xref: /netbsd-src/external/gpl3/gdb.old/dist/bfd/elfxx-x86.h (revision 2f62cc9c12bc202c40224f32c879f81443fee079)
1 /* x86 specific support for ELF
2    Copyright (C) 2017-2020 Free Software Foundation, Inc.
3 
4    This file is part of BFD, the Binary File Descriptor library.
5 
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.
10 
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.
15 
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.  */
20 
21 #include "sysdep.h"
22 #include "bfd.h"
23 #include "bfdlink.h"
24 #include "libbfd.h"
25 #include "elf-bfd.h"
26 #include "hashtab.h"
27 #include "elf-linker-x86.h"
28 
29 #define PLT_CIE_LENGTH		20
30 #define PLT_FDE_LENGTH		36
31 #define PLT_FDE_START_OFFSET	4 + PLT_CIE_LENGTH + 8
32 #define PLT_FDE_LEN_OFFSET	4 + PLT_CIE_LENGTH + 12
33 
34 #define ABI_64_P(abfd) \
35   (get_elf_backend_data (abfd)->s->elfclass == ELFCLASS64)
36 
37 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
38    copying dynamic variables from a shared lib into an app's dynbss
39    section, and instead use a dynamic relocation to point into the
40    shared lib.  */
41 #define ELIMINATE_COPY_RELOCS 1
42 
43 #define elf_x86_hash_table(p, id) \
44   (is_elf_hash_table ((p)->hash) \
45    && elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) == (id) \
46     ? ((struct elf_x86_link_hash_table *) ((p)->hash)) : NULL)
47 
48 /* Will references to this symbol always be local in this object?  */
49 #define SYMBOL_REFERENCES_LOCAL_P(INFO, H) \
50   _bfd_x86_elf_link_symbol_references_local ((INFO), (H))
51 
52 /* TRUE if an undefined weak symbol should be resolved to 0.  Local
53    undefined weak symbol is always resolved to 0.  Reference to an
54    undefined weak symbol is resolved to 0 in executable if undefined
55    weak symbol should be resolved to 0 (zero_undefweak > 0).  */
56 #define UNDEFINED_WEAK_RESOLVED_TO_ZERO(INFO, EH) \
57   ((EH)->elf.root.type == bfd_link_hash_undefweak		 \
58    && (SYMBOL_REFERENCES_LOCAL_P ((INFO), &(EH)->elf)		 \
59        || (bfd_link_executable (INFO)				 \
60 	   && (EH)->zero_undefweak > 0)))
61 
62 /* Should copy relocation be generated for a symbol.  Don't generate
63    copy relocation against a protected symbol defined in a shared
64    object with GNU_PROPERTY_NO_COPY_ON_PROTECTED.  */
65 #define SYMBOL_NO_COPYRELOC(INFO, EH) \
66   ((EH)->def_protected \
67    && ((EH)->elf.root.type == bfd_link_hash_defined \
68        || (EH)->elf.root.type == bfd_link_hash_defweak) \
69    && elf_has_no_copy_on_protected ((EH)->elf.root.u.def.section->owner) \
70    && ((EH)->elf.root.u.def.section->owner->flags & DYNAMIC) != 0 \
71    && ((EH)->elf.root.u.def.section->flags & SEC_CODE) == 0)
72 
73 /* TRUE if dynamic relocation is needed.  If we are creating a shared
74    library, and this is a reloc against a global symbol, or a non PC
75    relative reloc against a local symbol, then we need to copy the reloc
76    into the shared library.  However, if we are linking with -Bsymbolic,
77    we do not need to copy a reloc against a global symbol which is
78    defined in an object we are including in the link (i.e., DEF_REGULAR
79    is set).
80 
81    If PCREL_PLT is true, don't generate dynamic relocation in PIE for
82    PC-relative relocation against a dynamic function definition in data
83    section when PLT address can be used.
84 
85    If on the other hand, we are creating an executable, we may need to
86    keep relocations for symbols satisfied by a dynamic library if we
87    manage to avoid copy relocs for the symbol.
