* coffgen.c (coff_print_symbol): Cast pointer different to long
[deliverable/binutils-gdb.git] / bfd / elf32-i386.c
1 /* Intel 80386/80486-specific support for 32-bit ELF
2 Copyright 1993 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
19
20 #include "bfd.h"
21 #include "sysdep.h"
22 #include "bfdlink.h"
23 #include "libbfd.h"
24 #include "libelf.h"
25
26 static CONST struct reloc_howto_struct *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_create_dynamic_sections
33 PARAMS ((bfd *, struct bfd_link_info *));
34 static boolean elf_i386_adjust_dynamic_symbol
35 PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *));
36 static boolean elf_i386_allocate_dynamic_section
37 PARAMS ((bfd *, const char *));
38 static boolean elf_i386_size_dynamic_sections
39 PARAMS ((bfd *, struct bfd_link_info *));
40 static boolean elf_i386_relocate_section
41 PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
42 Elf_Internal_Rela *, Elf_Internal_Sym *, asection **, char *));
43 static boolean elf_i386_finish_dynamic_symbol
44 PARAMS ((bfd *, struct bfd_link_info *, struct elf_link_hash_entry *,
45 Elf_Internal_Sym *));
46 static boolean elf_i386_finish_dynamic_sections
47 PARAMS ((bfd *, struct bfd_link_info *));
48
49 #define USE_REL 1 /* 386 uses REL relocations instead of RELA */
50
51 enum reloc_type
52 {
53 R_386_NONE = 0,
54 R_386_32,
55 R_386_PC32,
56 R_386_GOT32,
57 R_386_PLT32,
58 R_386_COPY,
59 R_386_GLOB_DAT,
60 R_386_JUMP_SLOT,
61 R_386_RELATIVE,
62 R_386_GOTOFF,
63 R_386_GOTPC,
64 R_386_max
65 };
66
67 #if 0
68 static CONST char *CONST reloc_type_names[] =
69 {
70 "R_386_NONE",
71 "R_386_32",
72 "R_386_PC32",
73 "R_386_GOT32",
74 "R_386_PLT32",
75 "R_386_COPY",
76 "R_386_GLOB_DAT",
77 "R_386_JUMP_SLOT",
78 "R_386_RELATIVE",
79 "R_386_GOTOFF",
80 "R_386_GOTPC",
81 };
82 #endif
83
84 static reloc_howto_type elf_howto_table[]=
85 {
86 HOWTO(R_386_NONE, 0,0, 0,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_NONE", true,0x00000000,0x00000000,false),
87 HOWTO(R_386_32, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_32", true,0xffffffff,0xffffffff,false),
88 HOWTO(R_386_PC32, 0,2,32,true, 0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_PC32", true,0xffffffff,0xffffffff,true),
89 HOWTO(R_386_GOT32, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_GOT32", true,0xffffffff,0xffffffff,false),
90 HOWTO(R_386_PLT32, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_PLT32", true,0xffffffff,0xffffffff,false),
91 HOWTO(R_386_COPY, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_COPY", true,0xffffffff,0xffffffff,false),
92 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),
93 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),
94 HOWTO(R_386_RELATIVE, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_RELATIVE", true,0xffffffff,0xffffffff,false),
95 HOWTO(R_386_GOTOFF, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_GOTOFF", true,0xffffffff,0xffffffff,false),
96 HOWTO(R_386_GOTPC, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_GOTPC", true,0xffffffff,0xffffffff,false),
97 };
98
99 #ifdef DEBUG_GEN_RELOC
100 #define TRACE(str) fprintf (stderr, "i386 bfd reloc lookup %d (%s)\n", code, str)
101 #else
102 #define TRACE(str)
103 #endif
104
105 static CONST struct reloc_howto_struct *
106 elf_i386_reloc_type_lookup (abfd, code)
107 bfd *abfd;
108 bfd_reloc_code_real_type code;
109 {
110 switch (code)
111 {
112 case BFD_RELOC_NONE:
113 TRACE ("BFD_RELOC_NONE");
114 return &elf_howto_table[ (int)R_386_NONE ];
115
116 case BFD_RELOC_32:
117 TRACE ("BFD_RELOC_32");
118 return &elf_howto_table[ (int)R_386_32 ];
119
120 case BFD_RELOC_32_PCREL:
121 TRACE ("BFD_RELOC_PC32");
122 return &elf_howto_table[ (int)R_386_PC32 ];
