* elf32-i386.c (elf_i386_relocate_section): When generating a
[deliverable/binutils-gdb.git] / bfd / elf32-i386.c
1 /* Intel 80386/80486-specific support for 32-bit ELF
2 Copyright 1993, 1994, 1995, 1996, 1997 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 2 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
19
20 #include "bfd.h"
21 #include "sysdep.h"
22 #include "bfdlink.h"
23 #include "libbfd.h"
24 #include "elf-bfd.h"
25
26 static reloc_howto_type *elf_i386_reloc_type_lookup
27 PARAMS ((bfd *, bfd_reloc_code_real_type));
28 static void elf_i386_info_to_howto
29 PARAMS ((bfd *, arelent *, Elf32_Internal_Rela *));
30 static void elf_i386_info_to_howto_rel
31 PARAMS ((bfd *, arelent *, Elf32_Internal_Rel *));
32 static boolean elf_i386_is_local_label_name PARAMS ((bfd *, const char *));
33 static struct bfd_hash_entry *elf_i386_link_hash_newfunc
34 PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *, const char *));
35 static struct bfd_link_hash_table *elf_i386_link_hash_table_create
36 PARAMS ((bfd *));
37 static boolean elf_i386_check_relocs
38 PARAMS ((bfd *, struct bfd_link_info *, asection *,
39 const Elf_Internal_Rela *));
40 static boolean elf_i386_adjust_dynamic_symbol
41 PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *));
42 static boolean elf_i386_size_dynamic_sections
43 PARAMS ((bfd *, struct bfd_link_info *));
44 static boolean elf_i386_relocate_section
45 PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
46 Elf_Internal_Rela *, Elf_Internal_Sym *, asection **));
47 static boolean elf_i386_finish_dynamic_symbol
48 PARAMS ((bfd *, struct bfd_link_info *, struct elf_link_hash_entry *,
49 Elf_Internal_Sym *));
50 static boolean elf_i386_finish_dynamic_sections
51 PARAMS ((bfd *, struct bfd_link_info *));
52
53 #define USE_REL 1 /* 386 uses REL relocations instead of RELA */
54
55 enum reloc_type
56 {
57 R_386_NONE = 0,
58 R_386_32,
59 R_386_PC32,
60 R_386_GOT32,
61 R_386_PLT32,
62 R_386_COPY,
63 R_386_GLOB_DAT,
64 R_386_JUMP_SLOT,
65 R_386_RELATIVE,
66 R_386_GOTOFF,
67 R_386_GOTPC,
68 FIRST_INVALID_RELOC,
69 LAST_INVALID_RELOC = 19,
70 /* The remaining relocs are a GNU extension. */
71 R_386_16 = 20,
72 R_386_PC16,
73 R_386_8,
74 R_386_PC8,
75 R_386_max
76 };
77
78 #if 0
79 static CONST char *CONST reloc_type_names[] =
80 {
81 "R_386_NONE",
82 "R_386_32",
83 "R_386_PC32",
84 "R_386_GOT32",
85 "R_386_PLT32",
86 "R_386_COPY",
87 "R_386_GLOB_DAT",
88 "R_386_JUMP_SLOT",
89 "R_386_RELATIVE",
90 "R_386_GOTOFF",
91 "R_386_GOTPC",
92 };
93 #endif
94
95 static reloc_howto_type elf_howto_table[]=
96 {
97 HOWTO(R_386_NONE, 0,0, 0,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_NONE", true,0x00000000,0x00000000,false),
98 HOWTO(R_386_32, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_32", true,0xffffffff,0xffffffff,false),
99 HOWTO(R_386_PC32, 0,2,32,true, 0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_PC32", true,0xffffffff,0xffffffff,true),
100 HOWTO(R_386_GOT32, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_GOT32", true,0xffffffff,0xffffffff,false),
101 HOWTO(R_386_PLT32, 0,2,32,true,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_PLT32", true,0xffffffff,0xffffffff,true),
102 HOWTO(R_386_COPY, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_COPY", true,0xffffffff,0xffffffff,false),
103 HOWTO(R_386_GLOB_DAT, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_GLOB_DAT", true,0xffffffff,0xffffffff,false),
104 HOWTO(R_386_JUMP_SLOT, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_JUMP_SLOT",true,0xffffffff,0xffffffff,false),
105 HOWTO(R_386_RELATIVE, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_RELATIVE", true,0xffffffff,0xffffffff,false),
106 HOWTO(R_386_GOTOFF, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_GOTOFF", true,0xffffffff,0xffffffff,false),
107 HOWTO(R_386_GOTPC, 0,2,32,true,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_GOTPC", true,0xffffffff,0xffffffff,true),
108 { 11 },
109 { 12 },
110 { 13 },
111 { 14 },
112 { 15 },
113 { 16 },
114 { 17 },
115 { 18 },
116 { 19 },
117 /* The remaining relocs are a GNU extension. */
118 HOWTO(R_386_16, 0,1,16,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_16", true,0xffff,0xffff,false),
119 HOWTO(R_386_PC16, 0,1,16,true, 0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_PC16", true,0xffff,0xffff,true),
120 HOWTO(R_386_8, 0,0,8,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_8", true,0xff,0xff,false),
121 HOWTO(R_386_PC8, 0,0,8,true, 0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_PC8", true,0xff,0xff,true),
122 };
123
124 #ifdef DEBUG_GEN_RELOC
125 #define TRACE(str) fprintf (stderr, "i386 bfd reloc lookup %d (%s)\n", code, str)
126 #else
127 #define TRACE(str)
128 #endif
129
130 static reloc_howto_type *
131 elf_i386_reloc_type_lookup (abfd, code)
132 bfd *abfd;
133 bfd_reloc_code_real_type code;
134 {
135 switch (code)
136 {
137 case BFD_RELOC_NONE:
138 TRACE ("BFD_RELOC_NONE");
139 return &elf_howto_table[ (int)R_386_NONE ];
140
141 case BFD_RELOC_32:
142 TRACE ("BFD_RELOC_32");
143 return &elf_howto_table[ (int)R_386_32 ];
144
145 case BFD_RELOC_32_PCREL:
146 TRACE ("BFD_RELOC_PC32");
147 return &elf_howto_table[ (int)R_386_PC32 ];
148
149 case BFD_RELOC_386_GOT32:
150 TRACE ("BFD_RELOC_386_GOT32");
151 return &elf_howto_table[ (int)R_386_GOT32 ];
152
153 case BFD_RELOC_386_PLT32:
154 TRACE ("BFD_RELOC_386_PLT32");
155 return &elf_howto_table[ (int)R_386_PLT32 ];
156
157 case BFD_RELOC_386_COPY:
158 TRACE ("BFD_RELOC_386_COPY");
159 return &elf_howto_table[ (int)R_386_COPY ];
160
161 case BFD_RELOC_386_GLOB_DAT:
162 TRACE ("BFD_RELOC_386_GLOB_DAT");
163 return &elf_howto_table[ (int)R_386_GLOB_DAT ];
164
165 case BFD_RELOC_386_JUMP_SLOT:
166 TRACE ("BFD_RELOC_386_JUMP_SLOT");
167 return &elf_howto_table[ (int)R_386_JUMP_SLOT ];
168
169 case BFD_RELOC_386_RELATIVE:
170 TRACE ("BFD_RELOC_386_RELATIVE");
171 return &elf_howto_table[ (int)R_386_RELATIVE ];
172
173 case BFD_RELOC_386_GOTOFF:
174 TRACE ("BFD_RELOC_386_GOTOFF");
175 return &elf_howto_table[ (int)R_386_GOTOFF ];
176
177 case BFD_RELOC_386_GOTPC:
178 TRACE ("BFD_RELOC_386_GOTPC");
179 return &elf_howto_table[ (int)R_386_GOTPC ];
180
181 /* The remaining relocs are a GNU extension. */
182 case BFD_RELOC_16:
183 TRACE ("BFD_RELOC_16");
184 return &elf_howto_table[(int) R_386_16];
185
186 case BFD_RELOC_16_PCREL:
187 TRACE ("BFD_RELOC_16_PCREL");
188 return &elf_howto_table[(int) R_386_PC16];
189
190 case BFD_RELOC_8:
191 TRACE ("BFD_RELOC_8");
192 return &elf_howto_table[(int) R_386_8];
193
194 case BFD_RELOC_8_PCREL:
195 TRACE ("BFD_RELOC_8_PCREL");
196 return &elf_howto_table[(int) R_386_PC8];
197
198 default:
199 break;
200 }
201
202 TRACE ("Unknown");
203 return 0;
204 }
205
206 static void
207 elf_i386_info_to_howto (abfd, cache_ptr, dst)
208 bfd *abfd;
209 arelent *cache_ptr;
210 Elf32_Internal_Rela *dst;
211 {
212 abort ();
213 }
214
215 static void
216 elf_i386_info_to_howto_rel (abfd, cache_ptr, dst)
217 bfd *abfd;
218 arelent *cache_ptr;
219 Elf32_Internal_Rel *dst;
220 {
221 enum reloc_type type;
222
223 type = (enum reloc_type) ELF32_R_TYPE (dst->r_info);
224 BFD_ASSERT (type < R_386_max);
225 BFD_ASSERT (type < FIRST_INVALID_RELOC || type > LAST_INVALID_RELOC);
226
227 cache_ptr->howto = &elf_howto_table[(int) type];
228 }
229
230 /* Return whether a symbol name implies a local label. The UnixWare
231 2.1 cc generates temporary symbols that start with .X, so we
232 recognize them here. FIXME: do other SVR4 compilers also use .X?.
