->splt->output_offset
2333 + h->plt.offset);
2334 unresolved_reloc = FALSE;
2335 break;
2337 case R_X86_64_PC8:
2338 case R_X86_64_PC16:
2339 case R_X86_64_PC32:
2340 if (info->shared
2341 && !SYMBOL_REFERENCES_LOCAL (info, h)
2342 && (input_section->flags & SEC_ALLOC) != 0
2343 && (input_section->flags & SEC_READONLY) != 0
2344 && (!h->def_regular
2345 || r_type != R_X86_64_PC32
2346 || h->type != STT_FUNC
2347 || ELF_ST_VISIBILITY (h->other) != STV_PROTECTED
2348 || !is_32bit_relative_branch (contents,
2349 rel->r_offset)))
2351 if (h->def_regular
2352 && r_type == R_X86_64_PC32
2353 && h->type == STT_FUNC
2354 && ELF_ST_VISIBILITY (h->other) == STV_PROTECTED)
2355 (*_bfd_error_handler)
2356 (_("%B: relocation R_X86_64_PC32 against protected function `%s' can not be used when making a shared object"),
2357 input_bfd, h->root.root.string);
2358 else
2359 (*_bfd_error_handler)
2360 (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
2361 input_bfd, x86_64_elf_howto_table[r_type].name,
2362 h->root.root.string);
2363 bfd_set_error (bfd_error_bad_value);
2364 return FALSE;
2366 /* Fall through. */
2368 case R_X86_64_8:
2369 case R_X86_64_16:
2370 case R_X86_64_32:
2371 case R_X86_64_PC64:
2372 case R_X86_64_64:
2373 /* FIXME: The ABI says the linker should make sure the value is
2374 the same when it's zeroextended to 64 bit. */
2376 if ((input_section->flags & SEC_ALLOC) == 0)
2377 break;
2379 if ((info->shared
2380 && (h == NULL
2381 || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
2382 || h->root.type != bfd_link_hash_undefweak)
2383 && ((r_type != R_X86_64_PC8
2384 && r_type != R_X86_64_PC16
2385 && r_type != R_X86_64_PC32
2386 && r_type != R_X86_64_PC64)
2387 || !SYMBOL_CALLS_LOCAL (info, h)))
2388 || (ELIMINATE_COPY_RELOCS
2389 && !info->shared
2390 && h != NULL
2391 && h->dynindx != -1
2392 && !h->non_got_ref
2393 && ((h->def_dynamic
2394 && !h->def_regular)
2395 || h->root.type == bfd_link_hash_undefweak
2396 || h->root.type == bfd_link_hash_undefined)))
2398 Elf_Internal_Rela outrel;
2399 bfd_byte *loc;
2400 bfd_boolean skip, relocate;
2401 asection *sreloc;
2403 /* When generating a shared object, these relocations
2404 are copied into the output file to be resolved at run
2405 time. */
2406 skip = FALSE;
2407 relocate = FALSE;
2409 outrel.r_offset =
2410 _bfd_elf_section_offset (output_bfd, info, input_section,
2411 rel->r_offset);
2412 if (outrel.r_offset == (bfd_vma) -1)
2413 skip = TRUE;
2414 else if (outrel.r_offset == (bfd_vma) -2)
2415 skip = TRUE, relocate = TRUE;
2417 outrel.r_offset += (input_section->output_section->vma
2418 + input_section->output_offset);
2420 if (skip)
2421 memset (&outrel, 0, sizeof outrel);
2423 /* h->dynindx may be -1 if this symbol was marked to
2424 become local. */
2425 else if (h != NULL
2426 && h->dynindx != -1
2427 && (r_type == R_X86_64_PC8
2428 || r_type == R_X86_64_PC16
2429 || r_type == R_X86_64_PC32
2430 || r_type == R_X86_64_PC64
2431 || !info->shared
2432 || !SYMBOLIC_BIND (info, h)
2433 || !h->def_regular))
2435 outrel.r_info = ELF64_R_INFO (h->dynindx, r_type);
2436 outrel.r_addend = rel->r_addend;
2438 else
2440 /* This symbol is local, or marked to become local. */
2441 if (r_type == R_X86_64_64)
2443 relocate = TRUE;
2444 outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE);
2445 outrel.r_addend = relocation + rel->r_addend;
2447 else
2449 long sindx;
2451 if (bfd_is_abs_section (sec))
2452 sindx = 0;
2453 else if (sec == NULL || sec->owner == NULL)
2455 bfd_set_error (bfd_error_bad_value);
2456 return FALSE;
2458 else
2460 asection *osec;
2462 /* We are turning this relocation into one
2463 against a section symbol. It would be
2464 proper to subtract the symbol's value,
2465 osec->vma, from the emitted reloc addend,
2466 but ld.so expects buggy relocs. */
2467 osec = sec->output_section;
2468 sindx = elf_section_data (osec)->dynindx;
2469 if (sindx == 0)
2471 asection *oi = htab->elf.text_index_section;
2472 sindx = elf_section_data (oi)->dynindx;
2474 BFD_ASSERT (sindx != 0);
2477 outrel.r_info = ELF64_R_INFO (sindx, r_type);
2478 outrel.r_addend = relocation + rel->r_addend;
2482 sreloc = elf_section_data (input_section)->sreloc;
2483 if (sreloc == NULL)
2484 abort ();
2486 loc = sreloc->contents;
2487 loc += sreloc->reloc_count++ * sizeof (Elf64_External_Rela);
2488 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2490 /* If this reloc is against an external symbol, we do
2491 not want to fiddle with the addend. Otherwise, we
2492 need to include the symbol value so that it becomes
2493 an addend for the dynamic reloc. */
2494 if (! relocate)
2495 continue;
2498 break;
2500 case R_X86_64_TLSGD:
2501 case R_X86_64_GOTPC32_TLSDESC:
2502 case R_X86_64_TLSDESC_CALL:
2503 case R_X86_64_GOTTPOFF:
2504 r_type = elf64_x86_64_tls_transition (info, r_type, h == NULL);
2505 tls_type = GOT_UNKNOWN;
2506 if (h == NULL && local_got_offsets)
2507 tls_type = elf64_x86_64_local_got_tls_type (input_bfd) [r_symndx];
2508 else if (h != NULL)
2510 tls_type = elf64_x86_64_hash_entry (h)->tls_type;
2511 if (!info->shared && h->dynindx == -1 && tls_type == GOT_TLS_IE)
2512 r_type = R_X86_64_TPOFF32;
2514 if (r_type == R_X86_64_TLSGD
2515 || r_type == R_X86_64_GOTPC32_TLSDESC
2516 || r_type == R_X86_64_TLSDESC_CALL)
2518 if (tls_type == GOT_TLS_IE)
2519 r_type = R_X86_64_GOTTPOFF;
2522 if (r_type == R_X86_64_TPOFF32)
2524 BFD_ASSERT (! unresolved_reloc);
2525 if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSGD)
2527 unsigned int i;
2528 static unsigned char tlsgd[8]
2529 = { 0x66, 0x48, 0x8d, 0x3d, 0x66, 0x66, 0x48, 0xe8 };
2531 /* GD->LE transition.