123
124 case BFD_RELOC_386_GOT32:
125 TRACE ("BFD_RELOC_386_GOT32");
126 return &elf_howto_table[ (int)R_386_GOT32 ];
127
128 case BFD_RELOC_386_PLT32:
129 TRACE ("BFD_RELOC_386_PLT32");
130 return &elf_howto_table[ (int)R_386_PLT32 ];
131
132 case BFD_RELOC_386_COPY:
133 TRACE ("BFD_RELOC_386_COPY");
134 return &elf_howto_table[ (int)R_386_COPY ];
135
136 case BFD_RELOC_386_GLOB_DAT:
137 TRACE ("BFD_RELOC_386_GLOB_DAT");
138 return &elf_howto_table[ (int)R_386_GLOB_DAT ];
139
140 case BFD_RELOC_386_JUMP_SLOT:
141 TRACE ("BFD_RELOC_386_JUMP_SLOT");
142 return &elf_howto_table[ (int)R_386_JUMP_SLOT ];
143
144 case BFD_RELOC_386_RELATIVE:
145 TRACE ("BFD_RELOC_386_RELATIVE");
146 return &elf_howto_table[ (int)R_386_RELATIVE ];
147
148 case BFD_RELOC_386_GOTOFF:
149 TRACE ("BFD_RELOC_386_GOTOFF");
150 return &elf_howto_table[ (int)R_386_GOTOFF ];
151
152 case BFD_RELOC_386_GOTPC:
153 TRACE ("BFD_RELOC_386_GOTPC");
154 return &elf_howto_table[ (int)R_386_GOTPC ];
155
156 default:
157 break;
158 }
159
160 TRACE ("Unknown");
161 return 0;
162 }
163
164 static void
165 elf_i386_info_to_howto (abfd, cache_ptr, dst)
166 bfd *abfd;
167 arelent *cache_ptr;
168 Elf32_Internal_Rela *dst;
169 {
170 BFD_ASSERT (ELF32_R_TYPE(dst->r_info) < (unsigned int) R_386_max);
171
172 cache_ptr->howto = &elf_howto_table[ELF32_R_TYPE(dst->r_info)];
173 }
174
175 static void
176 elf_i386_info_to_howto_rel (abfd, cache_ptr, dst)
177 bfd *abfd;
178 arelent *cache_ptr;
179 Elf32_Internal_Rel *dst;
180 {
181 BFD_ASSERT (ELF32_R_TYPE(dst->r_info) < (unsigned int) R_386_max);
182
183 cache_ptr->howto = &elf_howto_table[ELF32_R_TYPE(dst->r_info)];
184 }
185 \f
186 /* Functions for the i386 ELF linker. */
187
188 /* The name of the dynamic interpreter. This is put in the .interp
189 section. */
190
191 #define ELF_DYNAMIC_INTERPRETER "/usr/lib/libc.so.1"
192
193 /* The size in bytes of an entry in the procedure linkage table. */
194
195 #define PLT_ENTRY_SIZE 16
196
197 /* The first entry in an absolute procedure linkage table looks like
198 this. See the SVR4 ABI i386 supplement to see how this works. */
199
200 static bfd_byte elf_i386_plt0_entry[PLT_ENTRY_SIZE] =
201 {
202 0xff, 0x35, /* pushl contents of address */
203 0, 0, 0, 0, /* replaced with address of .got + 4. */
204 0xff, 0x25, /* jmp indirect */
205 0, 0, 0, 0, /* replaced with address of .got + 8. */
206 0, 0, 0, 0 /* pad out to 16 bytes. */
207 };
208
209 /* Subsequent entries in an absolute procedure linkage table look like
210 this. */
211
212 static bfd_byte elf_i386_plt_entry[PLT_ENTRY_SIZE] =
213 {
214 0xff, 0x25, /* jmp indirect */
215 0, 0, 0, 0, /* replaced with address of this symbol in .got. */
216 0x68, /* pushl immediate */
217 0, 0, 0, 0, /* replaced with offset into relocation table. */
218 0xe9, /* jmp relative */
219 0, 0, 0, 0 /* replaced with offset to start of .plt. */
220 };
221
222 /* Create dynamic sections when linking against a dynamic object. */
223
224 static boolean
225 elf_i386_create_dynamic_sections (abfd, info)
226 bfd *abfd;
227 struct bfd_link_info *info;
228 {
229 flagword flags;
230 register asection *s;
231 struct elf_link_hash_entry *h;
232
233 /* We need to create .plt, .rel.plt, .got, .dynbss, and .rel.bss
234 sections. */
235
236 flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY;
237
238 s = bfd_make_section (abfd, ".plt");
239 if (s == NULL
240 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY | SEC_CODE)
241 || ! bfd_set_section_alignment (abfd, s, 2))
242 return false;
243
244 s = bfd_make_section (abfd, ".rel.plt");
245 if (s == NULL
246 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
247 || ! bfd_set_section_alignment (abfd, s, 2))
