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[binutils-gdb.git] / bfd / elfxx-x86.h
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1 /* x86 specific support for ELF
2 Copyright (C) 2017-2022 Free Software Foundation, Inc.
4 This file is part of BFD, the Binary File Descriptor library.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19 MA 02110-1301, USA. */
21 /* Don't generate unused section symbols. */
22 #define TARGET_KEEP_UNUSED_SECTION_SYMBOLS false
24 #include "sysdep.h"
25 #include "bfd.h"
26 #include "bfdlink.h"
27 #include "libbfd.h"
28 #include "elf-bfd.h"
29 #include "hashtab.h"
30 #include "elf-linker-x86.h"
31 #include "elf/i386.h"
32 #include "elf/x86-64.h"
34 #define X86_64_PCREL_TYPE_P(TYPE) \
35 ((TYPE) == R_X86_64_PC8 \
36 || (TYPE) == R_X86_64_PC16 \
37 || (TYPE) == R_X86_64_PC32 \
38 || (TYPE) == R_X86_64_PC32_BND \
39 || (TYPE) == R_X86_64_PC64)
40 #define I386_PCREL_TYPE_P(TYPE) ((TYPE) == R_386_PC32)
41 #define X86_PCREL_TYPE_P(IS_X86_64, TYPE) \
42 ((IS_X86_64) ? X86_64_PCREL_TYPE_P (TYPE) : I386_PCREL_TYPE_P (TYPE))
44 #define X86_64_SIZE_TYPE_P(TYPE) \
45 ((TYPE) == R_X86_64_SIZE32 || (TYPE) == R_X86_64_SIZE64)
46 #define I386_SIZE_TYPE_P(TYPE) ((TYPE) == R_386_SIZE32)
47 #define X86_SIZE_TYPE_P(IS_X86_64, TYPE) \
48 ((IS_X86_64) ? X86_64_SIZE_TYPE_P(TYPE) : I386_SIZE_TYPE_P (TYPE))
50 #define X86_64_GOT_TYPE_P(TYPE) \
51 ((TYPE) == R_X86_64_GOTPCREL \
52 || (TYPE) == R_X86_64_GOTPCRELX \
53 || (TYPE) == R_X86_64_REX_GOTPCRELX \
54 || (TYPE) == R_X86_64_GOT32 \
55 || (TYPE) == R_X86_64_GOT64 \
56 || (TYPE) == R_X86_64_GOTPCREL64 \
57 || (TYPE) == R_X86_64_GOTPLT64)
58 #define I386_GOT_TYPE_P(TYPE) \
59 ((TYPE) == R_386_GOT32 || (TYPE) == R_386_GOT32X)
60 #define X86_GOT_TYPE_P(IS_X86_64, TYPE) \
61 ((IS_X86_64) ? X86_64_GOT_TYPE_P (TYPE) : I386_GOT_TYPE_P (TYPE))
63 #define X86_64_RELATIVE_RELOC_TYPE_P(TYPE) \
64 (X86_64_PCREL_TYPE_P (TYPE) \
65 || (TYPE) == R_X86_64_8 \
66 || (TYPE) == R_X86_64_16 \
67 || (TYPE) == R_X86_64_32 \
68 || (TYPE) == R_X86_64_32S \
69 || (TYPE) == R_X86_64_64)
70 #define I386_RELATIVE_RELOC_TYPE_P(TYPE) \
71 ((TYPE) == R_386_32 || (TYPE) == R_386_PC32)
72 #define X86_RELATIVE_RELOC_TYPE_P(IS_X86_64, TYPE) \
73 ((IS_X86_64) \
74 ? X86_64_RELATIVE_RELOC_TYPE_P (TYPE) \
75 : I386_RELATIVE_RELOC_TYPE_P(TYPE))
77 #define X86_64_NEED_DYNAMIC_RELOC_TYPE_P(TYPE) \
78 (X86_64_SIZE_TYPE_P (TYPE) \
79 || X86_64_RELATIVE_RELOC_TYPE_P (TYPE))
80 #define I386_NEED_DYNAMIC_RELOC_TYPE_P(TYPE) \
81 (I386_SIZE_TYPE_P (TYPE) \
82 || I386_RELATIVE_RELOC_TYPE_P (TYPE) \
83 || (TYPE) == R_386_TLS_IE \
84 || (TYPE) == R_386_TLS_LE \
85 || (TYPE) == R_386_TLS_LE_32)
86 #define X86_NEED_DYNAMIC_RELOC_TYPE_P(IS_X86_64, TYPE) \
87 ((IS_X86_64) \
88 ? X86_64_NEED_DYNAMIC_RELOC_TYPE_P (TYPE) \
89 : I386_NEED_DYNAMIC_RELOC_TYPE_P (TYPE))
91 #define X86_LOCAL_GOT_RELATIVE_RELOC_P(IS_X86_64, INFO, SYM) \
92 (bfd_link_pic (INFO) \
93 && (!(IS_X86_64) || ((SYM) != NULL && (SYM)->st_shndx != SHN_ABS)))
95 #define PLT_CIE_LENGTH 20
96 #define PLT_FDE_LENGTH 36
97 #define PLT_FDE_START_OFFSET 4 + PLT_CIE_LENGTH + 8
98 #define PLT_FDE_LEN_OFFSET 4 + PLT_CIE_LENGTH + 12
100 #define I386_PCREL_TYPE_P(TYPE) ((TYPE) == R_386_PC32)
101 #define X86_64_PCREL_TYPE_P(TYPE) \
102 ((TYPE) == R_X86_64_PC8 \
103 || (TYPE) == R_X86_64_PC16 \
104 || (TYPE) == R_X86_64_PC32 \
105 || (TYPE) == R_X86_64_PC32_BND \
106 || (TYPE) == R_X86_64_PC64)
108 #define ABI_64_P(abfd) \
109 (get_elf_backend_data (abfd)->s->elfclass == ELFCLASS64)
111 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