2532 .byte 0x66; leaq foo@tlsgd(%rip), %rdi
2533 .word 0x6666; rex64; call __tls_get_addr@plt
2534 Change it into:
2535 movq %fs:0, %rax
2536 leaq foo@tpoff(%rax), %rax */
2537 BFD_ASSERT (rel->r_offset >= 4);
2538 for (i = 0; i < 4; i++)
2539 BFD_ASSERT (bfd_get_8 (input_bfd,
2540 contents + rel->r_offset - 4 + i)
2541 == tlsgd[i]);
2542 BFD_ASSERT (rel->r_offset + 12 <= input_section->size);
2543 for (i = 0; i < 4; i++)
2544 BFD_ASSERT (bfd_get_8 (input_bfd,
2545 contents + rel->r_offset + 4 + i)
2546 == tlsgd[i+4]);
2547 BFD_ASSERT (rel + 1 < relend);
2548 BFD_ASSERT (ELF64_R_TYPE (rel[1].r_info) == R_X86_64_PLT32);
2549 memcpy (contents + rel->r_offset - 4,
2550 "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0",
2551 16);
2552 bfd_put_32 (output_bfd, tpoff (info, relocation),
2553 contents + rel->r_offset + 8);
2554 /* Skip R_X86_64_PLT32. */
2555 rel++;
2556 continue;
2558 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_GOTPC32_TLSDESC)
2560 /* GDesc -> LE transition.
2561 It's originally something like:
2562 leaq x@tlsdesc(%rip), %rax
2564 Change it to:
2565 movl $x@tpoff, %rax
2567 Registers other than %rax may be set up here. */
2569 unsigned int val, type, type2;
2570 bfd_vma roff;
2572 /* First, make sure it's a leaq adding rip to a
2573 32-bit offset into any register, although it's
2574 probably almost always going to be rax. */
2575 roff = rel->r_offset;
2576 BFD_ASSERT (roff >= 3);
2577 type = bfd_get_8 (input_bfd, contents + roff - 3);
2578 BFD_ASSERT ((type & 0xfb) == 0x48);
2579 type2 = bfd_get_8 (input_bfd, contents + roff - 2);
2580 BFD_ASSERT (type2 == 0x8d);
2581 val = bfd_get_8 (input_bfd, contents + roff - 1);
2582 BFD_ASSERT ((val & 0xc7) == 0x05);
2583 BFD_ASSERT (roff + 4 <= input_section->size);
2585 /* Now modify the instruction as appropriate. */
2586 bfd_put_8 (output_bfd, 0x48 | ((type >> 2) & 1),
2587 contents + roff - 3);
2588 bfd_put_8 (output_bfd, 0xc7, contents + roff - 2);
2589 bfd_put_8 (output_bfd, 0xc0 | ((val >> 3) & 7),
2590 contents + roff - 1);
2591 bfd_put_32 (output_bfd, tpoff (info, relocation),
2592 contents + roff);
2593 continue;
2595 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSDESC_CALL)
2597 /* GDesc -> LE transition.
2598 It's originally:
2599 call *(%rax)
2600 Turn it into:
2601 nop; nop. */
2603 unsigned int val, type;
2604 bfd_vma roff;
2606 /* First, make sure it's a call *(%rax). */
2607 roff = rel->r_offset;
2608 BFD_ASSERT (roff + 2 <= input_section->size);
2609 type = bfd_get_8 (input_bfd, contents + roff);
2610 BFD_ASSERT (type == 0xff);
2611 val = bfd_get_8 (input_bfd, contents + roff + 1);
2612 BFD_ASSERT (val == 0x10);
2614 /* Now modify the instruction as appropriate. Use
2615 xchg %ax,%ax instead of 2 nops. */
2616 bfd_put_8 (output_bfd, 0x66, contents + roff);
2617 bfd_put_8 (output_bfd, 0x90, contents + roff + 1);
2618 continue;
2620 else
2622 unsigned int val, type, reg;
2624 /* IE->LE transition:
2625 Originally it can be one of:
2626 movq foo@gottpoff(%rip), %reg
2627 addq foo@gottpoff(%rip), %reg
2628 We change it into:
2629 movq $foo, %reg
2630 leaq foo(%reg), %reg
2631 addq $foo, %reg. */
2632 BFD_ASSERT (rel->r_offset >= 3);
2633 val = bfd_get_8 (input_bfd, contents + rel->r_offset - 3);
2634 BFD_ASSERT (val == 0x48 || val == 0x4c);
2635 type = bfd_get_8 (input_bfd, contents + rel->r_offset - 2);
2636 BFD_ASSERT (type == 0x8b || type == 0x03);
2637 reg = bfd_get_8 (input_bfd, contents + rel->r_offset - 1);
2638 BFD_ASSERT ((reg & 0xc7) == 5);
2639 reg >>= 3;
2640 BFD_ASSERT (rel->r_offset + 4 <= input_section->size);
2641 if (type == 0x8b)
2643 /* movq */
2644 if (val == 0x4c)
2645 bfd_put_8 (output_bfd, 0x49,
2646 contents + rel->r_offset - 3);
2647 bfd_put_8 (output_bfd, 0xc7,
2648 contents + rel->r_offset - 2);
2649 bfd_put_8 (output_bfd, 0xc0 | reg,
2650 contents + rel->r_offset - 1);
2652 else if (reg == 4)
2654 /* addq -> addq - addressing with %rsp/%r12 is
2655 special */
2656 if (val == 0x4c)
2657 bfd_put_8 (output_bfd, 0x49,
2658 contents + rel->r_offset - 3);
2659 bfd_put_8 (output_bfd, 0x81,
2660 contents + rel->r_offset - 2);
2661 bfd_put_8 (output_bfd, 0xc0 | reg,
2662 contents + rel->r_offset - 1);
2664 else
2666 /* addq -> leaq */
2667 if (val == 0x4c)
2668 bfd_put_8 (output_bfd, 0x4d,
2669 contents + rel->r_offset - 3);
2670 bfd_put_8 (output_bfd, 0x8d,
2671 contents + rel->r_offset - 2);
2672 bfd_put_8 (output_bfd, 0x80 | reg | (reg << 3),
2673 contents + rel->r_offset - 1);
2675 bfd_put_32 (output_bfd, tpoff (info, relocation),
2676 contents + rel->r_offset);
2677 continue;
2681 if (htab->sgot == NULL)
2682 abort ();
2684 if (h != NULL)
2686 off = h->got.offset;