88 
89    We also need to generate dynamic pointer relocation against
90    STT_GNU_IFUNC symbol in the non-code section.  */
91 #define NEED_DYNAMIC_RELOCATION_P(INFO, PCREL_PLT, H, SEC, R_TYPE, \
92 				  POINTER_TYPE) \
93   ((bfd_link_pic (INFO) \
94     && (! X86_PCREL_TYPE_P (R_TYPE) \
95 	|| ((H) != NULL \
96 	    && (! (bfd_link_pie (INFO) \
97 		   || SYMBOLIC_BIND ((INFO), (H))) \
98 		|| (H)->root.type == bfd_link_hash_defweak \
99 		|| (!(bfd_link_pie (INFO) \
100 		      && (PCREL_PLT) \
101 		      && (H)->plt.refcount > 0 \
102 		      && ((SEC)->flags & SEC_CODE) == 0 \
103 		      && (H)->type == STT_FUNC \
104 		      && (H)->def_dynamic) \
105 		    && !(H)->def_regular))))) \
106    || ((H) != NULL \
107        && (H)->type == STT_GNU_IFUNC \
108        && (R_TYPE) == POINTER_TYPE \
109        && ((SEC)->flags & SEC_CODE) == 0) \
110    || (ELIMINATE_COPY_RELOCS \
111        && !bfd_link_pic (INFO) \
112        && (H) != NULL \
113        && ((H)->root.type == bfd_link_hash_defweak \
114 	   || !(H)->def_regular)))
115 
116 /* TRUE if dynamic relocation should be generated.  Don't copy a
117    pc-relative relocation into the output file if the symbol needs
118    copy reloc or the symbol is undefined when building executable.
119    Copy dynamic function pointer relocations.  Don't generate dynamic
120    relocations against resolved undefined weak symbols in PIE, except
121    when PC32_RELOC is TRUE.  Undefined weak symbol is bound locally
122    when PIC is false.  Don't generate dynamic relocations against
123    non-preemptible absolute symbol.  */
124 #define GENERATE_DYNAMIC_RELOCATION_P(INFO, EH, R_TYPE, SEC, \
125 				      NEED_COPY_RELOC_IN_PIE, \
126 				      RESOLVED_TO_ZERO, PC32_RELOC) \
127   ((bfd_link_pic (INFO) \
128     && !(bfd_is_abs_section (SEC) \
129 	 && ((EH) == NULL \
130 	     || SYMBOL_REFERENCES_LOCAL (INFO, &(EH)->elf))) \
131     && !(NEED_COPY_RELOC_IN_PIE) \
132     && ((EH) == NULL \
133 	|| ((ELF_ST_VISIBILITY ((EH)->elf.other) == STV_DEFAULT \
134 	     && (!(RESOLVED_TO_ZERO) || PC32_RELOC)) \
135 	    || (EH)->elf.root.type != bfd_link_hash_undefweak)) \
136     && ((!X86_PCREL_TYPE_P (R_TYPE) && !X86_SIZE_TYPE_P (R_TYPE)) \
137 	|| ! SYMBOL_CALLS_LOCAL ((INFO), \
138 				 (struct elf_link_hash_entry *) (EH)))) \
139    || (ELIMINATE_COPY_RELOCS \
140        && !bfd_link_pic (INFO) \
141        && (EH) != NULL \
142        && (EH)->elf.dynindx != -1 \
143        && (!(EH)->elf.non_got_ref \
144 	   || ((EH)->elf.root.type == bfd_link_hash_undefweak \
145 	       && !(RESOLVED_TO_ZERO))) \
146 	       && (((EH)->elf.def_dynamic && !(EH)->elf.def_regular) \
147 		   || (EH)->elf.root.type == bfd_link_hash_undefined)))
148 
149 /* TRUE if this input relocation should be copied to output.  H->dynindx
150    may be -1 if this symbol was marked to become local.  */
151 #define COPY_INPUT_RELOC_P(INFO, H, R_TYPE) \
152   ((H) != NULL \
153    && (H)->dynindx != -1 \
154    && (X86_PCREL_TYPE_P (R_TYPE) \
155        || !(bfd_link_executable (INFO) || SYMBOLIC_BIND ((INFO), (H))) \
156        || !(H)->def_regular))
157 
158 /* TRUE if this is actually a static link, or it is a -Bsymbolic link
159    and the symbol is defined locally, or the symbol was forced to be
160    local because of a version file.  */
161 #define RESOLVED_LOCALLY_P(INFO, H, HTAB) \
162   (!WILL_CALL_FINISH_DYNAMIC_SYMBOL ((HTAB)->elf.dynamic_sections_created, \
