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binutils-gdb/bfd/elf32-arm.h
Nick Clifton f7a74f8c82 Support big endian PLT entries.
2001-05-28 10:50:31 +00:00

3457 lines
102 KiB
C
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/* 32-bit ELF support for ARM
Copyright 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
This file is part of BFD, the Binary File Descriptor library.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
typedef unsigned long int insn32;
typedef unsigned short int insn16;
static boolean elf32_arm_set_private_flags
PARAMS ((bfd *, flagword));
static boolean elf32_arm_copy_private_bfd_data
PARAMS ((bfd *, bfd *));
static boolean elf32_arm_merge_private_bfd_data
PARAMS ((bfd *, bfd *));
static boolean elf32_arm_print_private_bfd_data
PARAMS ((bfd *, PTR));
static int elf32_arm_get_symbol_type
PARAMS (( Elf_Internal_Sym *, int));
static struct bfd_link_hash_table *elf32_arm_link_hash_table_create
PARAMS ((bfd *));
static bfd_reloc_status_type elf32_arm_final_link_relocate
PARAMS ((reloc_howto_type *, bfd *, bfd *, asection *, bfd_byte *,
Elf_Internal_Rela *, bfd_vma, struct bfd_link_info *, asection *,
const char *, unsigned char, struct elf_link_hash_entry *));
static insn32 insert_thumb_branch
PARAMS ((insn32, int));
static struct elf_link_hash_entry *find_thumb_glue
PARAMS ((struct bfd_link_info *, CONST char *, bfd *));
static struct elf_link_hash_entry *find_arm_glue
PARAMS ((struct bfd_link_info *, CONST char *, bfd *));
static void record_arm_to_thumb_glue
PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *));
static void record_thumb_to_arm_glue
PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *));
static void elf32_arm_post_process_headers
PARAMS ((bfd *, struct bfd_link_info *));
static int elf32_arm_to_thumb_stub
PARAMS ((struct bfd_link_info *, const char *, bfd *, bfd *, asection *,
bfd_byte *, asection *, bfd_vma, bfd_signed_vma, bfd_vma));
static int elf32_thumb_to_arm_stub
PARAMS ((struct bfd_link_info *, const char *, bfd *, bfd *, asection *,
bfd_byte *, asection *, bfd_vma, bfd_signed_vma, bfd_vma));
#define INTERWORK_FLAG(abfd) (elf_elfheader (abfd)->e_flags & EF_ARM_INTERWORK)
/* The linker script knows the section names for placement.
The entry_names are used to do simple name mangling on the stubs.
Given a function name, and its type, the stub can be found. The
name can be changed. The only requirement is the %s be present. */
#define THUMB2ARM_GLUE_SECTION_NAME ".glue_7t"
#define THUMB2ARM_GLUE_ENTRY_NAME "__%s_from_thumb"
#define ARM2THUMB_GLUE_SECTION_NAME ".glue_7"
#define ARM2THUMB_GLUE_ENTRY_NAME "__%s_from_arm"
/* The name of the dynamic interpreter. This is put in the .interp
section. */
#define ELF_DYNAMIC_INTERPRETER "/usr/lib/ld.so.1"
/* The size in bytes of an entry in the procedure linkage table. */
#define PLT_ENTRY_SIZE 16
/* The first entry in a procedure linkage table looks like
this. It is set up so that any shared library function that is
called before the relocation has been set up calls the dynamic
linker first. */
static const bfd_byte elf32_arm_plt0_entry [PLT_ENTRY_SIZE] =
{
0xe52de004, /* str lr, [sp, #-4]! */
0xe59fe010, /* ldr lr, [pc, #16] */
0xe08fe00e, /* add lr, pc, lr */
0xe5bef008 /* ldr pc, [lr, #8]! */
};
/* Subsequent entries in a procedure linkage table look like
this. */
static const bfd_byte elf32_arm_plt_entry [PLT_ENTRY_SIZE] =
{
0xe59fc004, /* ldr ip, [pc, #4] */
0xe08fc00c, /* add ip, pc, ip */
0xe59cf000, /* ldr pc, [ip] */
0x00000000 /* offset to symbol in got */
};
/* The ARM linker needs to keep track of the number of relocs that it
decides to copy in check_relocs for each symbol. This is so that
it can discard PC relative relocs if it doesn't need them when
linking with -Bsymbolic. We store the information in a field
extending the regular ELF linker hash table. */
/* This structure keeps track of the number of PC relative relocs we
have copied for a given symbol. */
struct elf32_arm_pcrel_relocs_copied
{
/* Next section. */
struct elf32_arm_pcrel_relocs_copied * next;
/* A section in dynobj. */
asection * section;
/* Number of relocs copied in this section. */
bfd_size_type count;
};
/* Arm ELF linker hash entry. */
struct elf32_arm_link_hash_entry
{
struct elf_link_hash_entry root;
/* Number of PC relative relocs copied for this symbol. */
struct elf32_arm_pcrel_relocs_copied * pcrel_relocs_copied;
};
/* Declare this now that the above structures are defined. */
static boolean elf32_arm_discard_copies
PARAMS ((struct elf32_arm_link_hash_entry *, PTR));
/* Traverse an arm ELF linker hash table. */
#define elf32_arm_link_hash_traverse(table, func, info) \
(elf_link_hash_traverse \
(&(table)->root, \
(boolean (*) PARAMS ((struct elf_link_hash_entry *, PTR))) (func), \
(info)))
/* Get the ARM elf linker hash table from a link_info structure. */
#define elf32_arm_hash_table(info) \
((struct elf32_arm_link_hash_table *) ((info)->hash))
/* ARM ELF linker hash table. */
struct elf32_arm_link_hash_table
{
/* The main hash table. */
struct elf_link_hash_table root;
/* The size in bytes of the section containg the Thumb-to-ARM glue. */
long int thumb_glue_size;
/* The size in bytes of the section containg the ARM-to-Thumb glue. */
long int arm_glue_size;
/* An arbitary input BFD chosen to hold the glue sections. */
bfd * bfd_of_glue_owner;
/* A boolean indicating whether knowledge of the ARM's pipeline
length should be applied by the linker. */
int no_pipeline_knowledge;
};
/* Create an entry in an ARM ELF linker hash table. */
static struct bfd_hash_entry *
elf32_arm_link_hash_newfunc (entry, table, string)
struct bfd_hash_entry * entry;
struct bfd_hash_table * table;
const char * string;
{
struct elf32_arm_link_hash_entry * ret =
(struct elf32_arm_link_hash_entry *) entry;
/* Allocate the structure if it has not already been allocated by a
subclass. */
if (ret == (struct elf32_arm_link_hash_entry *) NULL)
ret = ((struct elf32_arm_link_hash_entry *)
bfd_hash_allocate (table,
sizeof (struct elf32_arm_link_hash_entry)));
if (ret == (struct elf32_arm_link_hash_entry *) NULL)
return (struct bfd_hash_entry *) ret;
/* Call the allocation method of the superclass. */
ret = ((struct elf32_arm_link_hash_entry *)
_bfd_elf_link_hash_newfunc ((struct bfd_hash_entry *) ret,
table, string));
if (ret != (struct elf32_arm_link_hash_entry *) NULL)
ret->pcrel_relocs_copied = NULL;
return (struct bfd_hash_entry *) ret;
}
/* Create an ARM elf linker hash table. */
static struct bfd_link_hash_table *
elf32_arm_link_hash_table_create (abfd)
bfd *abfd;
{
struct elf32_arm_link_hash_table *ret;
ret = ((struct elf32_arm_link_hash_table *)
bfd_alloc (abfd, sizeof (struct elf32_arm_link_hash_table)));
if (ret == (struct elf32_arm_link_hash_table *) NULL)
return NULL;
if (!_bfd_elf_link_hash_table_init (&ret->root, abfd,
elf32_arm_link_hash_newfunc))
{
bfd_release (abfd, ret);
return NULL;
}
ret->thumb_glue_size = 0;
ret->arm_glue_size = 0;
ret->bfd_of_glue_owner = NULL;
ret->no_pipeline_knowledge = 0;
return &ret->root.root;
}
/* Locate the Thumb encoded calling stub for NAME. */
static struct elf_link_hash_entry *
find_thumb_glue (link_info, name, input_bfd)
struct bfd_link_info *link_info;
CONST char *name;
bfd *input_bfd;
{
char *tmp_name;
struct elf_link_hash_entry *hash;
struct elf32_arm_link_hash_table *hash_table;
/* We need a pointer to the armelf specific hash table. */
hash_table = elf32_arm_hash_table (link_info);
tmp_name = ((char *)
bfd_malloc (strlen (name) + strlen (THUMB2ARM_GLUE_ENTRY_NAME) + 1));
BFD_ASSERT (tmp_name);
sprintf (tmp_name, THUMB2ARM_GLUE_ENTRY_NAME, name);
hash = elf_link_hash_lookup
(&(hash_table)->root, tmp_name, false, false, true);
if (hash == NULL)
/* xgettext:c-format */
_bfd_error_handler (_("%s: unable to find THUMB glue '%s' for `%s'"),
bfd_get_filename (input_bfd), tmp_name, name);
free (tmp_name);
return hash;
}
/* Locate the ARM encoded calling stub for NAME. */
static struct elf_link_hash_entry *
find_arm_glue (link_info, name, input_bfd)
struct bfd_link_info *link_info;
CONST char *name;
bfd *input_bfd;
{
char *tmp_name;
struct elf_link_hash_entry *myh;
struct elf32_arm_link_hash_table *hash_table;
/* We need a pointer to the elfarm specific hash table. */
hash_table = elf32_arm_hash_table (link_info);
tmp_name = ((char *)
bfd_malloc (strlen (name) + strlen (ARM2THUMB_GLUE_ENTRY_NAME) + 1));
BFD_ASSERT (tmp_name);
sprintf (tmp_name, ARM2THUMB_GLUE_ENTRY_NAME, name);
myh = elf_link_hash_lookup
(&(hash_table)->root, tmp_name, false, false, true);
if (myh == NULL)
/* xgettext:c-format */
_bfd_error_handler (_("%s: unable to find ARM glue '%s' for `%s'"),
bfd_get_filename (input_bfd), tmp_name, name);
free (tmp_name);
return myh;
}
/* ARM->Thumb glue:
.arm
__func_from_arm:
ldr r12, __func_addr
bx r12
__func_addr:
.word func @ behave as if you saw a ARM_32 reloc. */
#define ARM2THUMB_GLUE_SIZE 12
static const insn32 a2t1_ldr_insn = 0xe59fc000;
static const insn32 a2t2_bx_r12_insn = 0xe12fff1c;
static const insn32 a2t3_func_addr_insn = 0x00000001;
/* Thumb->ARM: Thumb->(non-interworking aware) ARM
.thumb .thumb
.align 2 .align 2
__func_from_thumb: __func_from_thumb:
bx pc push {r6, lr}
nop ldr r6, __func_addr
.arm mov lr, pc
__func_change_to_arm: bx r6
b func .arm
__func_back_to_thumb:
ldmia r13! {r6, lr}
bx lr
__func_addr:
.word func */
#define THUMB2ARM_GLUE_SIZE 8
static const insn16 t2a1_bx_pc_insn = 0x4778;
static const insn16 t2a2_noop_insn = 0x46c0;
static const insn32 t2a3_b_insn = 0xea000000;
static const insn16 t2a1_push_insn = 0xb540;
static const insn16 t2a2_ldr_insn = 0x4e03;
static const insn16 t2a3_mov_insn = 0x46fe;
static const insn16 t2a4_bx_insn = 0x4730;
static const insn32 t2a5_pop_insn = 0xe8bd4040;
static const insn32 t2a6_bx_insn = 0xe12fff1e;
boolean
