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1 /* 32-bit ELF support for ARM
2 Copyright 1998, 1999, 2000 Free Software Foundation, Inc.
4 This file is part of BFD, the Binary File Descriptor library.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
21 typedef unsigned long int insn32;
22 typedef unsigned short int insn16;
24 static boolean elf32_arm_set_private_flags
25 PARAMS ((bfd *, flagword));
26 static boolean elf32_arm_copy_private_bfd_data
27 PARAMS ((bfd *, bfd *));
28 static boolean elf32_arm_merge_private_bfd_data
29 PARAMS ((bfd *, bfd *));
30 static boolean elf32_arm_print_private_bfd_data
31 PARAMS ((bfd *, PTR));
32 static int elf32_arm_get_symbol_type
33 PARAMS (( Elf_Internal_Sym *, int));
34 static struct bfd_link_hash_table *elf32_arm_link_hash_table_create
35 PARAMS ((bfd *));
36 static bfd_reloc_status_type elf32_arm_final_link_relocate
37 PARAMS ((reloc_howto_type *, bfd *, bfd *, asection *, bfd_byte *,
38 Elf_Internal_Rela *, bfd_vma, struct bfd_link_info *, asection *,
39 const char *, unsigned char, struct elf_link_hash_entry *));
40 static insn32 insert_thumb_branch
41 PARAMS ((insn32, int));
42 static struct elf_link_hash_entry *find_thumb_glue
43 PARAMS ((struct bfd_link_info *, CONST char *, bfd *));
44 static struct elf_link_hash_entry *find_arm_glue
45 PARAMS ((struct bfd_link_info *, CONST char *, bfd *));
46 static void record_arm_to_thumb_glue
47 PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *));
48 static void record_thumb_to_arm_glue
49 PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *));
50 static void elf32_arm_post_process_headers
51 PARAMS ((bfd *, struct bfd_link_info *));
52 static int elf32_arm_to_thumb_stub
53 PARAMS ((struct bfd_link_info *, const char *, bfd *, bfd *, asection *,
54 bfd_byte *, asection *, bfd_vma, bfd_signed_vma, bfd_vma));
55 static int elf32_thumb_to_arm_stub
56 PARAMS ((struct bfd_link_info *, const char *, bfd *, bfd *, asection *,
57 bfd_byte *, asection *, bfd_vma, bfd_signed_vma, bfd_vma));
59 #define INTERWORK_FLAG(abfd) (elf_elfheader (abfd)->e_flags & EF_INTERWORK)
61 /* The linker script knows the section names for placement.
62 The entry_names are used to do simple name mangling on the stubs.
63 Given a function name, and its type, the stub can be found. The
64 name can be changed. The only requirement is the %s be present. */
65 #define THUMB2ARM_GLUE_SECTION_NAME ".glue_7t"
66 #define THUMB2ARM_GLUE_ENTRY_NAME "__%s_from_thumb"
68 #define ARM2THUMB_GLUE_SECTION_NAME ".glue_7"
69 #define ARM2THUMB_GLUE_ENTRY_NAME "__%s_from_arm"
71 /* The name of the dynamic interpreter. This is put in the .interp
72 section. */
73 #define ELF_DYNAMIC_INTERPRETER "/usr/lib/ld.so.1"
75 /* The size in bytes of an entry in the procedure linkage table. */
76 #define PLT_ENTRY_SIZE 16
78 /* The first entry in a procedure linkage table looks like
79 this. It is set up so that any shared library function that is
80 called before the relocation has been set up calls the dynamic
81 linker first. */
82 static const bfd_byte elf32_arm_plt0_entry [PLT_ENTRY_SIZE] =
84 0x04, 0xe0, 0x2d, 0xe5, /* str lr, [sp, #-4]! */
85 0x10, 0xe0, 0x9f, 0xe5, /* ldr lr, [pc, #16] */
86 0x0e, 0xe0, 0x8f, 0xe0, /* adr lr, pc, lr */
87 0x08, 0xf0, 0xbe, 0xe5 /* ldr pc, [lr, #8]! */
90 /* Subsequent entries in a procedure linkage table look like
91 this. */
92 static const bfd_byte elf32_arm_plt_entry [PLT_ENTRY_SIZE] =
94 0x04, 0xc0, 0x9f, 0xe5, /* ldr ip, [pc, #4] */
95 0x0c, 0xc0, 0x8f, 0xe0, /* add ip, pc, ip */
96 0x00, 0xf0, 0x9c, 0xe5, /* ldr pc, [ip] */
97 0x00, 0x00, 0x00, 0x00 /* offset to symbol in got */
100 /* The ARM linker needs to keep track of the number of relocs that it
101 decides to copy in check_relocs for each symbol. This is so that
102 it can discard PC relative relocs if it doesn't need them when
103 linking with -Bsymbolic. We store the information in a field
104 extending the regular ELF linker hash table. */
106 /* This structure keeps track of the number of PC relative relocs we
107 have copied for a given symbol. */
108 struct elf32_arm_pcrel_relocs_copied
110 /* Next section. */
111 struct elf32_arm_pcrel_relocs_copied * next;
112 /* A section in dynobj. */
113 asection * section;
114 /* Number of relocs copied in this section. */
115 bfd_size_type count;
118 /* Arm ELF linker hash entry. */
119 struct elf32_arm_link_hash_entry
121 struct elf_link_hash_entry root;
123 /* Number of PC relative relocs copied for this symbol. */
124 struct elf32_arm_pcrel_relocs_copied * pcrel_relocs_copied;
127 /* Declare this now that the above structures are defined. */
128 static boolean elf32_arm_discard_copies
129 PARAMS ((struct elf32_arm_link_hash_entry *, PTR));
131 /* Traverse an arm ELF linker hash table. */
132 #define elf32_arm_link_hash_traverse(table, func, info) \
133 (elf_link_hash_traverse \
134 (&(table)->root, \
135 (boolean (*) PARAMS ((struct elf_link_hash_entry *, PTR))) (func), \
136 (info)))
138 /* Get the ARM elf linker hash table from a link_info structure. */
139 #define elf32_arm_hash_table(info) \
140 ((struct elf32_arm_link_hash_table *) ((info)->hash))
142 /* ARM ELF linker hash table. */
143 struct elf32_arm_link_hash_table
145 /* The main hash table. */
146 struct elf_link_hash_table root;
148 /* The size in bytes of the section containg the Thumb-to-ARM glue. */
149 long int thumb_glue_size;
151 /* The size in bytes of the section containg the ARM-to-Thumb glue. */
152 long int arm_glue_size;
154 /* An arbitary input BFD chosen to hold the glue sections. */
155 bfd * bfd_of_glue_owner;
157 /* A boolean indicating whether knowledge of the ARM's pipeline
158 length should be applied by the linker. */
159 int no_pipeline_knowledge;
163 /* Create an entry in an ARM ELF linker hash table. */
165 static struct bfd_hash_entry *
166 elf32_arm_link_hash_newfunc (entry, table, string)
167 struct bfd_hash_entry * entry;
168 struct bfd_hash_table * table;
169 const char * string;
171 struct elf32_arm_link_hash_entry * ret =
172 (struct elf32_arm_link_hash_entry *) entry;
174 /* Allocate the structure if it has not already been allocated by a
175 subclass. */
176 if (ret == (struct elf32_arm_link_hash_entry *) NULL)
177 ret = ((struct elf32_arm_link_hash_entry *)
178 bfd_hash_allocate (table,
179 sizeof (struct elf32_arm_link_hash_entry)));
180 if (ret == (struct elf32_arm_link_hash_entry *) NULL)
181 return (struct bfd_hash_entry *) ret;
183 /* Call the allocation method of the superclass. */
184 ret = ((struct elf32_arm_link_hash_entry *)
185 _bfd_elf_link_hash_newfunc ((struct bfd_hash_entry *) ret,
186 table, string));
187 if (ret != (struct elf32_arm_link_hash_entry *) NULL)
188 ret->pcrel_relocs_copied = NULL;
190 return (struct bfd_hash_entry *) ret;
193 /* Create an ARM elf linker hash table. */
195 static struct bfd_link_hash_table *
196 elf32_arm_link_hash_table_create (abfd)
197 bfd *abfd;
199 struct elf32_arm_link_hash_table *ret;
201 ret = ((struct elf32_arm_link_hash_table *)
202 bfd_alloc (abfd, sizeof (struct elf32_arm_link_hash_table)));
203 if (ret == (struct elf32_arm_link_hash_table *) NULL)
204 return NULL;
206 if (!_bfd_elf_link_hash_table_init (&ret->root, abfd,
207 elf32_arm_link_hash_newfunc))
209 bfd_release (abfd, ret);
210 return NULL;
213 ret->thumb_glue_size = 0;
214 ret->arm_glue_size = 0;
215 ret->bfd_of_glue_owner = NULL;
216 ret->no_pipeline_knowledge = 0;
218 return &ret->root.root;
221 /* Locate the Thumb encoded calling stub for NAME. */
223 static struct elf_link_hash_entry *
224 find_thumb_glue (link_info, name, input_bfd)
225 struct bfd_link_info *link_info;
226 CONST char *name;
227 bfd *input_bfd;
229 char *tmp_name;
230 struct elf_link_hash_entry *hash;
231 struct elf32_arm_link_hash_table *hash_table;
233 /* We need a pointer to the armelf specific hash table. */
234 hash_table = elf32_arm_hash_table (link_info);
236 tmp_name = ((char *)
237 bfd_malloc (strlen (name) + strlen (THUMB2ARM_GLUE_ENTRY_NAME) + 1));
239 BFD_ASSERT (tmp_name);
241 sprintf (tmp_name, THUMB2ARM_GLUE_ENTRY_NAME, name);
243 hash = elf_link_hash_lookup
244 (&(hash_table)->root, tmp_name, false, false, true);
246 if (hash == NULL)
247 /* xgettext:c-format */
248 _bfd_error_handler (_("%s: unable to find THUMB glue '%s' for `%s'"),
249 bfd_get_filename (input_bfd), tmp_name, name);
251 free (tmp_name);
253 return hash;
256 /* Locate the ARM encoded calling stub for NAME. */
258 static struct elf_link_hash_entry *
259 find_arm_glue (link_info, name, input_bfd)
260 struct bfd_link_info *link_info;
261 CONST char *name;
262 bfd *input_bfd;
264 char *tmp_name;
265 struct elf_link_hash_entry *myh;
266 struct elf32_arm_link_hash_table *hash_table;
268 /* We need a pointer to the elfarm specific hash table. */
269 hash_table = elf32_arm_hash_table (link_info);
271 tmp_name = ((char *)
272 bfd_malloc (strlen (name) + strlen (ARM2THUMB_GLUE_ENTRY_NAME) + 1));
274 BFD_ASSERT (tmp_name);
276 sprintf (tmp_name, ARM2THUMB_GLUE_ENTRY_NAME, name);
278 myh = elf_link_hash_lookup
279 (&(hash_table)->root, tmp_name, false, false, true);
281 if (myh == NULL)
282 /* xgettext:c-format */
283 _bfd_error_handler (_("%s: unable to find ARM glue '%s' for `%s'"),
284 bfd_get_filename (input_bfd), tmp_name, name);
286 free (tmp_name);
288 return myh;
291 /* ARM->Thumb glue:
293 .arm
294 __func_from_arm:
295 ldr r12, __func_addr
296 bx r12
297 __func_addr:
298 .word func @ behave as if you saw a ARM_32 reloc. */
300 #define ARM2THUMB_GLUE_SIZE 12
301 static const insn32 a2t1_ldr_insn = 0xe59fc000;
302 static const insn32 a2t2_bx_r12_insn = 0xe12fff1c;
303 static const insn32 a2t3_func_addr_insn = 0x00000001;
305 /* Thumb->ARM: Thumb->(non-interworking aware) ARM
307 .thumb .thumb
308 .align 2 .align 2
309 __func_from_thumb: __func_from_thumb:
310 bx pc push {r6, lr}
311 nop ldr r6, __func_addr
312 .arm mov lr, pc
313 __func_change_to_arm: bx r6
314 b func .arm
315 __func_back_to_thumb:
316 ldmia r13! {r6, lr}
317 bx lr
318 __func_addr:
319 .word func */
321 #define THUMB2ARM_GLUE_SIZE 8
322 static const insn16 t2a1_bx_pc_insn = 0x4778;
323 static const insn16 t2a2_noop_insn = 0x46c0;
324 static const insn32 t2a3_b_insn = 0xea000000;
326 static const insn16 t2a1_push_insn = 0xb540;
327 static const insn16 t2a2_ldr_insn = 0x4e03;
328 static const insn16 t2a3_mov_insn = 0x46fe;
329 static const insn16 t2a4_bx_insn = 0x4730;
330 static const insn32 t2a5_pop_insn = 0xe8bd4040;
331 static const insn32 t2a6_bx_insn = 0xe12fff1e;
333 boolean
334 bfd_elf32_arm_allocate_interworking_sections (info)
335 struct bfd_link_info * info;
337 asection * s;
338 bfd_byte * foo;
339 struct elf32_arm_link_hash_table * globals;
341 globals = elf32_arm_hash_table (info);
343 BFD_ASSERT (globals != NULL);
345 if (globals->arm_glue_size != 0)
347 BFD_ASSERT (globals->bfd_of_glue_owner != NULL);
349 s = bfd_get_section_by_name
350 (globals->bfd_of_glue_owner, ARM2THUMB_GLUE_SECTION_NAME);
352 BFD_ASSERT (s != NULL);
354 foo = (bfd_byte *) bfd_alloc
355 (globals->bfd_of_glue_owner, globals->arm_glue_size);
357 s->_raw_size = s->_cooked_size = globals->arm_glue_size;
358 s->contents = foo;
361 if (globals->thumb_glue_size != 0)
363 BFD_ASSERT (globals->bfd_of_glue_owner != NULL);
365 s = bfd_get_section_by_name
366 (globals->bfd_of_glue_owner, THUMB2ARM_GLUE_SECTION_NAME);
368 BFD_ASSERT (s != NULL);
370 foo = (bfd_byte *) bfd_alloc
371 (globals->bfd_of_glue_owner, globals->thumb_glue_size);
373 s->_raw_size = s->_cooked_size = globals->thumb_glue_size;
374 s->contents = foo;
377 return true;
380 static void
381 record_arm_to_thumb_glue (link_info, h)
382 struct bfd_link_info * link_info;
383 struct elf_link_hash_entry * h;
385 const char * name = h->root.root.string;
386 register asection * s;
387 char * tmp_name;
388 struct elf_link_hash_entry * myh;
389 struct elf32_arm_link_hash_table * globals;
391 globals = elf32_arm_hash_table (link_info);
393 BFD_ASSERT (globals != NULL);
394 BFD_ASSERT (globals->bfd_of_glue_owner != NULL);
396 s = bfd_get_section_by_name
397 (globals->bfd_of_glue_owner, ARM2THUMB_GLUE_SECTION_NAME);
399 BFD_ASSERT (s != NULL);
401 tmp_name = ((char *)
402 bfd_malloc (strlen (name) + strlen (ARM2THUMB_GLUE_ENTRY_NAME) + 1));
404 BFD_ASSERT (tmp_name);
406 sprintf (tmp_name, ARM2THUMB_GLUE_ENTRY_NAME, name);
408 myh = elf_link_hash_lookup
409 (&(globals)->root, tmp_name, false, false, true);
411 if (myh != NULL)
413 /* We've already seen this guy. */
414 free (tmp_name);
415 return;
418 /* The only trick here is using hash_table->arm_glue_size as the value. Even
419 though the section isn't allocated yet, this is where we will be putting
420 it. */
421 _bfd_generic_link_add_one_symbol (link_info, globals->bfd_of_glue_owner, tmp_name,
422 BSF_GLOBAL,
423 s, globals->arm_glue_size + 1,
424 NULL, true, false,
425 (struct bfd_link_hash_entry **) &myh);
427 free (tmp_name);
429 globals->arm_glue_size += ARM2THUMB_GLUE_SIZE;
431 return;
434 static void
435 record_thumb_to_arm_glue (link_info, h)
436 struct bfd_link_info *link_info;
437 struct elf_link_hash_entry *h;
439 const char *name = h->root.root.string;
440 register asection *s;
441 char *tmp_name;
442 struct elf_link_hash_entry *myh;
443 struct elf32_arm_link_hash_table *hash_table;
444 char bind;
446 hash_table = elf32_arm_hash_table (link_info);
448 BFD_ASSERT (hash_table != NULL);
449 BFD_ASSERT (hash_table->bfd_of_glue_owner != NULL);
451 s = bfd_get_section_by_name
452 (hash_table->bfd_of_glue_owner, THUMB2ARM_GLUE_SECTION_NAME);
454 BFD_ASSERT (s != NULL);
456 tmp_name = (char *) bfd_malloc (strlen (name) + strlen (THUMB2ARM_GLUE_ENTRY_NAME) + 1);
458 BFD_ASSERT (tmp_name);
460 sprintf (tmp_name, THUMB2ARM_GLUE_ENTRY_NAME, name);
462 myh = elf_link_hash_lookup
463 (&(hash_table)->root, tmp_name, false, false, true);
465 if (myh != NULL)
467 /* We've already seen this guy. */
468 free (tmp_name);
469 return;
472 _bfd_generic_link_add_one_symbol (link_info, hash_table->bfd_of_glue_owner, tmp_name,
473 BSF_GLOBAL, s, hash_table->thumb_glue_size + 1,
474 NULL, true, false,
475 (struct bfd_link_hash_entry **) &myh);
477 /* If we mark it 'Thumb', the disassembler will do a better job. */
478 bind = ELF_ST_BIND (myh->type);
479 myh->type = ELF_ST_INFO (bind, STT_ARM_TFUNC);
481 free (tmp_name);
483 #define CHANGE_TO_ARM "__%s_change_to_arm"
484 #define BACK_FROM_ARM "__%s_back_from_arm"
486 /* Allocate another symbol to mark where we switch to Arm mode. */
487 tmp_name = (char *) bfd_malloc (strlen (name) + strlen (CHANGE_TO_ARM) + 1);
489 BFD_ASSERT (tmp_name);
491 sprintf (tmp_name, CHANGE_TO_ARM, name);
493 myh = NULL;
495 _bfd_generic_link_add_one_symbol (link_info, hash_table->bfd_of_glue_owner, tmp_name,
496 BSF_LOCAL, s, hash_table->thumb_glue_size + 4,
497 NULL, true, false,
498 (struct bfd_link_hash_entry **) &myh);
500 free (tmp_name);
502 hash_table->thumb_glue_size += THUMB2ARM_GLUE_SIZE;
504 return;
507 /* Select a BFD to be used to hold the sections used by the glue code.