163 				     bfd_link_pic (INFO), (H)) \
164    || (bfd_link_pic (INFO) \
165        && SYMBOL_REFERENCES_LOCAL_P ((INFO), (H))) \
166        || (ELF_ST_VISIBILITY ((H)->other) \
167 	   && (H)->root.type == bfd_link_hash_undefweak))
168 
169 /* TRUE if this symbol isn't defined by a shared object.  */
170 #define SYMBOL_DEFINED_NON_SHARED_P(H) \
171   ((H)->def_regular \
172    || (H)->root.linker_def \
173    || (H)->root.ldscript_def \
174    || ((struct elf_x86_link_hash_entry *) (H))->linker_def \
175    || ELF_COMMON_DEF_P (H))
176 
177 /* Return TRUE if the symbol described by a linker hash entry H is
178    going to be absolute.  Similar to bfd_is_abs_symbol, but excluding
179    all linker-script defined symbols.  */
180 #define ABS_SYMBOL_P(H) \
181   (bfd_is_abs_symbol (&(H)->root) && !(H)->root.ldscript_def)
182 
183 /* TRUE if relative relocation should be generated.  GOT reference to
184    global symbol in PIC will lead to dynamic symbol.  It becomes a
185    problem when "time" or "times" is defined as a variable in an
186    executable, clashing with functions of the same name in libc.  If a
187    symbol isn't undefined weak symbol, don't make it dynamic in PIC and
188    generate relative relocation.   Don't generate relative relocation
189    against non-preemptible absolute symbol.  */
190 #define GENERATE_RELATIVE_RELOC_P(INFO, H) \
191   ((H)->dynindx == -1 \
192    && !(H)->forced_local \
193    && (H)->root.type != bfd_link_hash_undefweak \
194    && bfd_link_pic (INFO) \
195    && !ABS_SYMBOL_P (H))
196 
197 /* TRUE if this is a pointer reference to a local IFUNC.  */
198 #define POINTER_LOCAL_IFUNC_P(INFO, H) \
199   ((H)->dynindx == -1 \
200    || (H)->forced_local \
201    || bfd_link_executable (INFO))
202 
203 /* TRUE if this is a PLT reference to a local IFUNC.  */
204 #define PLT_LOCAL_IFUNC_P(INFO, H) \
205   ((H)->dynindx == -1 \
206    || ((bfd_link_executable (INFO) \
207 	|| ELF_ST_VISIBILITY ((H)->other) != STV_DEFAULT) \
208 	&& (H)->def_regular \
209 	&& (H)->type == STT_GNU_IFUNC))
210 
211 /* TRUE if TLS IE->LE transition is OK.  */
212 #define TLS_TRANSITION_IE_TO_LE_P(INFO, H, TLS_TYPE) \
213   (bfd_link_executable (INFO) \
214    && (H) != NULL \
215    && (H)->dynindx == -1 \
216    && (TLS_TYPE & GOT_TLS_IE))
217 
218 /* Verify that the symbol has an entry in the procedure linkage table.  */
219 #define VERIFY_PLT_ENTRY(INFO, H, PLT, GOTPLT, RELPLT, LOCAL_UNDEFWEAK) \
220   do \
221     { \
222       if (((H)->dynindx == -1 \
223 	   && !LOCAL_UNDEFWEAK \
224 	   && !(((H)->forced_local || bfd_link_executable (INFO)) \
225 		&& (H)->def_regular \
226 		&& (H)->type == STT_GNU_IFUNC)) \
227 	  || (PLT) == NULL \
228 	  || (GOTPLT) == NULL \
229 	  || (RELPLT) == NULL) \
230 	abort (); \
231     } \
232   while (0);
233 
234 /* Verify that the symbol supports copy relocation.  */
235 #define VERIFY_COPY_RELOC(H, HTAB) \
236   do \
237     { \
238       if ((H)->dynindx == -1 \
239 	  || ((H)->root.type != bfd_link_hash_defined \
240 	      && (H)->root.type != bfd_link_hash_defweak) \
241 	  || (HTAB)->elf.srelbss == NULL \
242 	  || (HTAB)->elf.sreldynrelro == NULL) \
243 	abort (); \
244     } \
245   while (0);
246 
247 /* x86 ELF linker hash entry.  */
248 
249 struct elf_x86_link_hash_entry
250 {
251   struct elf_link_hash_entry elf;
252 
253   unsigned char tls_type;
254 
255   /* Bit 0: Symbol has no GOT nor PLT relocations.