bfd_elf32_arm_allocate_interworking_sections (info)
struct bfd_link_info * info;
{
asection * s;
bfd_byte * foo;
struct elf32_arm_link_hash_table * globals;
globals = elf32_arm_hash_table (info);
BFD_ASSERT (globals != NULL);
if (globals->arm_glue_size != 0)
{
BFD_ASSERT (globals->bfd_of_glue_owner != NULL);
s = bfd_get_section_by_name
(globals->bfd_of_glue_owner, ARM2THUMB_GLUE_SECTION_NAME);
BFD_ASSERT (s != NULL);
foo = (bfd_byte *) bfd_alloc
(globals->bfd_of_glue_owner, globals->arm_glue_size);
s->_raw_size = s->_cooked_size = globals->arm_glue_size;
s->contents = foo;
}
if (globals->thumb_glue_size != 0)
{
BFD_ASSERT (globals->bfd_of_glue_owner != NULL);
s = bfd_get_section_by_name
(globals->bfd_of_glue_owner, THUMB2ARM_GLUE_SECTION_NAME);
BFD_ASSERT (s != NULL);
foo = (bfd_byte *) bfd_alloc
(globals->bfd_of_glue_owner, globals->thumb_glue_size);
s->_raw_size = s->_cooked_size = globals->thumb_glue_size;
s->contents = foo;
}
return true;
}
static void
record_arm_to_thumb_glue (link_info, h)
struct bfd_link_info * link_info;
struct elf_link_hash_entry * h;
{
const char * name = h->root.root.string;
register asection * s;
char * tmp_name;
struct elf_link_hash_entry * myh;
struct elf32_arm_link_hash_table * globals;
globals = elf32_arm_hash_table (link_info);
BFD_ASSERT (globals != NULL);
BFD_ASSERT (globals->bfd_of_glue_owner != NULL);
s = bfd_get_section_by_name
(globals->bfd_of_glue_owner, ARM2THUMB_GLUE_SECTION_NAME);
BFD_ASSERT (s != NULL);
tmp_name = ((char *)
bfd_malloc (strlen (name) + strlen (ARM2THUMB_GLUE_ENTRY_NAME) + 1));
BFD_ASSERT (tmp_name);
sprintf (tmp_name, ARM2THUMB_GLUE_ENTRY_NAME, name);
myh = elf_link_hash_lookup
(&(globals)->root, tmp_name, false, false, true);
if (myh != NULL)
{
/* We've already seen this guy. */
free (tmp_name);
return;
}
/* The only trick here is using hash_table->arm_glue_size as the value. Even
though the section isn't allocated yet, this is where we will be putting
it. */
_bfd_generic_link_add_one_symbol (link_info, globals->bfd_of_glue_owner, tmp_name,
BSF_GLOBAL,
s, globals->arm_glue_size + 1,
NULL, true, false,
(struct bfd_link_hash_entry **) &myh);
free (tmp_name);
globals->arm_glue_size += ARM2THUMB_GLUE_SIZE;
return;
}
static void
record_thumb_to_arm_glue (link_info, h)
struct bfd_link_info *link_info;
struct elf_link_hash_entry *h;
{
const char *name = h->root.root.string;
register asection *s;
char *tmp_name;
struct elf_link_hash_entry *myh;
struct elf32_arm_link_hash_table *hash_table;
char bind;
hash_table = elf32_arm_hash_table (link_info);
BFD_ASSERT (hash_table != NULL);
BFD_ASSERT (hash_table->bfd_of_glue_owner != NULL);
s = bfd_get_section_by_name
(hash_table->bfd_of_glue_owner, THUMB2ARM_GLUE_SECTION_NAME);
BFD_ASSERT (s != NULL);
tmp_name = (char *) bfd_malloc (strlen (name) + strlen (THUMB2ARM_GLUE_ENTRY_NAME) + 1);
BFD_ASSERT (tmp_name);
sprintf (tmp_name, THUMB2ARM_GLUE_ENTRY_NAME, name);
myh = elf_link_hash_lookup
(&(hash_table)->root, tmp_name, false, false, true);
if (myh != NULL)
{
/* We've already seen this guy. */
free (tmp_name);
return;
}
_bfd_generic_link_add_one_symbol (link_info, hash_table->bfd_of_glue_owner, tmp_name,
BSF_GLOBAL, s, hash_table->thumb_glue_size + 1,
NULL, true, false,
(struct bfd_link_hash_entry **) &myh);
/* If we mark it 'Thumb', the disassembler will do a better job. */
bind = ELF_ST_BIND (myh->type);
myh->type = ELF_ST_INFO (bind, STT_ARM_TFUNC);
free (tmp_name);
#define CHANGE_TO_ARM "__%s_change_to_arm"
#define BACK_FROM_ARM "__%s_back_from_arm"
/* Allocate another symbol to mark where we switch to Arm mode. */
tmp_name = (char *) bfd_malloc (strlen (name) + strlen (CHANGE_TO_ARM) + 1);
BFD_ASSERT (tmp_name);
sprintf (tmp_name, CHANGE_TO_ARM, name);
myh = NULL;
_bfd_generic_link_add_one_symbol (link_info, hash_table->bfd_of_glue_owner, tmp_name,
BSF_LOCAL, s, hash_table->thumb_glue_size + 4,
NULL, true, false,
(struct bfd_link_hash_entry **) &myh);
free (tmp_name);
hash_table->thumb_glue_size += THUMB2ARM_GLUE_SIZE;
return;
}
/* Select a BFD to be used to hold the sections used by the glue code.
This function is called from the linker scripts in ld/emultempl/
{armelf/pe}.em */
boolean
bfd_elf32_arm_get_bfd_for_interworking (abfd, info)
bfd *abfd;
struct bfd_link_info *info;
{
struct elf32_arm_link_hash_table *globals;
flagword flags;
asection *sec;
/* If we are only performing a partial link do not bother
getting a bfd to hold the glue. */
if (info->relocateable)
return true;
globals = elf32_arm_hash_table (info);
BFD_ASSERT (globals != NULL);
if (globals->bfd_of_glue_owner != NULL)
return true;
sec = bfd_get_section_by_name (abfd, ARM2THUMB_GLUE_SECTION_NAME);
if (sec == NULL)
{
/* Note: we do not include the flag SEC_LINKER_CREATED, as this
will prevent elf_link_input_bfd() from processing the contents
of this section. */
flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_CODE | SEC_READONLY;
sec = bfd_make_section (abfd, ARM2THUMB_GLUE_SECTION_NAME);
if (sec == NULL
|| !bfd_set_section_flags (abfd, sec, flags)
|| !bfd_set_section_alignment (abfd, sec, 2))
return false;
/* Set the gc mark to prevent the section from being removed by garbage
collection, despite the fact that no relocs refer to this section. */
sec->gc_mark = 1;
}
sec = bfd_get_section_by_name (abfd, THUMB2ARM_GLUE_SECTION_NAME);
if (sec == NULL)
{
flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_CODE | SEC_READONLY;
sec = bfd_make_section (abfd, THUMB2ARM_GLUE_SECTION_NAME);
if (sec == NULL
|| !bfd_set_section_flags (abfd, sec, flags)
|| !bfd_set_section_alignment (abfd, sec, 2))
return false;
sec->gc_mark = 1;
}
/* Save the bfd for later use. */
globals->bfd_of_glue_owner = abfd;
return true;
}
boolean
bfd_elf32_arm_process_before_allocation (abfd, link_info, no_pipeline_knowledge)
bfd *abfd;
struct bfd_link_info *link_info;
int no_pipeline_knowledge;
{
Elf_Internal_Shdr *symtab_hdr;
Elf_Internal_Rela *free_relocs = NULL;
Elf_Internal_Rela *irel, *irelend;
bfd_byte *contents = NULL;
bfd_byte *free_contents = NULL;
Elf32_External_Sym *extsyms = NULL;
Elf32_External_Sym *free_extsyms = NULL;
asection *sec;
struct elf32_arm_link_hash_table *globals;
/* If we are only performing a partial link do not bother
to construct any glue. */
if (link_info->relocateable)
return true;
/* Here we have a bfd that is to be included on the link. We have a hook
to do reloc rummaging, before section sizes are nailed down. */
globals = elf32_arm_hash_table (link_info);
BFD_ASSERT (globals != NULL);
BFD_ASSERT (globals->bfd_of_glue_owner != NULL);
globals->no_pipeline_knowledge = no_pipeline_knowledge;
/* Rummage around all the relocs and map the glue vectors. */
sec = abfd->sections;
if (sec == NULL)
return true;
for (; sec != NULL; sec = sec->next)
{
if (sec->reloc_count == 0)
continue;
symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
/* Load the relocs. */
irel = (_bfd_elf32_link_read_relocs (abfd, sec, (PTR) NULL,
(Elf_Internal_Rela *) NULL, false));
BFD_ASSERT (irel != 0);
irelend = irel + sec->reloc_count;
for (; irel < irelend; irel++)
{
long r_type;
unsigned long r_index;
struct elf_link_hash_entry *h;
r_type = ELF32_R_TYPE (irel->r_info);
r_index = ELF32_R_SYM (irel->r_info);
/* These are the only relocation types we care about. */
if ( r_type != R_ARM_PC24
&& r_type != R_ARM_THM_PC22)
continue;
/* Get the section contents if we haven't done so already. */
if (contents == NULL)
{
/* Get cached copy if it exists. */
if (elf_section_data (sec)->this_hdr.contents != NULL)
contents = elf_section_data (sec)->this_hdr.contents;
else
{
/* Go get them off disk. */
contents = (bfd_byte *) bfd_malloc (sec->_raw_size);
if (contents == NULL)
goto error_return;
free_contents = contents;
if (!bfd_get_section_contents (abfd, sec, contents,
(file_ptr) 0, sec->_raw_size))
goto error_return;
}
}
/* Read this BFD's symbols if we haven't done so already. */
if (extsyms == NULL)
{
/* Get cached copy if it exists. */
if (symtab_hdr->contents != NULL)
extsyms = (Elf32_External_Sym *) symtab_hdr->contents;
else
{
/* Go get them off disk. */
extsyms = ((Elf32_External_Sym *)
bfd_malloc (symtab_hdr->sh_size));
if (extsyms == NULL)
goto error_return;
free_extsyms = extsyms;
if (bfd_seek (abfd, symtab_hdr->sh_offset, SEEK_SET) != 0
|| (bfd_read (extsyms, 1, symtab_hdr->sh_size, abfd)
!= symtab_hdr->sh_size))
goto error_return;
}
}
/* If the relocation is not against a symbol it cannot concern us. */
h = NULL;
/* We don't care about local symbols. */
if (r_index < symtab_hdr->sh_info)
continue;
/* This is an external symbol. */
r_index -= symtab_hdr->sh_info;
h = (struct elf_link_hash_entry *)
elf_sym_hashes (abfd)[r_index];
/* If the relocation is against a static symbol it must be within
the current section and so cannot be a cross ARM/Thumb relocation. */
if (h == NULL)
continue;
switch (r_type)
{
case R_ARM_PC24:
/* This one is a call from arm code. We need to look up
the target of the call. If it is a thumb target, we
insert glue. */
if (ELF_ST_TYPE(h->type) == STT_ARM_TFUNC)
record_arm_to_thumb_glue (link_info, h);
break;
case R_ARM_THM_PC22:
/* This one is a call from thumb code. We look
up the target of the call. If it is not a thumb
target, we insert glue. */
if (ELF_ST_TYPE (h->type) != STT_ARM_TFUNC)
record_thumb_to_arm_glue (link_info, h);
break;
default:
break;
}
}
}
return true;
error_return:
if (free_relocs != NULL)
free (free_relocs);
if (free_contents != NULL)
free (free_contents);
if (free_extsyms != NULL)
free (free_extsyms);
return false;
}
/* The thumb form of a long branch is a bit finicky, because the offset
encoding is split over two fields, each in it's own instruction. They
can occur in any order. So given a thumb form of long branch, and an
offset, insert the offset into the thumb branch and return finished
instruction.