233 If so, we should move the .X recognition into
234 _bfd_elf_is_local_label_name. */
235
236 static boolean
237 elf_i386_is_local_label_name (abfd, name)
238 bfd *abfd;
239 const char *name;
240 {
241 if (name[0] == '.' && name[1] == 'X')
242 return true;
243
244 return _bfd_elf_is_local_label_name (abfd, name);
245 }
246 \f
247 /* Functions for the i386 ELF linker. */
248
249 /* The name of the dynamic interpreter. This is put in the .interp
250 section. */
251
252 #define ELF_DYNAMIC_INTERPRETER "/usr/lib/libc.so.1"
253
254 /* The size in bytes of an entry in the procedure linkage table. */
255
256 #define PLT_ENTRY_SIZE 16
257
258 /* The first entry in an absolute procedure linkage table looks like
259 this. See the SVR4 ABI i386 supplement to see how this works. */
260
261 static const bfd_byte elf_i386_plt0_entry[PLT_ENTRY_SIZE] =
262 {
263 0xff, 0x35, /* pushl contents of address */
264 0, 0, 0, 0, /* replaced with address of .got + 4. */
265 0xff, 0x25, /* jmp indirect */
266 0, 0, 0, 0, /* replaced with address of .got + 8. */
267 0, 0, 0, 0 /* pad out to 16 bytes. */
268 };
269
270 /* Subsequent entries in an absolute procedure linkage table look like
271 this. */
272
273 static const bfd_byte elf_i386_plt_entry[PLT_ENTRY_SIZE] =
274 {
275 0xff, 0x25, /* jmp indirect */
276 0, 0, 0, 0, /* replaced with address of this symbol in .got. */
277 0x68, /* pushl immediate */
278 0, 0, 0, 0, /* replaced with offset into relocation table. */
279 0xe9, /* jmp relative */
280 0, 0, 0, 0 /* replaced with offset to start of .plt. */
281 };
282
283 /* The first entry in a PIC procedure linkage table look like this. */
284
285 static const bfd_byte elf_i386_pic_plt0_entry[PLT_ENTRY_SIZE] =
286 {
287 0xff, 0xb3, 4, 0, 0, 0, /* pushl 4(%ebx) */
288 0xff, 0xa3, 8, 0, 0, 0, /* jmp *8(%ebx) */
289 0, 0, 0, 0 /* pad out to 16 bytes. */
290 };
291
292 /* Subsequent entries in a PIC procedure linkage table look like this. */
293
294 static const bfd_byte elf_i386_pic_plt_entry[PLT_ENTRY_SIZE] =
295 {
296 0xff, 0xa3, /* jmp *offset(%ebx) */
297 0, 0, 0, 0, /* replaced with offset of this symbol in .got. */
298 0x68, /* pushl immediate */
299 0, 0, 0, 0, /* replaced with offset into relocation table. */
300 0xe9, /* jmp relative */
301 0, 0, 0, 0 /* replaced with offset to start of .plt. */
302 };
303
304 /* The i386 linker needs to keep track of the number of relocs that it
305 decides to copy in check_relocs for each symbol. This is so that
306 it can discard PC relative relocs if it doesn't need them when
307 linking with -Bsymbolic. We store the information in a field
308 extending the regular ELF linker hash table. */
309
310 /* This structure keeps track of the number of PC relative relocs we
311 have copied for a given symbol. */
312
313 struct elf_i386_pcrel_relocs_copied
314 {
315 /* Next section. */
316 struct elf_i386_pcrel_relocs_copied *next;
317 /* A section in dynobj. */
318 asection *section;
319 /* Number of relocs copied in this section. */
320 bfd_size_type count;
321 };
322
323 /* i386 ELF linker hash entry. */
324
325 struct elf_i386_link_hash_entry
326 {
327 struct elf_link_hash_entry root;
328
329 /* Number of PC relative relocs copied for this symbol. */
330 struct elf_i386_pcrel_relocs_copied *pcrel_relocs_copied;
331 };
332
333 /* i386 ELF linker hash table. */
334
335 struct elf_i386_link_hash_table
336 {
337 struct elf_link_hash_table root;
338 };
339
340 /* Declare this now that the above structures are defined. */
341
342 static boolean elf_i386_discard_copies
343 PARAMS ((struct elf_i386_link_hash_entry *, PTR));
344
345 /* Traverse an i386 ELF linker hash table. */
346
347 #define elf_i386_link_hash_traverse(table, func, info) \
348 (elf_link_hash_traverse \
349 (&(table)->root, \
350 (boolean (*) PARAMS ((struct elf_link_hash_entry *, PTR))) (func), \
351 (info)))
352
353 /* Get the i386 ELF linker hash table from a link_info structure. */
354
355 #define elf_i386_hash_table(p) \
356 ((struct elf_i386_link_hash_table *) ((p)->hash))
357
358 /* Create an entry in an i386 ELF linker hash table. */
359
360 static struct bfd_hash_entry *
361 elf_i386_link_hash_newfunc (entry, table, string)
362 struct bfd_hash_entry *entry;
363 struct bfd_hash_table *table;
364 const char *string;
365 {
366 struct elf_i386_link_hash_entry *ret =
367 (struct elf_i386_link_hash_entry *) entry;
368
369 /* Allocate the structure if it has not already been allocated by a
370 subclass. */
371 if (ret == (struct elf_i386_link_hash_entry *) NULL)
372 ret = ((struct elf_i386_link_hash_entry *)
373 bfd_hash_allocate (table,
374 sizeof (struct elf_i386_link_hash_entry)));
375 if (ret == (struct elf_i386_link_hash_entry *) NULL)
376 return (struct bfd_hash_entry *) ret;
377
378 /* Call the allocation method of the superclass. */
379 ret = ((struct elf_i386_link_hash_entry *)
380 _bfd_elf_link_hash_newfunc ((struct bfd_hash_entry *) ret,
381 table, string));
382 if (ret != (struct elf_i386_link_hash_entry *) NULL)
383 {
384 ret->pcrel_relocs_copied = NULL;
385 }
386
387 return (struct bfd_hash_entry *) ret;
388 }
389
390 /* Create an i386 ELF linker hash table. */
391
392 static struct bfd_link_hash_table *
393 elf_i386_link_hash_table_create (abfd)
394 bfd *abfd;
395 {
396 struct elf_i386_link_hash_table *ret;
397
398 ret = ((struct elf_i386_link_hash_table *)
399 bfd_alloc (abfd, sizeof (struct elf_i386_link_hash_table)));
400 if (ret == (struct elf_i386_link_hash_table *) NULL)
401 return NULL;
402
403 if (! _bfd_elf_link_hash_table_init (&ret->root, abfd,
404 elf_i386_link_hash_newfunc))
405 {
406 bfd_release (abfd, ret);
407 return NULL;
408 }
409
410 return &ret->root.root;
411 }
412
413 /* Look through the relocs for a section during the first phase, and
414 allocate space in the global offset table or procedure linkage
415 table. */
416
417 static boolean
418 elf_i386_check_relocs (abfd, info, sec, relocs)
419 bfd *abfd;
420 struct bfd_link_info *info;
421 asection *sec;
422 const Elf_Internal_Rela *relocs;
423 {
424 bfd *dynobj;
425 Elf_Internal_Shdr *symtab_hdr;
426 struct elf_link_hash_entry **sym_hashes;
427 bfd_vma *local_got_offsets;
428 const Elf_Internal_Rela *rel;
429 const Elf_Internal_Rela *rel_end;
430 asection *sgot;
431 asection *srelgot;
432 asection *sreloc;
433
434 if (info->relocateable)
435 return true;
436
437 dynobj = elf_hash_table (info)->dynobj;
438 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
439 sym_hashes = elf_sym_hashes (abfd);
440 local_got_offsets = elf_local_got_offsets (abfd);
441
442 sgot = NULL;
443 srelgot = NULL;
444 sreloc = NULL;
445
446 rel_end = relocs + sec->reloc_count;
447 for (rel = relocs; rel < rel_end; rel++)
448 {