256      Bit 1: Symbol has non-GOT/non-PLT relocations in text sections.
257      zero_undefweak is initialized to 1 and undefined weak symbol
258      should be resolved to 0 if zero_undefweak > 0.  */
259   unsigned int zero_undefweak : 2;
260 
261   /* Don't call finish_dynamic_symbol on this symbol.  */
262   unsigned int no_finish_dynamic_symbol : 1;
263 
264   /* TRUE if symbol is __tls_get_addr.  */
265   unsigned int tls_get_addr : 1;
266 
267   /* TRUE if symbol is defined as a protected symbol.  */
268   unsigned int def_protected : 1;
269 
270   /* 0: Symbol references are unknown.
271      1: Symbol references aren't local.
272      2: Symbol references are local.
273    */
274   unsigned int local_ref : 2;
275 
276   /* TRUE if symbol is defined by linker.  */
277   unsigned int linker_def : 1;
278 
279   /* TRUE if symbol is referenced by R_386_GOTOFF relocation.  This is
280      only used by i386.  */
281   unsigned int gotoff_ref : 1;
282 
283   /* TRUE if a weak symbol with a real definition needs a copy reloc.
284      When there is a weak symbol with a real definition, the processor
285      independent code will have arranged for us to see the real
286      definition first.  We need to copy the needs_copy bit from the
287      real definition and check it when allowing copy reloc in PIE.  This
288      is only used by x86-64.  */
289   unsigned int needs_copy : 1;
290 
291   /* Information about the GOT PLT entry. Filled when there are both
292      GOT and PLT relocations against the same function.  */
293   union gotplt_union plt_got;
294 
295   /* Information about the second PLT entry.   */
296   union gotplt_union plt_second;
297 
298   /* Offset of the GOTPLT entry reserved for the TLS descriptor,
299      starting at the end of the jump table.  */
300   bfd_vma tlsdesc_got;
301 };
302 
303 struct elf_x86_lazy_plt_layout
304 {
305   /* The first entry in a lazy procedure linkage table looks like this.  */
306   const bfd_byte *plt0_entry;
307   unsigned int plt0_entry_size;		 /* Size of PLT0 entry.  */
308 
309   /* Later entries in a lazy procedure linkage table look like this.  */
310   const bfd_byte *plt_entry;
311   unsigned int plt_entry_size;		/* Size of each PLT entry.  */
312 
313   /* The TLSDESC entry in a lazy procedure linkage table looks like
314      this.  This is for x86-64 only.  */
315   const bfd_byte *plt_tlsdesc_entry;
316   unsigned int plt_tlsdesc_entry_size;	 /* Size of TLSDESC entry.  */
317 
318   /* Offsets into the TLSDESC entry that are to be replaced with
319      GOT+8 and GOT+TDG.  These are for x86-64 only.  */
320   unsigned int plt_tlsdesc_got1_offset;
321   unsigned int plt_tlsdesc_got2_offset;
322 
323   /* Offset of the end of the PC-relative instructions containing
324      plt_tlsdesc_got1_offset and plt_tlsdesc_got2_offset.  These
325      are for x86-64 only.  */
326   unsigned int plt_tlsdesc_got1_insn_end;
327   unsigned int plt_tlsdesc_got2_insn_end;
328 
329   /* Offsets into plt0_entry that are to be replaced with GOT[1] and
330      GOT[2].  */
331   unsigned int plt0_got1_offset;
332   unsigned int plt0_got2_offset;
333 
334   /* Offset of the end of the PC-relative instruction containing
335      plt0_got2_offset.  This is for x86-64 only.  */
336   unsigned int plt0_got2_insn_end;
337 
338   /* Offsets into plt_entry that are to be replaced with...  */
339   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
340   unsigned int plt_reloc_offset;  /* ... offset into relocation table. */
341   unsigned int plt_plt_offset;    /* ... offset to start of .plt. */
342 
343   /* Length of the PC-relative instruction containing plt_got_offset.