It takes two thumb instructions to encode the target address. Each has
11 bits to invest. The upper 11 bits are stored in one (identifed by
H-0.. see below), the lower 11 bits are stored in the other (identified
by H-1).
Combine together and shifted left by 1 (it's a half word address) and
there you have it.
Op: 1111 = F,
H-0, upper address-0 = 000
Op: 1111 = F,
H-1, lower address-0 = 800
They can be ordered either way, but the arm tools I've seen always put
the lower one first. It probably doesn't matter. krk@cygnus.com
XXX: Actually the order does matter. The second instruction (H-1)
moves the computed address into the PC, so it must be the second one
in the sequence. The problem, however is that whilst little endian code
stores the instructions in HI then LOW order, big endian code does the
reverse. nickc@cygnus.com. */
#define LOW_HI_ORDER 0xF800F000
#define HI_LOW_ORDER 0xF000F800
static insn32
insert_thumb_branch (br_insn, rel_off)
insn32 br_insn;
int rel_off;
{
unsigned int low_bits;
unsigned int high_bits;
BFD_ASSERT ((rel_off & 1) != 1);
rel_off >>= 1; /* Half word aligned address. */
low_bits = rel_off & 0x000007FF; /* The bottom 11 bits. */
high_bits = (rel_off >> 11) & 0x000007FF; /* The top 11 bits. */
if ((br_insn & LOW_HI_ORDER) == LOW_HI_ORDER)
br_insn = LOW_HI_ORDER | (low_bits << 16) | high_bits;
else if ((br_insn & HI_LOW_ORDER) == HI_LOW_ORDER)
br_insn = HI_LOW_ORDER | (high_bits << 16) | low_bits;
else
/* FIXME: abort is probably not the right call. krk@cygnus.com */
abort (); /* error - not a valid branch instruction form. */
return br_insn;
}
/* Thumb code calling an ARM function. */
static int
elf32_thumb_to_arm_stub (info, name, input_bfd, output_bfd, input_section,
hit_data, sym_sec, offset, addend, val)
struct bfd_link_info * info;
const char * name;
bfd * input_bfd;
bfd * output_bfd;
asection * input_section;
bfd_byte * hit_data;
asection * sym_sec;
bfd_vma offset;
bfd_signed_vma addend;
bfd_vma val;
{
asection * s = 0;
long int my_offset;
unsigned long int tmp;
long int ret_offset;
struct elf_link_hash_entry * myh;
struct elf32_arm_link_hash_table * globals;
myh = find_thumb_glue (info, name, input_bfd);
if (myh == NULL)
return false;
globals = elf32_arm_hash_table (info);
BFD_ASSERT (globals != NULL);
BFD_ASSERT (globals->bfd_of_glue_owner != NULL);
my_offset = myh->root.u.def.value;
s = bfd_get_section_by_name (globals->bfd_of_glue_owner,
THUMB2ARM_GLUE_SECTION_NAME);
BFD_ASSERT (s != NULL);
BFD_ASSERT (s->contents != NULL);
BFD_ASSERT (s->output_section != NULL);
if ((my_offset & 0x01) == 0x01)
{
if (sym_sec != NULL
&& sym_sec->owner != NULL
&& !INTERWORK_FLAG (sym_sec->owner))
{
_bfd_error_handler
(_("%s(%s): warning: interworking not enabled."),
bfd_get_filename (sym_sec->owner), name);
_bfd_error_handler
(_(" first occurrence: %s: thumb call to arm"),
bfd_get_filename (input_bfd));
return false;
}
--my_offset;
myh->root.u.def.value = my_offset;
bfd_put_16 (output_bfd, t2a1_bx_pc_insn,
s->contents + my_offset);
bfd_put_16 (output_bfd, t2a2_noop_insn,
s->contents + my_offset + 2);
ret_offset =
/* Address of destination of the stub. */
((bfd_signed_vma) val)
- ((bfd_signed_vma)
/* Offset from the start of the current section to the start of the stubs. */
(s->output_offset
/* Offset of the start of this stub from the start of the stubs. */
+ my_offset
/* Address of the start of the current section. */
+ s->output_section->vma)
/* The branch instruction is 4 bytes into the stub. */
+ 4
/* ARM branches work from the pc of the instruction + 8. */
+ 8);
bfd_put_32 (output_bfd,
t2a3_b_insn | ((ret_offset >> 2) & 0x00FFFFFF),
s->contents + my_offset + 4);
}
BFD_ASSERT (my_offset <= globals->thumb_glue_size);
/* Now go back and fix up the original BL insn to point
to here. */
ret_offset =
s->output_offset
+ my_offset
- (input_section->output_offset
+ offset + addend)
- 8;
tmp = bfd_get_32 (input_bfd, hit_data
- input_section->vma);
bfd_put_32 (output_bfd,
insert_thumb_branch (tmp, ret_offset),
hit_data - input_section->vma);
return true;
}
/* Arm code calling a Thumb function. */
static int
elf32_arm_to_thumb_stub (info, name, input_bfd, output_bfd, input_section,
hit_data, sym_sec, offset, addend, val)
struct bfd_link_info * info;
const char * name;
bfd * input_bfd;
bfd * output_bfd;
asection * input_section;
bfd_byte * hit_data;
asection * sym_sec;
bfd_vma offset;
bfd_signed_vma addend;
bfd_vma val;
{
unsigned long int tmp;
long int my_offset;
asection * s;
long int ret_offset;
struct elf_link_hash_entry * myh;
struct elf32_arm_link_hash_table * globals;
myh = find_arm_glue (info, name, input_bfd);
if (myh == NULL)
return false;
globals = elf32_arm_hash_table (info);
BFD_ASSERT (globals != NULL);
BFD_ASSERT (globals->bfd_of_glue_owner != NULL);
my_offset = myh->root.u.def.value;
s = bfd_get_section_by_name (globals->bfd_of_glue_owner,
ARM2THUMB_GLUE_SECTION_NAME);
BFD_ASSERT (s != NULL);
BFD_ASSERT (s->contents != NULL);
BFD_ASSERT (s->output_section != NULL);
if ((my_offset & 0x01) == 0x01)
{
if (sym_sec != NULL
&& sym_sec->owner != NULL
&& !INTERWORK_FLAG (sym_sec->owner))
{
_bfd_error_handler
(_("%s(%s): warning: interworking not enabled."),
bfd_get_filename (sym_sec->owner), name);
_bfd_error_handler
(_(" first occurrence: %s: arm call to thumb"),
bfd_get_filename (input_bfd));
}
--my_offset;
myh->root.u.def.value = my_offset;
bfd_put_32 (output_bfd, a2t1_ldr_insn,
s->contents + my_offset);
bfd_put_32 (output_bfd, a2t2_bx_r12_insn,
s->contents + my_offset + 4);
/* It's a thumb address. Add the low order bit. */
bfd_put_32 (output_bfd, val | a2t3_func_addr_insn,
s->contents + my_offset + 8);
}
BFD_ASSERT (my_offset <= globals->arm_glue_size);
tmp = bfd_get_32 (input_bfd, hit_data);
tmp = tmp & 0xFF000000;
/* Somehow these are both 4 too far, so subtract 8. */
ret_offset = s->output_offset
+ my_offset
+ s->output_section->vma
- (input_section->output_offset
+ input_section->output_section->vma
+ offset + addend)
- 8;
tmp = tmp | ((ret_offset >> 2) & 0x00FFFFFF);
bfd_put_32 (output_bfd, tmp, hit_data
- input_section->vma);
return true;
}
/* Perform a relocation as part of a final link. */
static bfd_reloc_status_type
elf32_arm_final_link_relocate (howto, input_bfd, output_bfd,
input_section, contents, rel, value,
info, sym_sec, sym_name, sym_flags, h)
reloc_howto_type * howto;
bfd * input_bfd;
bfd * output_bfd;
asection * input_section;
bfd_byte * contents;
Elf_Internal_Rela * rel;
bfd_vma value;
struct bfd_link_info * info;
asection * sym_sec;
const char * sym_name;
unsigned char sym_flags;
struct elf_link_hash_entry * h;
{
unsigned long r_type = howto->type;
unsigned long r_symndx;
bfd_byte * hit_data = contents + rel->r_offset;
bfd * dynobj = NULL;
Elf_Internal_Shdr * symtab_hdr;
struct elf_link_hash_entry ** sym_hashes;
bfd_vma * local_got_offsets;
asection * sgot = NULL;
asection * splt = NULL;
asection * sreloc = NULL;
bfd_vma addend;
bfd_signed_vma signed_addend;
struct elf32_arm_link_hash_table * globals;
/* If the start address has been set, then set the EF_ARM_HASENTRY
flag. Setting this more than once is redundant, but the cost is
not too high, and it keeps the code simple.