508 This function is called from the linker scripts in ld/emultempl/
509 {armelf/pe}.em */
511 boolean
512 bfd_elf32_arm_get_bfd_for_interworking (abfd, info)
513 bfd *abfd;
514 struct bfd_link_info *info;
516 struct elf32_arm_link_hash_table *globals;
517 flagword flags;
518 asection *sec;
520 /* If we are only performing a partial link do not bother
521 getting a bfd to hold the glue. */
522 if (info->relocateable)
523 return true;
525 globals = elf32_arm_hash_table (info);
527 BFD_ASSERT (globals != NULL);
529 if (globals->bfd_of_glue_owner != NULL)
530 return true;
532 sec = bfd_get_section_by_name (abfd, ARM2THUMB_GLUE_SECTION_NAME);
534 if (sec == NULL)
536 /* Note: we do not include the flag SEC_LINKER_CREATED, as this
537 will prevent elf_link_input_bfd() from processing the contents
538 of this section. */
539 flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_CODE | SEC_READONLY;
541 sec = bfd_make_section (abfd, ARM2THUMB_GLUE_SECTION_NAME);
543 if (sec == NULL
544 || !bfd_set_section_flags (abfd, sec, flags)
545 || !bfd_set_section_alignment (abfd, sec, 2))
546 return false;
548 /* Set the gc mark to prevent the section from being removed by garbage
549 collection, despite the fact that no relocs refer to this section. */
550 sec->gc_mark = 1;
553 sec = bfd_get_section_by_name (abfd, THUMB2ARM_GLUE_SECTION_NAME);
555 if (sec == NULL)
557 flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_CODE | SEC_READONLY;
559 sec = bfd_make_section (abfd, THUMB2ARM_GLUE_SECTION_NAME);
561 if (sec == NULL
562 || !bfd_set_section_flags (abfd, sec, flags)
563 || !bfd_set_section_alignment (abfd, sec, 2))
564 return false;
566 sec->gc_mark = 1;
569 /* Save the bfd for later use. */
570 globals->bfd_of_glue_owner = abfd;
572 return true;
575 boolean
576 bfd_elf32_arm_process_before_allocation (abfd, link_info, no_pipeline_knowledge)
577 bfd *abfd;
578 struct bfd_link_info *link_info;
579 int no_pipeline_knowledge;
581 Elf_Internal_Shdr *symtab_hdr;
582 Elf_Internal_Rela *free_relocs = NULL;
583 Elf_Internal_Rela *irel, *irelend;
584 bfd_byte *contents = NULL;
585 bfd_byte *free_contents = NULL;
586 Elf32_External_Sym *extsyms = NULL;
587 Elf32_External_Sym *free_extsyms = NULL;
589 asection *sec;
590 struct elf32_arm_link_hash_table *globals;
592 /* If we are only performing a partial link do not bother
593 to construct any glue. */
594 if (link_info->relocateable)
595 return true;
597 /* Here we have a bfd that is to be included on the link. We have a hook
598 to do reloc rummaging, before section sizes are nailed down. */
599 globals = elf32_arm_hash_table (link_info);
601 BFD_ASSERT (globals != NULL);
602 BFD_ASSERT (globals->bfd_of_glue_owner != NULL);
604 globals->no_pipeline_knowledge = no_pipeline_knowledge;
606 /* Rummage around all the relocs and map the glue vectors. */
607 sec = abfd->sections;
609 if (sec == NULL)
610 return true;
612 for (; sec != NULL; sec = sec->next)
614 if (sec->reloc_count == 0)
615 continue;
617 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
619 /* Load the relocs. */
620 irel = (_bfd_elf32_link_read_relocs (abfd, sec, (PTR) NULL,
621 (Elf_Internal_Rela *) NULL, false));
623 BFD_ASSERT (irel != 0);
625 irelend = irel + sec->reloc_count;
626 for (; irel < irelend; irel++)
628 long r_type;
629 unsigned long r_index;
631 struct elf_link_hash_entry *h;
633 r_type = ELF32_R_TYPE (irel->r_info);
634 r_index = ELF32_R_SYM (irel->r_info);
636 /* These are the only relocation types we care about. */
637 if ( r_type != R_ARM_PC24
638 && r_type != R_ARM_THM_PC22)
639 continue;
641 /* Get the section contents if we haven't done so already. */
642 if (contents == NULL)
644 /* Get cached copy if it exists. */
645 if (elf_section_data (sec)->this_hdr.contents != NULL)
646 contents = elf_section_data (sec)->this_hdr.contents;
647 else
649 /* Go get them off disk. */
650 contents = (bfd_byte *) bfd_malloc (sec->_raw_size);
651 if (contents == NULL)
652 goto error_return;
654 free_contents = contents;
656 if (!bfd_get_section_contents (abfd, sec, contents,
657 (file_ptr) 0, sec->_raw_size))
658 goto error_return;
662 /* Read this BFD's symbols if we haven't done so already. */
663 if (extsyms == NULL)
665 /* Get cached copy if it exists. */
666 if (symtab_hdr->contents != NULL)
667 extsyms = (Elf32_External_Sym *) symtab_hdr->contents;
668 else
670 /* Go get them off disk. */
671 extsyms = ((Elf32_External_Sym *)
672 bfd_malloc (symtab_hdr->sh_size));
673 if (extsyms == NULL)
674 goto error_return;
676 free_extsyms = extsyms;
678 if (bfd_seek (abfd, symtab_hdr->sh_offset, SEEK_SET) != 0
679 || (bfd_read (extsyms, 1, symtab_hdr->sh_size, abfd)
680 != symtab_hdr->sh_size))
681 goto error_return;
685 /* If the relocation is not against a symbol it cannot concern us. */
686 h = NULL;
688 /* We don't care about local symbols. */
689 if (r_index < symtab_hdr->sh_info)
690 continue;
692 /* This is an external symbol. */
693 r_index -= symtab_hdr->sh_info;
694 h = (struct elf_link_hash_entry *)
695 elf_sym_hashes (abfd)[r_index];
697 /* If the relocation is against a static symbol it must be within
698 the current section and so cannot be a cross ARM/Thumb relocation. */
699 if (h == NULL)
700 continue;
702 switch (r_type)
704 case R_ARM_PC24:
705 /* This one is a call from arm code. We need to look up
706 the target of the call. If it is a thumb target, we
707 insert glue. */
708 if (ELF_ST_TYPE(h->type) == STT_ARM_TFUNC)
709 record_arm_to_thumb_glue (link_info, h);
710 break;
712 case R_ARM_THM_PC22:
713 /* This one is a call from thumb code. We look
714 up the target of the call. If it is not a thumb
715 target, we insert glue. */
716 if (ELF_ST_TYPE (h->type) != STT_ARM_TFUNC)
717 record_thumb_to_arm_glue (link_info, h);
718 break;
720 default:
721 break;
726 return true;
728 error_return:
729 if (free_relocs != NULL)
730 free (free_relocs);
731 if (free_contents != NULL)
732 free (free_contents);
733 if (free_extsyms != NULL)
734 free (free_extsyms);
736 return false;
739 /* The thumb form of a long branch is a bit finicky, because the offset
740 encoding is split over two fields, each in it's own instruction. They
741 can occur in any order. So given a thumb form of long branch, and an
742 offset, insert the offset into the thumb branch and return finished
743 instruction.
745 It takes two thumb instructions to encode the target address. Each has
746 11 bits to invest. The upper 11 bits are stored in one (identifed by
747 H-0.. see below), the lower 11 bits are stored in the other (identified
748 by H-1).
750 Combine together and shifted left by 1 (it's a half word address) and
751 there you have it.