344      This is used for x86-64 only.  */
345   unsigned int plt_got_insn_size;
346 
347   /* Offset of the end of the PC-relative jump to plt0_entry.  This is
348      used for x86-64 only.  */
349   unsigned int plt_plt_insn_end;
350 
351   /* Offset into plt_entry where the initial value of the GOT entry
352      points.  */
353   unsigned int plt_lazy_offset;
354 
355   /* The first entry in a PIC lazy procedure linkage table looks like
356      this.  */
357   const bfd_byte *pic_plt0_entry;
358 
359   /* Subsequent entries in a PIC lazy procedure linkage table look
360      like this.  */
361   const bfd_byte *pic_plt_entry;
362 
363   /* .eh_frame covering the lazy .plt section.  */
364   const bfd_byte *eh_frame_plt;
365   unsigned int eh_frame_plt_size;
366 };
367 
368 struct elf_x86_non_lazy_plt_layout
369 {
370   /* Entries in a non-lazy procedure linkage table look like this.  */
371   const bfd_byte *plt_entry;
372   /* Entries in a PIC non-lazy procedure linkage table look like this.
373      This is only used for i386 where absolute PLT and PIC PLT are
374      different.  */
375   const bfd_byte *pic_plt_entry;
376 
377   unsigned int plt_entry_size;		/* Size of each PLT entry.  */
378 
379   /* Offsets into plt_entry that are to be replaced with...  */
380   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
381 
382   /* Length of the PC-relative instruction containing plt_got_offset.
383      This is used for x86-64 only.  */
384   unsigned int plt_got_insn_size;
385 
386   /* .eh_frame covering the non-lazy .plt section.  */
387   const bfd_byte *eh_frame_plt;
388   unsigned int eh_frame_plt_size;
389 };
390 
391 struct elf_x86_plt_layout
392 {
393   /* The first entry in a lazy procedure linkage table looks like this.  */
394   const bfd_byte *plt0_entry;
395   /* Entries in a procedure linkage table look like this.  */
396   const bfd_byte *plt_entry;
397   unsigned int plt_entry_size;		/* Size of each PLT entry.  */
398 
399   /* 1 has PLT0.  */
400   unsigned int has_plt0;
401 
402   /* Offsets into plt_entry that are to be replaced with...  */
403   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
404 
405   /* Length of the PC-relative instruction containing plt_got_offset.
406      This is only used for x86-64.  */
407   unsigned int plt_got_insn_size;
408 
409   /* Alignment of the .iplt section.  */
410   unsigned int iplt_alignment;
411 
412   /* .eh_frame covering the .plt section.  */
413   const bfd_byte *eh_frame_plt;
414   unsigned int eh_frame_plt_size;
415 };
416 
417 /* Values in tls_type of x86 ELF linker hash entry.  */
418 #define GOT_UNKNOWN	0
419 #define GOT_NORMAL	1
420 #define GOT_TLS_GD	2
421 #define GOT_TLS_IE	4
422 #define GOT_TLS_IE_POS	5
423 #define GOT_TLS_IE_NEG	6
424 #define GOT_TLS_IE_BOTH 7
425 #define GOT_TLS_GDESC	8
426 #define GOT_ABS		9
427 #define GOT_TLS_GD_BOTH_P(type)	\
428   ((type) == (GOT_TLS_GD | GOT_TLS_GDESC))
429 #define GOT_TLS_GD_P(type) \
430   ((type) == GOT_TLS_GD || GOT_TLS_GD_BOTH_P (type))
431 #define GOT_TLS_GDESC_P(type) \
432   ((type) == GOT_TLS_GDESC || GOT_TLS_GD_BOTH_P (type))
433 #define GOT_TLS_GD_ANY_P(type) \
434   (GOT_TLS_GD_P (type) || GOT_TLS_GDESC_P (type))
435 
436 #define elf_x86_hash_entry(ent) \