2687 offplt = elf64_x86_64_hash_entry (h)->tlsdesc_got;
2689 else
2691 if (local_got_offsets == NULL)
2692 abort ();
2694 off = local_got_offsets[r_symndx];
2695 offplt = local_tlsdesc_gotents[r_symndx];
2698 if ((off & 1) != 0)
2699 off &= ~1;
2700 else
2702 Elf_Internal_Rela outrel;
2703 bfd_byte *loc;
2704 int dr_type, indx;
2705 asection *sreloc;
2707 if (htab->srelgot == NULL)
2708 abort ();
2710 indx = h && h->dynindx != -1 ? h->dynindx : 0;
2712 if (GOT_TLS_GDESC_P (tls_type))
2714 outrel.r_info = ELF64_R_INFO (indx, R_X86_64_TLSDESC);
2715 BFD_ASSERT (htab->sgotplt_jump_table_size + offplt
2716 + 2 * GOT_ENTRY_SIZE <= htab->sgotplt->size);
2717 outrel.r_offset = (htab->sgotplt->output_section->vma
2718 + htab->sgotplt->output_offset
2719 + offplt
2720 + htab->sgotplt_jump_table_size);
2721 sreloc = htab->srelplt;
2722 loc = sreloc->contents;
2723 loc += sreloc->reloc_count++
2724 * sizeof (Elf64_External_Rela);
2725 BFD_ASSERT (loc + sizeof (Elf64_External_Rela)
2726 <= sreloc->contents + sreloc->size);
2727 if (indx == 0)
2728 outrel.r_addend = relocation - dtpoff_base (info);
2729 else
2730 outrel.r_addend = 0;
2731 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2734 sreloc = htab->srelgot;
2736 outrel.r_offset = (htab->sgot->output_section->vma
2737 + htab->sgot->output_offset + off);
2739 if (GOT_TLS_GD_P (tls_type))
2740 dr_type = R_X86_64_DTPMOD64;
2741 else if (GOT_TLS_GDESC_P (tls_type))
2742 goto dr_done;
2743 else
2744 dr_type = R_X86_64_TPOFF64;
2746 bfd_put_64 (output_bfd, 0, htab->sgot->contents + off);
2747 outrel.r_addend = 0;
2748 if ((dr_type == R_X86_64_TPOFF64
2749 || dr_type == R_X86_64_TLSDESC) && indx == 0)
2750 outrel.r_addend = relocation - dtpoff_base (info);
2751 outrel.r_info = ELF64_R_INFO (indx, dr_type);
2753 loc = sreloc->contents;
2754 loc += sreloc->reloc_count++ * sizeof (Elf64_External_Rela);
2755 BFD_ASSERT (loc + sizeof (Elf64_External_Rela)
2756 <= sreloc->contents + sreloc->size);
2757 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2759 if (GOT_TLS_GD_P (tls_type))
2761 if (indx == 0)
2763 BFD_ASSERT (! unresolved_reloc);
2764 bfd_put_64 (output_bfd,
2765 relocation - dtpoff_base (info),
2766 htab->sgot->contents + off + GOT_ENTRY_SIZE);
2768 else
2770 bfd_put_64 (output_bfd, 0,
2771 htab->sgot->contents + off + GOT_ENTRY_SIZE);
2772 outrel.r_info = ELF64_R_INFO (indx,
2773 R_X86_64_DTPOFF64);
2774 outrel.r_offset += GOT_ENTRY_SIZE;
2775 sreloc->reloc_count++;
2776 loc += sizeof (Elf64_External_Rela);
2777 BFD_ASSERT (loc + sizeof (Elf64_External_Rela)
2778 <= sreloc->contents + sreloc->size);
2779 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2783 dr_done:
2784 if (h != NULL)
2785 h->got.offset |= 1;
2786 else
2787 local_got_offsets[r_symndx] |= 1;
2790 if (off >= (bfd_vma) -2
2791 && ! GOT_TLS_GDESC_P (tls_type))
2792 abort ();
2793 if (r_type == ELF64_R_TYPE (rel->r_info))
2795 if (r_type == R_X86_64_GOTPC32_TLSDESC
2796 || r_type == R_X86_64_TLSDESC_CALL)
2797 relocation = htab->sgotplt->output_section->vma
2798 + htab->sgotplt->output_offset
2799 + offplt + htab->sgotplt_jump_table_size;
2800 else
2801 relocation = htab->sgot->output_section->vma
2802 + htab->sgot->output_offset + off;
2803 unresolved_reloc = FALSE;
2805 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSGD)
2807 unsigned int i;
2808 static unsigned char tlsgd[8]
2809 = { 0x66, 0x48, 0x8d, 0x3d, 0x66, 0x66, 0x48, 0xe8 };
2811 /* GD->IE transition.
2812 .byte 0x66; leaq foo@tlsgd(%rip), %rdi
2813 .word 0x6666; rex64; call __tls_get_addr@plt
2814 Change it into:
2815 movq %fs:0, %rax
2816 addq foo@gottpoff(%rip), %rax */
2817 BFD_ASSERT (rel->r_offset >= 4);
2818 for (i = 0; i < 4; i++)
2819 BFD_ASSERT (bfd_get_8 (input_bfd,
2820 contents + rel->r_offset - 4 + i)
2821 == tlsgd[i]);
2822 BFD_ASSERT (rel->r_offset + 12 <= input_section->size);
2823 for (i = 0; i < 4; i++)
2824 BFD_ASSERT (bfd_get_8 (input_bfd,
2825 contents + rel->r_offset + 4 + i)
2826 == tlsgd[i+4]);
2827 BFD_ASSERT (rel + 1 < relend);
2828 BFD_ASSERT (ELF64_R_TYPE (rel[1].r_info) == R_X86_64_PLT32);
2829 memcpy (contents + rel->r_offset - 4,
2830 "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0",
2831 16);
2833 relocation = (htab->sgot->output_section->vma
2834 + htab->sgot->output_offset + off
2835 - rel->r_offset
2836 - input_section->output_section->vma
2837 - input_section->output_offset
2838 - 12);
2839 bfd_put_32 (output_bfd, relocation,
2840 contents + rel->r_offset + 8);
2841 /* Skip R_X86_64_PLT32. */
2842 rel++;
2843 continue;
2845 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_GOTPC32_TLSDESC)
2847 /* GDesc -> IE transition.