753 Op: 1111 = F,
754 H-0, upper address-0 = 000
755 Op: 1111 = F,
756 H-1, lower address-0 = 800
758 They can be ordered either way, but the arm tools I've seen always put
759 the lower one first. It probably doesn't matter. krk@cygnus.com
761 XXX: Actually the order does matter. The second instruction (H-1)
762 moves the computed address into the PC, so it must be the second one
763 in the sequence. The problem, however is that whilst little endian code
764 stores the instructions in HI then LOW order, big endian code does the
765 reverse. nickc@cygnus.com. */
767 #define LOW_HI_ORDER 0xF800F000
768 #define HI_LOW_ORDER 0xF000F800
770 static insn32
771 insert_thumb_branch (br_insn, rel_off)
772 insn32 br_insn;
773 int rel_off;
775 unsigned int low_bits;
776 unsigned int high_bits;
778 BFD_ASSERT ((rel_off & 1) != 1);
780 rel_off >>= 1; /* Half word aligned address. */
781 low_bits = rel_off & 0x000007FF; /* The bottom 11 bits. */
782 high_bits = (rel_off >> 11) & 0x000007FF; /* The top 11 bits. */
784 if ((br_insn & LOW_HI_ORDER) == LOW_HI_ORDER)
785 br_insn = LOW_HI_ORDER | (low_bits << 16) | high_bits;
786 else if ((br_insn & HI_LOW_ORDER) == HI_LOW_ORDER)
787 br_insn = HI_LOW_ORDER | (high_bits << 16) | low_bits;
788 else
789 /* FIXME: abort is probably not the right call. krk@cygnus.com */
790 abort (); /* error - not a valid branch instruction form. */
792 return br_insn;
795 /* Thumb code calling an ARM function. */
797 static int
798 elf32_thumb_to_arm_stub (info, name, input_bfd, output_bfd, input_section,
799 hit_data, sym_sec, offset, addend, val)
800 struct bfd_link_info * info;
801 const char * name;
802 bfd * input_bfd;
803 bfd * output_bfd;
804 asection * input_section;
805 bfd_byte * hit_data;
806 asection * sym_sec;
807 bfd_vma offset;
808 bfd_signed_vma addend;
809 bfd_vma val;
811 asection * s = 0;
812 long int my_offset;
813 unsigned long int tmp;
814 long int ret_offset;
815 struct elf_link_hash_entry * myh;
816 struct elf32_arm_link_hash_table * globals;
818 myh = find_thumb_glue (info, name, input_bfd);
819 if (myh == NULL)
820 return false;
822 globals = elf32_arm_hash_table (info);
824 BFD_ASSERT (globals != NULL);
825 BFD_ASSERT (globals->bfd_of_glue_owner != NULL);
827 my_offset = myh->root.u.def.value;
829 s = bfd_get_section_by_name (globals->bfd_of_glue_owner,
830 THUMB2ARM_GLUE_SECTION_NAME);
832 BFD_ASSERT (s != NULL);
833 BFD_ASSERT (s->contents != NULL);
834 BFD_ASSERT (s->output_section != NULL);
836 if ((my_offset & 0x01) == 0x01)
838 if (sym_sec != NULL
839 && sym_sec->owner != NULL
840 && !INTERWORK_FLAG (sym_sec->owner))
842 _bfd_error_handler
843 (_("%s(%s): warning: interworking not enabled."),
844 bfd_get_filename (sym_sec->owner), name);
845 _bfd_error_handler
846 (_(" first occurrence: %s: thumb call to arm"),
847 bfd_get_filename (input_bfd));
849 return false;
852 --my_offset;
853 myh->root.u.def.value = my_offset;
855 bfd_put_16 (output_bfd, t2a1_bx_pc_insn,
856 s->contents + my_offset);
858 bfd_put_16 (output_bfd, t2a2_noop_insn,
859 s->contents + my_offset + 2);
861 ret_offset =
862 /* Address of destination of the stub. */
863 ((bfd_signed_vma) val)
864 - ((bfd_signed_vma)
865 /* Offset from the start of the current section to the start of the stubs. */
866 (s->output_offset
867 /* Offset of the start of this stub from the start of the stubs. */
868 + my_offset
869 /* Address of the start of the current section. */
870 + s->output_section->vma)
871 /* The branch instruction is 4 bytes into the stub. */
873 /* ARM branches work from the pc of the instruction + 8. */
874 + 8);
876 bfd_put_32 (output_bfd,
877 t2a3_b_insn | ((ret_offset >> 2) & 0x00FFFFFF),
878 s->contents + my_offset + 4);
881 BFD_ASSERT (my_offset <= globals->thumb_glue_size);
883 /* Now go back and fix up the original BL insn to point
884 to here. */
885 ret_offset =
886 s->output_offset
887 + my_offset
888 - (input_section->output_offset
889 + offset + addend)
890 - 8;
892 tmp = bfd_get_32 (input_bfd, hit_data
893 - input_section->vma);
895 bfd_put_32 (output_bfd,
896 insert_thumb_branch (tmp, ret_offset),
897 hit_data - input_section->vma);
899 return true;
902 /* Arm code calling a Thumb function. */
904 static int
905 elf32_arm_to_thumb_stub (info, name, input_bfd, output_bfd, input_section,
906 hit_data, sym_sec, offset, addend, val)
907 struct bfd_link_info * info;
908 const char * name;
909 bfd * input_bfd;
910 bfd * output_bfd;
911 asection * input_section;
912 bfd_byte * hit_data;
913 asection * sym_sec;
914 bfd_vma offset;
915 bfd_signed_vma addend;
916 bfd_vma val;
918 unsigned long int tmp;
919 long int my_offset;
920 asection * s;
921 long int ret_offset;
922 struct elf_link_hash_entry * myh;
923 struct elf32_arm_link_hash_table * globals;
925 myh = find_arm_glue (info, name, input_bfd);
926 if (myh == NULL)
927 return false;
929 globals = elf32_arm_hash_table (info);
931 BFD_ASSERT (globals != NULL);
932 BFD_ASSERT (globals->bfd_of_glue_owner != NULL);
934 my_offset = myh->root.u.def.value;
935 s = bfd_get_section_by_name (globals->bfd_of_glue_owner,
936 ARM2THUMB_GLUE_SECTION_NAME);
937 BFD_ASSERT (s != NULL);
938 BFD_ASSERT (s->contents != NULL);
939 BFD_ASSERT (s->output_section != NULL);
941 if ((my_offset & 0x01) == 0x01)
943 if (sym_sec != NULL
944 && sym_sec->owner != NULL
945 && !INTERWORK_FLAG (sym_sec->owner))
947 _bfd_error_handler
948 (_("%s(%s): warning: interworking not enabled."),
949 bfd_get_filename (sym_sec->owner), name);
950 _bfd_error_handler
951 (_(" first occurrence: %s: arm call to thumb"),
952 bfd_get_filename (input_bfd));
955 --my_offset;
956 myh->root.u.def.value = my_offset;
958 bfd_put_32 (output_bfd, a2t1_ldr_insn,
959 s->contents + my_offset);
961 bfd_put_32 (output_bfd, a2t2_bx_r12_insn,
962 s->contents + my_offset + 4);
964 /* It's a thumb address. Add the low order bit. */
965 bfd_put_32 (output_bfd, val | a2t3_func_addr_insn,
966 s->contents + my_offset + 8);
969 BFD_ASSERT (my_offset <= globals->arm_glue_size);
971 tmp = bfd_get_32 (input_bfd, hit_data);
972 tmp = tmp & 0xFF000000;
974 /* Somehow these are both 4 too far, so subtract 8. */
975 ret_offset = s->output_offset
976 + my_offset
977 + s->output_section->vma
978 - (input_section->output_offset
979 + input_section->output_section->vma
980 + offset + addend)
981 - 8;
983 tmp = tmp | ((ret_offset >> 2) & 0x00FFFFFF);
985 bfd_put_32 (output_bfd, tmp, hit_data
986 - input_section->vma);
988 return true;
991 /* Perform a relocation as part of a final link. */
993 static bfd_reloc_status_type
994 elf32_arm_final_link_relocate (howto, input_bfd, output_bfd,
995 input_section, contents, rel, value,
996 info, sym_sec, sym_name, sym_flags, h)
997 reloc_howto_type * howto;
998 bfd * input_bfd;
999 bfd * output_bfd;
1000 asection * input_section;
1001 bfd_byte * contents;
1002 Elf_Internal_Rela * rel;
1003 bfd_vma value;
1004 struct bfd_link_info * info;
1005 asection * sym_sec;
1006 const char * sym_name;
1007 unsigned char sym_flags;
1008 struct elf_link_hash_entry * h;
1010 unsigned long r_type = howto->type;
1011 unsigned long r_symndx;
1012 bfd_byte * hit_data = contents + rel->r_offset;
1013 bfd * dynobj = NULL;
1014 Elf_Internal_Shdr * symtab_hdr;
1015 struct elf_link_hash_entry ** sym_hashes;
1016 bfd_vma * local_got_offsets;
1017 asection * sgot = NULL;
1018 asection * splt = NULL;
1019 asection * sreloc = NULL;
1020 bfd_vma addend;
1021 bfd_signed_vma signed_addend;
1022 struct elf32_arm_link_hash_table * globals;
1024 globals = elf32_arm_hash_table (info);
1026 dynobj = elf_hash_table (info)->dynobj;
1027 if (dynobj)
1029 sgot = bfd_get_section_by_name (dynobj, ".got");
1030 splt = bfd_get_section_by_name (dynobj, ".plt");
1032 symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
1033 sym_hashes = elf_sym_hashes (input_bfd);
1034 local_got_offsets = elf_local_got_offsets (input_bfd);
1035 r_symndx = ELF32_R_SYM (rel->r_info);
1037 #ifdef USE_REL
1038 addend = bfd_get_32 (input_bfd, hit_data) & howto->src_mask;
1040 if (addend & ((howto->src_mask + 1) >> 1))
1042 signed_addend = -1;
1043 signed_addend &= ~ howto->src_mask;
1044 signed_addend |= addend;
1046 else
1047 signed_addend = addend;
1048 #else
1049 addend = signed_addend = rel->r_addend;
1050 #endif
1052 switch (r_type)
1054 case R_ARM_NONE:
1055 return bfd_reloc_ok;
1057 case R_ARM_PC24:
1058 case R_ARM_ABS32:
1059 case R_ARM_REL32:
1060 #ifndef OLD_ARM_ABI
1061 case R_ARM_XPC25:
1062 #endif
1063 /* When generating a shared object, these relocations are copied
1064 into the output file to be resolved at run time. */
1065 if (info->shared
1066 && (r_type != R_ARM_PC24
1067 || (h != NULL
1068 && h->dynindx != -1
1069 && (! info->symbolic
1070 || (h->elf_link_hash_flags
1071 & ELF_LINK_HASH_DEF_REGULAR) == 0))))
1073 Elf_Internal_Rel outrel;
1074 boolean skip, relocate;
1076 if (sreloc == NULL)
1078 const char * name;
1080 name = (bfd_elf_string_from_elf_section
1081 (input_bfd,
1082 elf_elfheader (input_bfd)->e_shstrndx,
1083 elf_section_data (input_section)->rel_hdr.sh_name));
1084 if (name == NULL)
1085 return bfd_reloc_notsupported;
1087 BFD_ASSERT (strncmp (name, ".rel", 4) == 0
1088 && strcmp (bfd_get_section_name (input_bfd,
1089 input_section),
1090 name + 4) == 0);
1092 sreloc = bfd_get_section_by_name (dynobj, name);
1093 BFD_ASSERT (sreloc != NULL);
1096 skip = false;
1098 if (elf_section_data (input_section)->stab_info == NULL)
1099 outrel.r_offset = rel->r_offset;
1100 else
1102 bfd_vma off;
1104 off = (_bfd_stab_section_offset
1105 (output_bfd, &elf_hash_table (info)->stab_info,
1106 input_section,
1107 & elf_section_data (input_section)->stab_info,
1108 rel->r_offset));
1109 if (off == (bfd_vma) -1)
1110 skip = true;
1111 outrel.r_offset = off;
1114 outrel.r_offset += (input_section->output_section->vma
1115 + input_section->output_offset);
1117 if (skip)
1119 memset (&outrel, 0, sizeof outrel);
1120 relocate = false;
1122 else if (r_type == R_ARM_PC24)
1124 BFD_ASSERT (h != NULL && h->dynindx != -1);
1125 if ((input_section->flags & SEC_ALLOC) != 0)
1126 relocate = false;
1127 else
1128 relocate = true;
1129 outrel.r_info = ELF32_R_INFO (h->dynindx, R_ARM_PC24);
1131 else
1133 if (h == NULL
1134 || ((info->symbolic || h->dynindx == -1)
1135 && (h->elf_link_hash_flags
1136 & ELF_LINK_HASH_DEF_REGULAR) != 0))
1138 relocate = true;
1139 outrel.r_info = ELF32_R_INFO (0, R_ARM_RELATIVE);
1141 else
1143 BFD_ASSERT (h->dynindx != -1);
1144 if ((input_section->flags & SEC_ALLOC) != 0)
1145 relocate = false;
1146 else
1147 relocate = true;
1148 outrel.r_info = ELF32_R_INFO (h->dynindx, R_ARM_ABS32);
1152 bfd_elf32_swap_reloc_out (output_bfd, &outrel,
1153 (((Elf32_External_Rel *)
1154 sreloc->contents)
1155 + sreloc->reloc_count));
1156 ++sreloc->reloc_count;
1158 /* If this reloc is against an external symbol, we do not want to
1159 fiddle with the addend. Otherwise, we need to include the symbol
1160 value so that it becomes an addend for the dynamic reloc. */
1161 if (! relocate)
1162 return bfd_reloc_ok;
1164 return _bfd_final_link_relocate (howto, input_bfd, input_section,
1165 contents, rel->r_offset, value,
1166 (bfd_vma) 0);
1168 else switch (r_type)
1170 #ifndef OLD_ARM_ABI
1171 case R_ARM_XPC25: /* Arm BLX instruction. */
1172 #endif
1173 case R_ARM_PC24: /* Arm B/BL instruction */
1174 #ifndef OLD_ARM_ABI
1175 if (r_type == R_ARM_XPC25)
1177 /* Check for Arm calling Arm function. */
1178 /* FIXME: Should we translate the instruction into a BL
1179 instruction instead ? */
1180 if (sym_flags != STT_ARM_TFUNC)
1181 _bfd_error_handler (_("\
1182 %s: Warning: Arm BLX instruction targets Arm function '%s'."),
1183 bfd_get_filename (input_bfd),
1184 h ? h->root.root.string : "(local)");
1186 else
1187 #endif
1189 /* Check for Arm calling Thumb function. */
1190 if (sym_flags == STT_ARM_TFUNC)
1192 elf32_arm_to_thumb_stub (info, sym_name, input_bfd, output_bfd,
1193 input_section, hit_data, sym_sec, rel->r_offset,
1194 signed_addend, value);
1195 return bfd_reloc_ok;
1199 if ( strcmp (bfd_get_target (input_bfd), "elf32-littlearm-oabi") == 0
1200 || strcmp (bfd_get_target (input_bfd), "elf32-bigarm-oabi") == 0)
1202 /* The old way of doing things. Trearing the addend as a
1203 byte sized field and adding in the pipeline offset. */
1204 value -= (input_section->output_section->vma
1205 + input_section->output_offset);
1206 value -= rel->r_offset;
1207 value += addend;
1209 if (! globals->no_pipeline_knowledge)
1210 value -= 8;
1212 else
1214 /* The ARM ELF ABI says that this reloc is computed as: S - P + A
1215 where:
1216 S is the address of the symbol in the relocation.
1217 P is address of the instruction being relocated.
1218 A is the addend (extracted from the instruction) in bytes.
1220 S is held in 'value'.
1221 P is the base address of the section containing the instruction
1222 plus the offset of the reloc into that section, ie:
1223 (input_section->output_section->vma +
1224 input_section->output_offset +
1225 rel->r_offset).