437   ((struct elf_x86_link_hash_entry *)(ent))
438 
439 /* x86 ELF linker hash table.  */
440 
441 struct elf_x86_link_hash_table
442 {
443   struct elf_link_hash_table elf;
444 
445   /* Short-cuts to get to dynamic linker sections.  */
446   asection *interp;
447   asection *plt_eh_frame;
448   asection *plt_second;
449   asection *plt_second_eh_frame;
450   asection *plt_got;
451   asection *plt_got_eh_frame;
452 
453   /* Parameters describing PLT generation, lazy or non-lazy.  */
454   struct elf_x86_plt_layout plt;
455 
456   /* Parameters describing lazy PLT generation.  */
457   const struct elf_x86_lazy_plt_layout *lazy_plt;
458 
459   /* Parameters describing non-lazy PLT generation.  */
460   const struct elf_x86_non_lazy_plt_layout *non_lazy_plt;
461 
462   union
463   {
464     bfd_signed_vma refcount;
465     bfd_vma offset;
466   } tls_ld_or_ldm_got;
467 
468   /* The amount of space used by the jump slots in the GOT.  */
469   bfd_vma sgotplt_jump_table_size;
470 
471   /* _TLS_MODULE_BASE_ symbol.  */
472   struct bfd_link_hash_entry *tls_module_base;
473 
474   /* Used by local STT_GNU_IFUNC symbols.  */
475   htab_t loc_hash_table;
476   void * loc_hash_memory;
477 
478   /* The index of the next R_X86_64_JUMP_SLOT entry in .rela.plt.  */
479   bfd_vma next_jump_slot_index;
480   /* The index of the next R_X86_64_IRELATIVE entry in .rela.plt.  */
481   bfd_vma next_irelative_index;
482 
483   /* The (unloaded but important) .rel.plt.unloaded section on VxWorks.
484      This is used for i386 only.  */
485   asection *srelplt2;
486 
487   /* The index of the next unused R_386_TLS_DESC slot in .rel.plt.  This
488      is only used for i386.  */
489   bfd_vma next_tls_desc_index;
490 
491    /* Value used to fill the unused bytes of the first PLT entry.  This
492       is only used for i386.  */
493   bfd_byte plt0_pad_byte;
494 
495   /* TRUE if GOT is referenced.  */
496   unsigned int got_referenced : 1;
497 
498   /* TRUE if PLT is PC-relative.  PLT in PDE and PC-relative PLT in PIE
499      can be used as function address.
500 
501      NB: i386 has non-PIC PLT and PIC PLT.  Only non-PIC PLT in PDE can
502      be used as function address.  PIC PLT in PIE can't be used as
503      function address.  */
504   unsigned int pcrel_plt : 1;
505 
506   bfd_vma (*r_info) (bfd_vma, bfd_vma);
507   bfd_vma (*r_sym) (bfd_vma);
508   bfd_boolean (*is_reloc_section) (const char *);
509   unsigned int sizeof_reloc;
510   unsigned int got_entry_size;
511   unsigned int pointer_r_type;
512   int dynamic_interpreter_size;
513   const char *dynamic_interpreter;
514   const char *tls_get_addr;
515 
516   /* Options passed from the linker.  */
517   struct elf_linker_x86_params *params;
518 };
519 
520 struct elf_x86_init_table
521 {
522   /* The lazy PLT layout.  */
523   const struct elf_x86_lazy_plt_layout *lazy_plt;
524 
525   /* The non-lazy PLT layout.  */
526   const struct elf_x86_non_lazy_plt_layout *non_lazy_plt;
527 
528   /* The lazy PLT layout for IBT.  */
529   const struct elf_x86_lazy_plt_layout *lazy_ibt_plt;
530 
531   /* The non-lazy PLT layout for IBT.  */
532   const struct elf_x86_non_lazy_plt_layout *non_lazy_ibt_plt;
533 
534   bfd_byte plt0_pad_byte;
535 
536   bfd_vma (*r_info) (bfd_vma, bfd_vma);
537   bfd_vma (*r_sym) (bfd_vma);