248 return false;
249
250 s = bfd_make_section (abfd, ".got");
251 if (s == NULL
252 || ! bfd_set_section_flags (abfd, s, flags)
253 || ! bfd_set_section_alignment (abfd, s, 2))
254 return false;
255
256 /* Define the symbol _GLOBAL_OFFSET_TABLE_ at the start of the .got
257 section. We don't do this in the linker script because we don't
258 want to define the symbol if we are not creating a global offset
259 table. */
260 h = NULL;
261 if (! (_bfd_generic_link_add_one_symbol
262 (info, abfd, "_GLOBAL_OFFSET_TABLE_", BSF_GLOBAL, s, (bfd_vma) 0,
263 (const char *) NULL, false, get_elf_backend_data (abfd)->collect,
264 (struct bfd_link_hash_entry **) &h)))
265 return false;
266 h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
267
268 /* The first three global offset table entries are reserved. */
269 s->_raw_size += 3 * 4;
270
271 /* The .dynbss section is a place to put symbols which are defined
272 by dynamic objects, are referenced by regular objects, and are
273 not functions. We must allocate space for them in the process
274 image and use a R_386_COPY reloc to tell the dynamic linker to
275 initialize them at run time. The linker script puts the .dynbss
276 section into the .bss section of the final image. */
277 s = bfd_make_section (abfd, ".dynbss");
278 if (s == NULL
279 || ! bfd_set_section_flags (abfd, s, SEC_ALLOC))
280 return false;
281
282 /* The .rel.bss section holds copy relocs. This section is not
283 normally needed. We need to create it here, though, so that the
284 linker will map it to an output section. If it turns out not to
285 be needed, we can discard it later. */
286 s = bfd_make_section (abfd, ".rel.bss");
287 if (s == NULL
288 || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
289 || ! bfd_set_section_alignment (abfd, s, 2))
290 return false;
291
292 return true;
293 }
294
295 /* Adjust a symbol defined by a dynamic object and referenced by a
296 regular object. The current definition is in some section of the
297 dynamic object, but we're not including those sections. We have to
298 change the definition to something the rest of the link can
299 understand. */
300
301 static boolean
302 elf_i386_adjust_dynamic_symbol (info, h)
303 struct bfd_link_info *info;
304 struct elf_link_hash_entry *h;
305 {
306 bfd *dynobj;
307 asection *s;
308 unsigned int power_of_two;
309
310 dynobj = elf_hash_table (info)->dynobj;
311
312 /* Make sure we know what is going on here. */
313 BFD_ASSERT (dynobj != NULL
314 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
315 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
316 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
317 && h->root.type == bfd_link_hash_defined
318 && (bfd_get_flavour (h->root.u.def.section->owner)
319 == bfd_target_elf_flavour)
320 && (elf_elfheader (h->root.u.def.section->owner)->e_type
321 == ET_DYN)
322 && h->root.u.def.section->output_section == NULL);
323
324 /* If this is a function, put it in the procedure linkage table. We
325 will fill in the contents of the procedure linkage table later,
326 when we know the address of the .got section. */
327 if (h->type == STT_FUNC)
328 {
329 s = bfd_get_section_by_name (dynobj, ".plt");
330 BFD_ASSERT (s != NULL);
331
332 /* If this is the first .plt entry, make room for the special
333 first entry. */
334 if (s->_raw_size == 0)
335 s->_raw_size += PLT_ENTRY_SIZE;
336
337 /* Set the symbol to this location in the .plt. */
338 h->root.u.def.section = s;
339 h->root.u.def.value = s->_raw_size;
340
341 /* Make room for this entry. */
342 s->_raw_size += PLT_ENTRY_SIZE;
343
344 /* We also need to make an entry in the .got section. */
345
346 s = bfd_get_section_by_name (dynobj, ".got");