1226 A is the addend, converted into bytes, ie:
1227 (signed_addend * 4)
1229 Note: None of these operations have knowledge of the pipeline
1230 size of the processor, thus it is up to the assembler to encode
1231 this information into the addend. */
1232 value -= (input_section->output_section->vma
1233 + input_section->output_offset);
1234 value -= rel->r_offset;
1235 value += (signed_addend << howto->size);
1237 /* Previous versions of this code also used to add in the pipeline
1238 offset here. This is wrong because the linker is not supposed
1239 to know about such things, and one day it might change. In order
1240 to support old binaries that need the old behaviour however, so
1241 we attempt to detect which ABI was used to create the reloc. */
1242 if (! globals->no_pipeline_knowledge)
1244 Elf_Internal_Ehdr * i_ehdrp; /* Elf file header, internal form */
1246 i_ehdrp = elf_elfheader (input_bfd);
1248 if (i_ehdrp->e_ident[EI_OSABI] == 0)
1249 value -= 8;
1253 signed_addend = value;
1254 signed_addend >>= howto->rightshift;
1256 /* It is not an error for an undefined weak reference to be
1257 out of range. Any program that branches to such a symbol
1258 is going to crash anyway, so there is no point worrying
1259 about getting the destination exactly right. */
1260 if (! h || h->root.type != bfd_link_hash_undefweak)
1262 /* Perform a signed range check. */
1263 if ( signed_addend > ((bfd_signed_vma) (howto->dst_mask >> 1))
1264 || signed_addend < - ((bfd_signed_vma) ((howto->dst_mask + 1) >> 1)))
1265 return bfd_reloc_overflow;
1268 #ifndef OLD_ARM_ABI
1269 /* If necessary set the H bit in the BLX instruction. */
1270 if (r_type == R_ARM_XPC25 && ((value & 2) == 2))
1271 value = (signed_addend & howto->dst_mask)
1272 | (bfd_get_32 (input_bfd, hit_data) & (~ howto->dst_mask))
1273 | (1 << 24);
1274 else
1275 #endif
1276 value = (signed_addend & howto->dst_mask)
1277 | (bfd_get_32 (input_bfd, hit_data) & (~ howto->dst_mask));
1278 break;
1280 case R_ARM_ABS32:
1281 value += addend;
1282 if (sym_flags == STT_ARM_TFUNC)
1283 value |= 1;
1284 break;
1286 case R_ARM_REL32:
1287 value -= (input_section->output_section->vma
1288 + input_section->output_offset);
1289 value += addend;
1290 break;
1293 bfd_put_32 (input_bfd, value, hit_data);
1294 return bfd_reloc_ok;
1296 case R_ARM_ABS8:
1297 value += addend;
1298 if ((long) value > 0x7f || (long) value < -0x80)
1299 return bfd_reloc_overflow;
1301 bfd_put_8 (input_bfd, value, hit_data);
1302 return bfd_reloc_ok;
1304 case R_ARM_ABS16:
1305 value += addend;
1307 if ((long) value > 0x7fff || (long) value < -0x8000)
1308 return bfd_reloc_overflow;
1310 bfd_put_16 (input_bfd, value, hit_data);
1311 return bfd_reloc_ok;
1313 case R_ARM_ABS12:
1314 /* Support ldr and str instruction for the arm */
1315 /* Also thumb b (unconditional branch). ??? Really? */
1316 value += addend;
1318 if ((long) value > 0x7ff || (long) value < -0x800)
1319 return bfd_reloc_overflow;
1321 value |= (bfd_get_32 (input_bfd, hit_data) & 0xfffff000);
1322 bfd_put_32 (input_bfd, value, hit_data);
1323 return bfd_reloc_ok;
1325 case R_ARM_THM_ABS5:
1326 /* Support ldr and str instructions for the thumb. */
1327 #ifdef USE_REL
1328 /* Need to refetch addend. */
1329 addend = bfd_get_16 (input_bfd, hit_data) & howto->src_mask;
1330 /* ??? Need to determine shift amount from operand size. */
1331 addend >>= howto->rightshift;
1332 #endif
1333 value += addend;
1335 /* ??? Isn't value unsigned? */
1336 if ((long) value > 0x1f || (long) value < -0x10)
1337 return bfd_reloc_overflow;
1339 /* ??? Value needs to be properly shifted into place first. */
1340 value |= bfd_get_16 (input_bfd, hit_data) & 0xf83f;
1341 bfd_put_16 (input_bfd, value, hit_data);
1342 return bfd_reloc_ok;
1344 #ifndef OLD_ARM_ABI
1345 case R_ARM_THM_XPC22:
1346 #endif
1347 case R_ARM_THM_PC22:
1348 /* Thumb BL (branch long instruction). */
1350 bfd_vma relocation;
1351 boolean overflow = false;
1352 bfd_vma upper_insn = bfd_get_16 (input_bfd, hit_data);
1353 bfd_vma lower_insn = bfd_get_16 (input_bfd, hit_data + 2);
1354 bfd_signed_vma reloc_signed_max = (1 << (howto->bitsize - 1)) - 1;
1355 bfd_signed_vma reloc_signed_min = ~ reloc_signed_max;
1356 bfd_vma check;
1357 bfd_signed_vma signed_check;
1359 #ifdef USE_REL
1360 /* Need to refetch the addend and squish the two 11 bit pieces
1361 together. */
1363 bfd_vma upper = upper_insn & 0x7ff;
1364 bfd_vma lower = lower_insn & 0x7ff;
1365 upper = (upper ^ 0x400) - 0x400; /* Sign extend. */
1366 addend = (upper << 12) | (lower << 1);
1367 signed_addend = addend;
1369 #endif
1370 #ifndef OLD_ARM_ABI
1371 if (r_type == R_ARM_THM_XPC22)
1373 /* Check for Thumb to Thumb call. */
1374 /* FIXME: Should we translate the instruction into a BL
1375 instruction instead ? */
1376 if (sym_flags == STT_ARM_TFUNC)
1377 _bfd_error_handler (_("\
1378 %s: Warning: Thumb BLX instruction targets thumb function '%s'."),
1379 bfd_get_filename (input_bfd),
1380 h ? h->root.root.string : "(local)");
1382 else
1383 #endif
1385 /* If it is not a call to Thumb, assume call to Arm.
1386 If it is a call relative to a section name, then it is not a
1387 function call at all, but rather a long jump. */
1388 if (sym_flags != STT_ARM_TFUNC && sym_flags != STT_SECTION)
1390 if (elf32_thumb_to_arm_stub
1391 (info, sym_name, input_bfd, output_bfd, input_section,
1392 hit_data, sym_sec, rel->r_offset, signed_addend, value))
1393 return bfd_reloc_ok;
1394 else
1395 return bfd_reloc_dangerous;
1399 relocation = value + signed_addend;
1401 relocation -= (input_section->output_section->vma
1402 + input_section->output_offset
1403 + rel->r_offset);
1405 if (! globals->no_pipeline_knowledge)
1407 Elf_Internal_Ehdr * i_ehdrp; /* Elf file header, internal form. */
1409 i_ehdrp = elf_elfheader (input_bfd);
1411 /* Previous versions of this code also used to add in the pipline
1412 offset here. This is wrong because the linker is not supposed
1413 to know about such things, and one day it might change. In order
1414 to support old binaries that need the old behaviour however, so
1415 we attempt to detect which ABI was used to create the reloc. */
1416 if ( strcmp (bfd_get_target (input_bfd), "elf32-littlearm-oabi") == 0
1417 || strcmp (bfd_get_target (input_bfd), "elf32-bigarm-oabi") == 0
1418 || i_ehdrp->e_ident[EI_OSABI] == 0)
1419 relocation += 4;
1422 check = relocation >> howto->rightshift;
1424 /* If this is a signed value, the rightshift just dropped
1425 leading 1 bits (assuming twos complement). */
1426 if ((bfd_signed_vma) relocation >= 0)
1427 signed_check = check;
1428 else
1429 signed_check = check | ~((bfd_vma) -1 >> howto->rightshift);
1431 /* Assumes two's complement. */
1432 if (signed_check > reloc_signed_max || signed_check < reloc_signed_min)
1433 overflow = true;
1435 /* Put RELOCATION back into the insn. */
1436 upper_insn = (upper_insn & ~(bfd_vma) 0x7ff) | ((relocation >> 12) & 0x7ff);
1437 lower_insn = (lower_insn & ~(bfd_vma) 0x7ff) | ((relocation >> 1) & 0x7ff);
1439 /* Put the relocated value back in the object file: */
1440 bfd_put_16 (input_bfd, upper_insn, hit_data);
1441 bfd_put_16 (input_bfd, lower_insn, hit_data + 2);
1443 return (overflow ? bfd_reloc_overflow : bfd_reloc_ok);
1445 break;
1447 case R_ARM_GNU_VTINHERIT:
1448 case R_ARM_GNU_VTENTRY:
1449 return bfd_reloc_ok;
1451 case R_ARM_COPY:
1452 return bfd_reloc_notsupported;
1454 case R_ARM_GLOB_DAT:
1455 return bfd_reloc_notsupported;
1457 case R_ARM_JUMP_SLOT:
1458 return bfd_reloc_notsupported;
1460 case R_ARM_RELATIVE:
1461 return bfd_reloc_notsupported;
1463 case R_ARM_GOTOFF:
1464 /* Relocation is relative to the start of the
1465 global offset table. */
1467 BFD_ASSERT (sgot != NULL);
1468 if (sgot == NULL)
1469 return bfd_reloc_notsupported;
1471 /* Note that sgot->output_offset is not involved in this
1472 calculation. We always want the start of .got. If we
1473 define _GLOBAL_OFFSET_TABLE in a different way, as is
1474 permitted by the ABI, we might have to change this
1475 calculation. */
1476 value -= sgot->output_section->vma;
1477 return _bfd_final_link_relocate (howto, input_bfd, input_section,
1478 contents, rel->r_offset, value,
1479 (bfd_vma) 0);
1481 case R_ARM_GOTPC:
1482 /* Use global offset table as symbol value. */
1483 BFD_ASSERT (sgot != NULL);
1485 if (sgot == NULL)
1486 return bfd_reloc_notsupported;
1488 value = sgot->output_section->vma;
1489 return _bfd_final_link_relocate (howto, input_bfd, input_section,
1490 contents, rel->r_offset, value,
1491 (bfd_vma) 0);
1493 case R_ARM_GOT32:
1494 /* Relocation is to the entry for this symbol in the
1495 global offset table. */
1496 if (sgot == NULL)
1497 return bfd_reloc_notsupported;
1499 if (h != NULL)
1501 bfd_vma off;
1503 off = h->got.offset;
1504 BFD_ASSERT (off != (bfd_vma) -1);
1506 if (!elf_hash_table (info)->dynamic_sections_created ||
1507 (info->shared && (info->symbolic || h->dynindx == -1)
1508 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
1510 /* This is actually a static link, or it is a -Bsymbolic link
1511 and the symbol is defined locally. We must initialize this
1512 entry in the global offset table. Since the offset must
1513 always be a multiple of 4, we use the least significant bit
1514 to record whether we have initialized it already.
1516 When doing a dynamic link, we create a .rel.got relocation
1517 entry to initialize the value. This is done in the
1518 finish_dynamic_symbol routine. */
1519 if ((off & 1) != 0)
1520 off &= ~1;
1521 else
1523 bfd_put_32 (output_bfd, value, sgot->contents + off);
1524 h->got.offset |= 1;
1528 value = sgot->output_offset + off;
1530 else
1532 bfd_vma off;
1534 BFD_ASSERT (local_got_offsets != NULL &&
1535 local_got_offsets[r_symndx] != (bfd_vma) -1);
1537 off = local_got_offsets[r_symndx];
1539 /* The offset must always be a multiple of 4. We use the
1540 least significant bit to record whether we have already
1541 generated the necessary reloc. */
1542 if ((off & 1) != 0)
1543 off &= ~1;
1544 else
1546 bfd_put_32 (output_bfd, value, sgot->contents + off);
1548 if (info->shared)
1550 asection * srelgot;
1551 Elf_Internal_Rel outrel;
1553 srelgot = bfd_get_section_by_name (dynobj, ".rel.got");
1554 BFD_ASSERT (srelgot != NULL);
1556 outrel.r_offset = (sgot->output_section->vma
1557 + sgot->output_offset
1558 + off);
1559 outrel.r_info = ELF32_R_INFO (0, R_ARM_RELATIVE);
1560 bfd_elf32_swap_reloc_out (output_bfd, &outrel,
1561 (((Elf32_External_Rel *)
1562 srelgot->contents)
1563 + srelgot->reloc_count));
1564 ++srelgot->reloc_count;
1567 local_got_offsets[r_symndx] |= 1;
1570 value = sgot->output_offset + off;
1573 return _bfd_final_link_relocate (howto, input_bfd, input_section,
1574 contents, rel->r_offset, value,
1575 (bfd_vma) 0);
1577 case R_ARM_PLT32:
1578 /* Relocation is to the entry for this symbol in the
1579 procedure linkage table. */
1581 /* Resolve a PLT32 reloc against a local symbol directly,
1582 without using the procedure linkage table. */
1583 if (h == NULL)
1584 return _bfd_final_link_relocate (howto, input_bfd, input_section,
1585 contents, rel->r_offset, value,
1586 (bfd_vma) 0);
1588 if (h->plt.offset == (bfd_vma) -1)
1589 /* We didn't make a PLT entry for this symbol. This
1590 happens when statically linking PIC code, or when
1591 using -Bsymbolic. */
1592 return _bfd_final_link_relocate (howto, input_bfd, input_section,
1593 contents, rel->r_offset, value,
1594 (bfd_vma) 0);
1596 BFD_ASSERT(splt != NULL);
1597 if (splt == NULL)
1598 return bfd_reloc_notsupported;
1600 value = (splt->output_section->vma
1601 + splt->output_offset
1602 + h->plt.offset);
1603 return _bfd_final_link_relocate (howto, input_bfd, input_section,
1604 contents, rel->r_offset, value,
1605 (bfd_vma) 0);
1607 case R_ARM_SBREL32:
1608 return bfd_reloc_notsupported;
1610 case R_ARM_AMP_VCALL9:
1611 return bfd_reloc_notsupported;
1613 case R_ARM_RSBREL32:
1614 return bfd_reloc_notsupported;
1616 case R_ARM_THM_RPC22:
1617 return bfd_reloc_notsupported;
1619 case R_ARM_RREL32:
1620 return bfd_reloc_notsupported;
1622 case R_ARM_RABS32:
1623 return bfd_reloc_notsupported;
1625 case R_ARM_RPC24:
1626 return bfd_reloc_notsupported;
1628 case R_ARM_RBASE:
1629 return bfd_reloc_notsupported;
1631 default:
1632 return bfd_reloc_notsupported;
1636 #ifdef USE_REL
1637 /* Add INCREMENT to the reloc (of type HOWTO) at ADDRESS. */
1638 static void
1639 arm_add_to_rel (abfd, address, howto, increment)
1640 bfd * abfd;
1641 bfd_byte * address;
1642 reloc_howto_type * howto;
1643 bfd_signed_vma increment;
1645 bfd_signed_vma addend;
1647 if (howto->type == R_ARM_THM_PC22)
1649 int upper_insn, lower_insn;
1650 int upper, lower;
1652 upper_insn = bfd_get_16 (abfd, address);
1653 lower_insn = bfd_get_16 (abfd, address + 2);
1654 upper = upper_insn & 0x7ff;
1655 lower = lower_insn & 0x7ff;
1657 addend = (upper << 12) | (lower << 1);
1658 addend += increment;
1659 addend >>= 1;
1661 upper_insn = (upper_insn & 0xf800) | ((addend >> 11) & 0x7ff);
1662 lower_insn = (lower_insn & 0xf800) | (addend & 0x7ff);
1664 bfd_put_16 (abfd, upper_insn, address);
1665 bfd_put_16 (abfd, lower_insn, address + 2);
1667 else
1669 bfd_vma contents;
1671 contents = bfd_get_32 (abfd, address);
1673 /* Get the (signed) value from the instruction. */
1674 addend = contents & howto->src_mask;
1675 if (addend & ((howto->src_mask + 1) >> 1))
1677 bfd_signed_vma mask;
1679 mask = -1;
1680 mask &= ~ howto->src_mask;
1681 addend |= mask;
1684 /* Add in the increment, (which is a byte value). */
1685 switch (howto->type)
1687 default:
1688 addend += increment;
1689 break;
1691 case R_ARM_PC24:
1692 addend <<= howto->size;
1693 addend += increment;
1695 /* Should we check for overflow here ? */
1697 /* Drop any undesired bits. */
1698 addend >>= howto->rightshift;
1699 break;
1702 contents = (contents & ~ howto->dst_mask) | (addend & howto->dst_mask);
1704 bfd_put_32 (abfd, contents, address);
1707 #endif /* USE_REL */
1709 /* Relocate an ARM ELF section. */
1710 static boolean
1711 elf32_arm_relocate_section (output_bfd, info, input_bfd, input_section,
1712 contents, relocs, local_syms, local_sections)
1713 bfd * output_bfd;
1714 struct bfd_link_info * info;
1715 bfd * input_bfd;
1716 asection * input_section;
1717 bfd_byte * contents;
1718 Elf_Internal_Rela * relocs;
1719 Elf_Internal_Sym * local_syms;
1720 asection ** local_sections;
1722 Elf_Internal_Shdr * symtab_hdr;
1723 struct elf_link_hash_entry ** sym_hashes;
1724 Elf_Internal_Rela * rel;
1725 Elf_Internal_Rela * relend;
1726 const char * name;
1728 symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
1729 sym_hashes = elf_sym_hashes (input_bfd);
1731 rel = relocs;
1732 relend = relocs + input_section->reloc_count;
1733 for (; rel < relend; rel++)
1735 int r_type;
1736 reloc_howto_type * howto;
1737 unsigned long r_symndx;
1738 Elf_Internal_Sym * sym;
1739 asection * sec;
1740 struct elf_link_hash_entry * h;
1741 bfd_vma relocation;
1742 bfd_reloc_status_type r;
1743 arelent bfd_reloc;
1745 r_symndx = ELF32_R_SYM (rel->r_info);
1746 r_type = ELF32_R_TYPE (rel->r_info);
1748 if ( r_type == R_ARM_GNU_VTENTRY
1749 || r_type == R_ARM_GNU_VTINHERIT)
1750 continue;
1752 elf32_arm_info_to_howto (input_bfd, & bfd_reloc, rel);
1753 howto = bfd_reloc.howto;
1755 if (info->relocateable)
1757 /* This is a relocateable link. We don't have to change
1758 anything, unless the reloc is against a section symbol,
1759 in which case we have to adjust according to where the
1760 section symbol winds up in the output section. */
1761 if (r_symndx < symtab_hdr->sh_info)
1763 sym = local_syms + r_symndx;
1764 if (ELF_ST_TYPE (sym->st_info) == STT_SECTION)
1766 sec = local_sections[r_symndx];
1767 #ifdef USE_REL
1768 arm_add_to_rel (input_bfd, contents + rel->r_offset,
1769 howto, sec->output_offset + sym->st_value);
1770 #else
1771 rel->r_addend += (sec->output_offset + sym->st_value)
1772 >> howto->rightshift;
1773 #endif
1777 continue;
1780 /* This is a final link. */
1781 h = NULL;
1782 sym = NULL;
1783 sec = NULL;
1785 if (r_symndx < symtab_hdr->sh_info)
1787 sym = local_syms + r_symndx;
1788 sec = local_sections[r_symndx];
1789 relocation = (sec->output_section->vma
1790 + sec->output_offset
1791 + sym->st_value);
1793 else
1795 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
1797 while ( h->root.type == bfd_link_hash_indirect
1798 || h->root.type == bfd_link_hash_warning)
1799 h = (struct elf_link_hash_entry *) h->root.u.i.link;
1801 if ( h->root.type == bfd_link_hash_defined
1802 || h->root.type == bfd_link_hash_defweak)
1804 int relocation_needed = 1;
1806 sec = h->root.u.def.section;
1808 /* In these cases, we don't need the relocation value.