538 };
539 
540 struct elf_x86_obj_tdata
541 {
542   struct elf_obj_tdata root;
543 
544   /* tls_type for each local got entry.  */
545   char *local_got_tls_type;
546 
547   /* GOTPLT entries for TLS descriptors.  */
548   bfd_vma *local_tlsdesc_gotent;
549 };
550 
551 enum elf_x86_plt_type
552 {
553   plt_non_lazy = 0,
554   plt_lazy = 1 << 0,
555   plt_pic = 1 << 1,
556   plt_second = 1 << 2,
557   plt_unknown = -1
558 };
559 
560 struct elf_x86_plt
561 {
562   const char *name;
563   asection *sec;
564   bfd_byte *contents;
565   enum elf_x86_plt_type type;
566   unsigned int plt_got_offset;
567   unsigned int plt_entry_size;
568   unsigned int plt_got_insn_size;	/* Only used for x86-64.  */
569   long count;
570 };
571 
572 /* Set if a relocation is converted from a GOTPCREL relocation.  */
573 #define R_X86_64_converted_reloc_bit (1 << 7)
574 
575 #define elf_x86_tdata(abfd) \
576   ((struct elf_x86_obj_tdata *) (abfd)->tdata.any)
577 
578 #define elf_x86_local_got_tls_type(abfd) \
579   (elf_x86_tdata (abfd)->local_got_tls_type)
580 
581 #define elf_x86_local_tlsdesc_gotent(abfd) \
582   (elf_x86_tdata (abfd)->local_tlsdesc_gotent)
583 
584 #define elf_x86_compute_jump_table_size(htab) \
585   ((htab)->elf.srelplt->reloc_count * (htab)->got_entry_size)
586 
587 #define is_x86_elf(bfd, htab)				\
588   (bfd_get_flavour (bfd) == bfd_target_elf_flavour	\
589    && elf_tdata (bfd) != NULL				\
590    && elf_object_id (bfd) == (htab)->elf.hash_table_id)
591 
592 extern bfd_boolean _bfd_x86_elf_mkobject
593   (bfd *);
594 
595 extern void _bfd_x86_elf_set_tls_module_base
596   (struct bfd_link_info *);
597 
598 extern bfd_vma _bfd_x86_elf_dtpoff_base
599   (struct bfd_link_info *);
600 
601 extern bfd_boolean _bfd_x86_elf_readonly_dynrelocs
602   (struct elf_link_hash_entry *, void *);
603 
604 extern struct elf_link_hash_entry * _bfd_elf_x86_get_local_sym_hash
605   (struct elf_x86_link_hash_table *, bfd *, const Elf_Internal_Rela *,
606    bfd_boolean);
607 
608 extern hashval_t _bfd_x86_elf_local_htab_hash
609   (const void *);
610 
611 extern int _bfd_x86_elf_local_htab_eq
612   (const void *, const void *);
613 
614 extern struct bfd_hash_entry * _bfd_x86_elf_link_hash_newfunc
615   (struct bfd_hash_entry *, struct bfd_hash_table *, const char *);
616 
617 extern struct bfd_link_hash_table * _bfd_x86_elf_link_hash_table_create
618   (bfd *);
619 
620 extern int _bfd_x86_elf_compare_relocs
621   (const void *, const void *);
622 
623 extern bfd_boolean _bfd_x86_elf_link_check_relocs
624   (bfd *, struct bfd_link_info *);
625 
626 extern bfd_boolean _bfd_elf_x86_valid_reloc_p
627   (asection *, struct bfd_link_info *, struct elf_x86_link_hash_table *,
628    const Elf_Internal_Rela *, struct elf_link_hash_entry *,
629    Elf_Internal_Sym *, Elf_Internal_Shdr *, bfd_boolean *);
630 
631 extern bfd_boolean _bfd_x86_elf_size_dynamic_sections
632   (bfd *, struct bfd_link_info *);
633 
634 extern struct elf_x86_link_hash_table *_bfd_x86_elf_finish_dynamic_sections
635   (bfd *, struct bfd_link_info *);
636 
637 extern bfd_boolean _bfd_x86_elf_always_size_sections
638   (bfd *, struct bfd_link_info *);
639 
640 extern void _bfd_x86_elf_merge_symbol_attribute
641   (struct elf_link_hash_entry *, const Elf_Internal_Sym *,