347 BFD_ASSERT (s != NULL);
348 s->_raw_size += 4;
349
350 /* We also need to make an entry in the .rel.plt section. */
351
352 s = bfd_get_section_by_name (dynobj, ".rel.plt");
353 BFD_ASSERT (s != NULL);
354 s->_raw_size += sizeof (Elf32_External_Rel);
355
356 return true;
357 }
358
359 /* If this is a weak symbol, and there is a real definition, the
360 processor independent code will have arranged for us to see the
361 real definition first, and we can just use the same value. */
362 if (h->weakdef != NULL)
363 {
364 BFD_ASSERT (h->weakdef->root.type == bfd_link_hash_defined);
365 h->root.u.def.section = h->weakdef->root.u.def.section;
366 h->root.u.def.value = h->weakdef->root.u.def.value;
367 h->copy_offset = (bfd_vma) -1;
368 return true;
369 }
370
371 /* This is a reference to a symbol defined by a dynamic object which
372 is not a function. We must allocate it in our .dynbss section,
373 which will become part of the .bss section of the executable.
374 There will be an entry for this symbol in the .dynsym section.
375 The dynamic object will contain position independent code, so all
376 references from the dynamic object to this symbol will go through
377 the global offset table. The dynamic linker will use the .dynsym
378 entry to determine the address it must put in the global offset
379 table, so both the dynamic object and the regular object will
380 refer to the same memory location for the variable. */
381
382 s = bfd_get_section_by_name (dynobj, ".dynbss");
383 BFD_ASSERT (s != NULL);
384
385 /* If the symbol is currently defined in the .bss section of the
386 dynamic object, then it is OK to simply initialize it to zero.
387 If the symbol is in some other section, we must generate a
388 R_386_COPY reloc to tell the dynamic linker to copy the initial
389 value out of the dynamic object and into the runtime process
390 image. We need to remember the offset into the .rel.bss section
391 we are going to use. */
392 if ((h->root.u.def.section->flags & SEC_LOAD) == 0)
393 h->copy_offset = (bfd_vma) -1;
394 else
395 {
396 asection *srel;
397
398 srel = bfd_get_section_by_name (dynobj, ".rel.bss");
399 BFD_ASSERT (srel != NULL);
400 h->copy_offset = srel->_raw_size;
401 srel->_raw_size += sizeof (Elf32_External_Rel);
402 }
403
404 /* We need to figure out the alignment required for this symbol. I
405 have no idea how ELF linkers handle this. */
406 power_of_two = bfd_log2 (h->size);
407 if (power_of_two > 3)
408 power_of_two = 3;
409
410 /* Apply the required alignment. */
411 s->_raw_size = BFD_ALIGN (s->_raw_size,
412 (bfd_size_type) (1 << power_of_two));
413 if (power_of_two > bfd_get_section_alignment (dynobj, s))
414 {
415 if (! bfd_set_section_alignment (dynobj, s, power_of_two))
416 return false;
417 }
418
419 /* Define the symbol as being at this point in the section. */
420 h->root.u.def.section = s;
421 h->root.u.def.value = s->_raw_size;
422
423 /* Increment the section size to make room for the symbol. */
424 s->_raw_size += h->size;
425
426 return true;
427 }
428
429 /* Allocate contents for a section. */
430
431 static INLINE boolean
432 elf_i386_allocate_dynamic_section (dynobj, name)
433 bfd *dynobj;
434 const char *name;
435 {
436 register asection *s;
437
438 s = bfd_get_section_by_name (dynobj, name);
439 BFD_ASSERT (s != NULL);
440 s->contents = (bfd_byte *) bfd_alloc (dynobj, s->_raw_size);
441 if (s->contents == NULL && s->_raw_size != 0)
442 {
443 bfd_set_error (bfd_error_no_memory);
444 return false;
445 }
446 return true;
447 }
448
449 /* Set the sizes of the dynamic sections. */
450
451 static boolean
452 elf_i386_size_dynamic_sections (output_bfd, info)
453 bfd *output_bfd;