112 copying dynamic variables from a shared lib into an app's dynbss
113 section, and instead use a dynamic relocation to point into the
114 shared lib. */
115 #define ELIMINATE_COPY_RELOCS 1
117 #define elf_x86_hash_table(p, id) \
118 (is_elf_hash_table ((p)->hash) \
119 && elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) == (id) \
120 ? ((struct elf_x86_link_hash_table *) ((p)->hash)) : NULL)
122 /* Will references to this symbol always be local in this object? */
123 #define SYMBOL_REFERENCES_LOCAL_P(INFO, H) \
124 _bfd_x86_elf_link_symbol_references_local ((INFO), (H))
126 /* TRUE if an undefined weak symbol should be resolved to 0. Local
127 undefined weak symbol is always resolved to 0. Reference to an
128 undefined weak symbol is resolved to 0 in executable if undefined
129 weak symbol should be resolved to 0 (zero_undefweak > 0). */
130 #define UNDEFINED_WEAK_RESOLVED_TO_ZERO(INFO, EH) \
131 ((EH)->elf.root.type == bfd_link_hash_undefweak \
132 && (SYMBOL_REFERENCES_LOCAL_P ((INFO), &(EH)->elf) \
133 || (bfd_link_executable (INFO) \
134 && (EH)->zero_undefweak > 0)))
136 /* Should copy relocation be generated for a symbol. Don't generate
137 copy relocation against a protected symbol defined in a shared
138 object. */
139 #define SYMBOL_NO_COPYRELOC(INFO, EH) \
140 ((EH)->def_protected \
141 && ((EH)->elf.root.type == bfd_link_hash_defined \
142 || (EH)->elf.root.type == bfd_link_hash_defweak) \
143 && ((EH)->elf.root.u.def.section->owner->flags & DYNAMIC) != 0 \
144 && ((EH)->elf.root.u.def.section->flags & SEC_CODE) == 0)
146 /* TRUE if dynamic relocation is needed. If we are creating a shared
147 library, and this is a reloc against a global symbol, or a non PC
148 relative reloc against a local symbol, then we need to copy the reloc
149 into the shared library. However, if we are linking with -Bsymbolic,
150 we do not need to copy a reloc against a global symbol which is
151 defined in an object we are including in the link (i.e., DEF_REGULAR
152 is set).
154 If PCREL_PLT is true, don't generate dynamic relocation in PIE for
155 PC-relative relocation against a dynamic function definition in data
156 section when PLT address can be used.
158 If on the other hand, we are creating an executable, we may need to
159 keep relocations for symbols satisfied by a dynamic library if we
160 manage to avoid copy relocs for the symbol.
162 We also need to generate dynamic pointer relocation against
163 STT_GNU_IFUNC symbol in the non-code section. */
164 #define NEED_DYNAMIC_RELOCATION_P(IS_X86_64, INFO, PCREL_PLT, H, SEC, \
165 R_TYPE, POINTER_TYPE) \
166 ((bfd_link_pic (INFO) \
167 && (! X86_PCREL_TYPE_P (IS_X86_64, R_TYPE) \
168 || ((H) != NULL \
169 && (! (bfd_link_pie (INFO) \
170 || SYMBOLIC_BIND ((INFO), (H))) \
171 || (H)->root.type == bfd_link_hash_defweak \
172 || (!(bfd_link_pie (INFO) \
173 && (PCREL_PLT) \
174 && (H)->plt.refcount > 0 \
175 && ((SEC)->flags & SEC_CODE) == 0 \
176 && (H)->type == STT_FUNC \
177 && (H)->def_dynamic) \
178 && !(H)->def_regular))))) \
179 || ((H) != NULL \
180 && (H)->type == STT_GNU_IFUNC \
181 && (R_TYPE) == POINTER_TYPE \
182 && ((SEC)->flags & SEC_CODE) == 0) \
183 || (ELIMINATE_COPY_RELOCS \
184 && !bfd_link_pic (INFO) \
185 && (H) != NULL \
186 && ((H)->root.type == bfd_link_hash_defweak \
187 || !(H)->def_regular)))
189 /* TRUE if dynamic relocation should be generated. Don't copy a
190 pc-relative relocation into the output file if the symbol needs
191 copy reloc or the symbol is undefined when building executable.