1809 We check specially because in some obscure cases
1810 sec->output_section will be NULL. */
1811 switch (r_type)
1813 case R_ARM_PC24:
1814 case R_ARM_ABS32:
1815 if (info->shared
1816 && (
1817 (!info->symbolic && h->dynindx != -1)
1818 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
1820 && ((input_section->flags & SEC_ALLOC) != 0
1821 /* DWARF will emit R_ARM_ABS32 relocations in its
1822 sections against symbols defined externally
1823 in shared libraries. We can't do anything
1824 with them here. */
1825 || ((input_section->flags & SEC_DEBUGGING) != 0
1826 && (h->elf_link_hash_flags
1827 & ELF_LINK_HASH_DEF_DYNAMIC) != 0))
1829 relocation_needed = 0;
1830 break;
1832 case R_ARM_GOTPC:
1833 relocation_needed = 0;
1834 break;
1836 case R_ARM_GOT32:
1837 if (elf_hash_table(info)->dynamic_sections_created
1838 && (!info->shared
1839 || (!info->symbolic && h->dynindx != -1)
1840 || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
1843 relocation_needed = 0;
1844 break;
1846 case R_ARM_PLT32:
1847 if (h->plt.offset != (bfd_vma)-1)
1848 relocation_needed = 0;
1849 break;
1851 default:
1852 if (sec->output_section == NULL)
1854 (*_bfd_error_handler)
1855 (_("%s: warning: unresolvable relocation against symbol `%s' from %s section"),
1856 bfd_get_filename (input_bfd), h->root.root.string,
1857 bfd_get_section_name (input_bfd, input_section));
1858 relocation_needed = 0;
1862 if (relocation_needed)
1863 relocation = h->root.u.def.value
1864 + sec->output_section->vma
1865 + sec->output_offset;
1866 else
1867 relocation = 0;
1869 else if (h->root.type == bfd_link_hash_undefweak)
1870 relocation = 0;
1871 else if (info->shared && !info->symbolic
1872 && !info->no_undefined
1873 && ELF_ST_VISIBILITY (h->other) == STV_DEFAULT)
1874 relocation = 0;
1875 else
1877 if (!((*info->callbacks->undefined_symbol)
1878 (info, h->root.root.string, input_bfd,
1879 input_section, rel->r_offset,
1880 (!info->shared || info->no_undefined
1881 || ELF_ST_VISIBILITY (h->other)))))
1882 return false;
1883 relocation = 0;
1887 if (h != NULL)
1888 name = h->root.root.string;
1889 else
1891 name = (bfd_elf_string_from_elf_section
1892 (input_bfd, symtab_hdr->sh_link, sym->st_name));
1893 if (name == NULL || *name == '\0')
1894 name = bfd_section_name (input_bfd, sec);
1897 r = elf32_arm_final_link_relocate (howto, input_bfd, output_bfd,
1898 input_section, contents, rel,
1899 relocation, info, sec, name,
1900 (h ? ELF_ST_TYPE (h->type) :
1901 ELF_ST_TYPE (sym->st_info)), h);
1903 if (r != bfd_reloc_ok)
1905 const char * msg = (const char *) 0;
1907 switch (r)
1909 case bfd_reloc_overflow:
1910 if (!((*info->callbacks->reloc_overflow)
1911 (info, name, howto->name, (bfd_vma) 0,
1912 input_bfd, input_section, rel->r_offset)))
1913 return false;
1914 break;
1916 case bfd_reloc_undefined:
1917 if (!((*info->callbacks->undefined_symbol)
1918 (info, name, input_bfd, input_section,
1919 rel->r_offset, true)))
1920 return false;
1921 break;
1923 case bfd_reloc_outofrange:
1924 msg = _("internal error: out of range error");
1925 goto common_error;
1927 case bfd_reloc_notsupported:
1928 msg = _("internal error: unsupported relocation error");
1929 goto common_error;
1931 case bfd_reloc_dangerous:
1932 msg = _("internal error: dangerous error");
1933 goto common_error;
1935 default:
1936 msg = _("internal error: unknown error");
1937 /* fall through */
1939 common_error:
1940 if (!((*info->callbacks->warning)
1941 (info, msg, name, input_bfd, input_section,
1942 rel->r_offset)))
1943 return false;
1944 break;
1949 return true;
1952 /* Function to keep ARM specific flags in the ELF header. */
1953 static boolean
1954 elf32_arm_set_private_flags (abfd, flags)
1955 bfd *abfd;
1956 flagword flags;
1958 if (elf_flags_init (abfd)
1959 && elf_elfheader (abfd)->e_flags != flags)
1961 if (EF_ARM_EABI_VERSION (flags) == EF_ARM_EABI_UNKNOWN)
1963 if (flags & EF_INTERWORK)
1964 _bfd_error_handler (_("\
1965 Warning: Not setting interwork flag of %s since it has already been specified as non-interworking"),
1966 bfd_get_filename (abfd));
1967 else
1968 _bfd_error_handler (_("\
1969 Warning: Clearing the interwork flag of %s due to outside request"),
1970 bfd_get_filename (abfd));
1973 else
1975 elf_elfheader (abfd)->e_flags = flags;
1976 elf_flags_init (abfd) = true;
1979 return true;
1982 /* Copy backend specific data from one object module to another. */
1984 static boolean
1985 elf32_arm_copy_private_bfd_data (ibfd, obfd)
1986 bfd *ibfd;
1987 bfd *obfd;
1989 flagword in_flags;
1990 flagword out_flags;
1992 if ( bfd_get_flavour (ibfd) != bfd_target_elf_flavour
1993 || bfd_get_flavour (obfd) != bfd_target_elf_flavour)
1994 return true;
1996 in_flags = elf_elfheader (ibfd)->e_flags;
1997 out_flags = elf_elfheader (obfd)->e_flags;
1999 if (elf_flags_init (obfd)
2000 && EF_ARM_EABI_VERSION (out_flags) == EF_ARM_EABI_UNKNOWN
2001 && in_flags != out_flags)
2003 /* Cannot mix APCS26 and APCS32 code. */
2004 if ((in_flags & EF_APCS_26) != (out_flags & EF_APCS_26))
2005 return false;
2007 /* Cannot mix float APCS and non-float APCS code. */
2008 if ((in_flags & EF_APCS_FLOAT) != (out_flags & EF_APCS_FLOAT))
2009 return false;
2011 /* If the src and dest have different interworking flags
2012 then turn off the interworking bit. */
2013 if ((in_flags & EF_INTERWORK) != (out_flags & EF_INTERWORK))
2015 if (out_flags & EF_INTERWORK)
2016 _bfd_error_handler (_("\
2017 Warning: Clearing the interwork flag in %s because non-interworking code in %s has been linked with it"),
2018 bfd_get_filename (obfd), bfd_get_filename (ibfd));
2020 in_flags &= ~EF_INTERWORK;
2023 /* Likewise for PIC, though don't warn for this case. */
2024 if ((in_flags & EF_PIC) != (out_flags & EF_PIC))
2025 in_flags &= ~EF_PIC;
2028 elf_elfheader (obfd)->e_flags = in_flags;
2029 elf_flags_init (obfd) = true;
2031 return true;
2034 /* Merge backend specific data from an object file to the output
2035 object file when linking. */
2037 static boolean
2038 elf32_arm_merge_private_bfd_data (ibfd, obfd)
2039 bfd * ibfd;
2040 bfd * obfd;
2042 flagword out_flags;
2043 flagword in_flags;
2044 boolean flags_compatible = true;
2046 /* Check if we have the same endianess. */
2047 if (_bfd_generic_verify_endian_match (ibfd, obfd) == false)
2048 return false;
2050 if ( bfd_get_flavour (ibfd) != bfd_target_elf_flavour
2051 || bfd_get_flavour (obfd) != bfd_target_elf_flavour)
2052 return true;
2054 /* The input BFD must have had its flags initialised. */
2055 /* The following seems bogus to me -- The flags are initialized in
2056 the assembler but I don't think an elf_flags_init field is
2057 written into the object. */
2058 /* BFD_ASSERT (elf_flags_init (ibfd)); */
2060 in_flags = elf_elfheader (ibfd)->e_flags;
2061 out_flags = elf_elfheader (obfd)->e_flags;
2063 if (!elf_flags_init (obfd))
2065 /* If the input is the default architecture and had the default
2066 flags then do not bother setting the flags for the output
2067 architecture, instead allow future merges to do this. If no
2068 future merges ever set these flags then they will retain their
2069 uninitialised values, which surprise surprise, correspond
2070 to the default values. */
2071 if (bfd_get_arch_info (ibfd)->the_default
2072 && elf_elfheader (ibfd)->e_flags == 0)
2073 return true;
2075 elf_flags_init (obfd) = true;
2076 elf_elfheader (obfd)->e_flags = in_flags;
2078 if (bfd_get_arch (obfd) == bfd_get_arch (ibfd)
2079 && bfd_get_arch_info (obfd)->the_default)
2080 return bfd_set_arch_mach (obfd, bfd_get_arch (ibfd), bfd_get_mach (ibfd));
2082 return true;
2085 /* Identical flags must be compatible. */
2086 if (in_flags == out_flags)
2087 return true;
2089 /* Complain about various flag mismatches. */
2090 if (EF_ARM_EABI_VERSION (in_flags) != EF_ARM_EABI_VERSION (out_flags))
2092 _bfd_error_handler (_("\
2093 Error: %s compiled for EABI version %d, whereas %s is compiled for version %d"),
2094 bfd_get_filename (ibfd),
2095 (in_flags & EF_ARM_EABIMASK) >> 24,
2096 bfd_get_filename (obfd),
2097 (out_flags & EF_ARM_EABIMASK) >> 24);
2098 return false;
2101 /* Not sure what needs to be checked for EABI versions >= 1. */
2102 if (EF_ARM_EABI_VERSION (in_flags) == EF_ARM_EABI_UNKNOWN)
2104 if ((in_flags & EF_APCS_26) != (out_flags & EF_APCS_26))
2106 _bfd_error_handler (_("\
2107 Error: %s compiled for APCS-%d, whereas %s is compiled for APCS-%d"),
2108 bfd_get_filename (ibfd),
2109 in_flags & EF_APCS_26 ? 26 : 32,
2110 bfd_get_filename (obfd),
2111 out_flags & EF_APCS_26 ? 26 : 32);
2112 flags_compatible = false;
2115 if ((in_flags & EF_APCS_FLOAT) != (out_flags & EF_APCS_FLOAT))
2117 _bfd_error_handler (_("\
2118 Error: %s passes floats in %s registers, whereas %s passes them in %s registers"),
2119 bfd_get_filename (ibfd),
2120 in_flags & EF_APCS_FLOAT ? _("float") : _("integer"),
2121 bfd_get_filename (obfd),
2122 out_flags & EF_APCS_26 ? _("float") : _("integer"));
2123 flags_compatible = false;
2126 #ifdef EF_SOFT_FLOAT
2127 if ((in_flags & EF_SOFT_FLOAT) != (out_flags & EF_SOFT_FLOAT))
2129 _bfd_error_handler (_ ("\
2130 Error: %s uses %s floating point, whereas %s uses %s floating point"),
2131 bfd_get_filename (ibfd),
2132 in_flags & EF_SOFT_FLOAT ? _("soft") : _("hard"),
2133 bfd_get_filename (obfd),
2134 out_flags & EF_SOFT_FLOAT ? _("soft") : _("hard"));
2135 flags_compatible = false;
2137 #endif
2139 /* Interworking mismatch is only a warning. */
2140 if ((in_flags & EF_INTERWORK) != (out_flags & EF_INTERWORK))
2141 _bfd_error_handler (_("\
2142 Warning: %s %s interworking, whereas %s %s"),
2143 bfd_get_filename (ibfd),
2144 in_flags & EF_INTERWORK ? _("supports") : _("does not support"),
2145 bfd_get_filename (obfd),
2146 out_flags & EF_INTERWORK ? _("does not") : _("does"));
2149 return flags_compatible;
2152 /* Display the flags field. */
2154 static boolean
2155 elf32_arm_print_private_bfd_data (abfd, ptr)
2156 bfd *abfd;
2157 PTR ptr;
2159 FILE * file = (FILE *) ptr;
2160 unsigned long flags;
2162 BFD_ASSERT (abfd != NULL && ptr != NULL);
2164 /* Print normal ELF private data. */
2165 _bfd_elf_print_private_bfd_data (abfd, ptr);
2167 flags = elf_elfheader (abfd)->e_flags;
2168 /* Ignore init flag - it may not be set, despite the flags field
2169 containing valid data. */
2171 /* xgettext:c-format */
2172 fprintf (file, _("private flags = %lx:"), elf_elfheader (abfd)->e_flags);
2174 switch (EF_ARM_EABI_VERSION (flags))
2176 case EF_ARM_EABI_UNKNOWN:
2177 /* The following flag bits are GNU extenstions and not part of the
2178 official ARM ELF extended ABI. Hence they are only decoded if
2179 the EABI version is not set. */
2180 if (flags & EF_INTERWORK)
2181 fprintf (file, _(" [interworking enabled]"));
2183 if (flags & EF_APCS_26)
2184 fprintf (file, _(" [APCS-26]"));