454 struct bfd_link_info *info;
455 {
456 bfd *dynobj;
457 asection *s;
458
459 dynobj = elf_hash_table (info)->dynobj;
460 BFD_ASSERT (dynobj != NULL);
461
462 /* Set the contents of the .interp section to the interpreter. */
463 if (! info->shared)
464 {
465 s = bfd_get_section_by_name (dynobj, ".interp");
466 BFD_ASSERT (s != NULL);
467 s->_raw_size = sizeof ELF_DYNAMIC_INTERPRETER;
468 s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER;
469 }
470
471 /* The adjust_dynamic_symbol entry point has determined the sizes of
472 the various dynamic sections. Allocate some memory for them to
473 hold contents. */
474 if (! elf_i386_allocate_dynamic_section (dynobj, ".plt")
475 || ! elf_i386_allocate_dynamic_section (dynobj, ".rel.plt")
476 || ! elf_i386_allocate_dynamic_section (dynobj, ".got")
477 || ! elf_i386_allocate_dynamic_section (dynobj, ".rel.bss"))
478 return false;
479
480 /* Add some entries to the .dynamic section. We fill in the values
481 later, in elf_i386_finish_dynamic_sections, but we must add the
482 entries now so that we get the correct size for the .dynamic
483 section. The DT_DEBUG entry is filled in by the dynamic linker
484 and used by the debugger. */
485 if (! bfd_elf32_add_dynamic_entry (info, DT_DEBUG, 0)
486 || ! bfd_elf32_add_dynamic_entry (info, DT_PLTGOT, 0))
487 return false;
488
489 s = bfd_get_section_by_name (dynobj, ".plt");
490 BFD_ASSERT (s != NULL);
491 if (s->_raw_size != 0)
492 {
493 if (! bfd_elf32_add_dynamic_entry (info, DT_PLTRELSZ, 0)
494 || ! bfd_elf32_add_dynamic_entry (info, DT_PLTREL, DT_REL)
495 || ! bfd_elf32_add_dynamic_entry (info, DT_JMPREL, 0))
496 return false;
497 }
498
499 /* If we didn't need the .rel.bss section, then discard it from the
500 output file. This is a hack. We don't bother to do it for the
501 other sections because they normally are needed. */
502 s = bfd_get_section_by_name (dynobj, ".rel.bss");
503 BFD_ASSERT (s != NULL);
504 if (s->_raw_size == 0)
505 {
506 asection **spp;
507
508 for (spp = &s->output_section->owner->sections;
509 *spp != s->output_section;
510 spp = &(*spp)->next)
511 ;
512 *spp = s->output_section->next;
513 --s->output_section->owner->section_count;
514 }
515 else
516 {
517 if (! bfd_elf32_add_dynamic_entry (info, DT_REL, 0)
518 || ! bfd_elf32_add_dynamic_entry (info, DT_RELSZ, 0)
519 || ! bfd_elf32_add_dynamic_entry (info, DT_RELENT,
520 sizeof (Elf32_External_Rel)))
521 return false;
522 }
523
524 return true;
525 }
526
527 /* Relocate an i386 ELF section. */
528
529 static boolean
530 elf_i386_relocate_section (output_bfd, info, input_bfd, input_section,
531 contents, relocs, local_syms, local_sections,
532 output_names)
533 bfd *output_bfd;
534 struct bfd_link_info *info;
535 bfd *input_bfd;
536 asection *input_section;
537 bfd_byte *contents;
538 Elf_Internal_Rela *relocs;
539 Elf_Internal_Sym *local_syms;
540 asection **local_sections;
541 char *output_names;
542 {
543 Elf_Internal_Shdr *symtab_hdr;
544 Elf_Internal_Rela *rel;
545 Elf_Internal_Rela *relend;
546
547 symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
548
549 rel = relocs;
550 relend = relocs + input_section->reloc_count;
551 for (; rel < relend; rel++)
552 {
553 int r_type;
554 const reloc_howto_type *howto;
555 long r_symndx;
556 struct elf_link_hash_entry *h;
557 Elf_Internal_Sym *sym;
558 asection *sec;
559 bfd_vma relocation;
560 bfd_reloc_status_type r;
561
562 r_type = ELF32_R_TYPE (rel->r_info);
563 if (r_type < 0 || r_type >= (int) R_386_max)
564 {
565 bfd_set_error (bfd_error_bad_value);
566 return false;
567 }
568 howto = elf_howto_table + r_type;
569
570 r_symndx = ELF32_R_SYM (rel->r_info);
571
572 if (info->relocateable)
573 {