192 Copy dynamic function pointer relocations. Don't generate dynamic
193 relocations against resolved undefined weak symbols in PIE, except
194 when PC32_RELOC is TRUE. Undefined weak symbol is bound locally
195 when PIC is false. Don't generate dynamic relocations against
196 non-preemptible absolute symbol. NB: rel_from_abs is set on symbols
197 defined by linker scripts from "dot" (also SEGMENT_START or ORIGIN)
198 outside of an output section statement, which will be converted from
199 absolute to section-relative in set_sym_sections called from
200 ldexp_finalize_syms after ldemul_finish. */
201 #define GENERATE_DYNAMIC_RELOCATION_P(IS_X86_64, INFO, EH, R_TYPE, \
202 SEC, NEED_COPY_RELOC_IN_PIE, \
203 RESOLVED_TO_ZERO, PC32_RELOC) \
204 ((bfd_link_pic (INFO) \
205 && !(bfd_is_abs_section (SEC) \
206 && ((EH) == NULL \
207 || (EH)->elf.root.rel_from_abs == 0) \
208 && ((EH) == NULL \
209 || SYMBOL_REFERENCES_LOCAL (INFO, &(EH)->elf))) \
210 && !(NEED_COPY_RELOC_IN_PIE) \
211 && ((EH) == NULL \
212 || ((ELF_ST_VISIBILITY ((EH)->elf.other) == STV_DEFAULT \
213 && (!(RESOLVED_TO_ZERO) || PC32_RELOC)) \
214 || (EH)->elf.root.type != bfd_link_hash_undefweak)) \
215 && ((!X86_PCREL_TYPE_P (IS_X86_64, R_TYPE) \
216 && !X86_SIZE_TYPE_P (IS_X86_64, R_TYPE)) \
217 || ! SYMBOL_CALLS_LOCAL ((INFO), \
218 (struct elf_link_hash_entry *) (EH)))) \
219 || (ELIMINATE_COPY_RELOCS \
220 && !bfd_link_pic (INFO) \
221 && (EH) != NULL \
222 && (EH)->elf.dynindx != -1 \
223 && (!(EH)->elf.non_got_ref \
224 || ((EH)->elf.root.type == bfd_link_hash_undefweak \
225 && !(RESOLVED_TO_ZERO))) \
226 && (((EH)->elf.def_dynamic && !(EH)->elf.def_regular) \
227 || (EH)->elf.root.type == bfd_link_hash_undefined)))
229 /* TRUE if this input relocation should be copied to output. H->dynindx
230 may be -1 if this symbol was marked to become local. */
231 #define COPY_INPUT_RELOC_P(IS_X86_64, INFO, H, R_TYPE) \
232 ((H) != NULL \
233 && (H)->dynindx != -1 \
234 && (X86_PCREL_TYPE_P (IS_X86_64, R_TYPE) \
235 || !(bfd_link_executable (INFO) || SYMBOLIC_BIND ((INFO), (H))) \
236 || !(H)->def_regular))
238 /* TRUE if this is actually a static link, or it is a -Bsymbolic link
239 and the symbol is defined locally, or the symbol was forced to be
240 local because of a version file. */
241 #define RESOLVED_LOCALLY_P(INFO, H, HTAB) \
242 (!WILL_CALL_FINISH_DYNAMIC_SYMBOL ((HTAB)->elf.dynamic_sections_created, \
243 bfd_link_pic (INFO), (H)) \
244 || (bfd_link_pic (INFO) \
245 && SYMBOL_REFERENCES_LOCAL_P ((INFO), (H))) \
246 || (ELF_ST_VISIBILITY ((H)->other) \
247 && (H)->root.type == bfd_link_hash_undefweak))
249 /* TRUE if this symbol isn't defined by a shared object. */
250 #define SYMBOL_DEFINED_NON_SHARED_P(H) \
251 ((H)->def_regular \
252 || (H)->root.linker_def \
253 || (H)->root.ldscript_def \
254 || ((struct elf_x86_link_hash_entry *) (H))->linker_def \
255 || ELF_COMMON_DEF_P (H))
257 /* Return TRUE if the symbol described by a linker hash entry H is
258 going to be absolute. Similar to bfd_is_abs_symbol, but excluding
259 all linker-script defined symbols. */
260 #define ABS_SYMBOL_P(H) \
261 (bfd_is_abs_symbol (&(H)->root) && !(H)->root.ldscript_def)
263 /* TRUE if relative relocation should be generated. GOT reference to
264 global symbol in PIC will lead to dynamic symbol. It becomes a
265 problem when "time" or "times" is defined as a variable in an
266 executable, clashing with functions of the same name in libc. If a
267 symbol isn't undefined weak symbol, don't make it dynamic in PIC and
268 generate relative relocation. Don't generate relative relocation
269 against non-preemptible absolute symbol. */
270 #define GENERATE_RELATIVE_RELOC_P(INFO, H) \
271 ((H)->dynindx == -1 \
272 && !(H)->forced_local \
273 && (H)->root.type != bfd_link_hash_undefweak \
274 && bfd_link_pic (INFO) \
275 && !ABS_SYMBOL_P (H))
277 /* TRUE if this is a pointer reference to a local IFUNC. */
278 #define POINTER_LOCAL_IFUNC_P(INFO, H) \
279 ((H)->dynindx == -1 \
280 || (H)->forced_local \
281 || bfd_link_executable (INFO))
283 /* TRUE if this is a PLT reference to a local IFUNC. */
284 #define PLT_LOCAL_IFUNC_P(INFO, H) \
285 ((H)->dynindx == -1 \
286 || ((bfd_link_executable (INFO) \
287 || ELF_ST_VISIBILITY ((H)->other) != STV_DEFAULT) \
288 && (H)->def_regular \
289 && (H)->type == STT_GNU_IFUNC))
291 /* TRUE if TLS IE->LE transition is OK. */
292 #define TLS_TRANSITION_IE_TO_LE_P(INFO, H, TLS_TYPE) \
293 (bfd_link_executable (INFO) \
294 && (H) != NULL \
295 && (H)->dynindx == -1 \
296 && (TLS_TYPE & GOT_TLS_IE))
298 /* Verify that the symbol has an entry in the procedure linkage table. */