2185 else
2186 fprintf (file, _(" [APCS-32]"));
2188 if (flags & EF_APCS_FLOAT)
2189 fprintf (file, _(" [floats passed in float registers]"));
2191 if (flags & EF_PIC)
2192 fprintf (file, _(" [position independent]"));
2194 if (flags & EF_NEW_ABI)
2195 fprintf (file, _(" [new ABI]"));
2197 if (flags & EF_OLD_ABI)
2198 fprintf (file, _(" [old ABI]"));
2200 if (flags & EF_SOFT_FLOAT)
2201 fprintf (file, _(" [software FP]"));
2203 flags &= ~(EF_INTERWORK | EF_APCS_26 | EF_APCS_FLOAT | EF_PIC
2204 | EF_NEW_ABI | EF_OLD_ABI | EF_SOFT_FLOAT);
2205 break;
2207 case EF_ARM_EABI_VER1:
2208 fprintf (file, _(" [Version1 EABI]"));
2210 if (flags & EF_ARM_SYMSARESORTED)
2211 fprintf (file, _(" [sorted symbol table]"));
2212 else
2213 fprintf (file, _(" [unsorted symbol table]"));
2215 flags &= ~ EF_ARM_SYMSARESORTED;
2216 break;
2218 default:
2219 fprintf (file, _(" <EABI version unrecognised>"));
2220 break;
2223 flags &= ~ EF_ARM_EABIMASK;
2225 if (flags & EF_ARM_RELEXEC)
2226 fprintf (file, _(" [relocatable executable]"));
2228 if (flags & EF_ARM_HASENTRY)
2229 fprintf (file, _(" [has entry point]"));
2231 flags &= ~ (EF_ARM_RELEXEC | EF_ARM_HASENTRY);
2233 if (flags)
2234 fprintf (file, _("<Unrecognised flag bits set>"));
2236 fputc ('\n', file);
2238 return true;
2241 static int
2242 elf32_arm_get_symbol_type (elf_sym, type)
2243 Elf_Internal_Sym * elf_sym;
2244 int type;
2246 switch (ELF_ST_TYPE (elf_sym->st_info))
2248 case STT_ARM_TFUNC:
2249 return ELF_ST_TYPE (elf_sym->st_info);
2251 case STT_ARM_16BIT:
2252 /* If the symbol is not an object, return the STT_ARM_16BIT flag.
2253 This allows us to distinguish between data used by Thumb instructions
2254 and non-data (which is probably code) inside Thumb regions of an
2255 executable. */
2256 if (type != STT_OBJECT)
2257 return ELF_ST_TYPE (elf_sym->st_info);
2258 break;
2260 default:
2261 break;
2264 return type;
2267 static asection *
2268 elf32_arm_gc_mark_hook (abfd, info, rel, h, sym)
2269 bfd *abfd;
2270 struct bfd_link_info *info ATTRIBUTE_UNUSED;
2271 Elf_Internal_Rela *rel;
2272 struct elf_link_hash_entry *h;
2273 Elf_Internal_Sym *sym;
2275 if (h != NULL)
2277 switch (ELF32_R_TYPE (rel->r_info))
2279 case R_ARM_GNU_VTINHERIT:
2280 case R_ARM_GNU_VTENTRY:
2281 break;
2283 default:
2284 switch (h->root.type)
2286 case bfd_link_hash_defined:
2287 case bfd_link_hash_defweak:
2288 return h->root.u.def.section;
2290 case bfd_link_hash_common:
2291 return h->root.u.c.p->section;
2293 default:
2294 break;
2298 else
2300 if (!(elf_bad_symtab (abfd)
2301 && ELF_ST_BIND (sym->st_info) != STB_LOCAL)
2302 && ! ((sym->st_shndx <= 0 || sym->st_shndx >= SHN_LORESERVE)
2303 && sym->st_shndx != SHN_COMMON))
2305 return bfd_section_from_elf_index (abfd, sym->st_shndx);
2308 return NULL;
2311 /* Update the got entry reference counts for the section being removed. */
2313 static boolean
2314 elf32_arm_gc_sweep_hook (abfd, info, sec, relocs)
2315 bfd *abfd ATTRIBUTE_UNUSED;
2316 struct bfd_link_info *info ATTRIBUTE_UNUSED;
2317 asection *sec ATTRIBUTE_UNUSED;
2318 const Elf_Internal_Rela *relocs ATTRIBUTE_UNUSED;
2320 /* We don't support garbage collection of GOT and PLT relocs yet. */
2321 return true;
2324 /* Look through the relocs for a section during the first phase. */
2326 static boolean
2327 elf32_arm_check_relocs (abfd, info, sec, relocs)
2328 bfd * abfd;
2329 struct bfd_link_info * info;
2330 asection * sec;
2331 const Elf_Internal_Rela * relocs;
2333 Elf_Internal_Shdr * symtab_hdr;
2334 struct elf_link_hash_entry ** sym_hashes;
2335 struct elf_link_hash_entry ** sym_hashes_end;
2336 const Elf_Internal_Rela * rel;
2337 const Elf_Internal_Rela * rel_end;
2338 bfd * dynobj;
2339 asection * sgot, *srelgot, *sreloc;
2340 bfd_vma * local_got_offsets;
2342 if (info->relocateable)
2343 return true;
2345 sgot = srelgot = sreloc = NULL;
2347 dynobj = elf_hash_table (info)->dynobj;
2348 local_got_offsets = elf_local_got_offsets (abfd);
2350 symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
2351 sym_hashes = elf_sym_hashes (abfd);
2352 sym_hashes_end = sym_hashes
2353 + symtab_hdr->sh_size / sizeof (Elf32_External_Sym);
2355 if (!elf_bad_symtab (abfd))
2356 sym_hashes_end -= symtab_hdr->sh_info;
2358 rel_end = relocs + sec->reloc_count;
2359 for (rel = relocs; rel < rel_end; rel++)
2361 struct elf_link_hash_entry *h;
2362 unsigned long r_symndx;
2364 r_symndx = ELF32_R_SYM (rel->r_info);
2365 if (r_symndx < symtab_hdr->sh_info)
2366 h = NULL;
2367 else
2368 h = sym_hashes[r_symndx - symtab_hdr->sh_info];
2370 /* Some relocs require a global offset table. */
2371 if (dynobj == NULL)
2373 switch (ELF32_R_TYPE (rel->r_info))
2375 case R_ARM_GOT32:
2376 case R_ARM_GOTOFF:
2377 case R_ARM_GOTPC:
2378 elf_hash_table (info)->dynobj = dynobj = abfd;
2379 if (! _bfd_elf_create_got_section (dynobj, info))
2380 return false;
2381 break;
2383 default:
2384 break;
2388 switch (ELF32_R_TYPE (rel->r_info))
2390 case R_ARM_GOT32:
2391 /* This symbol requires a global offset table entry. */
2392 if (sgot == NULL)
2394 sgot = bfd_get_section_by_name (dynobj, ".got");
2395 BFD_ASSERT (sgot != NULL);
2398 /* Get the got relocation section if necessary. */
2399 if (srelgot == NULL
2400 && (h != NULL || info->shared))
2402 srelgot = bfd_get_section_by_name (dynobj, ".rel.got");
2404 /* If no got relocation section, make one and initialize. */
2405 if (srelgot == NULL)
2407 srelgot = bfd_make_section (dynobj, ".rel.got");
2408 if (srelgot == NULL
2409 || ! bfd_set_section_flags (dynobj, srelgot,
2410 (SEC_ALLOC
2411 | SEC_LOAD
2412 | SEC_HAS_CONTENTS
2413 | SEC_IN_MEMORY
2414 | SEC_LINKER_CREATED
2415 | SEC_READONLY))
2416 || ! bfd_set_section_alignment (dynobj, srelgot, 2))
2417 return false;
2421 if (h != NULL)
2423 if (h->got.offset != (bfd_vma) -1)
2424 /* We have already allocated space in the .got. */
2425 break;
2427 h->got.offset = sgot->_raw_size;
2429 /* Make sure this symbol is output as a dynamic symbol. */
2430 if (h->dynindx == -1)
2431 if (! bfd_elf32_link_record_dynamic_symbol (info, h))
2432 return false;
2434 srelgot->_raw_size += sizeof (Elf32_External_Rel);
2436 else
2438 /* This is a global offset table entry for a local
2439 symbol. */
2440 if (local_got_offsets == NULL)
2442 size_t size;
2443 register unsigned int i;
2445 size = symtab_hdr->sh_info * sizeof (bfd_vma);
2446 local_got_offsets = (bfd_vma *) bfd_alloc (abfd, size);
2447 if (local_got_offsets == NULL)
2448 return false;
2449 elf_local_got_offsets (abfd) = local_got_offsets;
2450 for (i = 0; i < symtab_hdr->sh_info; i++)
2451 local_got_offsets[i] = (bfd_vma) -1;
2454 if (local_got_offsets[r_symndx] != (bfd_vma) -1)
2455 /* We have already allocated space in the .got. */
2456 break;
2458 local_got_offsets[r_symndx] = sgot->_raw_size;
2460 if (info->shared)
2461 /* If we are generating a shared object, we need to
2462 output a R_ARM_RELATIVE reloc so that the dynamic
2463 linker can adjust this GOT entry. */
2464 srelgot->_raw_size += sizeof (Elf32_External_Rel);
2467 sgot->_raw_size += 4;
2468 break;
2470 case R_ARM_PLT32:
2471 /* This symbol requires a procedure linkage table entry. We
2472 actually build the entry in adjust_dynamic_symbol,
2473 because this might be a case of linking PIC code which is
2474 never referenced by a dynamic object, in which case we
2475 don't need to generate a procedure linkage table entry
2476 after all. */
2478 /* If this is a local symbol, we resolve it directly without
2479 creating a procedure linkage table entry. */
2480 if (h == NULL)
2481 continue;
2483 h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_PLT;
2484 break;
2486 case R_ARM_ABS32:
2487 case R_ARM_REL32:
2488 case R_ARM_PC24:
2489 /* If we are creating a shared library, and this is a reloc
2490 against a global symbol, or a non PC relative reloc
2491 against a local symbol, then we need to copy the reloc
2492 into the shared library. However, if we are linking with
2493 -Bsymbolic, we do not need to copy a reloc against a
2494 global symbol which is defined in an object we are
2495 including in the link (i.e., DEF_REGULAR is set). At
2496 this point we have not seen all the input files, so it is
2497 possible that DEF_REGULAR is not set now but will be set
2498 later (it is never cleared). We account for that
2499 possibility below by storing information in the
2500 pcrel_relocs_copied field of the hash table entry. */
2501 if (info->shared
2502 && (ELF32_R_TYPE (rel->r_info) != R_ARM_PC24
2503 || (h != NULL
2504 && (! info->symbolic
2505 || (h->elf_link_hash_flags
2506 & ELF_LINK_HASH_DEF_REGULAR) == 0))))
2508 /* When creating a shared object, we must copy these
2509 reloc types into the output file. We create a reloc
2510 section in dynobj and make room for this reloc. */
2511 if (sreloc == NULL)
2513 const char * name;
2515 name = (bfd_elf_string_from_elf_section
2516 (abfd,
2517 elf_elfheader (abfd)->e_shstrndx,
2518 elf_section_data (sec)->rel_hdr.sh_name));
2519 if (name == NULL)
2520 return false;
2522 BFD_ASSERT (strncmp (name, ".rel", 4) == 0
2523 && strcmp (bfd_get_section_name (abfd, sec),
2524 name + 4) == 0);
2526 sreloc = bfd_get_section_by_name (dynobj, name);
2527 if (sreloc == NULL)
2529 flagword flags;
2531 sreloc = bfd_make_section (dynobj, name);
2532 flags = (SEC_HAS_CONTENTS | SEC_READONLY
2533 | SEC_IN_MEMORY | SEC_LINKER_CREATED);
2534 if ((sec->flags & SEC_ALLOC) != 0)
2535 flags |= SEC_ALLOC | SEC_LOAD;
2536 if (sreloc == NULL
2537 || ! bfd_set_section_flags (dynobj, sreloc, flags)
2538 || ! bfd_set_section_alignment (dynobj, sreloc, 2))
2539 return false;
2543 sreloc->_raw_size += sizeof (Elf32_External_Rel);
2544 /* If we are linking with -Bsymbolic, and this is a
2545 global symbol, we count the number of PC relative
2546 relocations we have entered for this symbol, so that
2547 we can discard them again if the symbol is later
2548 defined by a regular object. Note that this function
2549 is only called if we are using an elf_i386 linker
2550 hash table, which means that h is really a pointer to
2551 an elf_i386_link_hash_entry. */
2552 if (h != NULL && info->symbolic
2553 && ELF32_R_TYPE (rel->r_info) == R_ARM_PC24)
2555 struct elf32_arm_link_hash_entry * eh;
2556 struct elf32_arm_pcrel_relocs_copied * p;
2558 eh = (struct elf32_arm_link_hash_entry *) h;
2560 for (p = eh->pcrel_relocs_copied; p != NULL; p = p->next)
2561 if (p->section == sreloc)
2562 break;
2564 if (p == NULL)
2566 p = ((struct elf32_arm_pcrel_relocs_copied *)
2567 bfd_alloc (dynobj, sizeof * p));
2569 if (p == NULL)
2570 return false;
2571 p->next = eh->pcrel_relocs_copied;
2572 eh->pcrel_relocs_copied = p;
2573 p->section = sreloc;
2574 p->count = 0;
2577 ++p->count;
2580 break;
2582 /* This relocation describes the C++ object vtable hierarchy.