574 /* This is a relocateable link. We don't have to change
575 anything, unless the reloc is against a section symbol,
576 in which case we have to adjust according to where the
577 section symbol winds up in the output section. */
578 if (r_symndx < symtab_hdr->sh_info)
579 {
580 sym = local_syms + r_symndx;
581 if (ELF_ST_TYPE (sym->st_info) == STT_SECTION)
582 {
583 bfd_vma val;
584
585 sec = local_sections[r_symndx];
586 val = bfd_get_32 (input_bfd, contents + rel->r_offset);
587 val += sec->output_offset + sym->st_value;
588 bfd_put_32 (input_bfd, val, contents + rel->r_offset);
589 }
590 }
591
592 continue;
593 }
594
595 /* This is a final link. */
596 h = NULL;
597 sym = NULL;
598 sec = NULL;
599 if (r_symndx < symtab_hdr->sh_info)
600 {
601 sym = local_syms + r_symndx;
602 sec = local_sections[r_symndx];
603 relocation = (sec->output_section->vma
604 + sec->output_offset
605 + sym->st_value);
606 }
607 else
608 {
609 long indx;
610
611 indx = r_symndx - symtab_hdr->sh_info;
612 h = elf_sym_hashes (input_bfd)[indx];
613 if (h->root.type == bfd_link_hash_defined)
614 {
615 sec = h->root.u.def.section;
616 relocation = (h->root.u.def.value
617 + sec->output_section->vma
618 + sec->output_offset);
619 }
620 else if (h->root.type == bfd_link_hash_weak)
621 relocation = 0;
622 else
623 {
624 if (! ((*info->callbacks->undefined_symbol)
625 (info, h->root.root.string, input_bfd,
626 input_section, rel->r_offset)))
627 return false;
628 relocation = 0;
629 }
630 }
631
632 r = _bfd_final_link_relocate (howto, input_bfd, input_section,
633 contents, rel->r_offset,
634 relocation, (bfd_vma) 0);
635
636 if (r != bfd_reloc_ok)
637 {
638 switch (r)
639 {
640 default:
641 case bfd_reloc_outofrange:
642 abort ();
643 case bfd_reloc_overflow:
644 {
645 const char *name;
646
647 if (h != NULL)
648 name = h->root.root.string;
649 else
650 {
651 name = output_names + sym->st_name;
652 if (name == NULL)
653 return false;
654 if (*name == '\0')
655 name = bfd_section_name (input_bfd, sec);
656 }
657 if (! ((*info->callbacks->reloc_overflow)
658 (info, name, howto->name, (bfd_vma) 0,
659 input_bfd, input_section, rel->r_offset)))
660 return false;
661 }
662 break;
663 }
664 }
665 }
666
667 return true;
668 }
669
670 /* Finish up dynamic symbol handling. We set the contents of various
671 dynamic sections here. */
672
673 static boolean
674 elf_i386_finish_dynamic_symbol (output_bfd, info, h, sym)
675 bfd *output_bfd;
676 struct bfd_link_info *info;
677 struct elf_link_hash_entry *h;
678 Elf_Internal_Sym *sym;
679 {
680 /* If this symbol is not defined by a dynamic object, or is not
681 referenced by a regular object, ignore it. */
682 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
683 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
684 || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
685 {
686 /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */
687 if (strcmp (h->root.root.string, "_DYNAMIC") == 0
688 || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0)
689 sym->st_shndx = SHN_ABS;
690 return true;
691 }
692
693 BFD_ASSERT (h->root.type == bfd_link_hash_defined);
694 BFD_ASSERT (h->dynindx != -1);
695
696 if (h->type == STT_FUNC)
697 {
698 asection *splt;
699 asection *sgot;
700 asection *srel;
701 bfd_vma plt_index;
702 bfd_vma got_offset;
703 Elf_Internal_Rel rel;
704
705 splt = h->root.u.def.section;
706 BFD_ASSERT (strcmp (bfd_get_section_name (splt->owner, splt), ".plt")
707 == 0);
708 sgot = bfd_get_section_by_name (splt->owner, ".got");
709 BFD_ASSERT (sgot != NULL);
710 srel = bfd_get_section_by_name (splt->owner, ".rel.plt");
711 BFD_ASSERT (srel != NULL);
712
713 /* FIXME: This only handles an absolute procedure linkage table.