299 #define VERIFY_PLT_ENTRY(INFO, H, PLT, GOTPLT, RELPLT, LOCAL_UNDEFWEAK) \
300 do \
302 if (((H)->dynindx == -1 \
303 && !LOCAL_UNDEFWEAK \
304 && !(((H)->forced_local || bfd_link_executable (INFO)) \
305 && (H)->def_regular \
306 && (H)->type == STT_GNU_IFUNC)) \
307 || (PLT) == NULL \
308 || (GOTPLT) == NULL \
309 || (RELPLT) == NULL) \
310 abort (); \
312 while (0);
314 /* Verify that the symbol supports copy relocation. */
315 #define VERIFY_COPY_RELOC(H, HTAB) \
316 do \
318 if ((H)->dynindx == -1 \
319 || ((H)->root.type != bfd_link_hash_defined \
320 && (H)->root.type != bfd_link_hash_defweak) \
321 || (HTAB)->elf.srelbss == NULL \
322 || (HTAB)->elf.sreldynrelro == NULL) \
323 abort (); \
325 while (0);
327 /* x86 ELF linker hash entry. */
329 struct elf_x86_link_hash_entry
331 struct elf_link_hash_entry elf;
333 unsigned char tls_type;
335 /* Bit 0: Symbol has no GOT nor PLT relocations.
336 Bit 1: Symbol has non-GOT/non-PLT relocations in text sections.
337 zero_undefweak is initialized to 1 and undefined weak symbol
338 should be resolved to 0 if zero_undefweak > 0. */
339 unsigned int zero_undefweak : 2;
341 /* Don't call finish_dynamic_symbol on this symbol. */
342 unsigned int no_finish_dynamic_symbol : 1;
344 /* R_*_RELATIVE relocation in GOT for this symbol has been
345 processed. */
346 unsigned int got_relative_reloc_done : 1;
348 /* TRUE if symbol is __tls_get_addr. */
349 unsigned int tls_get_addr : 1;
351 /* TRUE if symbol is defined as a protected symbol. */
352 unsigned int def_protected : 1;
354 /* 0: Symbol references are unknown.
355 1: Symbol references aren't local.
356 2: Symbol references are local.
358 unsigned int local_ref : 2;
360 /* TRUE if symbol is defined by linker. */
361 unsigned int linker_def : 1;
363 /* TRUE if symbol is referenced by a non-GOT/non-PLT relocation in a
364 relocatable object file without indirect external access marker. */
365 unsigned int non_got_ref_without_indirect_extern_access : 1;
367 /* TRUE if symbol is referenced by R_386_GOTOFF relocation. This is
368 only used by i386. */
369 unsigned int gotoff_ref : 1;
371 /* TRUE if a weak symbol with a real definition needs a copy reloc.
372 When there is a weak symbol with a real definition, the processor
373 independent code will have arranged for us to see the real
374 definition first. We need to copy the needs_copy bit from the
375 real definition and check it when allowing copy reloc in PIE. This
376 is only used by x86-64. */
377 unsigned int needs_copy : 1;
379 /* Information about the GOT PLT entry. Filled when there are both
380 GOT and PLT relocations against the same function. */
381 union gotplt_union plt_got;
383 /* Information about the second PLT entry. */
384 union gotplt_union plt_second;
386 /* Offset of the GOTPLT entry reserved for the TLS descriptor,
387 starting at the end of the jump table. */
388 bfd_vma tlsdesc_got;
391 struct elf_x86_lazy_plt_layout
393 /* The first entry in a lazy procedure linkage table looks like this. */
394 const bfd_byte *plt0_entry;
395 unsigned int plt0_entry_size; /* Size of PLT0 entry. */
397 /* Later entries in a lazy procedure linkage table look like this. */
398 const bfd_byte *plt_entry;
399 unsigned int plt_entry_size; /* Size of each PLT entry. */
401 /* The TLSDESC entry in a lazy procedure linkage table looks like
402 this. This is for x86-64 only. */
403 const bfd_byte *plt_tlsdesc_entry;
404 unsigned int plt_tlsdesc_entry_size; /* Size of TLSDESC entry. */
406 /* Offsets into the TLSDESC entry that are to be replaced with
407 GOT+8 and GOT+TDG. These are for x86-64 only. */
408 unsigned int plt_tlsdesc_got1_offset;
409 unsigned int plt_tlsdesc_got2_offset;
411 /* Offset of the end of the PC-relative instructions containing
412 plt_tlsdesc_got1_offset and plt_tlsdesc_got2_offset. These
413 are for x86-64 only. */
414 unsigned int plt_tlsdesc_got1_insn_end;
415 unsigned int plt_tlsdesc_got2_insn_end;
417 /* Offsets into plt0_entry that are to be replaced with GOT[1] and
418 GOT[2]. */
419 unsigned int plt0_got1_offset;
420 unsigned int plt0_got2_offset;
422 /* Offset of the end of the PC-relative instruction containing
423 plt0_got2_offset. This is for x86-64 only. */
424 unsigned int plt0_got2_insn_end;
426 /* Offsets into plt_entry that are to be replaced with... */
427 unsigned int plt_got_offset; /* ... address of this symbol in .got. */
428 unsigned int plt_reloc_offset; /* ... offset into relocation table. */
429 unsigned int plt_plt_offset; /* ... offset to start of .plt. */
431 /* Length of the PC-relative instruction containing plt_got_offset.