449 unsigned long r_symndx;
450 struct elf_link_hash_entry *h;
451
452 r_symndx = ELF32_R_SYM (rel->r_info);
453
454 if (r_symndx < symtab_hdr->sh_info)
455 h = NULL;
456 else
457 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
458
459 /* Some relocs require a global offset table. */
460 if (dynobj == NULL)
461 {
462 switch (ELF32_R_TYPE (rel->r_info))
463 {
464 case R_386_GOT32:
465 case R_386_GOTOFF:
466 case R_386_GOTPC:
467 elf_hash_table (info)->dynobj = dynobj = abfd;
468 if (! _bfd_elf_create_got_section (dynobj, info))
469 return false;
470 break;
471
472 default:
473 break;
474 }
475 }
476
477 switch (ELF32_R_TYPE (rel->r_info))
478 {
479 case R_386_GOT32:
480 /* This symbol requires a global offset table entry. */
481
482 if (sgot == NULL)
483 {
484 sgot = bfd_get_section_by_name (dynobj, ".got");
485 BFD_ASSERT (sgot != NULL);
486 }
487
488 if (srelgot == NULL
489 && (h != NULL || info->shared))
490 {
491 srelgot = bfd_get_section_by_name (dynobj, ".rel.got");
492 if (srelgot == NULL)
493 {
494 srelgot = bfd_make_section (dynobj, ".rel.got");
495 if (srelgot == NULL
496 || ! bfd_set_section_flags (dynobj, srelgot,
497 (SEC_ALLOC
498 | SEC_LOAD
499 | SEC_HAS_CONTENTS
500 | SEC_IN_MEMORY
501 | SEC_LINKER_CREATED
502 | SEC_READONLY))
503 || ! bfd_set_section_alignment (dynobj, srelgot, 2))
504 return false;
505 }
506 }
507
508 if (h != NULL)
509 {
510 if (h->got_offset != (bfd_vma) -1)
511 {
512 /* We have already allocated space in the .got. */
513 break;
514 }
515 h->got_offset = sgot->_raw_size;
516
517 /* Make sure this symbol is output as a dynamic symbol. */
518 if (h->dynindx == -1)
519 {
520 if (! bfd_elf32_link_record_dynamic_symbol (info, h))
521 return false;
522 }
523
524 srelgot->_raw_size += sizeof (Elf32_External_Rel);
525 }
526 else
527 {
528 /* This is a global offset table entry for a local
529 symbol. */
530 if (local_got_offsets == NULL)
531 {
532 size_t size;
533 register unsigned int i;
534
535 size = symtab_hdr->sh_info * sizeof (bfd_vma);
536 local_got_offsets = (bfd_vma *) bfd_alloc (abfd, size);
537 if (local_got_offsets == NULL)
538 return false;
539 elf_local_got_offsets (abfd) = local_got_offsets;
540 for (i = 0; i < symtab_hdr->sh_info; i++)
541 local_got_offsets[i] = (bfd_vma) -1;
542 }
543 if (local_got_offsets[r_symndx] != (bfd_vma) -1)
544 {
545 /* We have already allocated space in the .got. */
546 break;
547 }
548 local_got_offsets[r_symndx] = sgot->_raw_size;
549
550 if (info->shared)
551 {
552 /* If we are generating a shared object, we need to
553 output a R_386_RELATIVE reloc so that the dynamic
554 linker can adjust this GOT entry. */
555 srelgot->_raw_size += sizeof (Elf32_External_Rel);
556 }
557 }
558
559 sgot->_raw_size += 4;
560
561 break;
562
563 case R_386_PLT32:
564 /* This symbol requires a procedure linkage table entry. We
565 actually build the entry in adjust_dynamic_symbol,
566 because this might be a case of linking PIC code which is
567 never referenced by a dynamic object, in which case we
568 don't need to generate a procedure linkage table entry
569 after all. */
570
571 /* If this is a local symbol, we resolve it directly without
572 creating a procedure linkage table entry. */
573 if (h == NULL)
574 continue;
575
576 h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_PLT;
577
578 break;
579
580 case R_386_32:
581 case R_386_PC32:
582 /* If we are creating a shared library, and this is a reloc
583 against a global symbol, or a non PC relative reloc
584 against a local symbol, then we need to copy the reloc
585 into the shared library. However, if we are linking with
586 -Bsymbolic, we do not need to copy a reloc against a
587 global symbol which is defined in an object we are
588 including in the link (i.e., DEF_REGULAR is set). At
589 this point we have not seen all the input files, so it is
590 possible that DEF_REGULAR is not set now but will be set
591 later (it is never cleared). We account for that
592 possibility below by storing information in the
593 pcrel_relocs_copied field of the hash table entry. */
594 if (info->shared
595 && (ELF32_R_TYPE (rel->r_info) != R_386_PC32
596 || (h != NULL
597 && (! info->symbolic
598 || (h->elf_link_hash_flags
599 & ELF_LINK_HASH_DEF_REGULAR) == 0))))
600 {
601 /* When creating a shared object, we must copy these
602 reloc types into the output file. We create a reloc
603 section in dynobj and make room for this reloc. */
604 if (sreloc == NULL)
605 {
606 const char *name;
607
608 name = (bfd_elf_string_from_elf_section
609 (abfd,
610 elf_elfheader (abfd)->e_shstrndx,
611 elf_section_data (sec)->rel_hdr.sh_name));
612 if (name == NULL)
613 return false;
614
615 BFD_ASSERT (strncmp (name, ".rel", 4) == 0
616 && strcmp (bfd_get_section_name (abfd, sec),
617 name + 4) == 0);
618
619 sreloc = bfd_get_section_by_name (dynobj, name);
620 if (sreloc == NULL)
621 {
622 flagword flags;
623
624 sreloc = bfd_make_section (dynobj, name);
625 flags = (SEC_HAS_CONTENTS | SEC_READONLY
626 | SEC_IN_MEMORY | SEC_LINKER_CREATED);
627 if ((sec->flags & SEC_ALLOC) != 0)
628 flags |= SEC_ALLOC | SEC_LOAD;
629 if (sreloc == NULL
630 || ! bfd_set_section_flags (dynobj, sreloc, flags)
631 || ! bfd_set_section_alignment (dynobj, sreloc, 2))
632 return false;
633 }
634 }
635
636 sreloc->_raw_size += sizeof (Elf32_External_Rel);
637
638 /* If we are linking with -Bsymbolic, and this is a
639 global symbol, we count the number of PC relative
640 relocations we have entered for this symbol, so that
641 we can discard them again if the symbol is later
642 defined by a regular object. Note that this function
643 is only called if we are using an elf_i386 linker
644 hash table, which means that h is really a pointer to
645 an elf_i386_link_hash_entry. */
646 if (h != NULL && info->symbolic
647 && ELF32_R_TYPE (rel->r_info) == R_386_PC32)
648 {
649 struct elf_i386_link_hash_entry *eh;
650 struct elf_i386_pcrel_relocs_copied *p;
651
652 eh = (struct elf_i386_link_hash_entry *) h;
653
654 for (p = eh->pcrel_relocs_copied; p != NULL; p = p->next)
655 if (p->section == sreloc)
656 break;
657
658 if (p == NULL)
659 {
660 p = ((struct elf_i386_pcrel_relocs_copied *)
661 bfd_alloc (dynobj, sizeof *p));
662 if (p == NULL)
663 return false;
664 p->next = eh->pcrel_relocs_copied;
665 eh->pcrel_relocs_copied = p;
666 p->section = sreloc;
667 p->count = 0;
668 }
669
670 ++p->count;
671 }
672 }
673
674 break;
675
676 default:
677 break;
678 }
679 }
680
681 return true;
682 }
683
684 /* Adjust a symbol defined by a dynamic object and referenced by a
685 regular object. The current definition is in some section of the
686 dynamic object, but we're not including those sections. We have to