2848 It's originally something like:
2849 leaq x@tlsdesc(%rip), %rax
2851 Change it to:
2852 movq x@gottpoff(%rip), %rax # before nop; nop
2854 Registers other than %rax may be set up here. */
2856 unsigned int val, type, type2;
2857 bfd_vma roff;
2859 /* First, make sure it's a leaq adding rip to a 32-bit
2860 offset into any register, although it's probably
2861 almost always going to be rax. */
2862 roff = rel->r_offset;
2863 BFD_ASSERT (roff >= 3);
2864 type = bfd_get_8 (input_bfd, contents + roff - 3);
2865 BFD_ASSERT ((type & 0xfb) == 0x48);
2866 type2 = bfd_get_8 (input_bfd, contents + roff - 2);
2867 BFD_ASSERT (type2 == 0x8d);
2868 val = bfd_get_8 (input_bfd, contents + roff - 1);
2869 BFD_ASSERT ((val & 0xc7) == 0x05);
2870 BFD_ASSERT (roff + 4 <= input_section->size);
2872 /* Now modify the instruction as appropriate. */
2873 /* To turn a leaq into a movq in the form we use it, it
2874 suffices to change the second byte from 0x8d to
2875 0x8b. */
2876 bfd_put_8 (output_bfd, 0x8b, contents + roff - 2);
2878 bfd_put_32 (output_bfd,
2879 htab->sgot->output_section->vma
2880 + htab->sgot->output_offset + off
2881 - rel->r_offset
2882 - input_section->output_section->vma
2883 - input_section->output_offset
2884 - 4,
2885 contents + roff);
2886 continue;
2888 else if (ELF64_R_TYPE (rel->r_info) == R_X86_64_TLSDESC_CALL)
2890 /* GDesc -> IE transition.
2891 It's originally:
2892 call *(%rax)
2894 Change it to:
2895 nop; nop. */
2897 unsigned int val, type;
2898 bfd_vma roff;
2900 /* First, make sure it's a call *(%eax). */
2901 roff = rel->r_offset;
2902 BFD_ASSERT (roff + 2 <= input_section->size);
2903 type = bfd_get_8 (input_bfd, contents + roff);
2904 BFD_ASSERT (type == 0xff);
2905 val = bfd_get_8 (input_bfd, contents + roff + 1);
2906 BFD_ASSERT (val == 0x10);
2908 /* Now modify the instruction as appropriate. Use
2909 xchg %ax,%ax instead of 2 nops. */
2910 bfd_put_8 (output_bfd, 0x66, contents + roff);
2911 bfd_put_8 (output_bfd, 0x90, contents + roff + 1);
2913 continue;
2915 else
2916 BFD_ASSERT (FALSE);
2917 break;
2919 case R_X86_64_TLSLD:
2920 if (! info->shared)
2922 /* LD->LE transition:
2923 Ensure it is:
2924 leaq foo@tlsld(%rip), %rdi; call __tls_get_addr@plt.
2925 We change it into:
2926 .word 0x6666; .byte 0x66; movl %fs:0, %rax. */
2927 BFD_ASSERT (rel->r_offset >= 3);
2928 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset - 3)
2929 == 0x48);
2930 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset - 2)
2931 == 0x8d);
2932 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset - 1)
2933 == 0x3d);
2934 BFD_ASSERT (rel->r_offset + 9 <= input_section->size);
2935 BFD_ASSERT (bfd_get_8 (input_bfd, contents + rel->r_offset + 4)
2936 == 0xe8);
2937 BFD_ASSERT (rel + 1 < relend);
2938 BFD_ASSERT (ELF64_R_TYPE (rel[1].r_info) == R_X86_64_PLT32);
2939 memcpy (contents + rel->r_offset - 3,
2940 "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0", 12);
2941 /* Skip R_X86_64_PLT32. */
2942 rel++;
2943 continue;
2946 if (htab->sgot == NULL)
2947 abort ();
2949 off = htab->tls_ld_got.offset;
2950 if (off & 1)
2951 off &= ~1;
2952 else
2954 Elf_Internal_Rela outrel;
2955 bfd_byte *loc;
2957 if (htab->srelgot == NULL)
2958 abort ();
2960 outrel.r_offset = (htab->sgot->output_section->vma
2961 + htab->sgot->output_offset + off);
2963 bfd_put_64 (output_bfd, 0,
2964 htab->sgot->contents + off);
2965 bfd_put_64 (output_bfd, 0,
2966 htab->sgot->contents + off + GOT_ENTRY_SIZE);
2967 outrel.r_info = ELF64_R_INFO (0, R_X86_64_DTPMOD64);
2968 outrel.r_addend = 0;
2969 loc = htab->srelgot->contents;
2970 loc += htab->srelgot->reloc_count++ * sizeof (Elf64_External_Rela);
2971 bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
2972 htab->tls_ld_got.offset |= 1;
2974 relocation = htab->sgot->output_section->vma
2975 + htab->sgot->output_offset + off;
2976 unresolved_reloc = FALSE;
2977 break;
2979 case R_X86_64_DTPOFF32:
2980 if (info->shared || (input_section->flags & SEC_CODE) == 0)
2981 relocation -= dtpoff_base (info);
2982 else
2983 relocation = tpoff (info, relocation);
2984 break;
2986 case R_X86_64_TPOFF32:
2987 BFD_ASSERT (! info->shared);
2988 relocation = tpoff (info, relocation);
2989 break;
2991 default:
2992 break;
2995 /* Dynamic relocs are not propagated for SEC_DEBUGGING sections
2996 because such sections are not SEC_ALLOC and thus ld.so will
2997 not process them. */
2998 if (unresolved_reloc
2999 && !((input_section->flags & SEC_DEBUGGING) != 0
3000 && h->def_dynamic))
3001 (*_bfd_error_handler)
3002 (_("%B(%A+0x%lx): unresolvable %s relocation against symbol `%s'"),
3003 input_bfd,
3004 input_section,
3005 (long) rel->r_offset,
3006 howto->name,
3007 h->root.root.string);
3009 r = _bfd_final_link_relocate (howto, input_bfd, input_section,
3010 contents, rel->r_offset,
3011 relocation, rel->r_addend);
3013 if (r != bfd_reloc_ok)
3015 const char *name;
3017 if (h != NULL)
3018 name = h->root.root.string;