432 This is used for x86-64 only. */
433 unsigned int plt_got_insn_size;
435 /* Offset of the end of the PC-relative jump to plt0_entry. This is
436 used for x86-64 only. */
437 unsigned int plt_plt_insn_end;
439 /* Offset into plt_entry where the initial value of the GOT entry
440 points. */
441 unsigned int plt_lazy_offset;
443 /* The first entry in a PIC lazy procedure linkage table looks like
444 this. */
445 const bfd_byte *pic_plt0_entry;
447 /* Subsequent entries in a PIC lazy procedure linkage table look
448 like this. */
449 const bfd_byte *pic_plt_entry;
451 /* .eh_frame covering the lazy .plt section. */
452 const bfd_byte *eh_frame_plt;
453 unsigned int eh_frame_plt_size;
456 struct elf_x86_non_lazy_plt_layout
458 /* Entries in a non-lazy procedure linkage table look like this. */
459 const bfd_byte *plt_entry;
460 /* Entries in a PIC non-lazy procedure linkage table look like this.
461 This is only used for i386 where absolute PLT and PIC PLT are
462 different. */
463 const bfd_byte *pic_plt_entry;
465 unsigned int plt_entry_size; /* Size of each PLT entry. */
467 /* Offsets into plt_entry that are to be replaced with... */
468 unsigned int plt_got_offset; /* ... address of this symbol in .got. */
470 /* Length of the PC-relative instruction containing plt_got_offset.
471 This is used for x86-64 only. */
472 unsigned int plt_got_insn_size;
474 /* .eh_frame covering the non-lazy .plt section. */
475 const bfd_byte *eh_frame_plt;
476 unsigned int eh_frame_plt_size;
479 struct elf_x86_plt_layout
481 /* The first entry in a lazy procedure linkage table looks like this. */
482 const bfd_byte *plt0_entry;
483 /* Entries in a procedure linkage table look like this. */
484 const bfd_byte *plt_entry;
485 unsigned int plt_entry_size; /* Size of each PLT entry. */
487 /* 1 has PLT0. */
488 unsigned int has_plt0;
490 /* Offsets into plt_entry that are to be replaced with... */
491 unsigned int plt_got_offset; /* ... address of this symbol in .got. */
493 /* Length of the PC-relative instruction containing plt_got_offset.
494 This is only used for x86-64. */
495 unsigned int plt_got_insn_size;
497 /* Alignment of the .iplt section. */
498 unsigned int iplt_alignment;
500 /* .eh_frame covering the .plt section. */
501 const bfd_byte *eh_frame_plt;
502 unsigned int eh_frame_plt_size;
505 /* Values in tls_type of x86 ELF linker hash entry. */
506 #define GOT_UNKNOWN 0
507 #define GOT_NORMAL 1
508 #define GOT_TLS_GD 2
509 #define GOT_TLS_IE 4
510 #define GOT_TLS_IE_POS 5
511 #define GOT_TLS_IE_NEG 6
512 #define GOT_TLS_IE_BOTH 7
513 #define GOT_TLS_GDESC 8
514 #define GOT_ABS 9
515 #define GOT_TLS_GD_BOTH_P(type) \
516 ((type) == (GOT_TLS_GD | GOT_TLS_GDESC))
517 #define GOT_TLS_GD_P(type) \
518 ((type) == GOT_TLS_GD || GOT_TLS_GD_BOTH_P (type))
519 #define GOT_TLS_GDESC_P(type) \
520 ((type) == GOT_TLS_GDESC || GOT_TLS_GD_BOTH_P (type))
521 #define GOT_TLS_GD_ANY_P(type) \
522 (GOT_TLS_GD_P (type) || GOT_TLS_GDESC_P (type))
524 #define elf_x86_hash_entry(ent) \
525 ((struct elf_x86_link_hash_entry *)(ent))
527 /* Information of an input relocation used to compute its contribution
528 to the DT_RELR section size. */
530 struct elf_x86_relative_reloc_record
532 /* The original relocation info. */
533 Elf_Internal_Rela rel;
534 /* The input or the GOT section where the relocation is applied. */
535 asection *sec;
536 /* Local symbol info. NULL for global symbol. */
537 Elf_Internal_Sym *sym;
538 union
540 /* Section where the local symbol is defined. */
541 asection *sym_sec;
542 /* Global symbol hash. */
543 struct elf_link_hash_entry *h;
544 } u;
545 /* The offset into the output section where the relative relocation
546 will be applied at run-time. */
547 bfd_vma offset;
548 /* The run-time address. */
549 bfd_vma address;
552 struct elf_x86_relative_reloc_data
554 bfd_size_type count;
555 bfd_size_type size;
556 struct elf_x86_relative_reloc_record *data;
559 /* DT_RELR bitmap. */
560 struct elf_dt_relr_bitmap
562 bfd_size_type count;