687 change the definition to something the rest of the link can
688 understand. */
689
690 static boolean
691 elf_i386_adjust_dynamic_symbol (info, h)
692 struct bfd_link_info *info;
693 struct elf_link_hash_entry *h;
694 {
695 bfd *dynobj;
696 asection *s;
697 unsigned int power_of_two;
698
699 dynobj = elf_hash_table (info)->dynobj;
700
701 /* Make sure we know what is going on here. */
702 BFD_ASSERT (dynobj != NULL
703 && ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT)
704 || h->weakdef != NULL
705 || ((h->elf_link_hash_flags
706 & ELF_LINK_HASH_DEF_DYNAMIC) != 0
707 && (h->elf_link_hash_flags
708 & ELF_LINK_HASH_REF_REGULAR) != 0
709 && (h->elf_link_hash_flags
710 & ELF_LINK_HASH_DEF_REGULAR) == 0)));
711
712 /* If this is a function, put it in the procedure linkage table. We
713 will fill in the contents of the procedure linkage table later,
714 when we know the address of the .got section. */
715 if (h->type == STT_FUNC
716 || (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0)
717 {
718 if (! info->shared
719 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
720 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) == 0)
721 {
722 /* This case can occur if we saw a PLT32 reloc in an input
723 file, but the symbol was never referred to by a dynamic
724 object. In such a case, we don't actually need to build
725 a procedure linkage table, and we can just do a PC32
726 reloc instead. */
727 BFD_ASSERT ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0);
728 return true;
729 }
730
731 /* Make sure this symbol is output as a dynamic symbol. */
732 if (h->dynindx == -1)
733 {
734 if (! bfd_elf32_link_record_dynamic_symbol (info, h))
735 return false;
736 }
737
738 s = bfd_get_section_by_name (dynobj, ".plt");
739 BFD_ASSERT (s != NULL);
740
741 /* If this is the first .plt entry, make room for the special
742 first entry. */
743 if (s->_raw_size == 0)
744 s->_raw_size += PLT_ENTRY_SIZE;
745
746 /* If this symbol is not defined in a regular file, and we are
747 not generating a shared library, then set the symbol to this
748 location in the .plt. This is required to make function
749 pointers compare as equal between the normal executable and
750 the shared library. */
751 if (! info->shared
752 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
753 {
754 h->root.u.def.section = s;
755 h->root.u.def.value = s->_raw_size;
756 }
757
758 h->plt_offset = s->_raw_size;
759
760 /* Make room for this entry. */
761 s->_raw_size += PLT_ENTRY_SIZE;
762
763 /* We also need to make an entry in the .got.plt section, which
764 will be placed in the .got section by the linker script. */
765
766 s = bfd_get_section_by_name (dynobj, ".got.plt");
767 BFD_ASSERT (s != NULL);
768 s->_raw_size += 4;
769
770 /* We also need to make an entry in the .rel.plt section. */
771
772 s = bfd_get_section_by_name (dynobj, ".rel.plt");
773 BFD_ASSERT (s != NULL);
774 s->_raw_size += sizeof (Elf32_External_Rel);
775
776 return true;
777 }
778
779 /* If this is a weak symbol, and there is a real definition, the
780 processor independent code will have arranged for us to see the
781 real definition first, and we can just use the same value. */
782 if (h->weakdef != NULL)
783 {
784 BFD_ASSERT (h->weakdef->root.type == bfd_link_hash_defined
785 || h->weakdef->root.type == bfd_link_hash_defweak);
786 h->root.u.def.section = h->weakdef->root.u.def.section;
787 h->root.u.def.value = h->weakdef->root.u.def.value;
788 return true;
789 }
790
791 /* This is a reference to a symbol defined by a dynamic object which
792 is not a function. */
793
794 /* If we are creating a shared library, we must presume that the
795 only references to the symbol are via the global offset table.
796 For such cases we need not do anything here; the relocations will
797 be handled correctly by relocate_section. */
798 if (info->shared)
799 return true;
800
801 /* We must allocate the symbol in our .dynbss section, which will
802 become part of the .bss section of the executable. There will be
803 an entry for this symbol in the .dynsym section. The dynamic
804 object will contain position independent code, so all references
805 from the dynamic object to this symbol will go through the global
806 offset table. The dynamic linker will use the .dynsym entry to
807 determine the address it must put in the global offset table, so
808 both the dynamic object and the regular object will refer to the
809 same memory location for the variable. */
810
811 s = bfd_get_section_by_name (dynobj, ".dynbss");
812 BFD_ASSERT (s != NULL);
813
814 /* We must generate a R_386_COPY reloc to tell the dynamic linker to
815 copy the initial value out of the dynamic object and into the
816 runtime process image. We need to remember the offset into the
817 .rel.bss section we are going to use. */
818 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0)
819 {
820 asection *srel;
821
822 srel = bfd_get_section_by_name (dynobj, ".rel.bss");
823 BFD_ASSERT (srel != NULL);
824 srel->_raw_size += sizeof (Elf32_External_Rel);
825 h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_COPY;
826 }
827
828 /* We need to figure out the alignment required for this symbol. I
829 have no idea how ELF linkers handle this. */
830 power_of_two = bfd_log2 (h->size);
831 if (power_of_two > 3)
832 power_of_two = 3;
833
834 /* Apply the required alignment. */
835 s->_raw_size = BFD_ALIGN (s->_raw_size,
836 (bfd_size_type) (1 << power_of_two));
837 if (power_of_two > bfd_get_section_alignment (dynobj, s))
838 {
839 if (! bfd_set_section_alignment (dynobj, s, power_of_two))
840 return false;
841 }
842
843 /* Define the symbol as being at this point in the section. */
844 h->root.u.def.section = s;
845 h->root.u.def.value = s->_raw_size;
846
847 /* Increment the section size to make room for the symbol. */
848 s->_raw_size += h->size;
849
850 return true;
851 }
852
853 /* Set the sizes of the dynamic sections. */
854
855 static boolean
856 elf_i386_size_dynamic_sections (output_bfd, info)
857 bfd *output_bfd;
858 struct bfd_link_info *info;
859 {
860 bfd *dynobj;
861 asection *s;
862 boolean plt;
863 boolean relocs;
864 boolean reltext;
865
866 dynobj = elf_hash_table (info)->dynobj;
867 BFD_ASSERT (dynobj != NULL);
868
869 if (elf_hash_table (info)->dynamic_sections_created)
870 {
871 /* Set the contents of the .interp section to the interpreter. */
872 if (! info->shared)
873 {
874 s = bfd_get_section_by_name (dynobj, ".interp");
875 BFD_ASSERT (s != NULL);
876 s->_raw_size = sizeof ELF_DYNAMIC_INTERPRETER;
877 s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER;
878 }
879 }
880 else
881 {
882 /* We may have created entries in the .rel.got section.