714 When producing a dynamic object, we need to generate a
715 position independent procedure linkage table. */
716
717 /* Get the index in the procedure linkage table which
718 corresponds to this symbol. This is the index of this symbol
719 in all the symbols for which we are making plt entries. The
720 first entry in the procedure linkage table is reserved. */
721 plt_index = h->root.u.def.value / PLT_ENTRY_SIZE - 1;
722
723 /* Get the offset into the .got table of the entry that
724 corresponds to this function. Each .got entry is 4 bytes.
725 The first three are reserved. */
726 got_offset = (plt_index + 3) * 4;
727
728 /* Fill in the entry in the procedure linkage table. */
729 memcpy (splt->contents + h->root.u.def.value, elf_i386_plt_entry,
730 PLT_ENTRY_SIZE);
731 bfd_put_32 (output_bfd,
732 (sgot->output_section->vma
733 + sgot->output_offset
734 + got_offset),
735 splt->contents + h->root.u.def.value + 2);
736 bfd_put_32 (output_bfd, plt_index * sizeof (Elf32_External_Rel),
737 splt->contents + h->root.u.def.value + 7);
738 bfd_put_32 (output_bfd, - (h->root.u.def.value + PLT_ENTRY_SIZE),
739 splt->contents + h->root.u.def.value + 12);
740
741 /* Fill in the entry in the global offset table. */
742 bfd_put_32 (output_bfd,
743 (splt->output_section->vma
744 + splt->output_offset
745 + h->root.u.def.value
746 + 6),
747 sgot->contents + got_offset);
748
749 /* Fill in the entry in the .rel.plt section. */
750 rel.r_offset = (sgot->output_section->vma
751 + sgot->output_offset
752 + got_offset);
753 rel.r_info = ELF32_R_INFO (h->dynindx, R_386_JUMP_SLOT);
754 bfd_elf32_swap_reloc_out (output_bfd, &rel,
755 ((Elf32_External_Rel *) srel->contents
756 + plt_index));
757
758 /* Mark the symbol as undefined, rather than as defined in the
759 .plt section. Leave the value alone. */
760 sym->st_shndx = SHN_UNDEF;
761 }
762 else
763 {
764 /* This is not a function. We have already allocated memory for
765 it in the .bss section (via .dynbss). All we have to do here
766 is create a COPY reloc if required. */
767 if (h->copy_offset != (bfd_vma) -1)
768 {
769 asection *s;
770 Elf_Internal_Rel rel;
771
772 s = bfd_get_section_by_name (h->root.u.def.section->owner,
773 ".rel.bss");
774 BFD_ASSERT (s != NULL);
775
776 rel.r_offset = (h->root.u.def.value
777 + h->root.u.def.section->output_section->vma
778 + h->root.u.def.section->output_offset);
779 rel.r_info = ELF32_R_INFO (h->dynindx, R_386_COPY);
780 bfd_elf32_swap_reloc_out (output_bfd, &rel,
781 ((Elf32_External_Rel *)
782 (s->contents + h->copy_offset)));
783 }
784 }
785
786 return true;
787 }
788
789 /* Finish up the dynamic sections. */
790
791 static boolean
792 elf_i386_finish_dynamic_sections (output_bfd, info)
793 bfd *output_bfd;
794 struct bfd_link_info *info;
795 {
796 asection *splt;
797 asection *sgot;
798 asection *sdyn;
799 Elf32_External_Dyn *dyncon, *dynconend;
800
801 splt = bfd_get_section_by_name (elf_hash_table (info)->dynobj, ".plt");
802 sgot = bfd_get_section_by_name (elf_hash_table (info)->dynobj, ".got");
803 sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj, ".dynamic");
804 BFD_ASSERT (splt != NULL && sgot != NULL && sdyn != NULL);
805
806 dyncon = (Elf32_External_Dyn *) sdyn->contents;
807 dynconend = (Elf32_External_Dyn *) (sdyn->contents + sdyn->_raw_size);
808 for (; dyncon < dynconend; dyncon++)
809 {
810 Elf_Internal_Dyn dyn;
811 const char *name;
812 boolean size;
813
814 bfd_elf32_swap_dyn_in (elf_hash_table (info)->dynobj, dyncon, &dyn);
815
816 /* My reading of the SVR4 ABI indicates that the procedure
817 linkage table relocs (DT_JMPREL) should be included in the
818 overall relocs (DT_REL). This is what Solaris does.