2583 Reconstruct it for later use during GC. */
2584 case R_ARM_GNU_VTINHERIT:
2585 if (!_bfd_elf32_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
2586 return false;
2587 break;
2589 /* This relocation describes which C++ vtable entries are actually
2590 used. Record for later use during GC. */
2591 case R_ARM_GNU_VTENTRY:
2592 if (!_bfd_elf32_gc_record_vtentry (abfd, sec, h, rel->r_offset))
2593 return false;
2594 break;
2598 return true;
2602 /* Find the nearest line to a particular section and offset, for error
2603 reporting. This code is a duplicate of the code in elf.c, except
2604 that it also accepts STT_ARM_TFUNC as a symbol that names a function. */
2606 static boolean
2607 elf32_arm_find_nearest_line
2608 (abfd, section, symbols, offset, filename_ptr, functionname_ptr, line_ptr)
2609 bfd * abfd;
2610 asection * section;
2611 asymbol ** symbols;
2612 bfd_vma offset;
2613 CONST char ** filename_ptr;
2614 CONST char ** functionname_ptr;
2615 unsigned int * line_ptr;
2617 boolean found;
2618 const char * filename;
2619 asymbol * func;
2620 bfd_vma low_func;
2621 asymbol ** p;
2623 if (_bfd_dwarf2_find_nearest_line (abfd, section, symbols, offset,
2624 filename_ptr, functionname_ptr,
2625 line_ptr, 0))
2626 return true;
2628 if (! _bfd_stab_section_find_nearest_line (abfd, symbols, section, offset,
2629 &found, filename_ptr,
2630 functionname_ptr, line_ptr,
2631 &elf_tdata (abfd)->line_info))
2632 return false;
2634 if (found)
2635 return true;
2637 if (symbols == NULL)
2638 return false;
2640 filename = NULL;
2641 func = NULL;
2642 low_func = 0;
2644 for (p = symbols; *p != NULL; p++)
2646 elf_symbol_type *q;
2648 q = (elf_symbol_type *) *p;
2650 if (bfd_get_section (&q->symbol) != section)
2651 continue;
2653 switch (ELF_ST_TYPE (q->internal_elf_sym.st_info))
2655 default:
2656 break;
2657 case STT_FILE:
2658 filename = bfd_asymbol_name (&q->symbol);
2659 break;
2660 case STT_NOTYPE:
2661 case STT_FUNC:
2662 case STT_ARM_TFUNC:
2663 if (q->symbol.section == section
2664 && q->symbol.value >= low_func
2665 && q->symbol.value <= offset)
2667 func = (asymbol *) q;
2668 low_func = q->symbol.value;
2670 break;
2674 if (func == NULL)
2675 return false;
2677 *filename_ptr = filename;
2678 *functionname_ptr = bfd_asymbol_name (func);
2679 *line_ptr = 0;
2681 return true;
2684 /* Adjust a symbol defined by a dynamic object and referenced by a
2685 regular object. The current definition is in some section of the
2686 dynamic object, but we're not including those sections. We have to
2687 change the definition to something the rest of the link can
2688 understand. */
2690 static boolean
2691 elf32_arm_adjust_dynamic_symbol (info, h)
2692 struct bfd_link_info * info;
2693 struct elf_link_hash_entry * h;
2695 bfd * dynobj;
2696 asection * s;
2697 unsigned int power_of_two;
2699 dynobj = elf_hash_table (info)->dynobj;
2701 /* Make sure we know what is going on here. */
2702 BFD_ASSERT (dynobj != NULL
2703 && ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT)
2704 || h->weakdef != NULL
2705 || ((h->elf_link_hash_flags
2706 & ELF_LINK_HASH_DEF_DYNAMIC) != 0
2707 && (h->elf_link_hash_flags
2708 & ELF_LINK_HASH_REF_REGULAR) != 0
2709 && (h->elf_link_hash_flags
2710 & ELF_LINK_HASH_DEF_REGULAR) == 0)));
2712 /* If this is a function, put it in the procedure linkage table. We
2713 will fill in the contents of the procedure linkage table later,
2714 when we know the address of the .got section. */
2715 if (h->type == STT_FUNC
2716 || (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0)
2718 if (! info->shared
2719 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
2720 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) == 0)
2722 /* This case can occur if we saw a PLT32 reloc in an input
2723 file, but the symbol was never referred to by a dynamic
2724 object. In such a case, we don't actually need to build
2725 a procedure linkage table, and we can just do a PC32
2726 reloc instead. */
2727 BFD_ASSERT ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0);
2728 return true;
2731 /* Make sure this symbol is output as a dynamic symbol. */
2732 if (h->dynindx == -1)
2734 if (! bfd_elf32_link_record_dynamic_symbol (info, h))
2735 return false;
2738 s = bfd_get_section_by_name (dynobj, ".plt");
2739 BFD_ASSERT (s != NULL);
2741 /* If this is the first .plt entry, make room for the special
2742 first entry. */
2743 if (s->_raw_size == 0)
2744 s->_raw_size += PLT_ENTRY_SIZE;
2746 /* If this symbol is not defined in a regular file, and we are
2747 not generating a shared library, then set the symbol to this
2748 location in the .plt. This is required to make function
2749 pointers compare as equal between the normal executable and
2750 the shared library. */
2751 if (! info->shared
2752 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
2754 h->root.u.def.section = s;
2755 h->root.u.def.value = s->_raw_size;
2758 h->plt.offset = s->_raw_size;
2760 /* Make room for this entry. */
2761 s->_raw_size += PLT_ENTRY_SIZE;
2763 /* We also need to make an entry in the .got.plt section, which
2764 will be placed in the .got section by the linker script. */
2765 s = bfd_get_section_by_name (dynobj, ".got.plt");
2766 BFD_ASSERT (s != NULL);
2767 s->_raw_size += 4;
2769 /* We also need to make an entry in the .rel.plt section. */
2771 s = bfd_get_section_by_name (dynobj, ".rel.plt");
2772 BFD_ASSERT (s != NULL);
2773 s->_raw_size += sizeof (Elf32_External_Rel);
2775 return true;
2778 /* If this is a weak symbol, and there is a real definition, the
2779 processor independent code will have arranged for us to see the
2780 real definition first, and we can just use the same value. */
2781 if (h->weakdef != NULL)
2783 BFD_ASSERT (h->weakdef->root.type == bfd_link_hash_defined
2784 || h->weakdef->root.type == bfd_link_hash_defweak);
2785 h->root.u.def.section = h->weakdef->root.u.def.section;
2786 h->root.u.def.value = h->weakdef->root.u.def.value;
2787 return true;
2790 /* This is a reference to a symbol defined by a dynamic object which
2791 is not a function. */
2793 /* If we are creating a shared library, we must presume that the
2794 only references to the symbol are via the global offset table.
2795 For such cases we need not do anything here; the relocations will
2796 be handled correctly by relocate_section. */
2797 if (info->shared)
2798 return true;
2800 /* We must allocate the symbol in our .dynbss section, which will
2801 become part of the .bss section of the executable. There will be
2802 an entry for this symbol in the .dynsym section. The dynamic
2803 object will contain position independent code, so all references
2804 from the dynamic object to this symbol will go through the global
2805 offset table. The dynamic linker will use the .dynsym entry to
2806 determine the address it must put in the global offset table, so
2807 both the dynamic object and the regular object will refer to the
2808 same memory location for the variable. */
2809 s = bfd_get_section_by_name (dynobj, ".dynbss");
2810 BFD_ASSERT (s != NULL);
2812 /* We must generate a R_ARM_COPY reloc to tell the dynamic linker to
2813 copy the initial value out of the dynamic object and into the
2814 runtime process image. We need to remember the offset into the
2815 .rel.bss section we are going to use. */
2816 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0)
2818 asection *srel;
2820 srel = bfd_get_section_by_name (dynobj, ".rel.bss");
2821 BFD_ASSERT (srel != NULL);
2822 srel->_raw_size += sizeof (Elf32_External_Rel);
2823 h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_COPY;
2826 /* We need to figure out the alignment required for this symbol. I
2827 have no idea how ELF linkers handle this. */
2828 power_of_two = bfd_log2 (h->size);
2829 if (power_of_two > 3)
2830 power_of_two = 3;
2832 /* Apply the required alignment. */
2833 s->_raw_size = BFD_ALIGN (s->_raw_size,
2834 (bfd_size_type) (1 << power_of_two));
2835 if (power_of_two > bfd_get_section_alignment (dynobj, s))
2837 if (! bfd_set_section_alignment (dynobj, s, power_of_two))
2838 return false;
2841 /* Define the symbol as being at this point in the section. */
2842 h->root.u.def.section = s;
2843 h->root.u.def.value = s->_raw_size;
2845 /* Increment the section size to make room for the symbol. */
2846 s->_raw_size += h->size;
2848 return true;
2851 /* Set the sizes of the dynamic sections. */
2853 static boolean
2854 elf32_arm_size_dynamic_sections (output_bfd, info)
2855 bfd * output_bfd;
2856 struct bfd_link_info * info;
2858 bfd * dynobj;
2859 asection * s;
2860 boolean plt;
2861 boolean relocs;
2862 boolean reltext;
2864 dynobj = elf_hash_table (info)->dynobj;
2865 BFD_ASSERT (dynobj != NULL);
2867 if (elf_hash_table (info)->dynamic_sections_created)
2869 /* Set the contents of the .interp section to the interpreter. */
2870 if (! info->shared)
2872 s = bfd_get_section_by_name (dynobj, ".interp");
2873 BFD_ASSERT (s != NULL);
2874 s->_raw_size = sizeof ELF_DYNAMIC_INTERPRETER;
2875 s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER;
2878 else
2880 /* We may have created entries in the .rel.got section.
2881 However, if we are not creating the dynamic sections, we will
2882 not actually use these entries. Reset the size of .rel.got,
2883 which will cause it to get stripped from the output file
2884 below. */
2885 s = bfd_get_section_by_name (dynobj, ".rel.got");
2886 if (s != NULL)
2887 s->_raw_size = 0;