3019 else
3021 name = bfd_elf_string_from_elf_section (input_bfd,
3022 symtab_hdr->sh_link,
3023 sym->st_name);
3024 if (name == NULL)
3025 return FALSE;
3026 if (*name == '\0')
3027 name = bfd_section_name (input_bfd, sec);
3030 if (r == bfd_reloc_overflow)
3032 if (! ((*info->callbacks->reloc_overflow)
3033 (info, (h ? &h->root : NULL), name, howto->name,
3034 (bfd_vma) 0, input_bfd, input_section,
3035 rel->r_offset)))
3036 return FALSE;
3038 else
3040 (*_bfd_error_handler)
3041 (_("%B(%A+0x%lx): reloc against `%s': error %d"),
3042 input_bfd, input_section,
3043 (long) rel->r_offset, name, (int) r);
3044 return FALSE;
3049 return TRUE;
3052 /* Finish up dynamic symbol handling. We set the contents of various
3053 dynamic sections here. */
3055 static bfd_boolean
3056 elf64_x86_64_finish_dynamic_symbol (bfd *output_bfd,
3057 struct bfd_link_info *info,
3058 struct elf_link_hash_entry *h,
3059 Elf_Internal_Sym *sym)
3061 struct elf64_x86_64_link_hash_table *htab;
3063 htab = elf64_x86_64_hash_table (info);
3065 if (h->plt.offset != (bfd_vma) -1)
3067 bfd_vma plt_index;
3068 bfd_vma got_offset;
3069 Elf_Internal_Rela rela;
3070 bfd_byte *loc;
3072 /* This symbol has an entry in the procedure linkage table. Set
3073 it up. */
3074 if (h->dynindx == -1
3075 || htab->splt == NULL
3076 || htab->sgotplt == NULL
3077 || htab->srelplt == NULL)
3078 abort ();
3080 /* Get the index in the procedure linkage table which
3081 corresponds to this symbol. This is the index of this symbol
3082 in all the symbols for which we are making plt entries. The
3083 first entry in the procedure linkage table is reserved. */
3084 plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1;
3086 /* Get the offset into the .got table of the entry that
3087 corresponds to this function. Each .got entry is GOT_ENTRY_SIZE
3088 bytes. The first three are reserved for the dynamic linker. */
3089 got_offset = (plt_index + 3) * GOT_ENTRY_SIZE;
3091 /* Fill in the entry in the procedure linkage table. */
3092 memcpy (htab->splt->contents + h->plt.offset, elf64_x86_64_plt_entry,
3093 PLT_ENTRY_SIZE);
3095 /* Insert the relocation positions of the plt section. The magic
3096 numbers at the end of the statements are the positions of the
3097 relocations in the plt section. */
3098 /* Put offset for jmp *name@GOTPCREL(%rip), since the
3099 instruction uses 6 bytes, subtract this value. */
3100 bfd_put_32 (output_bfd,
3101 (htab->sgotplt->output_section->vma
3102 + htab->sgotplt->output_offset
3103 + got_offset
3104 - htab->splt->output_section->vma
3105 - htab->splt->output_offset
3106 - h->plt.offset
3107 - 6),
3108 htab->splt->contents + h->plt.offset + 2);
3109 /* Put relocation index. */
3110 bfd_put_32 (output_bfd, plt_index,
3111 htab->splt->contents + h->plt.offset + 7);
3112 /* Put offset for jmp .PLT0. */
3113 bfd_put_32 (output_bfd, - (h->plt.offset + PLT_ENTRY_SIZE),
3114 htab->splt->contents + h->plt.offset + 12);
3116 /* Fill in the entry in the global offset table, initially this
3117 points to the pushq instruction in the PLT which is at offset 6. */
3118 bfd_put_64 (output_bfd, (htab->splt->output_section->vma
3119 + htab->splt->output_offset
3120 + h->plt.offset + 6),
3121 htab->sgotplt->contents + got_offset);
3123 /* Fill in the entry in the .rela.plt section. */
3124 rela.r_offset = (htab->sgotplt->output_section->vma
3125 + htab->sgotplt->output_offset
3126 + got_offset);
3127 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_JUMP_SLOT);
3128 rela.r_addend = 0;
3129 loc = htab->srelplt->contents + plt_index * sizeof (Elf64_External_Rela);
3130 bfd_elf64_swap_reloca_out (output_bfd, &rela, loc);
3132 if (!h->def_regular)
3134 /* Mark the symbol as undefined, rather than as defined in
3135 the .plt section. Leave the value if there were any
3136 relocations where pointer equality matters (this is a clue
3137 for the dynamic linker, to make function pointer
3138 comparisons work between an application and shared
3139 library), otherwise set it to zero. If a function is only
3140 called from a binary, there is no need to slow down
3141 shared libraries because of that. */
3142 sym->st_shndx = SHN_UNDEF;
3143 if (!h->pointer_equality_needed)
3144 sym->st_value = 0;
3148 if (h->got.offset != (bfd_vma) -1
3149 && ! GOT_TLS_GD_ANY_P (elf64_x86_64_hash_entry (h)->tls_type)
3150 && elf64_x86_64_hash_entry (h)->tls_type != GOT_TLS_IE)
3152 Elf_Internal_Rela rela;
3153 bfd_byte *loc;
3155 /* This symbol has an entry in the global offset table. Set it
3156 up. */
3157 if (htab->sgot == NULL || htab->srelgot == NULL)
3158 abort ();
3160 rela.r_offset = (htab->sgot->output_section->vma
3161 + htab->sgot->output_offset
3162 + (h->got.offset &~ (bfd_vma) 1));
3164 /* If this is a static link, or it is a -Bsymbolic link and the
3165 symbol is defined locally or was forced to be local because
3166 of a version file, we just want to emit a RELATIVE reloc.