883 However, if we are not creating the dynamic sections, we will
884 not actually use these entries. Reset the size of .rel.got,
885 which will cause it to get stripped from the output file
886 below. */
887 s = bfd_get_section_by_name (dynobj, ".rel.got");
888 if (s != NULL)
889 s->_raw_size = 0;
890 }
891
892 /* If this is a -Bsymbolic shared link, then we need to discard all
893 PC relative relocs against symbols defined in a regular object.
894 We allocated space for them in the check_relocs routine, but we
895 will not fill them in in the relocate_section routine. */
896 if (info->shared && info->symbolic)
897 elf_i386_link_hash_traverse (elf_i386_hash_table (info),
898 elf_i386_discard_copies,
899 (PTR) NULL);
900
901 /* The check_relocs and adjust_dynamic_symbol entry points have
902 determined the sizes of the various dynamic sections. Allocate
903 memory for them. */
904 plt = false;
905 relocs = false;
906 reltext = false;
907 for (s = dynobj->sections; s != NULL; s = s->next)
908 {
909 const char *name;
910 boolean strip;
911
912 if ((s->flags & SEC_LINKER_CREATED) == 0)
913 continue;
914
915 /* It's OK to base decisions on the section name, because none
916 of the dynobj section names depend upon the input files. */
917 name = bfd_get_section_name (dynobj, s);
918
919 strip = false;
920
921 if (strcmp (name, ".plt") == 0)
922 {
923 if (s->_raw_size == 0)
924 {
925 /* Strip this section if we don't need it; see the
926 comment below. */
927 strip = true;
928 }
929 else
930 {
931 /* Remember whether there is a PLT. */
932 plt = true;
933 }
934 }
935 else if (strncmp (name, ".rel", 4) == 0)
936 {
937 if (s->_raw_size == 0)
938 {
939 /* If we don't need this section, strip it from the
940 output file. This is mostly to handle .rel.bss and
941 .rel.plt. We must create both sections in
942 create_dynamic_sections, because they must be created
943 before the linker maps input sections to output
944 sections. The linker does that before
945 adjust_dynamic_symbol is called, and it is that
946 function which decides whether anything needs to go
947 into these sections. */
948 strip = true;
949 }
950 else
951 {
952 asection *target;
953
954 /* Remember whether there are any reloc sections other
955 than .rel.plt. */
956 if (strcmp (name, ".rel.plt") != 0)
957 {
958 const char *outname;
959
960 relocs = true;
961
962 /* If this relocation section applies to a read only
963 section, then we probably need a DT_TEXTREL
964 entry. The entries in the .rel.plt section
965 really apply to the .got section, which we
966 created ourselves and so know is not readonly. */
967 outname = bfd_get_section_name (output_bfd,
968 s->output_section);
969 target = bfd_get_section_by_name (output_bfd, outname + 4);
970 if (target != NULL
971 && (target->flags & SEC_READONLY) != 0)
972 reltext = true;
973 }
974
975 /* We use the reloc_count field as a counter if we need
976 to copy relocs into the output file. */
977 s->reloc_count = 0;
978 }
979 }
980 else if (strncmp (name, ".got", 4) != 0)
981 {
982 /* It's not one of our sections, so don't allocate space. */
983 continue;
984 }
985
986 if (strip)
987 {
988 asection **spp;
989
990 for (spp = &s->output_section->owner->sections;
991 *spp != s->output_section;
992 spp = &(*spp)->next)
993 ;
994 *spp = s->output_section->next;
995 --s->output_section->owner->section_count;
996
997 continue;
998 }
999
1000 /* Allocate memory for the section contents. */
1001 s->contents = (bfd_byte *) bfd_alloc (dynobj, s->_raw_size);
1002 if (s->contents == NULL && s->_raw_size != 0)
1003 return false;
1004 }
1005
1006 if (elf_hash_table (info)->dynamic_sections_created)
1007 {
1008 /* Add some entries to the .dynamic section. We fill in the
1009 values later, in elf_i386_finish_dynamic_sections, but we
1010 must add the entries now so that we get the correct size for
1011 the .dynamic section. The DT_DEBUG entry is filled in by the
1012 dynamic linker and used by the debugger. */
1013 if (! info->shared)
1014 {
1015 if (! bfd_elf32_add_dynamic_entry (info, DT_DEBUG, 0))
1016 return false;
1017 }
1018
1019 if (plt)
1020 {
1021 if (! bfd_elf32_add_dynamic_entry (info, DT_PLTGOT, 0)
1022 || ! bfd_elf32_add_dynamic_entry (info, DT_PLTRELSZ, 0)
1023 || ! bfd_elf32_add_dynamic_entry (info, DT_PLTREL, DT_REL)
1024 || ! bfd_elf32_add_dynamic_entry (info, DT_JMPREL, 0))
1025 return false;
1026 }
1027
1028 if (relocs)
1029 {
1030 if (! bfd_elf32_add_dynamic_entry (info, DT_REL, 0)
1031 || ! bfd_elf32_add_dynamic_entry (info, DT_RELSZ, 0)
1032 || ! bfd_elf32_add_dynamic_entry (info, DT_RELENT,
1033 sizeof (Elf32_External_Rel)))
1034 return false;
1035 }
1036
1037 if (reltext)
1038 {
1039 if (! bfd_elf32_add_dynamic_entry (info, DT_TEXTREL, 0))
1040 return false;
1041 }
1042 }
1043
1044 return true;
1045 }
1046
1047 /* This function is called via elf_i386_link_hash_traverse if we are
1048 creating a shared object with -Bsymbolic. It discards the space
1049 allocated to copy PC relative relocs against symbols which are
1050 defined in regular objects. We allocated space for them in the
1051 check_relocs routine, but we won't fill them in in the
1052 relocate_section routine. */
1053
1054 /*ARGSUSED*/
1055 static boolean
1056 elf_i386_discard_copies (h, ignore)
1057 struct elf_i386_link_hash_entry *h;
1058 PTR ignore;
1059 {
1060 struct elf_i386_pcrel_relocs_copied *s;
1061
1062 /* We only discard relocs for symbols defined in a regular object. */
1063 if ((h->root.elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
1064 return true;
1065
1066 for (s = h->pcrel_relocs_copied; s != NULL; s = s->next)
1067 s->section->_raw_size -= s->count * sizeof (Elf32_External_Rel);
1068
1069 return true;
1070 }
1071
1072 /* Relocate an i386 ELF section. */
1073
1074 static boolean
1075 elf_i386_relocate_section (output_bfd, info, input_bfd, input_section,
1076 contents, relocs, local_syms, local_sections)
1077 bfd *output_bfd;
1078 struct bfd_link_info *info;
1079 bfd *input_bfd;
1080 asection *input_section;
1081 bfd_byte *contents;
1082 Elf_Internal_Rela *relocs;
1083 Elf_Internal_Sym *local_syms;
1084 asection **local_sections;
1085 {
1086 bfd *dynobj;
1087 Elf_Internal_Shdr *symtab_hdr;
1088 struct elf_link_hash_entry **sym_hashes;
1089 bfd_vma *local_got_offsets;
1090 asection *sgot;
1091 asection *splt;
1092 asection *sreloc;
1093 Elf_Internal_Rela *rel;
1094 Elf_Internal_Rela *relend;
1095
1096 dynobj = elf_hash_table (info)->dynobj;
1097 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
1098 sym_hashes = elf_sym_hashes (input_bfd);
1099 local_got_offsets = elf_local_got_offsets (input_bfd);
1100
1101 sgot = NULL;
1102 splt = NULL;
1103 sreloc = NULL;
1104
1105 rel = relocs;
1106 relend = relocs + input_section->reloc_count;
1107 for (; rel < relend; rel++)
1108 {
1109 int r_type;
1110 reloc_howto_type *howto;
1111 unsigned long r_symndx;
1112 struct elf_link_hash_entry *h;
1113 Elf_Internal_Sym *sym;
1114 asection *sec;
1115 bfd_vma relocation;
1116 bfd_reloc_status_type r;
1117
1118 r_type = ELF32_R_TYPE (rel->r_info);
1119 if (r_type < 0
1120 || r_type >= (int) R_386_max
1121 || (r_type >= (int) FIRST_INVALID_RELOC
1122 && r_type <= (int) LAST_INVALID_RELOC))
1123 {
1124 bfd_set_error (bfd_error_bad_value);