2890 /* If this is a -Bsymbolic shared link, then we need to discard all
2891 PC relative relocs against symbols defined in a regular object.
2892 We allocated space for them in the check_relocs routine, but we
2893 will not fill them in in the relocate_section routine. */
2894 if (info->shared && info->symbolic)
2895 elf32_arm_link_hash_traverse (elf32_arm_hash_table (info),
2896 elf32_arm_discard_copies,
2897 (PTR) NULL);
2899 /* The check_relocs and adjust_dynamic_symbol entry points have
2900 determined the sizes of the various dynamic sections. Allocate
2901 memory for them. */
2902 plt = false;
2903 relocs = false;
2904 reltext = false;
2905 for (s = dynobj->sections; s != NULL; s = s->next)
2907 const char * name;
2908 boolean strip;
2910 if ((s->flags & SEC_LINKER_CREATED) == 0)
2911 continue;
2913 /* It's OK to base decisions on the section name, because none
2914 of the dynobj section names depend upon the input files. */
2915 name = bfd_get_section_name (dynobj, s);
2917 strip = false;
2919 if (strcmp (name, ".plt") == 0)
2921 if (s->_raw_size == 0)
2923 /* Strip this section if we don't need it; see the
2924 comment below. */
2925 strip = true;
2927 else
2929 /* Remember whether there is a PLT. */
2930 plt = true;
2933 else if (strncmp (name, ".rel", 4) == 0)
2935 if (s->_raw_size == 0)
2937 /* If we don't need this section, strip it from the
2938 output file. This is mostly to handle .rel.bss and
2939 .rel.plt. We must create both sections in
2940 create_dynamic_sections, because they must be created
2941 before the linker maps input sections to output
2942 sections. The linker does that before
2943 adjust_dynamic_symbol is called, and it is that
2944 function which decides whether anything needs to go
2945 into these sections. */
2946 strip = true;
2948 else
2950 asection * target;
2952 /* Remember whether there are any reloc sections other
2953 than .rel.plt. */
2954 if (strcmp (name, ".rel.plt") != 0)
2956 const char *outname;
2958 relocs = true;
2960 /* If this relocation section applies to a read only
2961 section, then we probably need a DT_TEXTREL
2962 entry. The entries in the .rel.plt section
2963 really apply to the .got section, which we
2964 created ourselves and so know is not readonly. */
2965 outname = bfd_get_section_name (output_bfd,
2966 s->output_section);
2967 target = bfd_get_section_by_name (output_bfd, outname + 4);
2969 if (target != NULL
2970 && (target->flags & SEC_READONLY) != 0
2971 && (target->flags & SEC_ALLOC) != 0)
2972 reltext = true;
2975 /* We use the reloc_count field as a counter if we need
2976 to copy relocs into the output file. */
2977 s->reloc_count = 0;
2980 else if (strncmp (name, ".got", 4) != 0)
2982 /* It's not one of our sections, so don't allocate space. */
2983 continue;
2986 if (strip)
2988 asection ** spp;
2990 for (spp = &s->output_section->owner->sections;
2991 *spp != s->output_section;
2992 spp = &(*spp)->next)
2994 *spp = s->output_section->next;
2995 --s->output_section->owner->section_count;
2997 continue;
3000 /* Allocate memory for the section contents. */
3001 s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->_raw_size);
3002 if (s->contents == NULL && s->_raw_size != 0)
3003 return false;
3006 if (elf_hash_table (info)->dynamic_sections_created)
3008 /* Add some entries to the .dynamic section. We fill in the
3009 values later, in elf32_arm_finish_dynamic_sections, but we
3010 must add the entries now so that we get the correct size for
3011 the .dynamic section. The DT_DEBUG entry is filled in by the
3012 dynamic linker and used by the debugger. */
3013 if (! info->shared)
3015 if (! bfd_elf32_add_dynamic_entry (info, DT_DEBUG, 0))
3016 return false;
3019 if (plt)
3021 if ( ! bfd_elf32_add_dynamic_entry (info, DT_PLTGOT, 0)
3022 || ! bfd_elf32_add_dynamic_entry (info, DT_PLTRELSZ, 0)
3023 || ! bfd_elf32_add_dynamic_entry (info, DT_PLTREL, DT_REL)
3024 || ! bfd_elf32_add_dynamic_entry (info, DT_JMPREL, 0))
3025 return false;
3028 if (relocs)
3030 if ( ! bfd_elf32_add_dynamic_entry (info, DT_REL, 0)
3031 || ! bfd_elf32_add_dynamic_entry (info, DT_RELSZ, 0)
3032 || ! bfd_elf32_add_dynamic_entry (info, DT_RELENT,
3033 sizeof (Elf32_External_Rel)))
3034 return false;
3037 if (reltext)
3039 if (! bfd_elf32_add_dynamic_entry (info, DT_TEXTREL, 0))
3040 return false;
3041 info->flags |= DF_TEXTREL;
3045 return true;
3048 /* This function is called via elf32_arm_link_hash_traverse if we are
3049 creating a shared object with -Bsymbolic. It discards the space
3050 allocated to copy PC relative relocs against symbols which are
3051 defined in regular objects. We allocated space for them in the
3052 check_relocs routine, but we won't fill them in in the
3053 relocate_section routine. */
3055 static boolean
3056 elf32_arm_discard_copies (h, ignore)
3057 struct elf32_arm_link_hash_entry * h;
3058 PTR ignore ATTRIBUTE_UNUSED;
3060 struct elf32_arm_pcrel_relocs_copied * s;
3062 /* We only discard relocs for symbols defined in a regular object. */
3063 if ((h->root.elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
3064 return true;
3066 for (s = h->pcrel_relocs_copied; s != NULL; s = s->next)
3067 s->section->_raw_size -= s->count * sizeof (Elf32_External_Rel);
3069 return true;
3072 /* Finish up dynamic symbol handling. We set the contents of various
3073 dynamic sections here. */
3075 static boolean
3076 elf32_arm_finish_dynamic_symbol (output_bfd, info, h, sym)
3077 bfd * output_bfd;
3078 struct bfd_link_info * info;
3079 struct elf_link_hash_entry * h;
3080 Elf_Internal_Sym * sym;
3082 bfd * dynobj;
3084 dynobj = elf_hash_table (info)->dynobj;
3086 if (h->plt.offset != (bfd_vma) -1)
3088 asection * splt;
3089 asection * sgot;
3090 asection * srel;
3091 bfd_vma plt_index;
3092 bfd_vma got_offset;
3093 Elf_Internal_Rel rel;
3095 /* This symbol has an entry in the procedure linkage table. Set
3096 it up. */
3098 BFD_ASSERT (h->dynindx != -1);
3100 splt = bfd_get_section_by_name (dynobj, ".plt");
3101 sgot = bfd_get_section_by_name (dynobj, ".got.plt");
3102 srel = bfd_get_section_by_name (dynobj, ".rel.plt");
3103 BFD_ASSERT (splt != NULL && sgot != NULL && srel != NULL);
3105 /* Get the index in the procedure linkage table which
3106 corresponds to this symbol. This is the index of this symbol
3107 in all the symbols for which we are making plt entries. The
3108 first entry in the procedure linkage table is reserved. */
3109 plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1;
3111 /* Get the offset into the .got table of the entry that
3112 corresponds to this function. Each .got entry is 4 bytes.
3113 The first three are reserved. */
3114 got_offset = (plt_index + 3) * 4;
3116 /* Fill in the entry in the procedure linkage table. */
3117 memcpy (splt->contents + h->plt.offset,
3118 elf32_arm_plt_entry,
3119 PLT_ENTRY_SIZE);
3120 bfd_put_32 (output_bfd,
3121 (sgot->output_section->vma
3122 + sgot->output_offset
3123 + got_offset
3124 - splt->output_section->vma
3125 - splt->output_offset
3126 - h->plt.offset - 12),
3127 splt->contents + h->plt.offset + 12);
3129 /* Fill in the entry in the global offset table. */
3130 bfd_put_32 (output_bfd,
3131 (splt->output_section->vma
3132 + splt->output_offset),
3133 sgot->contents + got_offset);
3135 /* Fill in the entry in the .rel.plt section. */
3136 rel.r_offset = (sgot->output_section->vma
3137 + sgot->output_offset
3138 + got_offset);
3139 rel.r_info = ELF32_R_INFO (h->dynindx, R_ARM_JUMP_SLOT);
3140 bfd_elf32_swap_reloc_out (output_bfd, &rel,
3141 ((Elf32_External_Rel *) srel->contents
3142 + plt_index));
3144 if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
3146 /* Mark the symbol as undefined, rather than as defined in
3147 the .plt section. Leave the value alone. */
3148 sym->st_shndx = SHN_UNDEF;
3152 if (h->got.offset != (bfd_vma) -1)
3154 asection * sgot;
3155 asection * srel;
3156 Elf_Internal_Rel rel;
3158 /* This symbol has an entry in the global offset table. Set it
3159 up. */
3160 sgot = bfd_get_section_by_name (dynobj, ".got");
3161 srel = bfd_get_section_by_name (dynobj, ".rel.got");
3162 BFD_ASSERT (sgot != NULL && srel != NULL);
3164 rel.r_offset = (sgot->output_section->vma
3165 + sgot->output_offset
3166 + (h->got.offset &~ 1));
3168 /* If this is a -Bsymbolic link, and the symbol is defined
3169 locally, we just want to emit a RELATIVE reloc. The entry in
3170 the global offset table will already have been initialized in
3171 the relocate_section function. */
3172 if (info->shared
3173 && (info->symbolic || h->dynindx == -1)
3174 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))
3175 rel.r_info = ELF32_R_INFO (0, R_ARM_RELATIVE);
3176 else
3178 bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + h->got.offset);
3179 rel.r_info = ELF32_R_INFO (h->dynindx, R_ARM_GLOB_DAT);
3182 bfd_elf32_swap_reloc_out (output_bfd, &rel,
3183 ((Elf32_External_Rel *) srel->contents
3184 + srel->reloc_count));
3185 ++srel->reloc_count;
3188 if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_COPY) != 0)
3190 asection * s;
3191 Elf_Internal_Rel rel;
3193 /* This symbol needs a copy reloc. Set it up. */
3194 BFD_ASSERT (h->dynindx != -1
3195 && (h->root.type == bfd_link_hash_defined
3196 || h->root.type == bfd_link_hash_defweak));
3198 s = bfd_get_section_by_name (h->root.u.def.section->owner,
3199 ".rel.bss");
3200 BFD_ASSERT (s != NULL);
3202 rel.r_offset = (h->root.u.def.value
3203 + h->root.u.def.section->output_section->vma
3204 + h->root.u.def.section->output_offset);
3205 rel.r_info = ELF32_R_INFO (h->dynindx, R_ARM_COPY);
3206 bfd_elf32_swap_reloc_out (output_bfd, &rel,
3207 ((Elf32_External_Rel *) s->contents
3208 + s->reloc_count));
3209 ++s->reloc_count;
3212 /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */
3213 if (strcmp (h->root.root.string, "_DYNAMIC") == 0
3214 || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0)
3215 sym->st_shndx = SHN_ABS;
3217 return true;
3220 /* Finish up the dynamic sections. */
3222 static boolean
3223 elf32_arm_finish_dynamic_sections (output_bfd, info)
3224 bfd * output_bfd;
3225 struct bfd_link_info * info;
3227 bfd * dynobj;
3228 asection * sgot;
3229 asection * sdyn;
3231 dynobj = elf_hash_table (info)->dynobj;
3233 sgot = bfd_get_section_by_name (dynobj, ".got.plt");
3234 BFD_ASSERT (sgot != NULL);
3235 sdyn = bfd_get_section_by_name (dynobj, ".dynamic");
3237 if (elf_hash_table (info)->dynamic_sections_created)
3239 asection *splt;
3240 Elf32_External_Dyn *dyncon, *dynconend;
3242 splt = bfd_get_section_by_name (dynobj, ".plt");
3243 BFD_ASSERT (splt != NULL && sdyn != NULL);
3245 dyncon = (Elf32_External_Dyn *) sdyn->contents;
3246 dynconend = (Elf32_External_Dyn *) (sdyn->contents + sdyn->_raw_size);
3248 for (; dyncon < dynconend; dyncon++)
3250 Elf_Internal_Dyn dyn;
3251 const char * name;
3252 asection * s;
3254 bfd_elf32_swap_dyn_in (dynobj, dyncon, &dyn);
3256 switch (dyn.d_tag)
3258 default:
3259 break;
3261 case DT_PLTGOT:
3262 name = ".got";
3263 goto get_vma;
3264 case DT_JMPREL:
3265 name = ".rel.plt";
3266 get_vma:
3267 s = bfd_get_section_by_name (output_bfd, name);
3268 BFD_ASSERT (s != NULL);
3269 dyn.d_un.d_ptr = s->vma;
3270 bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
3271 break;
3273 case DT_PLTRELSZ:
3274 s = bfd_get_section_by_name (output_bfd, ".rel.plt");
3275 BFD_ASSERT (s != NULL);
3276 if (s->_cooked_size != 0)
3277 dyn.d_un.d_val = s->_cooked_size;
3278 else
3279 dyn.d_un.d_val = s->_raw_size;
3280 bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
3281 break;
3283 case DT_RELSZ:
3284 /* My reading of the SVR4 ABI indicates that the
3285 procedure linkage table relocs (DT_JMPREL) should be
3286 included in the overall relocs (DT_REL). This is
3287 what Solaris does. However, UnixWare can not handle
3288 that case. Therefore, we override the DT_RELSZ entry
3289 here to make it not include the JMPREL relocs. Since
3290 the linker script arranges for .rel.plt to follow all
3291 other relocation sections, we don't have to worry
3292 about changing the DT_REL entry. */
3293 s = bfd_get_section_by_name (output_bfd, ".rel.plt");
3294 if (s != NULL)
3296 if (s->_cooked_size != 0)
3297 dyn.d_un.d_val -= s->_cooked_size;
3298 else
3299 dyn.d_un.d_val -= s->_raw_size;
3301 bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
3302 break;
3306 /* Fill in the first entry in the procedure linkage table. */
3307 if (splt->_raw_size > 0)
3308 memcpy (splt->contents, elf32_arm_plt0_entry, PLT_ENTRY_SIZE);
3310 /* UnixWare sets the entsize of .plt to 4, although that doesn't
3311 really seem like the right value. */
3312 elf_section_data (splt->output_section)->this_hdr.sh_entsize = 4;
3315 /* Fill in the first three entries in the global offset table. */
3316 if (sgot->_raw_size > 0)
3318 if (sdyn == NULL)
3319 bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents);
3320 else
3321 bfd_put_32 (output_bfd,
3322 sdyn->output_section->vma + sdyn->output_offset,
3323 sgot->contents);
3324 bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + 4);
3325 bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + 8);
3328 elf_section_data (sgot->output_section)->this_hdr.sh_entsize = 4;
3330 return true;
3333 static void
3334 elf32_arm_post_process_headers (abfd, link_info)
3335 bfd * abfd;
3336 struct bfd_link_info * link_info ATTRIBUTE_UNUSED;
3338 Elf_Internal_Ehdr * i_ehdrp; /* ELF file header, internal form. */
3340 i_ehdrp = elf_elfheader (abfd);
3342 i_ehdrp->e_ident[EI_OSABI] = ARM_ELF_OS_ABI_VERSION;
3343 i_ehdrp->e_ident[EI_ABIVERSION] = ARM_ELF_ABI_VERSION;
3347 #define ELF_ARCH bfd_arch_arm
3348 #define ELF_MACHINE_CODE EM_ARM
3349 #define ELF_MAXPAGESIZE 0x8000
3352 #define bfd_elf32_bfd_copy_private_bfd_data elf32_arm_copy_private_bfd_data
3353 #define bfd_elf32_bfd_merge_private_bfd_data elf32_arm_merge_private_bfd_data
3354 #define bfd_elf32_bfd_set_private_flags elf32_arm_set_private_flags
3355 #define bfd_elf32_bfd_print_private_bfd_data elf32_arm_print_private_bfd_data
3356 #define bfd_elf32_bfd_link_hash_table_create elf32_arm_link_hash_table_create
3357 #define bfd_elf32_bfd_reloc_type_lookup elf32_arm_reloc_type_lookup
3358 #define bfd_elf32_find_nearest_line elf32_arm_find_nearest_line
3360 #define elf_backend_get_symbol_type elf32_arm_get_symbol_type
3361 #define elf_backend_gc_mark_hook elf32_arm_gc_mark_hook
3362 #define elf_backend_gc_sweep_hook elf32_arm_gc_sweep_hook
3363 #define elf_backend_check_relocs elf32_arm_check_relocs
3364 #define elf_backend_relocate_section elf32_arm_relocate_section
3365 #define elf_backend_adjust_dynamic_symbol elf32_arm_adjust_dynamic_symbol
3366 #define elf_backend_create_dynamic_sections _bfd_elf_create_dynamic_sections
3367 #define elf_backend_finish_dynamic_symbol elf32_arm_finish_dynamic_symbol
3368 #define elf_backend_finish_dynamic_sections elf32_arm_finish_dynamic_sections
3369 #define elf_backend_size_dynamic_sections elf32_arm_size_dynamic_sections
3370 #define elf_backend_post_process_headers elf32_arm_post_process_headers
3372 #define elf_backend_can_gc_sections 1
3373 #define elf_backend_plt_readonly 1
3374 #define elf_backend_want_got_plt 1
3375 #define elf_backend_want_plt_sym 0
3377 #define elf_backend_got_header_size 12
3378 #define elf_backend_plt_header_size PLT_ENTRY_SIZE
3380 #include "elf32-target.h"