3167 The entry in the global offset table will already have been
3168 initialized in the relocate_section function. */
3169 if (info->shared
3170 && SYMBOL_REFERENCES_LOCAL (info, h))
3172 BFD_ASSERT((h->got.offset & 1) != 0);
3173 rela.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE);
3174 rela.r_addend = (h->root.u.def.value
3175 + h->root.u.def.section->output_section->vma
3176 + h->root.u.def.section->output_offset);
3178 else
3180 BFD_ASSERT((h->got.offset & 1) == 0);
3181 bfd_put_64 (output_bfd, (bfd_vma) 0,
3182 htab->sgot->contents + h->got.offset);
3183 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_GLOB_DAT);
3184 rela.r_addend = 0;
3187 loc = htab->srelgot->contents;
3188 loc += htab->srelgot->reloc_count++ * sizeof (Elf64_External_Rela);
3189 bfd_elf64_swap_reloca_out (output_bfd, &rela, loc);
3192 if (h->needs_copy)
3194 Elf_Internal_Rela rela;
3195 bfd_byte *loc;
3197 /* This symbol needs a copy reloc. Set it up. */
3199 if (h->dynindx == -1
3200 || (h->root.type != bfd_link_hash_defined
3201 && h->root.type != bfd_link_hash_defweak)
3202 || htab->srelbss == NULL)
3203 abort ();
3205 rela.r_offset = (h->root.u.def.value
3206 + h->root.u.def.section->output_section->vma
3207 + h->root.u.def.section->output_offset);
3208 rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_COPY);
3209 rela.r_addend = 0;
3210 loc = htab->srelbss->contents;
3211 loc += htab->srelbss->reloc_count++ * sizeof (Elf64_External_Rela);
3212 bfd_elf64_swap_reloca_out (output_bfd, &rela, loc);
3215 /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */
3216 if (strcmp (h->root.root.string, "_DYNAMIC") == 0
3217 || h == htab->elf.hgot)
3218 sym->st_shndx = SHN_ABS;
3220 return TRUE;
3223 /* Used to decide how to sort relocs in an optimal manner for the
3224 dynamic linker, before writing them out. */
3226 static enum elf_reloc_type_class
3227 elf64_x86_64_reloc_type_class (const Elf_Internal_Rela *rela)
3229 switch ((int) ELF64_R_TYPE (rela->r_info))
3231 case R_X86_64_RELATIVE:
3232 return reloc_class_relative;
3233 case R_X86_64_JUMP_SLOT:
3234 return reloc_class_plt;
3235 case R_X86_64_COPY:
3236 return reloc_class_copy;
3237 default:
3238 return reloc_class_normal;
3242 /* Finish up the dynamic sections. */
3244 static bfd_boolean
3245 elf64_x86_64_finish_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info)
3247 struct elf64_x86_64_link_hash_table *htab;
3248 bfd *dynobj;
3249 asection *sdyn;
3251 htab = elf64_x86_64_hash_table (info);
3252 dynobj = htab->elf.dynobj;
3253 sdyn = bfd_get_section_by_name (dynobj, ".dynamic");
3255 if (htab->elf.dynamic_sections_created)
3257 Elf64_External_Dyn *dyncon, *dynconend;
3259 if (sdyn == NULL || htab->sgot == NULL)
3260 abort ();
3262 dyncon = (Elf64_External_Dyn *) sdyn->contents;
3263 dynconend = (Elf64_External_Dyn *) (sdyn->contents + sdyn->size);
3264 for (; dyncon < dynconend; dyncon++)
3266 Elf_Internal_Dyn dyn;
3267 asection *s;
3269 bfd_elf64_swap_dyn_in (dynobj, dyncon, &dyn);
3271 switch (dyn.d_tag)
3273 default:
3274 continue;
3276 case DT_PLTGOT:
3277 s = htab->sgotplt;
3278 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
3279 break;
3281 case DT_JMPREL:
3282 dyn.d_un.d_ptr = htab->srelplt->output_section->vma;
3283 break;
3285 case DT_PLTRELSZ:
3286 s = htab->srelplt->output_section;
3287 dyn.d_un.d_val = s->size;
3288 break;
3290 case DT_RELASZ:
3291 /* The procedure linkage table relocs (DT_JMPREL) should
3292 not be included in the overall relocs (DT_RELA).
3293 Therefore, we override the DT_RELASZ entry here to
3294 make it not include the JMPREL relocs. Since the
3295 linker script arranges for .rela.plt to follow all
3296 other relocation sections, we don't have to worry
3297 about changing the DT_RELA entry. */
3298 if (htab->srelplt != NULL)
3300 s = htab->srelplt->output_section;
3301 dyn.d_un.d_val -= s->size;
3303 break;
3305 case DT_TLSDESC_PLT:
3306 s = htab->splt;
3307 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset
3308 + htab->tlsdesc_plt;
3309 break;
3311 case DT_TLSDESC_GOT:
3312 s = htab->sgot;
3313 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset
3314 + htab->tlsdesc_got;
3315 break;
3318 bfd_elf64_swap_dyn_out (output_bfd, &dyn, dyncon);
3321 /* Fill in the special first entry in the procedure linkage table. */
3322 if (htab->splt && htab->splt->size > 0)
3324 /* Fill in the first entry in the procedure linkage table. */
3325 memcpy (htab->splt->contents, elf64_x86_64_plt0_entry,
3326 PLT_ENTRY_SIZE);
3327 /* Add offset for pushq GOT+8(%rip), since the instruction
3328 uses 6 bytes subtract this value. */
3329 bfd_put_32 (output_bfd,
3330 (htab->sgotplt->output_section->vma
3331 + htab->sgotplt->output_offset
3333 - htab->splt->output_section->vma
3334 - htab->splt->output_offset
3335 - 6),
3336 htab->splt->contents + 2);
3337 /* Add offset for jmp *GOT+16(%rip). The 12 is the offset to
3338 the end of the instruction. */
3339 bfd_put_32 (output_bfd,
3340 (htab->sgotplt->output_section->vma
3341 + htab->sgotplt->output_offset
3342 + 16
3343 - htab->splt->output_section->vma
3344 - htab->splt->output_offset
3345 - 12),
3346 htab->splt->contents + 8);
3348 elf_section_data (htab->splt->output_section)->this_hdr.sh_entsize =
3349 PLT_ENTRY_SIZE;
3351 if (htab->tlsdesc_plt)
3353 bfd_put_64 (output_bfd, (bfd_vma) 0,
3354 htab->sgot->contents + htab->tlsdesc_got);
3356 memcpy (htab->splt->contents + htab->tlsdesc_plt,
3357 elf64_x86_64_plt0_entry,
3358 PLT_ENTRY_SIZE);
3360 /* Add offset for pushq GOT+8(%rip), since the
3361 instruction uses 6 bytes subtract this value. */
3362 bfd_put_32 (output_bfd,
3363 (htab->sgotplt->output_section->vma
3364 + htab->sgotplt->output_offset
3366 - htab->splt->output_section->vma