1125 return false;
1126 }
1127 howto = elf_howto_table + r_type;
1128
1129 r_symndx = ELF32_R_SYM (rel->r_info);
1130
1131 if (info->relocateable)
1132 {
1133 /* This is a relocateable link. We don't have to change
1134 anything, unless the reloc is against a section symbol,
1135 in which case we have to adjust according to where the
1136 section symbol winds up in the output section. */
1137 if (r_symndx < symtab_hdr->sh_info)
1138 {
1139 sym = local_syms + r_symndx;
1140 if (ELF_ST_TYPE (sym->st_info) == STT_SECTION)
1141 {
1142 bfd_vma val;
1143
1144 sec = local_sections[r_symndx];
1145 val = bfd_get_32 (input_bfd, contents + rel->r_offset);
1146 val += sec->output_offset + sym->st_value;
1147 bfd_put_32 (input_bfd, val, contents + rel->r_offset);
1148 }
1149 }
1150
1151 continue;
1152 }
1153
1154 /* This is a final link. */
1155 h = NULL;
1156 sym = NULL;
1157 sec = NULL;
1158 if (r_symndx < symtab_hdr->sh_info)
1159 {
1160 sym = local_syms + r_symndx;
1161 sec = local_sections[r_symndx];
1162 relocation = (sec->output_section->vma
1163 + sec->output_offset
1164 + sym->st_value);
1165 }
1166 else
1167 {
1168 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
1169 while (h->root.type == bfd_link_hash_indirect
1170 || h->root.type == bfd_link_hash_warning)
1171 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1172 if (h->root.type == bfd_link_hash_defined
1173 || h->root.type == bfd_link_hash_defweak)
1174 {
1175 sec = h->root.u.def.section;
1176 if (r_type == R_386_GOTPC
1177 || (r_type == R_386_PLT32
1178 && h->plt_offset != (bfd_vma) -1)
1179 || (r_type == R_386_GOT32
1180 && elf_hash_table (info)->dynamic_sections_created
1181 && (! info->shared
1182 || (! info->symbolic && h->dynindx != -1)
1183 || (h->elf_link_hash_flags
1184 & ELF_LINK_HASH_DEF_REGULAR) == 0))
1185 || (info->shared
1186 && ((! info->symbolic && h->dynindx != -1)
1187 || (h->elf_link_hash_flags
1188 & ELF_LINK_HASH_DEF_REGULAR) == 0)
1189 && (r_type == R_386_32
1190 || r_type == R_386_PC32)
1191 && (input_section->flags & SEC_ALLOC) != 0))
1192 {
1193 /* In these cases, we don't need the relocation
1194 value. We check specially because in some
1195 obscure cases sec->output_section will be NULL. */
1196 relocation = 0;
1197 }
1198 else if (sec->output_section == NULL)
1199 {
1200 (*_bfd_error_handler)
1201 ("%s: warning: unresolvable relocation against symbol `%s' from %s section",
1202 bfd_get_filename (input_bfd), h->root.root.string,
1203 bfd_get_section_name (input_bfd, input_section));
1204 relocation = 0;
1205 }
1206 else
1207 relocation = (h->root.u.def.value
1208 + sec->output_section->vma
1209 + sec->output_offset);
1210 }
1211 else if (h->root.type == bfd_link_hash_undefweak)
1212 relocation = 0;
1213 else if (info->shared && !info->symbolic)
1214 relocation = 0;
1215 else
1216 {
1217 if (! ((*info->callbacks->undefined_symbol)
1218 (info, h->root.root.string, input_bfd,
1219 input_section, rel->r_offset)))
1220 return false;
1221 relocation = 0;
1222 }
1223 }
1224
1225 switch (r_type)
1226 {
1227 case R_386_GOT32:
1228 /* Relocation is to the entry for this symbol in the global
1229 offset table. */
1230 if (sgot == NULL)
1231 {
1232 sgot = bfd_get_section_by_name (dynobj, ".got");
1233 BFD_ASSERT (sgot != NULL);
1234 }
1235
1236 if (h != NULL)
1237 {
1238 bfd_vma off;
1239
1240 off = h->got_offset;
1241 BFD_ASSERT (off != (bfd_vma) -1);
1242
1243 if (! elf_hash_table (info)->dynamic_sections_created
1244 || (info->shared
1245 && (info->symbolic || h->dynindx == -1)
1246 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
1247 {
1248 /* This is actually a static link, or it is a
1249 -Bsymbolic link and the symbol is defined
1250 locally, or the symbol was forced to be local
1251 because of a version file. We must initialize
1252 this entry in the global offset table. Since the
1253 offset must always be a multiple of 4, we use the
1254 least significant bit to record whether we have
1255 initialized it already.
1256
1257 When doing a dynamic link, we create a .rel.got
1258 relocation entry to initialize the value. This
1259 is done in the finish_dynamic_symbol routine. */
1260 if ((off & 1) != 0)
1261 off &= ~1;
1262 else
1263 {
1264 bfd_put_32 (output_bfd, relocation,
1265 sgot->contents + off);
1266 h->got_offset |= 1;
1267 }
1268 }
1269
1270 relocation = sgot->output_offset + off;
1271 }
1272 else
1273 {
1274 bfd_vma off;
1275
1276 BFD_ASSERT (local_got_offsets != NULL
1277 && local_got_offsets[r_symndx] != (bfd_vma) -1);
1278
1279 off = local_got_offsets[r_symndx];
1280
1281 /* The offset must always be a multiple of 4. We use
1282 the least significant bit to record whether we have
1283 already generated the necessary reloc. */
1284 if ((off & 1) != 0)
1285 off &= ~1;
1286 else
1287 {
1288 bfd_put_32 (output_bfd, relocation, sgot->contents + off);
1289
1290 if (info->shared)
1291 {
1292 asection *srelgot;
1293 Elf_Internal_Rel outrel;
1294
1295 srelgot = bfd_get_section_by_name (dynobj, ".rel.got");
1296 BFD_ASSERT (srelgot != NULL);
1297
1298 outrel.r_offset = (sgot->output_section->vma
1299 + sgot->output_offset
1300 + off);
1301 outrel.r_info = ELF32_R_INFO (0, R_386_RELATIVE);
1302 bfd_elf32_swap_reloc_out (output_bfd, &outrel,
1303 (((Elf32_External_Rel *)
1304 srelgot->contents)
1305 + srelgot->reloc_count));
1306 ++srelgot->reloc_count;
1307 }
1308
1309 local_got_offsets[r_symndx] |= 1;
1310 }
1311
1312 relocation = sgot->output_offset + off;
1313 }
1314
1315 break;
1316
1317 case R_386_GOTOFF:
1318 /* Relocation is relative to the start of the global offset
1319 table. */
1320
1321 if (sgot == NULL)
1322 {
1323 sgot = bfd_get_section_by_name (dynobj, ".got");
1324 BFD_ASSERT (sgot != NULL);
1325 }
1326
1327 /* Note that sgot->output_offset is not involved in this
1328 calculation. We always want the start of .got. If we
1329 defined _GLOBAL_OFFSET_TABLE in a different way, as is
1330 permitted by the ABI, we might have to change this
1331 calculation. */
1332 relocation -= sgot->output_section->vma;
1333
1334 break;
1335
1336 case R_386_GOTPC:
1337 /* Use global offset table as symbol value. */
1338
1339 if (sgot == NULL)
1340 {
1341 sgot = bfd_get_section_by_name (dynobj, ".got");
1342 BFD_ASSERT (sgot != NULL);
1343 }
1344
1345 relocation = sgot->output_section->vma;
1346
1347 break;
1348
1349 case R_386_PLT32:
1350 /* Relocation is to the entry for this symbol in the
1351 procedure linkage table. */
1352
1353 /* Resolve a PLT32 reloc again a local symbol directly,
1354 without using the procedure linkage table. */
1355 if (h == NULL)
1356 break;
1357
1358 if (h->plt_offset == (bfd_vma) -1)
1359 {
1360 /* We didn't make a PLT entry for this symbol. This
1361 happens when statically linking PIC code, or when
1362 using -Bsymbolic. */
1363 break;
1364 }
1365
1366 if (splt == NULL)
1367 {
1368 splt = bfd_get_section_by_name (dynobj, ".plt");
1369 BFD_ASSERT (splt != NULL);
1370 }
1371
1372 relocation = (splt->output_section->vma
1373 + splt->output_offset
1374 + h->plt_offset);
1375
1376 break;
1377
1378 case R_386_32:
1379 case R_386_PC32:
1380 if (info->shared
1381 && (r_type != R_386_PC32
1382 || (h != NULL
1383 && (! info->symbolic
1384 || (h->elf_link_hash_flags