The test is done here, rather than somewhere else, because the
start address is only set just before the final link commences.
Note - if the user deliberately sets a start address of 0, the
flag will not be set. */
if (bfd_get_start_address (output_bfd) != 0)
elf_elfheader (output_bfd)->e_flags |= EF_ARM_HASENTRY;
globals = elf32_arm_hash_table (info);
dynobj = elf_hash_table (info)->dynobj;
if (dynobj)
{
sgot = bfd_get_section_by_name (dynobj, ".got");
splt = bfd_get_section_by_name (dynobj, ".plt");
}
symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
sym_hashes = elf_sym_hashes (input_bfd);
local_got_offsets = elf_local_got_offsets (input_bfd);
r_symndx = ELF32_R_SYM (rel->r_info);
#ifdef USE_REL
addend = bfd_get_32 (input_bfd, hit_data) & howto->src_mask;
if (addend & ((howto->src_mask + 1) >> 1))
{
signed_addend = -1;
signed_addend &= ~ howto->src_mask;
signed_addend |= addend;
}
else
signed_addend = addend;
#else
addend = signed_addend = rel->r_addend;
#endif
switch (r_type)
{
case R_ARM_NONE:
return bfd_reloc_ok;
case R_ARM_PC24:
case R_ARM_ABS32:
case R_ARM_REL32:
#ifndef OLD_ARM_ABI
case R_ARM_XPC25:
#endif
/* When generating a shared object, these relocations are copied
into the output file to be resolved at run time. */
if (info->shared
&& (r_type != R_ARM_PC24
|| (h != NULL
&& h->dynindx != -1
&& (! info->symbolic
|| (h->elf_link_hash_flags
& ELF_LINK_HASH_DEF_REGULAR) == 0))))
{
Elf_Internal_Rel outrel;
boolean skip, relocate;
if (sreloc == NULL)
{
const char * name;
name = (bfd_elf_string_from_elf_section
(input_bfd,
elf_elfheader (input_bfd)->e_shstrndx,
elf_section_data (input_section)->rel_hdr.sh_name));
if (name == NULL)
return bfd_reloc_notsupported;
BFD_ASSERT (strncmp (name, ".rel", 4) == 0
&& strcmp (bfd_get_section_name (input_bfd,
input_section),
name + 4) == 0);
sreloc = bfd_get_section_by_name (dynobj, name);
BFD_ASSERT (sreloc != NULL);
}
skip = false;
if (elf_section_data (input_section)->stab_info == NULL)
outrel.r_offset = rel->r_offset;
else
{
bfd_vma off;
off = (_bfd_stab_section_offset
(output_bfd, &elf_hash_table (info)->stab_info,
input_section,
& elf_section_data (input_section)->stab_info,
rel->r_offset));
if (off == (bfd_vma) -1)
skip = true;
outrel.r_offset = off;
}
outrel.r_offset += (input_section->output_section->vma
+ input_section->output_offset);
if (skip)
{
memset (&outrel, 0, sizeof outrel);
relocate = false;
}
else if (r_type == R_ARM_PC24)
{
BFD_ASSERT (h != NULL && h->dynindx != -1);
if ((input_section->flags & SEC_ALLOC) != 0)
relocate = false;
else
relocate = true;
outrel.r_info = ELF32_R_INFO (h->dynindx, R_ARM_PC24);
}
else
{
if (h == NULL
|| ((info->symbolic || h->dynindx == -1)
&& (h->elf_link_hash_flags
& ELF_LINK_HASH_DEF_REGULAR) != 0))
{
relocate = true;
outrel.r_info = ELF32_R_INFO (0, R_ARM_RELATIVE);
}
else
{
BFD_ASSERT (h->dynindx != -1);
if ((input_section->flags & SEC_ALLOC) != 0)
relocate = false;
else
relocate = true;
outrel.r_info = ELF32_R_INFO (h->dynindx, R_ARM_ABS32);
}
}
bfd_elf32_swap_reloc_out (output_bfd, &outrel,
(((Elf32_External_Rel *)
sreloc->contents)
+ sreloc->reloc_count));
++sreloc->reloc_count;
/* If this reloc is against an external symbol, we do not want to
fiddle with the addend. Otherwise, we need to include the symbol
value so that it becomes an addend for the dynamic reloc. */
if (! relocate)
return bfd_reloc_ok;
return _bfd_final_link_relocate (howto, input_bfd, input_section,
contents, rel->r_offset, value,
(bfd_vma) 0);
}
else switch (r_type)
{
#ifndef OLD_ARM_ABI
case R_ARM_XPC25: /* Arm BLX instruction. */
#endif
case R_ARM_PC24: /* Arm B/BL instruction */
#ifndef OLD_ARM_ABI
if (r_type == R_ARM_XPC25)
{
/* Check for Arm calling Arm function. */
/* FIXME: Should we translate the instruction into a BL
instruction instead ? */
if (sym_flags != STT_ARM_TFUNC)
_bfd_error_handler (_("\
%s: Warning: Arm BLX instruction targets Arm function '%s'."),
bfd_get_filename (input_bfd),
h ? h->root.root.string : "(local)");
}
else
#endif
{
/* Check for Arm calling Thumb function. */
if (sym_flags == STT_ARM_TFUNC)
{
elf32_arm_to_thumb_stub (info, sym_name, input_bfd, output_bfd,
input_section, hit_data, sym_sec, rel->r_offset,
signed_addend, value);
return bfd_reloc_ok;
}
}
if ( strcmp (bfd_get_target (input_bfd), "elf32-littlearm-oabi") == 0
|| strcmp (bfd_get_target (input_bfd), "elf32-bigarm-oabi") == 0)
{
/* The old way of doing things. Trearing the addend as a
byte sized field and adding in the pipeline offset. */
value -= (input_section->output_section->vma
+ input_section->output_offset);
value -= rel->r_offset;
value += addend;
if (! globals->no_pipeline_knowledge)
value -= 8;
}
else
{
/* The ARM ELF ABI says that this reloc is computed as: S - P + A
where:
S is the address of the symbol in the relocation.
P is address of the instruction being relocated.
A is the addend (extracted from the instruction) in bytes.
S is held in 'value'.
P is the base address of the section containing the instruction
plus the offset of the reloc into that section, ie:
(input_section->output_section->vma +
input_section->output_offset +
rel->r_offset).
A is the addend, converted into bytes, ie:
(signed_addend * 4)
Note: None of these operations have knowledge of the pipeline
size of the processor, thus it is up to the assembler to encode
this information into the addend. */
value -= (input_section->output_section->vma
+ input_section->output_offset);
value -= rel->r_offset;
value += (signed_addend << howto->size);
/* Previous versions of this code also used to add in the pipeline
offset here. This is wrong because the linker is not supposed
to know about such things, and one day it might change. In order
to support old binaries that need the old behaviour however, so
we attempt to detect which ABI was used to create the reloc. */
if (! globals->no_pipeline_knowledge)
{
Elf_Internal_Ehdr * i_ehdrp; /* Elf file header, internal form */
i_ehdrp = elf_elfheader (input_bfd);
if (i_ehdrp->e_ident[EI_OSABI] == 0)
value -= 8;
}
}
signed_addend = value;
signed_addend >>= howto->rightshift;
/* It is not an error for an undefined weak reference to be
out of range. Any program that branches to such a symbol
is going to crash anyway, so there is no point worrying
about getting the destination exactly right. */
if (! h || h->root.type != bfd_link_hash_undefweak)
{
/* Perform a signed range check. */
if ( signed_addend > ((bfd_signed_vma) (howto->dst_mask >> 1))
|| signed_addend < - ((bfd_signed_vma) ((howto->dst_mask + 1) >> 1)))
return bfd_reloc_overflow;
}
#ifndef OLD_ARM_ABI
/* If necessary set the H bit in the BLX instruction. */
if (r_type == R_ARM_XPC25 && ((value & 2) == 2))
value = (signed_addend & howto->dst_mask)
| (bfd_get_32 (input_bfd, hit_data) & (~ howto->dst_mask))
| (1 << 24);
else
#endif
value = (signed_addend & howto->dst_mask)
| (bfd_get_32 (input_bfd, hit_data) & (~ howto->dst_mask));
break;
case R_ARM_ABS32:
value += addend;
if (sym_flags == STT_ARM_TFUNC)
value |= 1;
break;
case R_ARM_REL32:
value -= (input_section->output_section->vma
+ input_section->output_offset);
value += addend;
break;
}
bfd_put_32 (input_bfd, value, hit_data);
return bfd_reloc_ok;
case R_ARM_ABS8:
value += addend;
if ((long) value > 0x7f || (long) value < -0x80)
return bfd_reloc_overflow;
bfd_put_8 (input_bfd, value, hit_data);
return bfd_reloc_ok;
case R_ARM_ABS16:
value += addend;
if ((long) value > 0x7fff || (long) value < -0x8000)
return bfd_reloc_overflow;
bfd_put_16 (input_bfd, value, hit_data);
return bfd_reloc_ok;
case R_ARM_ABS12:
/* Support ldr and str instruction for the arm */
/* Also thumb b (unconditional branch). ??? Really? */
value += addend;
if ((long) value > 0x7ff || (long) value < -0x800)
return bfd_reloc_overflow;
value |= (bfd_get_32 (input_bfd, hit_data) & 0xfffff000);
bfd_put_32 (input_bfd, value, hit_data);
return bfd_reloc_ok;
case R_ARM_THM_ABS5:
/* Support ldr and str instructions for the thumb. */
#ifdef USE_REL
/* Need to refetch addend. */
addend = bfd_get_16 (input_bfd, hit_data) & howto->src_mask;
/* ??? Need to determine shift amount from operand size. */
addend >>= howto->rightshift;
#endif
value += addend;
/* ??? Isn't value unsigned? */
if ((long) value > 0x1f || (long) value < -0x10)
return bfd_reloc_overflow;
/* ??? Value needs to be properly shifted into place first. */
value |= bfd_get_16 (input_bfd, hit_data) & 0xf83f;
bfd_put_16 (input_bfd, value, hit_data);
return bfd_reloc_ok;
#ifndef OLD_ARM_ABI
case R_ARM_THM_XPC22:
#endif
case R_ARM_THM_PC22:
/* Thumb BL (branch long instruction). */
{
bfd_vma relocation;
boolean overflow = false;
bfd_vma upper_insn = bfd_get_16 (input_bfd, hit_data);
bfd_vma lower_insn = bfd_get_16 (input_bfd, hit_data + 2);
bfd_signed_vma reloc_signed_max = (1 << (howto->bitsize - 1)) - 1;
bfd_signed_vma reloc_signed_min = ~ reloc_signed_max;
bfd_vma check;
bfd_signed_vma signed_check;
#ifdef USE_REL
/* Need to refetch the addend and squish the two 11 bit pieces
together. */
{
bfd_vma upper = upper_insn & 0x7ff;
bfd_vma lower = lower_insn & 0x7ff;
upper = (upper ^ 0x400) - 0x400; /* Sign extend. */
addend = (upper << 12) | (lower << 1);
signed_addend = addend;
}
#endif
#ifndef OLD_ARM_ABI
if (r_type == R_ARM_THM_XPC22)
{
/* Check for Thumb to Thumb call. */
/* FIXME: Should we translate the instruction into a BL
instruction instead ? */
if (sym_flags == STT_ARM_TFUNC)
_bfd_error_handler (_("\
%s: Warning: Thumb BLX instruction targets thumb function '%s'."),
bfd_get_filename (input_bfd),
h ? h->root.root.string : "(local)");
}
else
#endif
{
/* If it is not a call to Thumb, assume call to Arm.