563 bfd_size_type size;
564 union
566 /* 32-bit bitmap. */
567 uint32_t *elf32;
568 /* 64-bit bitmap. */
569 uint64_t *elf64;
570 } u;
573 /* x86 ELF linker hash table. */
575 struct elf_x86_link_hash_table
577 struct elf_link_hash_table elf;
579 /* Short-cuts to get to dynamic linker sections. */
580 asection *interp;
581 asection *plt_eh_frame;
582 asection *plt_second;
583 asection *plt_second_eh_frame;
584 asection *plt_got;
585 asection *plt_got_eh_frame;
587 /* Parameters describing PLT generation, lazy or non-lazy. */
588 struct elf_x86_plt_layout plt;
590 /* Parameters describing lazy PLT generation. */
591 const struct elf_x86_lazy_plt_layout *lazy_plt;
593 /* Parameters describing non-lazy PLT generation. */
594 const struct elf_x86_non_lazy_plt_layout *non_lazy_plt;
596 union
598 bfd_signed_vma refcount;
599 bfd_vma offset;
600 } tls_ld_or_ldm_got;
602 /* The amount of space used by the jump slots in the GOT. */
603 bfd_vma sgotplt_jump_table_size;
605 /* _TLS_MODULE_BASE_ symbol. */
606 struct bfd_link_hash_entry *tls_module_base;
608 /* Used by local STT_GNU_IFUNC symbols. */
609 htab_t loc_hash_table;
610 void * loc_hash_memory;
612 /* The index of the next R_X86_64_JUMP_SLOT entry in .rela.plt. */
613 bfd_vma next_jump_slot_index;
614 /* The index of the next R_X86_64_IRELATIVE entry in .rela.plt. */
615 bfd_vma next_irelative_index;
617 /* The (unloaded but important) .rel.plt.unloaded section on VxWorks.
618 This is used for i386 only. */
619 asection *srelplt2;
621 /* The index of the next unused R_386_TLS_DESC slot in .rel.plt. This
622 is only used for i386. */
623 bfd_vma next_tls_desc_index;
625 /* DT_RELR bitmap. */
626 struct elf_dt_relr_bitmap dt_relr_bitmap;
628 /* Relative relocation data. */
629 struct elf_x86_relative_reloc_data relative_reloc;
631 /* Unaligned relative relocation data. */
632 struct elf_x86_relative_reloc_data unaligned_relative_reloc;
634 /* Number of relative reloc generation pass. */
635 unsigned int generate_relative_reloc_pass;
637 /* Value used to fill the unused bytes of the first PLT entry. This
638 is only used for i386. */
639 bfd_byte plt0_pad_byte;
641 /* TRUE if GOT is referenced. */
642 unsigned int got_referenced : 1;
644 /* TRUE if PLT is PC-relative. PLT in PDE and PC-relative PLT in PIE
645 can be used as function address.
647 NB: i386 has non-PIC PLT and PIC PLT. Only non-PIC PLT in PDE can
648 be used as function address. PIC PLT in PIE can't be used as
649 function address. */
650 unsigned int pcrel_plt : 1;
652 bfd_vma (*r_info) (bfd_vma, bfd_vma);
653 bfd_vma (*r_sym) (bfd_vma);
654 bool (*is_reloc_section) (const char *);
655 unsigned int sizeof_reloc;
656 unsigned int got_entry_size;
657 unsigned int pointer_r_type;
658 unsigned int relative_r_type;
659 int dynamic_interpreter_size;
660 const char *dynamic_interpreter;
661 const char *tls_get_addr;
662 const char *relative_r_name;
663 void (*elf_append_reloc) (bfd *, asection *, Elf_Internal_Rela *);
664 void (*elf_write_addend) (bfd *, uint64_t, void *);
665 void (*elf_write_addend_in_got) (bfd *, uint64_t, void *);
667 /* Options passed from the linker. */
668 struct elf_linker_x86_params *params;
671 struct elf_x86_init_table
673 /* The lazy PLT layout. */
674 const struct elf_x86_lazy_plt_layout *lazy_plt;
676 /* The non-lazy PLT layout. */
677 const struct elf_x86_non_lazy_plt_layout *non_lazy_plt;
679 /* The lazy PLT layout for IBT. */
680 const struct elf_x86_lazy_plt_layout *lazy_ibt_plt;
682 /* The non-lazy PLT layout for IBT. */
683 const struct elf_x86_non_lazy_plt_layout *non_lazy_ibt_plt;
685 bfd_byte plt0_pad_byte;
687 bfd_vma (*r_info) (bfd_vma, bfd_vma);
688 bfd_vma (*r_sym) (bfd_vma);
691 struct elf_x86_obj_tdata
693 struct elf_obj_tdata root;
695 /* tls_type for each local got entry. */
696 char *local_got_tls_type;
698 /* GOTPLT entries for TLS descriptors. */
699 bfd_vma *local_tlsdesc_gotent;
701 /* R_*_RELATIVE relocation in GOT for this local symbol has been