1385 & ELF_LINK_HASH_DEF_REGULAR) == 0))))
1386 {
1387 Elf_Internal_Rel outrel;
1388 boolean skip, relocate;
1389
1390 /* When generating a shared object, these relocations
1391 are copied into the output file to be resolved at run
1392 time. */
1393
1394 if (sreloc == NULL)
1395 {
1396 const char *name;
1397
1398 name = (bfd_elf_string_from_elf_section
1399 (input_bfd,
1400 elf_elfheader (input_bfd)->e_shstrndx,
1401 elf_section_data (input_section)->rel_hdr.sh_name));
1402 if (name == NULL)
1403 return false;
1404
1405 BFD_ASSERT (strncmp (name, ".rel", 4) == 0
1406 && strcmp (bfd_get_section_name (input_bfd,
1407 input_section),
1408 name + 4) == 0);
1409
1410 sreloc = bfd_get_section_by_name (dynobj, name);
1411 BFD_ASSERT (sreloc != NULL);
1412 }
1413
1414 skip = false;
1415
1416 if (elf_section_data (input_section)->stab_info == NULL)
1417 outrel.r_offset = rel->r_offset;
1418 else
1419 {
1420 bfd_vma off;
1421
1422 off = (_bfd_stab_section_offset
1423 (output_bfd, &elf_hash_table (info)->stab_info,
1424 input_section,
1425 &elf_section_data (input_section)->stab_info,
1426 rel->r_offset));
1427 if (off == (bfd_vma) -1)
1428 skip = true;
1429 outrel.r_offset = off;
1430 }
1431
1432 outrel.r_offset += (input_section->output_section->vma
1433 + input_section->output_offset);
1434
1435 if (skip)
1436 {
1437 memset (&outrel, 0, sizeof outrel);
1438 relocate = false;
1439 }
1440 else if (r_type == R_386_PC32)
1441 {
1442 BFD_ASSERT (h != NULL && h->dynindx != -1);
1443 if ((input_section->flags & SEC_ALLOC) != 0)
1444 relocate = false;
1445 else
1446 relocate = true;
1447 outrel.r_info = ELF32_R_INFO (h->dynindx, R_386_PC32);
1448 }
1449 else
1450 {
1451 /* h->dynindx may be -1 if this symbol was marked to
1452 become local. */
1453 if (h == NULL
1454 || ((info->symbolic || h->dynindx == -1)
1455 && (h->elf_link_hash_flags
1456 & ELF_LINK_HASH_DEF_REGULAR) != 0))
1457 {
1458 relocate = true;
1459 outrel.r_info = ELF32_R_INFO (0, R_386_RELATIVE);
1460 }
1461 else
1462 {
1463 BFD_ASSERT (h->dynindx != -1);
1464 if ((input_section->flags & SEC_ALLOC) != 0)
1465 relocate = false;
1466 else
1467 relocate = true;
1468 outrel.r_info = ELF32_R_INFO (h->dynindx, R_386_32);
1469 }
1470 }
1471
1472 bfd_elf32_swap_reloc_out (output_bfd, &outrel,
1473 (((Elf32_External_Rel *)
1474 sreloc->contents)
1475 + sreloc->reloc_count));
1476 ++sreloc->reloc_count;
1477
1478 /* If this reloc is against an external symbol, we do
1479 not want to fiddle with the addend. Otherwise, we
1480 need to include the symbol value so that it becomes
1481 an addend for the dynamic reloc. */
1482 if (! relocate)
1483 continue;
1484 }
1485
1486 break;
1487
1488 default:
1489 break;
1490 }
1491
1492 r = _bfd_final_link_relocate (howto, input_bfd, input_section,
1493 contents, rel->r_offset,
1494 relocation, (bfd_vma) 0);
1495
1496 if (r != bfd_reloc_ok)
1497 {
1498 switch (r)
1499 {
1500 default:
1501 case bfd_reloc_outofrange:
1502 abort ();
1503 case bfd_reloc_overflow:
1504 {
1505 const char *name;
1506
1507 if (h != NULL)
1508 name = h->root.root.string;
1509 else
1510 {
1511 name = bfd_elf_string_from_elf_section (input_bfd,
1512 symtab_hdr->sh_link,
1513 sym->st_name);
1514 if (name == NULL)
1515 return false;
1516 if (*name == '\0')
1517 name = bfd_section_name (input_bfd, sec);
1518 }
1519 if (! ((*info->callbacks->reloc_overflow)
1520 (info, name, howto->name, (bfd_vma) 0,
1521 input_bfd, input_section, rel->r_offset)))
1522 return false;
1523 }
1524 break;
1525 }
1526 }
1527 }
1528
1529 return true;
1530 }
1531
1532 /* Finish up dynamic symbol handling. We set the contents of various
1533 dynamic sections here. */
1534
1535 static boolean
1536 elf_i386_finish_dynamic_symbol (output_bfd, info, h, sym)
1537 bfd *output_bfd;
1538 struct bfd_link_info *info;
1539 struct elf_link_hash_entry *h;
1540 Elf_Internal_Sym *sym;
1541 {
1542 bfd *dynobj;
1543
1544 dynobj = elf_hash_table (info)->dynobj;
1545
1546 if (h->plt_offset != (bfd_vma) -1)
1547 {
1548 asection *splt;
1549 asection *sgot;
1550 asection *srel;
1551 bfd_vma plt_index;
1552 bfd_vma got_offset;
1553 Elf_Internal_Rel rel;
1554
1555 /* This symbol has an entry in the procedure linkage table. Set
1556 it up. */
1557
1558 BFD_ASSERT (h->dynindx != -1);
1559
1560 splt = bfd_get_section_by_name (dynobj, ".plt");
1561 sgot = bfd_get_section_by_name (dynobj, ".got.plt");
1562 srel = bfd_get_section_by_name (dynobj, ".rel.plt");
1563 BFD_ASSERT (splt != NULL && sgot != NULL && srel != NULL);
1564
1565 /* Get the index in the procedure linkage table which
1566 corresponds to this symbol. This is the index of this symbol
1567 in all the symbols for which we are making plt entries. The
1568 first entry in the procedure linkage table is reserved. */
1569 plt_index = h->plt_offset / PLT_ENTRY_SIZE - 1;
1570
1571 /* Get the offset into the .got table of the entry that
1572 corresponds to this function. Each .got entry is 4 bytes.
1573 The first three are reserved. */
1574 got_offset = (plt_index + 3) * 4;
1575
1576 /* Fill in the entry in the procedure linkage table. */
1577 if (! info->shared)
1578 {
1579 memcpy (splt->contents + h->plt_offset, elf_i386_plt_entry,
1580 PLT_ENTRY_SIZE);
1581 bfd_put_32 (output_bfd,
1582 (sgot->output_section->vma
1583 + sgot->output_offset
1584 + got_offset),
1585 splt->contents + h->plt_offset + 2);
1586 }
1587 else
1588 {
1589 memcpy (splt->contents + h->plt_offset, elf_i386_pic_plt_entry,
1590 PLT_ENTRY_SIZE);
1591 bfd_put_32 (output_bfd, got_offset,
1592 splt->contents + h->plt_offset + 2);
1593 }
1594
1595 bfd_put_32 (output_bfd, plt_index * sizeof (Elf32_External_Rel),
1596 splt->contents + h->plt_offset + 7);
1597 bfd_put_32 (output_bfd, - (h->plt_offset + PLT_ENTRY_SIZE),
1598 splt->contents + h->plt_offset + 12);
1599
1600 /* Fill in the entry in the global offset table. */
1601 bfd_put_32 (output_bfd,
1602 (splt->output_section->vma
1603 + splt->output_offset
1604 + h->plt_offset
1605 + 6),
1606 sgot->contents + got_offset);
1607
1608 /* Fill in the entry in the .rel.plt section. */
1609 rel.r_offset = (sgot->output_section->vma
1610 + sgot->output_offset
1611 + got_offset);
1612 rel.r_info = ELF32_R_INFO (h->dynindx, R_386_JUMP_SLOT);
1613 bfd_elf32_swap_reloc_out (output_bfd, &rel,
1614 ((Elf32_External_Rel *) srel->contents
1615 + plt_index));
1616
1617 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
1618 {
1619 /* Mark the symbol as undefined, rather than as defined in
1620 the .plt section. Leave the value alone. */
1621 sym->st_shndx = SHN_UNDEF;
1622 }
1623 }
1624
1625 if (h->got_offset != (bfd_vma) -1)
1626 {
1627 asection *sgot;
1628 asection *srel;
1629 Elf_Internal_Rel rel;
1630
1631 /* This symbol has an entry in the global offset table. Set it
1632 up. */
1633
1634 sgot = bfd_get_section_by_name (dynobj, ".got");
1635 srel = bfd_get_section_by_name (dynobj, ".rel.got");
1636 BFD_ASSERT (sgot != NULL && srel != NULL);
1637
1638 rel.r_offset = (sgot->output_section->vma
1639 + sgot->output_offset
1640 + (h->got_offset &~ 1));
1641
1642 /* If this is a -Bsymbolic link, and the symbol is defined
1643 locally, we just want to emit a RELATIVE reloc. Likewise if
1644 the symbol was forced to be local because of a version file.