If it is a call relative to a section name, then it is not a
function call at all, but rather a long jump. */
if (sym_flags != STT_ARM_TFUNC && sym_flags != STT_SECTION)
{
if (elf32_thumb_to_arm_stub
(info, sym_name, input_bfd, output_bfd, input_section,
hit_data, sym_sec, rel->r_offset, signed_addend, value))
return bfd_reloc_ok;
else
return bfd_reloc_dangerous;
}
}
relocation = value + signed_addend;
relocation -= (input_section->output_section->vma
+ input_section->output_offset
+ rel->r_offset);
if (! globals->no_pipeline_knowledge)
{
Elf_Internal_Ehdr * i_ehdrp; /* Elf file header, internal form. */
i_ehdrp = elf_elfheader (input_bfd);
/* Previous versions of this code also used to add in the pipline
offset here. This is wrong because the linker is not supposed
to know about such things, and one day it might change. In order
to support old binaries that need the old behaviour however, so
we attempt to detect which ABI was used to create the reloc. */
if ( strcmp (bfd_get_target (input_bfd), "elf32-littlearm-oabi") == 0
|| strcmp (bfd_get_target (input_bfd), "elf32-bigarm-oabi") == 0
|| i_ehdrp->e_ident[EI_OSABI] == 0)
relocation += 4;
}
check = relocation >> howto->rightshift;
/* If this is a signed value, the rightshift just dropped
leading 1 bits (assuming twos complement). */
if ((bfd_signed_vma) relocation >= 0)
signed_check = check;
else
signed_check = check | ~((bfd_vma) -1 >> howto->rightshift);
/* Assumes two's complement. */
if (signed_check > reloc_signed_max || signed_check < reloc_signed_min)
overflow = true;
/* Put RELOCATION back into the insn. */
upper_insn = (upper_insn & ~(bfd_vma) 0x7ff) | ((relocation >> 12) & 0x7ff);
lower_insn = (lower_insn & ~(bfd_vma) 0x7ff) | ((relocation >> 1) & 0x7ff);
#ifndef OLD_ARM_ABI
if (r_type == R_ARM_THM_XPC22
&& ((lower_insn & 0x1800) == 0x0800))
/* Remove bit zero of the adjusted offset. Bit zero can only be
set if the upper insn is at a half-word boundary, since the
destination address, an ARM instruction, must always be on a
word boundary. The semantics of the BLX (1) instruction, however,
are that bit zero in the offset must always be zero, and the
corresponding bit one in the target address will be set from bit
one of the source address. */
lower_insn &= ~1;
#endif
/* Put the relocated value back in the object file: */
bfd_put_16 (input_bfd, upper_insn, hit_data);
bfd_put_16 (input_bfd, lower_insn, hit_data + 2);
return (overflow ? bfd_reloc_overflow : bfd_reloc_ok);
}
break;
case R_ARM_GNU_VTINHERIT:
case R_ARM_GNU_VTENTRY:
return bfd_reloc_ok;
case R_ARM_COPY:
return bfd_reloc_notsupported;
case R_ARM_GLOB_DAT:
return bfd_reloc_notsupported;
case R_ARM_JUMP_SLOT:
return bfd_reloc_notsupported;
case R_ARM_RELATIVE:
return bfd_reloc_notsupported;
case R_ARM_GOTOFF:
/* Relocation is relative to the start of the
global offset table. */
BFD_ASSERT (sgot != NULL);
if (sgot == NULL)
return bfd_reloc_notsupported;
/* Note that sgot->output_offset is not involved in this
calculation. We always want the start of .got. If we
define _GLOBAL_OFFSET_TABLE in a different way, as is
permitted by the ABI, we might have to change this
calculation. */
value -= sgot->output_section->vma;
return _bfd_final_link_relocate (howto, input_bfd, input_section,
contents, rel->r_offset, value,
(bfd_vma) 0);
case R_ARM_GOTPC:
/* Use global offset table as symbol value. */
BFD_ASSERT (sgot != NULL);
if (sgot == NULL)
return bfd_reloc_notsupported;
value = sgot->output_section->vma;
return _bfd_final_link_relocate (howto, input_bfd, input_section,
contents, rel->r_offset, value,
(bfd_vma) 0);
case R_ARM_GOT32:
/* Relocation is to the entry for this symbol in the
global offset table. */
if (sgot == NULL)
return bfd_reloc_notsupported;
if (h != NULL)
{
bfd_vma off;
off = h->got.offset;
BFD_ASSERT (off != (bfd_vma) -1);
if (!elf_hash_table (info)->dynamic_sections_created ||
(info->shared && (info->symbolic || h->dynindx == -1)
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
{
/* This is actually a static link, or it is a -Bsymbolic link
and the symbol is defined locally. We must initialize this
entry in the global offset table. Since the offset must
always be a multiple of 4, we use the least significant bit
to record whether we have initialized it already.
When doing a dynamic link, we create a .rel.got relocation
entry to initialize the value. This is done in the
finish_dynamic_symbol routine. */
if ((off & 1) != 0)
off &= ~1;
else
{
bfd_put_32 (output_bfd, value, sgot->contents + off);
h->got.offset |= 1;
}
}
value = sgot->output_offset + off;
}
else
{
bfd_vma off;
BFD_ASSERT (local_got_offsets != NULL &&
local_got_offsets[r_symndx] != (bfd_vma) -1);
off = local_got_offsets[r_symndx];
/* The offset must always be a multiple of 4. We use the
least significant bit to record whether we have already
generated the necessary reloc. */
if ((off & 1) != 0)
off &= ~1;
else
{
bfd_put_32 (output_bfd, value, sgot->contents + off);
if (info->shared)
{
asection * srelgot;
Elf_Internal_Rel outrel;
srelgot = bfd_get_section_by_name (dynobj, ".rel.got");
BFD_ASSERT (srelgot != NULL);
outrel.r_offset = (sgot->output_section->vma
+ sgot->output_offset
+ off);
outrel.r_info = ELF32_R_INFO (0, R_ARM_RELATIVE);
bfd_elf32_swap_reloc_out (output_bfd, &outrel,
(((Elf32_External_Rel *)
srelgot->contents)
+ srelgot->reloc_count));
++srelgot->reloc_count;
}
local_got_offsets[r_symndx] |= 1;
}
value = sgot->output_offset + off;
}
return _bfd_final_link_relocate (howto, input_bfd, input_section,
contents, rel->r_offset, value,
(bfd_vma) 0);
case R_ARM_PLT32:
/* Relocation is to the entry for this symbol in the
procedure linkage table. */
/* Resolve a PLT32 reloc against a local symbol directly,
without using the procedure linkage table. */
if (h == NULL)
return _bfd_final_link_relocate (howto, input_bfd, input_section,
contents, rel->r_offset, value,
(bfd_vma) 0);
if (h->plt.offset == (bfd_vma) -1)
/* We didn't make a PLT entry for this symbol. This
happens when statically linking PIC code, or when
using -Bsymbolic. */
return _bfd_final_link_relocate (howto, input_bfd, input_section,
contents, rel->r_offset, value,
(bfd_vma) 0);
BFD_ASSERT(splt != NULL);
if (splt == NULL)
return bfd_reloc_notsupported;
value = (splt->output_section->vma
+ splt->output_offset
+ h->plt.offset);
return _bfd_final_link_relocate (howto, input_bfd, input_section,
contents, rel->r_offset, value,
(bfd_vma) 0);
case R_ARM_SBREL32:
return bfd_reloc_notsupported;
case R_ARM_AMP_VCALL9:
return bfd_reloc_notsupported;
case R_ARM_RSBREL32:
return bfd_reloc_notsupported;
case R_ARM_THM_RPC22:
return bfd_reloc_notsupported;
case R_ARM_RREL32:
return bfd_reloc_notsupported;
case R_ARM_RABS32:
return bfd_reloc_notsupported;
case R_ARM_RPC24:
return bfd_reloc_notsupported;
case R_ARM_RBASE:
return bfd_reloc_notsupported;
default:
return bfd_reloc_notsupported;
}
}
#ifdef USE_REL
/* Add INCREMENT to the reloc (of type HOWTO) at ADDRESS. */
static void
arm_add_to_rel (abfd, address, howto, increment)
bfd * abfd;
bfd_byte * address;
reloc_howto_type * howto;
bfd_signed_vma increment;
{
bfd_signed_vma addend;
if (howto->type == R_ARM_THM_PC22)
{
int upper_insn, lower_insn;
int upper, lower;
upper_insn = bfd_get_16 (abfd, address);
lower_insn = bfd_get_16 (abfd, address + 2);
upper = upper_insn & 0x7ff;
lower = lower_insn & 0x7ff;
addend = (upper << 12) | (lower << 1);
addend += increment;
addend >>= 1;
upper_insn = (upper_insn & 0xf800) | ((addend >> 11) & 0x7ff);
lower_insn = (lower_insn & 0xf800) | (addend & 0x7ff);
bfd_put_16 (abfd, upper_insn, address);
bfd_put_16 (abfd, lower_insn, address + 2);
}
else
{
bfd_vma contents;
contents = bfd_get_32 (abfd, address);
/* Get the (signed) value from the instruction. */
addend = contents & howto->src_mask;
if (addend & ((howto->src_mask + 1) >> 1))
{
bfd_signed_vma mask;
mask = -1;
mask &= ~ howto->src_mask;
addend |= mask;
}
/* Add in the increment, (which is a byte value). */
switch (howto->type)
{
default:
addend += increment;
break;
case R_ARM_PC24:
addend <<= howto->size;
addend += increment;
/* Should we check for overflow here ? */
/* Drop any undesired bits. */
addend >>= howto->rightshift;
break;
}
contents = (contents & ~ howto->dst_mask) | (addend & howto->dst_mask);
bfd_put_32 (abfd, contents, address);
}
}
#endif /* USE_REL */
/* Relocate an ARM ELF section. */
static boolean
elf32_arm_relocate_section (output_bfd, info, input_bfd, input_section,
contents, relocs, local_syms, local_sections)
bfd * output_bfd;
struct bfd_link_info * info;
bfd * input_bfd;
asection * input_section;
bfd_byte * contents;
Elf_Internal_Rela * relocs;
Elf_Internal_Sym * local_syms;
asection ** local_sections;
{
Elf_Internal_Shdr * symtab_hdr;
struct elf_link_hash_entry ** sym_hashes;
Elf_Internal_Rela * rel;
Elf_Internal_Rela * relend;
const char * name;
symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
sym_hashes = elf_sym_hashes (input_bfd);
rel = relocs;
relend = relocs + input_section->reloc_count;
for (; rel < relend; rel++)
{
int r_type;
reloc_howto_type * howto;
unsigned long r_symndx;
Elf_Internal_Sym * sym;
asection * sec;
struct elf_link_hash_entry * h;
bfd_vma relocation;
bfd_reloc_status_type r;
arelent bfd_reloc;
r_symndx = ELF32_R_SYM (rel->r_info);
r_type = ELF32_R_TYPE (rel->r_info);
if ( r_type == R_ARM_GNU_VTENTRY
|| r_type == R_ARM_GNU_VTINHERIT)
continue;
elf32_arm_info_to_howto (input_bfd, & bfd_reloc, rel);
howto = bfd_reloc.howto;
if (info->relocateable)
{
/* This is a relocateable link. We don't have to change
anything, unless the reloc is against a section symbol,
in which case we have to adjust according to where the
section symbol winds up in the output section. */
if (r_symndx < symtab_hdr->sh_info)
{
sym = local_syms + r_symndx;
if (ELF_ST_TYPE (sym->st_info) == STT_SECTION)
{
sec = local_sections[r_symndx];
#ifdef USE_REL
arm_add_to_rel (input_bfd, contents + rel->r_offset,
howto, sec->output_offset + sym->st_value);
#else
rel->r_addend += (sec->output_offset + sym->st_value)
>> howto->rightshift;
#endif
}
}
continue;
}
/* This is a final link. */
h = NULL;
sym = NULL;
sec = NULL;
if (r_symndx < symtab_hdr->sh_info)
{
sym = local_syms + r_symndx;
sec = local_sections[r_symndx];
relocation = (sec->output_section->vma
+ sec->output_offset
+ sym->st_value);
}
else
{
h = sym_hashes[r_symndx - symtab_hdr->sh_info];
while ( h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if ( h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
{
int relocation_needed = 1;
sec = h->root.u.def.section;
/* In these cases, we don't need the relocation value.
We check specially because in some obscure cases
sec->output_section will be NULL. */
switch (r_type)
{
case R_ARM_PC24:
case R_ARM_ABS32:
if (info->shared
&& (
(!info->symbolic && h->dynindx != -1)
|| (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
)
&& ((input_section->flags & SEC_ALLOC) != 0
/* DWARF will emit R_ARM_ABS32 relocations in its
sections against symbols defined externally
in shared libraries. We can't do anything
with them here. */
|| ((input_section->flags & SEC_DEBUGGING) != 0
&& (h->elf_link_hash_flags
& ELF_LINK_HASH_DEF_DYNAMIC) != 0))
)
relocation_needed = 0;
break;
case R_ARM_GOTPC:
relocation_needed = 0;
break;
case R_ARM_GOT32:
if (elf_hash_table(info)->dynamic_sections_created
&& (!info->shared
|| (!info->symbolic && h->dynindx != -1)
|| (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
)
)
relocation_needed = 0;
break;
case R_ARM_PLT32:
if (h->plt.offset != (bfd_vma)-1)
relocation_needed = 0;
break;
default:
if (sec->output_section == NULL)
{
(*_bfd_error_handler)
(_("%s: warning: unresolvable relocation against symbol `%s' from %s section"),
bfd_get_filename (input_bfd), h->root.root.string,
bfd_get_section_name (input_bfd, input_section));
relocation_needed = 0;
}
}
if (relocation_needed)
relocation = h->root.u.def.value
+ sec->output_section->vma
+ sec->output_offset;
else
relocation = 0;
}
else if (h->root.type == bfd_link_hash_undefweak)
relocation = 0;
else if (info->shared && !info->symbolic
&& !info->no_undefined
&& ELF_ST_VISIBILITY (h->other) == STV_DEFAULT)
relocation = 0;
else
{
if (!((*info->callbacks->undefined_symbol)
(info, h->root.root.string, input_bfd,
input_section, rel->r_offset,
(!info->shared || info->no_undefined
|| ELF_ST_VISIBILITY (h->other)))))
return false;
relocation = 0;
}
}
if (h != NULL)
name = h->root.root.string;
else
{
name = (bfd_elf_string_from_elf_section
(input_bfd, symtab_hdr->sh_link, sym->st_name));
if (name == NULL || *name == '\0')
name = bfd_section_name (input_bfd, sec);
}
r = elf32_arm_final_link_relocate (howto, input_bfd, output_bfd,
input_section, contents, rel,
relocation, info, sec, name,
(h ? ELF_ST_TYPE (h->type) :
ELF_ST_TYPE (sym->st_info)), h);
if (r != bfd_reloc_ok)
{
const char * msg = (const char *) 0;
switch (r)
{
case bfd_reloc_overflow:
/* If the overflowing reloc was to an undefined symbol,
we have already printed one error message and there
is no point complaining again. */
if ((! h ||
h->root.type != bfd_link_hash_undefined)
&& (!((*info->callbacks->reloc_overflow)
(info, name, howto->name, (bfd_vma) 0,
input_bfd, input_section, rel->r_offset))))
return false;
break;
case bfd_reloc_undefined:
if (!((*info->callbacks->undefined_symbol)
(info, name, input_bfd, input_section,
rel->r_offset, true)))
return false;
break;
case bfd_reloc_outofrange:
msg = _("internal error: out of range error");
goto common_error;
case bfd_reloc_notsupported:
msg = _("internal error: unsupported relocation error");
goto common_error;
case bfd_reloc_dangerous:
msg = _("internal error: dangerous error");
goto common_error;
default:
msg = _("internal error: unknown error");
/* fall through */
common_error:
if (!((*info->callbacks->warning)
(info, msg, name, input_bfd, input_section,
rel->r_offset)))
return false;
break;
}
}
}
return true;
}
/* Function to keep ARM specific flags in the ELF header. */
static boolean
elf32_arm_set_private_flags (abfd, flags)
bfd *abfd;
flagword flags;
{
if (elf_flags_init (abfd)
&& elf_elfheader (abfd)->e_flags != flags)
{
if (EF_ARM_EABI_VERSION (flags) == EF_ARM_EABI_UNKNOWN)
{
if (flags & EF_ARM_INTERWORK)
_bfd_error_handler (_("\
Warning: Not setting interwork flag of %s since it has already been specified as non-interworking"),
bfd_get_filename (abfd));
else
_bfd_error_handler (_("\
Warning: Clearing the interwork flag of %s due to outside request"),
bfd_get_filename (abfd));
}
}
else
{
elf_elfheader (abfd)->e_flags = flags;
elf_flags_init (abfd) = true;
}
return true;
}
/* Copy backend specific data from one object module to another. */
static boolean
elf32_arm_copy_private_bfd_data (ibfd, obfd)
bfd *ibfd;
bfd *obfd;
{
flagword in_flags;
flagword out_flags;
if ( bfd_get_flavour (ibfd) != bfd_target_elf_flavour
|| bfd_get_flavour (obfd) != bfd_target_elf_flavour)
return true;
in_flags = elf_elfheader (ibfd)->e_flags;
out_flags = elf_elfheader (obfd)->e_flags;
if (elf_flags_init (obfd)
&& EF_ARM_EABI_VERSION (out_flags) == EF_ARM_EABI_UNKNOWN
&& in_flags != out_flags)
{
/* Cannot mix APCS26 and APCS32 code. */
if ((in_flags & EF_ARM_APCS_26) != (out_flags & EF_ARM_APCS_26))
return false;
/* Cannot mix float APCS and non-float APCS code. */
if ((in_flags & EF_ARM_APCS_FLOAT) != (out_flags & EF_ARM_APCS_FLOAT))
return false;
/* If the src and dest have different interworking flags
then turn off the interworking bit. */
if ((in_flags & EF_ARM_INTERWORK) != (out_flags & EF_ARM_INTERWORK))
{
if (out_flags & EF_ARM_INTERWORK)
_bfd_error_handler (_("\
Warning: Clearing the interwork flag in %s because non-interworking code in %s has been linked with it"),
bfd_get_filename (obfd), bfd_get_filename (ibfd));
in_flags &= ~EF_ARM_INTERWORK;
}
/* Likewise for PIC, though don't warn for this case. */
if ((in_flags & EF_ARM_PIC) != (out_flags & EF_ARM_PIC))
in_flags &= ~EF_ARM_PIC;
}
elf_elfheader (obfd)->e_flags = in_flags;
elf_flags_init (obfd) = true;
return true;
}
/* Merge backend specific data from an object file to the output
object file when linking. */
static boolean
elf32_arm_merge_private_bfd_data (ibfd, obfd)
bfd * ibfd;
bfd * obfd;
{
flagword out_flags;
flagword in_flags;
boolean flags_compatible = true;
boolean null_input_bfd = true;
asection *sec;
/* Check if we have the same endianess. */
if (_bfd_generic_verify_endian_match (ibfd, obfd) == false)
return false;
if ( bfd_get_flavour (ibfd) != bfd_target_elf_flavour
|| bfd_get_flavour (obfd) != bfd_target_elf_flavour)
return true;
/* The input BFD must have had its flags initialised. */
/* The following seems bogus to me -- The flags are initialized in
the assembler but I don't think an elf_flags_init field is
written into the object. */
/* BFD_ASSERT (elf_flags_init (ibfd)); */
in_flags = elf_elfheader (ibfd)->e_flags;
out_flags = elf_elfheader (obfd)->e_flags;
if (!elf_flags_init (obfd))
{
/* If the input is the default architecture and had the default
flags then do not bother setting the flags for the output
architecture, instead allow future merges to do this. If no
future merges ever set these flags then they will retain their
uninitialised values, which surprise surprise, correspond
to the default values. */
if (bfd_get_arch_info (ibfd)->the_default
&& elf_elfheader (ibfd)->e_flags == 0)
return true;
elf_flags_init (obfd) = true;
elf_elfheader (obfd)->e_flags = in_flags;
if (bfd_get_arch (obfd) == bfd_get_arch (ibfd)
&& bfd_get_arch_info (obfd)->the_default)
return bfd_set_arch_mach (obfd, bfd_get_arch (ibfd), bfd_get_mach (ibfd));
return true;
}
/* Identical flags must be compatible. */
if (in_flags == out_flags)
return true;
/* Check to see if the input BFD actually contains any sections.