819 However, UnixWare can not handle that case. Therefore, we
820 override the DT_REL and DT_RELSZ entries here to make them
821 not include the JMPREL relocs. */
822
823 switch (dyn.d_tag)
824 {
825 case DT_PLTGOT: name = ".got"; size = false; break;
826 case DT_PLTRELSZ: name = ".rel.plt"; size = true; break;
827 case DT_JMPREL: name = ".rel.plt"; size = false; break;
828 case DT_REL: name = ".rel.bss"; size = false; break;
829 case DT_RELSZ: name = ".rel.bss"; size = true; break;
830 default: name = NULL; size = false; break;
831 }
832
833 if (name != NULL)
834 {
835 asection *s;
836
837 s = bfd_get_section_by_name (output_bfd, name);
838 BFD_ASSERT (s != NULL);
839 if (! size)
840 dyn.d_un.d_ptr = s->vma;
841 else
842 {
843 if (s->_cooked_size != 0)
844 dyn.d_un.d_val = s->_cooked_size;
845 else
846 dyn.d_un.d_val = s->_raw_size;
847 }
848 bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
849 }
850 }
851
852 /* Fill in the first entry in the procedure linkage table. */
853 if (splt->_raw_size > 0)
854 {
855 memcpy (splt->contents, elf_i386_plt0_entry, PLT_ENTRY_SIZE);
856 bfd_put_32 (output_bfd,
857 sgot->output_section->vma + sgot->output_offset + 4,
858 splt->contents + 2);
859 bfd_put_32 (output_bfd,
860 sgot->output_section->vma + sgot->output_offset + 8,
861 splt->contents + 8);
862 }
863
864 /* Fill in the first three entries in the global offset table. */
865 if (sgot->_raw_size > 0)
866 {
867 bfd_put_32 (output_bfd,
868 sdyn->output_section->vma + sdyn->output_offset,
869 sgot->contents);
870 bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + 4);
871 bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + 8);
872 }
873
874 elf_section_data (sgot->output_section)->this_hdr.sh_entsize = 4;
875
876 /* UnixWare sets the entsize of .plt to 4, although that doesn't
877 really seem like the right value. */
878 elf_section_data (splt->output_section)->this_hdr.sh_entsize = 4;
879
880 return true;
881 }
882
883 #define TARGET_LITTLE_SYM bfd_elf32_i386_vec
884 #define TARGET_LITTLE_NAME "elf32-i386"
885 #define ELF_ARCH bfd_arch_i386
886 #define ELF_MACHINE_CODE EM_386
887 #define elf_info_to_howto elf_i386_info_to_howto
888 #define elf_info_to_howto_rel elf_i386_info_to_howto_rel
889 #define bfd_elf32_bfd_reloc_type_lookup elf_i386_reloc_type_lookup
890 #define ELF_MAXPAGESIZE 0x1000
891 #define elf_backend_create_dynamic_sections \
892 elf_i386_create_dynamic_sections
893 #define elf_backend_adjust_dynamic_symbol \
894 elf_i386_adjust_dynamic_symbol
895 #define elf_backend_size_dynamic_sections \
896 elf_i386_size_dynamic_sections
897 #define elf_backend_relocate_section elf_i386_relocate_section
898 #define elf_backend_finish_dynamic_symbol \
899 elf_i386_finish_dynamic_symbol
900 #define elf_backend_finish_dynamic_sections \
901 elf_i386_finish_dynamic_sections
902
903 #include "elf32-target.h"
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