3367 - htab->splt->output_offset
3368 - htab->tlsdesc_plt
3369 - 6),
3370 htab->splt->contents + htab->tlsdesc_plt + 2);
3371 /* Add offset for jmp *GOT+TDG(%rip), where TGD stands for
3372 htab->tlsdesc_got. The 12 is the offset to the end of
3373 the instruction. */
3374 bfd_put_32 (output_bfd,
3375 (htab->sgot->output_section->vma
3376 + htab->sgot->output_offset
3377 + htab->tlsdesc_got
3378 - htab->splt->output_section->vma
3379 - htab->splt->output_offset
3380 - htab->tlsdesc_plt
3381 - 12),
3382 htab->splt->contents + htab->tlsdesc_plt + 8);
3387 if (htab->sgotplt)
3389 /* Fill in the first three entries in the global offset table. */
3390 if (htab->sgotplt->size > 0)
3392 /* Set the first entry in the global offset table to the address of
3393 the dynamic section. */
3394 if (sdyn == NULL)
3395 bfd_put_64 (output_bfd, (bfd_vma) 0, htab->sgotplt->contents);
3396 else
3397 bfd_put_64 (output_bfd,
3398 sdyn->output_section->vma + sdyn->output_offset,
3399 htab->sgotplt->contents);
3400 /* Write GOT[1] and GOT[2], needed for the dynamic linker. */
3401 bfd_put_64 (output_bfd, (bfd_vma) 0, htab->sgotplt->contents + GOT_ENTRY_SIZE);
3402 bfd_put_64 (output_bfd, (bfd_vma) 0, htab->sgotplt->contents + GOT_ENTRY_SIZE*2);
3405 elf_section_data (htab->sgotplt->output_section)->this_hdr.sh_entsize =
3406 GOT_ENTRY_SIZE;
3409 if (htab->sgot && htab->sgot->size > 0)
3410 elf_section_data (htab->sgot->output_section)->this_hdr.sh_entsize
3411 = GOT_ENTRY_SIZE;
3413 return TRUE;
3416 /* Return address for Ith PLT stub in section PLT, for relocation REL
3417 or (bfd_vma) -1 if it should not be included. */
3419 static bfd_vma
3420 elf64_x86_64_plt_sym_val (bfd_vma i, const asection *plt,
3421 const arelent *rel ATTRIBUTE_UNUSED)
3423 return plt->vma + (i + 1) * PLT_ENTRY_SIZE;
3426 /* Handle an x86-64 specific section when reading an object file. This
3427 is called when elfcode.h finds a section with an unknown type. */
3429 static bfd_boolean
3430 elf64_x86_64_section_from_shdr (bfd *abfd,
3431 Elf_Internal_Shdr *hdr,
3432 const char *name,
3433 int shindex)
3435 if (hdr->sh_type != SHT_X86_64_UNWIND)
3436 return FALSE;
3438 if (! _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex))
3439 return FALSE;
3441 return TRUE;
3444 /* Hook called by the linker routine which adds symbols from an object
3445 file. We use it to put SHN_X86_64_LCOMMON items in .lbss, instead
3446 of .bss. */
3448 static bfd_boolean
3449 elf64_x86_64_add_symbol_hook (bfd *abfd,
3450 struct bfd_link_info *info ATTRIBUTE_UNUSED,
3451 Elf_Internal_Sym *sym,
3452 const char **namep ATTRIBUTE_UNUSED,
3453 flagword *flagsp ATTRIBUTE_UNUSED,
3454 asection **secp, bfd_vma *valp)
3456 asection *lcomm;
3458 switch (sym->st_shndx)
3460 case SHN_X86_64_LCOMMON:
3461 lcomm = bfd_get_section_by_name (abfd, "LARGE_COMMON");
3462 if (lcomm == NULL)
3464 lcomm = bfd_make_section_with_flags (abfd,
3465 "LARGE_COMMON",
3466 (SEC_ALLOC
3467 | SEC_IS_COMMON
3468 | SEC_LINKER_CREATED));
3469 if (lcomm == NULL)
3470 return FALSE;
3471 elf_section_flags (lcomm) |= SHF_X86_64_LARGE;
3473 *secp = lcomm;
3474 *valp = sym->st_size;
3475 break;
3477 return TRUE;
3481 /* Given a BFD section, try to locate the corresponding ELF section
3482 index. */
3484 static bfd_boolean
3485 elf64_x86_64_elf_section_from_bfd_section (bfd *abfd ATTRIBUTE_UNUSED,
3486 asection *sec, int *index)
3488 if (sec == &_bfd_elf_large_com_section)
3490 *index = SHN_X86_64_LCOMMON;
3491 return TRUE;
3493 return FALSE;
3496 /* Process a symbol. */
3498 static void
3499 elf64_x86_64_symbol_processing (bfd *abfd ATTRIBUTE_UNUSED,
3500 asymbol *asym)
3502 elf_symbol_type *elfsym = (elf_symbol_type *) asym;
3504 switch (elfsym->internal_elf_sym.st_shndx)
3506 case SHN_X86_64_LCOMMON:
3507 asym->section = &_bfd_elf_large_com_section;
3508 asym->value = elfsym->internal_elf_sym.st_size;
3509 /* Common symbol doesn't set BSF_GLOBAL. */
3510 asym->flags &= ~BSF_GLOBAL;
3511 break;
3515 static bfd_boolean
3516 elf64_x86_64_common_definition (Elf_Internal_Sym *sym)
3518 return (sym->st_shndx == SHN_COMMON
3519 || sym->st_shndx == SHN_X86_64_LCOMMON);
3522 static unsigned int
3523 elf64_x86_64_common_section_index (asection *sec)
3525 if ((elf_section_flags (sec) & SHF_X86_64_LARGE) == 0)
3526 return SHN_COMMON;
3527 else
3528 return SHN_X86_64_LCOMMON;
3531 static asection *
3532 elf64_x86_64_common_section (asection *sec)
3534 if ((elf_section_flags (sec) & SHF_X86_64_LARGE) == 0)
3535 return bfd_com_section_ptr;
3536 else
3537 return &_bfd_elf_large_com_section;
3540 static bfd_boolean
3541 elf64_x86_64_merge_symbol (struct bfd_link_info *info ATTRIBUTE_UNUSED,
3542 struct elf_link_hash_entry **sym_hash ATTRIBUTE_UNUSED,
3543 struct elf_link_hash_entry *h,
3544 Elf_Internal_Sym *sym,
3545 asection **psec,
3546 bfd_vma *pvalue ATTRIBUTE_UNUSED,
3547 unsigned int *pold_alignment ATTRIBUTE_UNUSED,
3548 bfd_boolean *skip ATTRIBUTE_UNUSED,
3549 bfd_boolean *override ATTRIBUTE_UNUSED,
3550 bfd_boolean *type_change_ok ATTRIBUTE_UNUSED,
3551 bfd_boolean *size_change_ok ATTRIBUTE_UNUSED,
3552 bfd_boolean *newdef ATTRIBUTE_UNUSED,
3553 bfd_boolean *newdyn,
3554 bfd_boolean *newdyncommon ATTRIBUTE_UNUSED,
3555 bfd_boolean *newweak ATTRIBUTE_UNUSED,
3556 bfd *abfd ATTRIBUTE_UNUSED,
3557 asection **sec,
3558 bfd_boolean *olddef ATTRIBUTE_UNUSED,
3559 bfd_boolean *olddyn,
3560 bfd_boolean *olddyncommon ATTRIBUTE_UNUSED,
3561 bfd_boolean *oldweak ATTRIBUTE_UNUSED,
3562 bfd *oldbfd,
3563 asection **oldsec)
3565 /* A normal common symbol and a large common symbol result in a
3566 normal common symbol. We turn the large common symbol into a
3567 normal one. */
3568 if (!*olddyn
3569 && h->root.type == bfd_link_hash_common
3570 && !*newdyn
3571 && bfd_is_com_section (*sec)