If not, its flags may not have been initialised either, but it cannot
actually cause any incompatibility. */
for (sec = ibfd->sections; sec != NULL; sec = sec->next)
{
/* Ignore synthetic glue sections. */
if (strcmp (sec->name, ".glue_7")
&& strcmp (sec->name, ".glue_7t"))
{
null_input_bfd = false;
break;
}
}
if (null_input_bfd)
return true;
/* Complain about various flag mismatches. */
if (EF_ARM_EABI_VERSION (in_flags) != EF_ARM_EABI_VERSION (out_flags))
{
_bfd_error_handler (_("\
Error: %s compiled for EABI version %d, whereas %s is compiled for version %d"),
bfd_get_filename (ibfd),
(in_flags & EF_ARM_EABIMASK) >> 24,
bfd_get_filename (obfd),
(out_flags & EF_ARM_EABIMASK) >> 24);
return false;
}
/* Not sure what needs to be checked for EABI versions >= 1. */
if (EF_ARM_EABI_VERSION (in_flags) == EF_ARM_EABI_UNKNOWN)
{
if ((in_flags & EF_ARM_APCS_26) != (out_flags & EF_ARM_APCS_26))
{
_bfd_error_handler (_("\
Error: %s compiled for APCS-%d, whereas %s is compiled for APCS-%d"),
bfd_get_filename (ibfd),
in_flags & EF_ARM_APCS_26 ? 26 : 32,
bfd_get_filename (obfd),
out_flags & EF_ARM_APCS_26 ? 26 : 32);
flags_compatible = false;
}
if ((in_flags & EF_ARM_APCS_FLOAT) != (out_flags & EF_ARM_APCS_FLOAT))
{
_bfd_error_handler (_("\
Error: %s passes floats in %s registers, whereas %s passes them in %s registers"),
bfd_get_filename (ibfd),
in_flags & EF_ARM_APCS_FLOAT ? _("float") : _("integer"),
bfd_get_filename (obfd),
out_flags & EF_ARM_APCS_26 ? _("float") : _("integer"));
flags_compatible = false;
}
#ifdef EF_ARM_SOFT_FLOAT
if ((in_flags & EF_ARM_SOFT_FLOAT) != (out_flags & EF_ARM_SOFT_FLOAT))
{
_bfd_error_handler (_ ("\
Error: %s uses %s floating point, whereas %s uses %s floating point"),
bfd_get_filename (ibfd),
in_flags & EF_ARM_SOFT_FLOAT ? _("soft") : _("hard"),
bfd_get_filename (obfd),
out_flags & EF_ARM_SOFT_FLOAT ? _("soft") : _("hard"));
flags_compatible = false;
}
#endif
/* Interworking mismatch is only a warning. */
if ((in_flags & EF_ARM_INTERWORK) != (out_flags & EF_ARM_INTERWORK))
_bfd_error_handler (_("\
Warning: %s %s interworking, whereas %s %s"),
bfd_get_filename (ibfd),
in_flags & EF_ARM_INTERWORK ? _("supports") : _("does not support"),
bfd_get_filename (obfd),
out_flags & EF_ARM_INTERWORK ? _("does") : _("does not"));
}
return flags_compatible;
}
/* Display the flags field. */
static boolean
elf32_arm_print_private_bfd_data (abfd, ptr)
bfd *abfd;
PTR ptr;
{
FILE * file = (FILE *) ptr;
unsigned long flags;
BFD_ASSERT (abfd != NULL && ptr != NULL);
/* Print normal ELF private data. */
_bfd_elf_print_private_bfd_data (abfd, ptr);
flags = elf_elfheader (abfd)->e_flags;
/* Ignore init flag - it may not be set, despite the flags field
containing valid data. */
/* xgettext:c-format */
fprintf (file, _("private flags = %lx:"), elf_elfheader (abfd)->e_flags);
switch (EF_ARM_EABI_VERSION (flags))
{
case EF_ARM_EABI_UNKNOWN:
/* The following flag bits are GNU extenstions and not part of the
official ARM ELF extended ABI. Hence they are only decoded if
the EABI version is not set. */
if (flags & EF_ARM_INTERWORK)
fprintf (file, _(" [interworking enabled]"));
if (flags & EF_ARM_APCS_26)
fprintf (file, _(" [APCS-26]"));
else
fprintf (file, _(" [APCS-32]"));
if (flags & EF_ARM_APCS_FLOAT)
fprintf (file, _(" [floats passed in float registers]"));
if (flags & EF_ARM_PIC)
fprintf (file, _(" [position independent]"));
if (flags & EF_ARM_NEW_ABI)
fprintf (file, _(" [new ABI]"));
if (flags & EF_ARM_OLD_ABI)
fprintf (file, _(" [old ABI]"));
if (flags & EF_ARM_SOFT_FLOAT)
fprintf (file, _(" [software FP]"));
flags &= ~(EF_ARM_INTERWORK | EF_ARM_APCS_26 | EF_ARM_APCS_FLOAT | EF_ARM_PIC
| EF_ARM_NEW_ABI | EF_ARM_OLD_ABI | EF_ARM_SOFT_FLOAT);
break;
case EF_ARM_EABI_VER1:
fprintf (file, _(" [Version1 EABI]"));
if (flags & EF_ARM_SYMSARESORTED)
fprintf (file, _(" [sorted symbol table]"));
else
fprintf (file, _(" [unsorted symbol table]"));
flags &= ~ EF_ARM_SYMSARESORTED;
break;
case EF_ARM_EABI_VER2:
fprintf (file, _(" [Version2 EABI]"));
if (flags & EF_ARM_SYMSARESORTED)
fprintf (file, _(" [sorted symbol table]"));
else
fprintf (file, _(" [unsorted symbol table]"));
if (flags & EF_ARM_DYNSYMSUSESEGIDX)
fprintf (file, _(" [dynamic symbols use segment index]"));
if (flags & EF_ARM_MAPSYMSFIRST)
fprintf (file, _(" [mapping symbols precede others]"));
flags &= ~(EF_ARM_SYMSARESORTED | EF_ARM_DYNSYMSUSESEGIDX
| EF_ARM_MAPSYMSFIRST);
break;
default:
fprintf (file, _(" <EABI version unrecognised>"));
break;
}
flags &= ~ EF_ARM_EABIMASK;
if (flags & EF_ARM_RELEXEC)
fprintf (file, _(" [relocatable executable]"));
if (flags & EF_ARM_HASENTRY)
fprintf (file, _(" [has entry point]"));
flags &= ~ (EF_ARM_RELEXEC | EF_ARM_HASENTRY);
if (flags)
fprintf (file, _("<Unrecognised flag bits set>"));
fputc ('\n', file);
return true;
}
static int
elf32_arm_get_symbol_type (elf_sym, type)
Elf_Internal_Sym * elf_sym;
int type;
{
switch (ELF_ST_TYPE (elf_sym->st_info))
{
case STT_ARM_TFUNC:
return ELF_ST_TYPE (elf_sym->st_info);
case STT_ARM_16BIT:
/* If the symbol is not an object, return the STT_ARM_16BIT flag.