642    bfd_boolean, bfd_boolean);
643 
644 extern void _bfd_x86_elf_copy_indirect_symbol
645   (struct bfd_link_info *, struct elf_link_hash_entry *,
646    struct elf_link_hash_entry *);
647 
648 extern bfd_boolean _bfd_x86_elf_fixup_symbol
649   (struct bfd_link_info *, struct elf_link_hash_entry *);
650 
651 extern bfd_boolean _bfd_x86_elf_hash_symbol
652   (struct elf_link_hash_entry *);
653 
654 extern bfd_boolean _bfd_x86_elf_adjust_dynamic_symbol
655   (struct bfd_link_info *, struct elf_link_hash_entry *);
656 
657 extern void _bfd_x86_elf_hide_symbol
658   (struct bfd_link_info *, struct elf_link_hash_entry *, bfd_boolean);
659 
660 extern bfd_boolean _bfd_x86_elf_link_symbol_references_local
661   (struct bfd_link_info *, struct elf_link_hash_entry *);
662 
663 extern asection * _bfd_x86_elf_gc_mark_hook
664   (asection *, struct bfd_link_info *, Elf_Internal_Rela *,
665    struct elf_link_hash_entry *, Elf_Internal_Sym *);
666 
667 extern long _bfd_x86_elf_get_synthetic_symtab
668   (bfd *, long, long, bfd_vma, struct elf_x86_plt [], asymbol **,
669    asymbol **);
670 
671 extern enum elf_property_kind _bfd_x86_elf_parse_gnu_properties
672   (bfd *, unsigned int, bfd_byte *, unsigned int);
673 
674 extern bfd_boolean _bfd_x86_elf_merge_gnu_properties
675   (struct bfd_link_info *, bfd *, bfd *, elf_property *, elf_property *);
676 
677 extern void _bfd_x86_elf_link_fixup_gnu_properties
678   (struct bfd_link_info *, elf_property_list **);
679 
680 extern bfd * _bfd_x86_elf_link_setup_gnu_properties
681   (struct bfd_link_info *, struct elf_x86_init_table *);
682 
683 extern void _bfd_x86_elf_link_fixup_ifunc_symbol
684   (struct bfd_link_info *, struct elf_x86_link_hash_table *,
685    struct elf_link_hash_entry *, Elf_Internal_Sym *sym);
686 
687 #define bfd_elf64_mkobject \
688   _bfd_x86_elf_mkobject
689 #define bfd_elf32_mkobject \
690   _bfd_x86_elf_mkobject
691 #define bfd_elf64_bfd_link_hash_table_create \
692   _bfd_x86_elf_link_hash_table_create
693 #define bfd_elf32_bfd_link_hash_table_create \
694   _bfd_x86_elf_link_hash_table_create
695 #define bfd_elf64_bfd_link_check_relocs	\
696   _bfd_x86_elf_link_check_relocs
697 #define bfd_elf32_bfd_link_check_relocs \
698   _bfd_x86_elf_link_check_relocs
699 
700 #define elf_backend_size_dynamic_sections \
701   _bfd_x86_elf_size_dynamic_sections
702 #define elf_backend_always_size_sections \
703   _bfd_x86_elf_always_size_sections
704 #define elf_backend_merge_symbol_attribute \
705   _bfd_x86_elf_merge_symbol_attribute
706 #define elf_backend_copy_indirect_symbol \
707   _bfd_x86_elf_copy_indirect_symbol
708 #define elf_backend_fixup_symbol \
709   _bfd_x86_elf_fixup_symbol
710 #define elf_backend_hash_symbol \
711   _bfd_x86_elf_hash_symbol
712 #define elf_backend_adjust_dynamic_symbol \
713   _bfd_x86_elf_adjust_dynamic_symbol
714 #define elf_backend_gc_mark_hook \
715   _bfd_x86_elf_gc_mark_hook
716 #define elf_backend_omit_section_dynsym \
717   _bfd_elf_omit_section_dynsym_all
718 #define elf_backend_parse_gnu_properties \
719   _bfd_x86_elf_parse_gnu_properties
720 #define elf_backend_merge_gnu_properties \
721   _bfd_x86_elf_merge_gnu_properties
722 #define elf_backend_fixup_gnu_properties \
723   _bfd_x86_elf_link_fixup_gnu_properties
724