1645 The entry in the global offset table will already have been
1646 initialized in the relocate_section function. */
1647 if (info->shared
1648 && (info->symbolic || h->dynindx == -1)
1649 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))
1650 rel.r_info = ELF32_R_INFO (0, R_386_RELATIVE);
1651 else
1652 {
1653 bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + h->got_offset);
1654 rel.r_info = ELF32_R_INFO (h->dynindx, R_386_GLOB_DAT);
1655 }
1656
1657 bfd_elf32_swap_reloc_out (output_bfd, &rel,
1658 ((Elf32_External_Rel *) srel->contents
1659 + srel->reloc_count));
1660 ++srel->reloc_count;
1661 }
1662
1663 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_COPY) != 0)
1664 {
1665 asection *s;
1666 Elf_Internal_Rel rel;
1667
1668 /* This symbol needs a copy reloc. Set it up. */
1669
1670 BFD_ASSERT (h->dynindx != -1
1671 && (h->root.type == bfd_link_hash_defined
1672 || h->root.type == bfd_link_hash_defweak));
1673
1674 s = bfd_get_section_by_name (h->root.u.def.section->owner,
1675 ".rel.bss");
1676 BFD_ASSERT (s != NULL);
1677
1678 rel.r_offset = (h->root.u.def.value
1679 + h->root.u.def.section->output_section->vma
1680 + h->root.u.def.section->output_offset);
1681 rel.r_info = ELF32_R_INFO (h->dynindx, R_386_COPY);
1682 bfd_elf32_swap_reloc_out (output_bfd, &rel,
1683 ((Elf32_External_Rel *) s->contents
1684 + s->reloc_count));
1685 ++s->reloc_count;
1686 }
1687
1688 /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */
1689 if (strcmp (h->root.root.string, "_DYNAMIC") == 0
1690 || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0)
1691 sym->st_shndx = SHN_ABS;
1692
1693 return true;
1694 }
1695
1696 /* Finish up the dynamic sections. */
1697
1698 static boolean
1699 elf_i386_finish_dynamic_sections (output_bfd, info)
1700 bfd *output_bfd;
1701 struct bfd_link_info *info;
1702 {
1703 bfd *dynobj;
1704 asection *sgot;
1705 asection *sdyn;
1706
1707 dynobj = elf_hash_table (info)->dynobj;
1708
1709 sgot = bfd_get_section_by_name (dynobj, ".got.plt");
1710 BFD_ASSERT (sgot != NULL);
1711 sdyn = bfd_get_section_by_name (dynobj, ".dynamic");
1712
1713 if (elf_hash_table (info)->dynamic_sections_created)
1714 {
1715 asection *splt;
1716 Elf32_External_Dyn *dyncon, *dynconend;
1717
1718 splt = bfd_get_section_by_name (dynobj, ".plt");
1719 BFD_ASSERT (splt != NULL && sdyn != NULL);
1720
1721 dyncon = (Elf32_External_Dyn *) sdyn->contents;
1722 dynconend = (Elf32_External_Dyn *) (sdyn->contents + sdyn->_raw_size);
1723 for (; dyncon < dynconend; dyncon++)
1724 {
1725 Elf_Internal_Dyn dyn;
1726 const char *name;
1727 asection *s;
1728
1729 bfd_elf32_swap_dyn_in (dynobj, dyncon, &dyn);
1730
1731 switch (dyn.d_tag)
1732 {
1733 default:
1734 break;
1735
1736 case DT_PLTGOT:
1737 name = ".got";
1738 goto get_vma;
1739 case DT_JMPREL:
1740 name = ".rel.plt";
1741 get_vma:
1742 s = bfd_get_section_by_name (output_bfd, name);
1743 BFD_ASSERT (s != NULL);
1744 dyn.d_un.d_ptr = s->vma;
1745 bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
1746 break;
1747
1748 case DT_PLTRELSZ:
1749 s = bfd_get_section_by_name (output_bfd, ".rel.plt");
1750 BFD_ASSERT (s != NULL);
1751 if (s->_cooked_size != 0)
1752 dyn.d_un.d_val = s->_cooked_size;
1753 else
1754 dyn.d_un.d_val = s->_raw_size;
1755 bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
1756 break;
1757
1758 case DT_RELSZ:
1759 /* My reading of the SVR4 ABI indicates that the
1760 procedure linkage table relocs (DT_JMPREL) should be
1761 included in the overall relocs (DT_REL). This is
1762 what Solaris does. However, UnixWare can not handle
1763 that case. Therefore, we override the DT_RELSZ entry
1764 here to make it not include the JMPREL relocs. Since
1765 the linker script arranges for .rel.plt to follow all
1766 other relocation sections, we don't have to worry
1767 about changing the DT_REL entry. */
1768 s = bfd_get_section_by_name (output_bfd, ".rel.plt");
1769 if (s != NULL)
1770 {
1771 if (s->_cooked_size != 0)
1772 dyn.d_un.d_val -= s->_cooked_size;
1773 else
1774 dyn.d_un.d_val -= s->_raw_size;
1775 }
1776 bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
1777 break;
1778 }
1779 }
1780
1781 /* Fill in the first entry in the procedure linkage table. */
1782 if (splt->_raw_size > 0)
1783 {
1784 if (info->shared)
1785 memcpy (splt->contents, elf_i386_pic_plt0_entry, PLT_ENTRY_SIZE);
1786 else
1787 {
1788 memcpy (splt->contents, elf_i386_plt0_entry, PLT_ENTRY_SIZE);
1789 bfd_put_32 (output_bfd,
1790 sgot->output_section->vma + sgot->output_offset + 4,
1791 splt->contents + 2);
1792 bfd_put_32 (output_bfd,
1793 sgot->output_section->vma + sgot->output_offset + 8,
1794 splt->contents + 8);
1795 }
1796 }
1797
1798 /* UnixWare sets the entsize of .plt to 4, although that doesn't
1799 really seem like the right value. */
1800 elf_section_data (splt->output_section)->this_hdr.sh_entsize = 4;
1801 }
1802
1803 /* Fill in the first three entries in the global offset table. */
1804 if (sgot->_raw_size > 0)
1805 {
1806 if (sdyn == NULL)
1807 bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents);
1808 else
1809 bfd_put_32 (output_bfd,
1810 sdyn->output_section->vma + sdyn->output_offset,
1811 sgot->contents);
1812 bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + 4);
1813 bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + 8);
1814 }
1815
1816 elf_section_data (sgot->output_section)->this_hdr.sh_entsize = 4;
1817
1818 return true;
1819 }
1820
1821 #define TARGET_LITTLE_SYM bfd_elf32_i386_vec
1822 #define TARGET_LITTLE_NAME "elf32-i386"
1823 #define ELF_ARCH bfd_arch_i386
1824 #define ELF_MACHINE_CODE EM_386
1825 #define ELF_MAXPAGESIZE 0x1000
1826 #define elf_info_to_howto elf_i386_info_to_howto
1827 #define elf_info_to_howto_rel elf_i386_info_to_howto_rel
1828 #define bfd_elf32_bfd_reloc_type_lookup elf_i386_reloc_type_lookup
1829 #define bfd_elf32_bfd_is_local_label_name \
1830 elf_i386_is_local_label_name
1831 #define elf_backend_create_dynamic_sections \
1832 _bfd_elf_create_dynamic_sections
1833 #define bfd_elf32_bfd_link_hash_table_create \
1834 elf_i386_link_hash_table_create
1835 #define elf_backend_check_relocs elf_i386_check_relocs
1836 #define elf_backend_adjust_dynamic_symbol \
1837 elf_i386_adjust_dynamic_symbol
1838 #define elf_backend_size_dynamic_sections \
1839 elf_i386_size_dynamic_sections
1840 #define elf_backend_relocate_section elf_i386_relocate_section
1841 #define elf_backend_finish_dynamic_symbol \
1842 elf_i386_finish_dynamic_symbol
1843 #define elf_backend_finish_dynamic_sections \
1844 elf_i386_finish_dynamic_sections
1845 #define elf_backend_want_got_plt 1
1846 #define elf_backend_plt_readonly 1
1847 #define elf_backend_want_plt_sym 0
1848
1849 #include "elf32-target.h"
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