702 processed. */
703 char *relative_reloc_done;
706 enum elf_x86_plt_type
708 plt_non_lazy = 0,
709 plt_lazy = 1 << 0,
710 plt_pic = 1 << 1,
711 plt_second = 1 << 2,
712 plt_unknown = -1
715 struct elf_x86_plt
717 const char *name;
718 asection *sec;
719 bfd_byte *contents;
720 enum elf_x86_plt_type type;
721 unsigned int plt_got_offset;
722 unsigned int plt_entry_size;
723 unsigned int plt_got_insn_size; /* Only used for x86-64. */
724 long count;
727 /* Set if a relocation is converted from a GOTPCREL relocation. */
728 #define R_X86_64_converted_reloc_bit (1 << 7)
730 #define elf_x86_tdata(abfd) \
731 ((struct elf_x86_obj_tdata *) (abfd)->tdata.any)
733 #define elf_x86_local_got_tls_type(abfd) \
734 (elf_x86_tdata (abfd)->local_got_tls_type)
736 #define elf_x86_local_tlsdesc_gotent(abfd) \
737 (elf_x86_tdata (abfd)->local_tlsdesc_gotent)
739 #define elf_x86_relative_reloc_done(abfd) \
740 (elf_x86_tdata (abfd)->relative_reloc_done)
742 #define elf_x86_compute_jump_table_size(htab) \
743 ((htab)->elf.srelplt->reloc_count * (htab)->got_entry_size)
745 #define is_x86_elf(bfd, htab) \
746 (bfd_get_flavour (bfd) == bfd_target_elf_flavour \
747 && elf_tdata (bfd) != NULL \
748 && elf_object_id (bfd) == (htab)->elf.hash_table_id)
750 /* Rename some of the generic section flags to better document how they
751 are used here. */
752 #define check_relocs_failed sec_flg0
753 #define relative_reloc_packed sec_flg1
755 extern bool _bfd_x86_elf_mkobject
756 (bfd *);
758 extern void _bfd_x86_elf_set_tls_module_base
759 (struct bfd_link_info *);
761 extern bfd_vma _bfd_x86_elf_dtpoff_base
762 (struct bfd_link_info *);
764 extern bool _bfd_x86_elf_readonly_dynrelocs
765 (struct elf_link_hash_entry *, void *);
767 extern struct elf_link_hash_entry * _bfd_elf_x86_get_local_sym_hash
768 (struct elf_x86_link_hash_table *, bfd *, const Elf_Internal_Rela *,
769 bool);
771 extern hashval_t _bfd_x86_elf_local_htab_hash
772 (const void *);
774 extern int _bfd_x86_elf_local_htab_eq
775 (const void *, const void *);
777 extern struct bfd_hash_entry * _bfd_x86_elf_link_hash_newfunc
778 (struct bfd_hash_entry *, struct bfd_hash_table *, const char *);
780 extern struct bfd_link_hash_table * _bfd_x86_elf_link_hash_table_create
781 (bfd *);
783 extern int _bfd_x86_elf_compare_relocs
784 (const void *, const void *);
786 extern bool _bfd_x86_elf_link_check_relocs
787 (bfd *, struct bfd_link_info *);
789 extern bool _bfd_x86_elf_check_relocs
790 (bfd *, struct bfd_link_info *, asection *,
791 const Elf_Internal_Rela *);
793 extern bool _bfd_x86_elf_link_relax_section
794 (bfd *, asection *, struct bfd_link_info *, bool *);
796 extern bool _bfd_elf_x86_size_relative_relocs
797 (struct bfd_link_info *, bool *);
799 extern bool _bfd_elf_x86_finish_relative_relocs
800 (struct bfd_link_info *);
802 extern void _bfd_elf32_write_addend (bfd *, uint64_t, void *);
803 extern void _bfd_elf64_write_addend (bfd *, uint64_t, void *);
805 extern bool _bfd_elf_x86_valid_reloc_p
806 (asection *, struct bfd_link_info *, struct elf_x86_link_hash_table *,
807 const Elf_Internal_Rela *, struct elf_link_hash_entry *,
808 Elf_Internal_Sym *, Elf_Internal_Shdr *, bool *);
810 extern bool _bfd_x86_elf_size_dynamic_sections
811 (bfd *, struct bfd_link_info *);
813 extern struct elf_x86_link_hash_table *_bfd_x86_elf_finish_dynamic_sections
814 (bfd *, struct bfd_link_info *);
816 extern bool _bfd_x86_elf_always_size_sections
817 (bfd *, struct bfd_link_info *);
819 extern void _bfd_x86_elf_merge_symbol_attribute
820 (struct elf_link_hash_entry *, unsigned int, bool, bool);
822 extern void _bfd_x86_elf_copy_indirect_symbol
823 (struct bfd_link_info *, struct elf_link_hash_entry *,
824 struct elf_link_hash_entry *);
826 extern bool _bfd_x86_elf_fixup_symbol
827 (struct bfd_link_info *, struct elf_link_hash_entry *);
829 extern bool _bfd_x86_elf_hash_symbol
830 (struct elf_link_hash_entry *);
832 extern bool _bfd_x86_elf_adjust_dynamic_symbol
833 (struct bfd_link_info *, struct elf_link_hash_entry *);