3572 && *oldsec != *sec)
3574 if (sym->st_shndx == SHN_COMMON
3575 && (elf_section_flags (*oldsec) & SHF_X86_64_LARGE) != 0)
3577 h->root.u.c.p->section
3578 = bfd_make_section_old_way (oldbfd, "COMMON");
3579 h->root.u.c.p->section->flags = SEC_ALLOC;
3581 else if (sym->st_shndx == SHN_X86_64_LCOMMON
3582 && (elf_section_flags (*oldsec) & SHF_X86_64_LARGE) == 0)
3583 *psec = *sec = bfd_com_section_ptr;
3586 return TRUE;
3589 static int
3590 elf64_x86_64_additional_program_headers (bfd *abfd,
3591 struct bfd_link_info *info ATTRIBUTE_UNUSED)
3593 asection *s;
3594 int count = 0;
3596 /* Check to see if we need a large readonly segment. */
3597 s = bfd_get_section_by_name (abfd, ".lrodata");
3598 if (s && (s->flags & SEC_LOAD))
3599 count++;
3601 /* Check to see if we need a large data segment. Since .lbss sections
3602 is placed right after the .bss section, there should be no need for
3603 a large data segment just because of .lbss. */
3604 s = bfd_get_section_by_name (abfd, ".ldata");
3605 if (s && (s->flags & SEC_LOAD))
3606 count++;
3608 return count;
3611 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
3613 static bfd_boolean
3614 elf64_x86_64_hash_symbol (struct elf_link_hash_entry *h)
3616 if (h->plt.offset != (bfd_vma) -1
3617 && !h->def_regular
3618 && !h->pointer_equality_needed)
3619 return FALSE;
3621 return _bfd_elf_hash_symbol (h);
3624 static const struct bfd_elf_special_section
3625 elf64_x86_64_special_sections[]=
3627 { STRING_COMMA_LEN (".gnu.linkonce.lb"), -2, SHT_NOBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE},
3628 { STRING_COMMA_LEN (".gnu.linkonce.lr"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_X86_64_LARGE},
3629 { STRING_COMMA_LEN (".gnu.linkonce.lt"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR + SHF_X86_64_LARGE},
3630 { STRING_COMMA_LEN (".lbss"), -2, SHT_NOBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE},
3631 { STRING_COMMA_LEN (".ldata"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE},
3632 { STRING_COMMA_LEN (".lrodata"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_X86_64_LARGE},
3633 { NULL, 0, 0, 0, 0 }
3636 #define TARGET_LITTLE_SYM bfd_elf64_x86_64_vec
3637 #define TARGET_LITTLE_NAME "elf64-x86-64"
3638 #define ELF_ARCH bfd_arch_i386
3639 #define ELF_MACHINE_CODE EM_X86_64
3640 #define ELF_MAXPAGESIZE 0x200000
3641 #define ELF_MINPAGESIZE 0x1000
3642 #define ELF_COMMONPAGESIZE 0x1000
3644 #define elf_backend_can_gc_sections 1
3645 #define elf_backend_can_refcount 1
3646 #define elf_backend_want_got_plt 1
3647 #define elf_backend_plt_readonly 1
3648 #define elf_backend_want_plt_sym 0
3649 #define elf_backend_got_header_size (GOT_ENTRY_SIZE*3)
3650 #define elf_backend_rela_normal 1
3652 #define elf_info_to_howto elf64_x86_64_info_to_howto
3654 #define bfd_elf64_bfd_link_hash_table_create \
3655 elf64_x86_64_link_hash_table_create
3656 #define bfd_elf64_bfd_reloc_type_lookup elf64_x86_64_reloc_type_lookup
3657 #define bfd_elf64_bfd_reloc_name_lookup \
3658 elf64_x86_64_reloc_name_lookup
3660 #define elf_backend_adjust_dynamic_symbol elf64_x86_64_adjust_dynamic_symbol
3661 #define elf_backend_check_relocs elf64_x86_64_check_relocs
3662 #define elf_backend_copy_indirect_symbol elf64_x86_64_copy_indirect_symbol
3663 #define elf_backend_create_dynamic_sections elf64_x86_64_create_dynamic_sections
3664 #define elf_backend_finish_dynamic_sections elf64_x86_64_finish_dynamic_sections
3665 #define elf_backend_finish_dynamic_symbol elf64_x86_64_finish_dynamic_symbol
3666 #define elf_backend_gc_mark_hook elf64_x86_64_gc_mark_hook
3667 #define elf_backend_gc_sweep_hook elf64_x86_64_gc_sweep_hook
3668 #define elf_backend_grok_prstatus elf64_x86_64_grok_prstatus
3669 #define elf_backend_grok_psinfo elf64_x86_64_grok_psinfo
3670 #define elf_backend_reloc_type_class elf64_x86_64_reloc_type_class
3671 #define elf_backend_relocate_section elf64_x86_64_relocate_section
3672 #define elf_backend_size_dynamic_sections elf64_x86_64_size_dynamic_sections
3673 #define elf_backend_always_size_sections elf64_x86_64_always_size_sections
3674 #define elf_backend_init_index_section _bfd_elf_init_1_index_section
3675 #define elf_backend_plt_sym_val elf64_x86_64_plt_sym_val
3676 #define elf_backend_object_p elf64_x86_64_elf_object_p
3677 #define bfd_elf64_mkobject elf64_x86_64_mkobject
3679 #define elf_backend_section_from_shdr \
3680 elf64_x86_64_section_from_shdr
3682 #define elf_backend_section_from_bfd_section \
3683 elf64_x86_64_elf_section_from_bfd_section
3684 #define elf_backend_add_symbol_hook \
3685 elf64_x86_64_add_symbol_hook
3686 #define elf_backend_symbol_processing \
3687 elf64_x86_64_symbol_processing
3688 #define elf_backend_common_section_index \
3689 elf64_x86_64_common_section_index
3690 #define elf_backend_common_section \
3691 elf64_x86_64_common_section
3692 #define elf_backend_common_definition \
3693 elf64_x86_64_common_definition
3694 #define elf_backend_merge_symbol \
3695 elf64_x86_64_merge_symbol
3696 #define elf_backend_special_sections \
3697 elf64_x86_64_special_sections
3698 #define elf_backend_additional_program_headers \
3699 elf64_x86_64_additional_program_headers
3700 #define elf_backend_hash_symbol \
3701 elf64_x86_64_hash_symbol
3703 #include "elf64-target.h"
3705 /* FreeBSD support. */
3707 #undef TARGET_LITTLE_SYM
3708 #define TARGET_LITTLE_SYM bfd_elf64_x86_64_freebsd_vec
3709 #undef TARGET_LITTLE_NAME
3710 #define TARGET_LITTLE_NAME "elf64-x86-64-freebsd"
3712 #undef ELF_OSABI
3713 #define ELF_OSABI ELFOSABI_FREEBSD
3715 #undef elf_backend_post_process_headers
3716 #define elf_backend_post_process_headers _bfd_elf_set_osabi
3718 #undef elf64_bed
3719 #define elf64_bed elf64_x86_64_fbsd_bed
3721 #include "elf64-target.h"