835 extern void _bfd_x86_elf_hide_symbol
836 (struct bfd_link_info *, struct elf_link_hash_entry *, bool);
838 extern bool _bfd_x86_elf_link_symbol_references_local
839 (struct bfd_link_info *, struct elf_link_hash_entry *);
841 extern asection * _bfd_x86_elf_gc_mark_hook
842 (asection *, struct bfd_link_info *, Elf_Internal_Rela *,
843 struct elf_link_hash_entry *, Elf_Internal_Sym *);
845 extern long _bfd_x86_elf_get_synthetic_symtab
846 (bfd *, long, long, bfd_vma, struct elf_x86_plt [], asymbol **,
847 asymbol **);
849 extern enum elf_property_kind _bfd_x86_elf_parse_gnu_properties
850 (bfd *, unsigned int, bfd_byte *, unsigned int);
852 extern bool _bfd_x86_elf_merge_gnu_properties
853 (struct bfd_link_info *, bfd *, bfd *, elf_property *, elf_property *);
855 extern void _bfd_x86_elf_link_fixup_gnu_properties
856 (struct bfd_link_info *, elf_property_list **);
858 extern bfd * _bfd_x86_elf_link_setup_gnu_properties
859 (struct bfd_link_info *, struct elf_x86_init_table *);
861 extern void _bfd_x86_elf_link_fixup_ifunc_symbol
862 (struct bfd_link_info *, struct elf_x86_link_hash_table *,
863 struct elf_link_hash_entry *, Elf_Internal_Sym *sym);
865 extern void _bfd_x86_elf_link_report_relative_reloc
866 (struct bfd_link_info *, asection *, struct elf_link_hash_entry *,
867 Elf_Internal_Sym *, const char *, const void *);
869 #define bfd_elf64_mkobject \
870 _bfd_x86_elf_mkobject
871 #define bfd_elf32_mkobject \
872 _bfd_x86_elf_mkobject
873 #define bfd_elf64_bfd_link_hash_table_create \
874 _bfd_x86_elf_link_hash_table_create
875 #define bfd_elf32_bfd_link_hash_table_create \
876 _bfd_x86_elf_link_hash_table_create
877 #define bfd_elf64_bfd_link_check_relocs \
878 _bfd_x86_elf_link_check_relocs
879 #define bfd_elf32_bfd_link_check_relocs \
880 _bfd_x86_elf_link_check_relocs
881 #define bfd_elf32_bfd_relax_section \
882 _bfd_x86_elf_link_relax_section
883 #define bfd_elf64_bfd_relax_section \
884 _bfd_x86_elf_link_relax_section
886 #define elf_backend_check_relocs \
887 _bfd_x86_elf_check_relocs
888 #define elf_backend_size_dynamic_sections \
889 _bfd_x86_elf_size_dynamic_sections
890 #define elf_backend_merge_symbol_attribute \
891 _bfd_x86_elf_merge_symbol_attribute
892 #define elf_backend_copy_indirect_symbol \
893 _bfd_x86_elf_copy_indirect_symbol
894 #define elf_backend_fixup_symbol \
895 _bfd_x86_elf_fixup_symbol
896 #define elf_backend_hash_symbol \
897 _bfd_x86_elf_hash_symbol
898 #define elf_backend_adjust_dynamic_symbol \
899 _bfd_x86_elf_adjust_dynamic_symbol
900 #define elf_backend_gc_mark_hook \
901 _bfd_x86_elf_gc_mark_hook
902 #define elf_backend_omit_section_dynsym \
903 _bfd_elf_omit_section_dynsym_all
904 #define elf_backend_parse_gnu_properties \
905 _bfd_x86_elf_parse_gnu_properties
906 #define elf_backend_merge_gnu_properties \
907 _bfd_x86_elf_merge_gnu_properties
908 #define elf_backend_fixup_gnu_properties \
909 _bfd_x86_elf_link_fixup_gnu_properties
910 #define elf_backend_size_relative_relocs \
911 _bfd_elf_x86_size_relative_relocs
912 #define elf_backend_finish_relative_relocs \
913 _bfd_elf_x86_finish_relative_relocs
915 #define ELF_P_ALIGN ELF_MINPAGESIZE
917 /* Allocate x86 GOT info for local symbols. */
919 static inline bool
920 elf_x86_allocate_local_got_info (bfd *abfd, bfd_size_type count)
922 bfd_signed_vma *local_got_refcounts = elf_local_got_refcounts (abfd);
923 if (local_got_refcounts == NULL)
925 bfd_size_type size = count * (sizeof (bfd_signed_vma)
926 + sizeof (bfd_vma)
927 + 2 * sizeof(char));
928 local_got_refcounts = (bfd_signed_vma *) bfd_zalloc (abfd, size);
929 if (local_got_refcounts == NULL)
930 return false;
931 elf_local_got_refcounts (abfd) = local_got_refcounts;
932 elf_x86_local_tlsdesc_gotent (abfd) =
933 (bfd_vma *) (local_got_refcounts + count);
934 elf_x86_local_got_tls_type (abfd) =
935 (char *) (local_got_refcounts + 2 * count);
936 elf_x86_relative_reloc_done (abfd) =
937 ((char *) (local_got_refcounts + 2 * count)) + count;
939 return true;