This allows us to distinguish between data used by Thumb instructions
and non-data (which is probably code) inside Thumb regions of an
executable. */
if (type != STT_OBJECT)
return ELF_ST_TYPE (elf_sym->st_info);
break;
default:
break;
}
return type;
}
static asection *
elf32_arm_gc_mark_hook (abfd, info, rel, h, sym)
bfd *abfd;
struct bfd_link_info *info ATTRIBUTE_UNUSED;
Elf_Internal_Rela *rel;
struct elf_link_hash_entry *h;
Elf_Internal_Sym *sym;
{
if (h != NULL)
{
switch (ELF32_R_TYPE (rel->r_info))
{
case R_ARM_GNU_VTINHERIT:
case R_ARM_GNU_VTENTRY:
break;
default:
switch (h->root.type)
{
case bfd_link_hash_defined:
case bfd_link_hash_defweak:
return h->root.u.def.section;
case bfd_link_hash_common:
return h->root.u.c.p->section;
default:
break;
}
}
}
else
{
if (!(elf_bad_symtab (abfd)
&& ELF_ST_BIND (sym->st_info) != STB_LOCAL)
&& ! ((sym->st_shndx <= 0 || sym->st_shndx >= SHN_LORESERVE)
&& sym->st_shndx != SHN_COMMON))
{
return bfd_section_from_elf_index (abfd, sym->st_shndx);
}
}
return NULL;
}
/* Update the got entry reference counts for the section being removed. */
static boolean
elf32_arm_gc_sweep_hook (abfd, info, sec, relocs)
bfd *abfd ATTRIBUTE_UNUSED;
struct bfd_link_info *info ATTRIBUTE_UNUSED;
asection *sec ATTRIBUTE_UNUSED;
const Elf_Internal_Rela *relocs ATTRIBUTE_UNUSED;
{
/* We don't support garbage collection of GOT and PLT relocs yet. */
return true;
}
/* Look through the relocs for a section during the first phase. */
static boolean
elf32_arm_check_relocs (abfd, info, sec, relocs)
bfd * abfd;
struct bfd_link_info * info;
asection * sec;
const Elf_Internal_Rela * relocs;
{
Elf_Internal_Shdr * symtab_hdr;
struct elf_link_hash_entry ** sym_hashes;
struct elf_link_hash_entry ** sym_hashes_end;
const Elf_Internal_Rela * rel;
const Elf_Internal_Rela * rel_end;
bfd * dynobj;
asection * sgot, *srelgot, *sreloc;
bfd_vma * local_got_offsets;
if (info->relocateable)
return true;
sgot = srelgot = sreloc = NULL;
dynobj = elf_hash_table (info)->dynobj;
local_got_offsets = elf_local_got_offsets (abfd);
symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
sym_hashes = elf_sym_hashes (abfd);
sym_hashes_end = sym_hashes
+ symtab_hdr->sh_size / sizeof (Elf32_External_Sym);
if (!elf_bad_symtab (abfd))
sym_hashes_end -= symtab_hdr->sh_info;
rel_end = relocs + sec->reloc_count;
for (rel = relocs; rel < rel_end; rel++)
{
struct elf_link_hash_entry *h;
unsigned long r_symndx;
r_symndx = ELF32_R_SYM (rel->r_info);
if (r_symndx < symtab_hdr->sh_info)
h = NULL;
else
h = sym_hashes[r_symndx - symtab_hdr->sh_info];
/* Some relocs require a global offset table. */
if (dynobj == NULL)
{
switch (ELF32_R_TYPE (rel->r_info))
{
case R_ARM_GOT32:
case R_ARM_GOTOFF:
case R_ARM_GOTPC:
elf_hash_table (info)->dynobj = dynobj = abfd;
if (! _bfd_elf_create_got_section (dynobj, info))
return false;
break;
default:
break;
}
}
switch (ELF32_R_TYPE (rel->r_info))
{
case R_ARM_GOT32:
/* This symbol requires a global offset table entry. */
if (sgot == NULL)
{
sgot = bfd_get_section_by_name (dynobj, ".got");
BFD_ASSERT (sgot != NULL);
}
/* Get the got relocation section if necessary. */
if (srelgot == NULL
&& (h != NULL || info->shared))
{
srelgot = bfd_get_section_by_name (dynobj, ".rel.got");
/* If no got relocation section, make one and initialize. */
if (srelgot == NULL)
{
srelgot = bfd_make_section (dynobj, ".rel.got");
if (srelgot == NULL
|| ! bfd_set_section_flags (dynobj, srelgot,
(SEC_ALLOC
| SEC_LOAD
| SEC_HAS_CONTENTS
| SEC_IN_MEMORY
| SEC_LINKER_CREATED
| SEC_READONLY))
|| ! bfd_set_section_alignment (dynobj, srelgot, 2))
return false;
}
}
if (h != NULL)
{
if (h->got.offset != (bfd_vma) -1)
/* We have already allocated space in the .got. */
break;
h->got.offset = sgot->_raw_size;
/* Make sure this symbol is output as a dynamic symbol. */
if (h->dynindx == -1)
if (! bfd_elf32_link_record_dynamic_symbol (info, h))
return false;
srelgot->_raw_size += sizeof (Elf32_External_Rel);
}
else
{
/* This is a global offset table entry for a local
symbol. */
if (local_got_offsets == NULL)
{
size_t size;
register unsigned int i;
size = symtab_hdr->sh_info * sizeof (bfd_vma);
local_got_offsets = (bfd_vma *) bfd_alloc (abfd, size);
if (local_got_offsets == NULL)
return false;
elf_local_got_offsets (abfd) = local_got_offsets;
for (i = 0; i < symtab_hdr->sh_info; i++)
local_got_offsets[i] = (bfd_vma) -1;
}
if (local_got_offsets[r_symndx] != (bfd_vma) -1)
/* We have already allocated space in the .got. */
break;
local_got_offsets[r_symndx] = sgot->_raw_size;
if (info->shared)
/* If we are generating a shared object, we need to
output a R_ARM_RELATIVE reloc so that the dynamic
linker can adjust this GOT entry. */
srelgot->_raw_size += sizeof (Elf32_External_Rel);
}
sgot->_raw_size += 4;
break;
case R_ARM_PLT32:
/* This symbol requires a procedure linkage table entry. We
actually build the entry in adjust_dynamic_symbol,
because this might be a case of linking PIC code which is
never referenced by a dynamic object, in which case we
don't need to generate a procedure linkage table entry
after all. */
/* If this is a local symbol, we resolve it directly without
creating a procedure linkage table entry. */
if (h == NULL)
continue;
h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_PLT;
break;
case R_ARM_ABS32:
case R_ARM_REL32:
case R_ARM_PC24:
/* If we are creating a shared library, and this is a reloc
against a global symbol, or a non PC relative reloc
against a local symbol, then we need to copy the reloc
into the shared library. However, if we are linking with
-Bsymbolic, we do not need to copy a reloc against a
global symbol which is defined in an object we are
including in the link (i.e., DEF_REGULAR is set). At
this point we have not seen all the input files, so it is
possible that DEF_REGULAR is not set now but will be set
later (it is never cleared). We account for that
possibility below by storing information in the
pcrel_relocs_copied field of the hash table entry. */
if (info->shared
&& (ELF32_R_TYPE (rel->r_info) != R_ARM_PC24
|| (h != NULL
&& (! info->symbolic
|| (h->elf_link_hash_flags
& ELF_LINK_HASH_DEF_REGULAR) == 0))))
{
/* When creating a shared object, we must copy these
reloc types into the output file. We create a reloc
section in dynobj and make room for this reloc. */
if (sreloc == NULL)
{
const char * name;
name = (bfd_elf_string_from_elf_section
(abfd,
elf_elfheader (abfd)->e_shstrndx,
elf_section_data (sec)->rel_hdr.sh_name));
if (name == NULL)
return false;
BFD_ASSERT (strncmp (name, ".rel", 4) == 0
&& strcmp (bfd_get_section_name (abfd, sec),
name + 4) == 0);
sreloc = bfd_get_section_by_name (dynobj, name);
if (sreloc == NULL)
{
flagword flags;
sreloc = bfd_make_section (dynobj, name);
flags = (SEC_HAS_CONTENTS | SEC_READONLY
| SEC_IN_MEMORY | SEC_LINKER_CREATED);
if ((sec->flags & SEC_ALLOC) != 0)
flags |= SEC_ALLOC | SEC_LOAD;
if (sreloc == NULL
|| ! bfd_set_section_flags (dynobj, sreloc, flags)
|| ! bfd_set_section_alignment (dynobj, sreloc, 2))
return false;
}
}
sreloc->_raw_size += sizeof (Elf32_External_Rel);
/* If we are linking with -Bsymbolic, and this is a
global symbol, we count the number of PC relative
relocations we have entered for this symbol, so that
we can discard them again if the symbol is later
defined by a regular object. Note that this function
is only called if we are using an elf_i386 linker
hash table, which means that h is really a pointer to
an elf_i386_link_hash_entry. */
if (h != NULL && info->symbolic
&& ELF32_R_TYPE (rel->r_info) == R_ARM_PC24)
{
struct elf32_arm_link_hash_entry * eh;
struct elf32_arm_pcrel_relocs_copied * p;
eh = (struct elf32_arm_link_hash_entry *) h;
for (p = eh->pcrel_relocs_copied; p != NULL; p = p->next)
if (p->section == sreloc)
break;
if (p == NULL)
{
p = ((struct elf32_arm_pcrel_relocs_copied *)
bfd_alloc (dynobj, sizeof * p));
if (p == NULL)
return false;
p->next = eh->pcrel_relocs_copied;
eh->pcrel_relocs_copied = p;
p->section = sreloc;
p->count = 0;
}
++p->count;
}
}
break;
/* This relocation describes the C++ object vtable hierarchy.
Reconstruct it for later use during GC. */
case R_ARM_GNU_VTINHERIT:
if (!_bfd_elf32_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
return false;
break;
/* This relocation describes which C++ vtable entries are actually
used. Record for later use during GC. */
case R_ARM_GNU_VTENTRY:
if (!_bfd_elf32_gc_record_vtentry (abfd, sec, h, rel->r_offset))
return false;
break;
}
}
return true;
}
/* Find the nearest line to a particular section and offset, for error
reporting. This code is a duplicate of the code in elf.c, except
that it also accepts STT_ARM_TFUNC as a symbol that names a function. */
static boolean
elf32_arm_find_nearest_line
(abfd, section, symbols, offset, filename_ptr, functionname_ptr, line_ptr)
bfd * abfd;
asection * section;
asymbol ** symbols;
bfd_vma offset;
CONST char ** filename_ptr;
CONST char ** functionname_ptr;
unsigned int * line_ptr;
{
boolean found;
const char * filename;
asymbol * func;
bfd_vma low_func;
asymbol ** p;
if (_bfd_dwarf2_find_nearest_line (abfd, section, symbols, offset,
filename_ptr, functionname_ptr,
line_ptr, 0,
&elf_tdata (abfd)->dwarf2_find_line_info))
return true;
if (! _bfd_stab_section_find_nearest_line (abfd, symbols, section, offset,
&found, filename_ptr,
functionname_ptr, line_ptr,
&elf_tdata (abfd)->line_info))
return false;
if (found)
return true;
if (symbols == NULL)
return false;
filename = NULL;
func = NULL;
low_func = 0;
for (p = symbols; *p != NULL; p++)
{
elf_symbol_type *q;
q = (elf_symbol_type *) *p;
if (bfd_get_section (&q->symbol) != section)
continue;
switch (ELF_ST_TYPE (q->internal_elf_sym.st_info))
{
default:
break;
case STT_FILE:
filename = bfd_asymbol_name (&q->symbol);
break;
case STT_NOTYPE:
case STT_FUNC:
case STT_ARM_TFUNC:
if (q->symbol.section == section
&& q->symbol.value >= low_func
&& q->symbol.value <= offset)
{
func = (asymbol *) q;
low_func = q->symbol.value;
}
break;
}
}
if (func == NULL)
return false;
*filename_ptr = filename;
*functionname_ptr = bfd_asymbol_name (func);
*line_ptr = 0;
return true;
}
/* Adjust a symbol defined by a dynamic object and referenced by a
regular object. The current definition is in some section of the
dynamic object, but we're not including those sections. We have to
change the definition to something the rest of the link can
understand. */
static boolean
elf32_arm_adjust_dynamic_symbol (info, h)
struct bfd_link_info * info;
struct elf_link_hash_entry * h;
{
bfd * dynobj;
asection * s;
unsigned int power_of_two;
dynobj = elf_hash_table (info)->dynobj;
/* Make sure we know what is going on here. */
BFD_ASSERT (dynobj != NULL
&& ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT)
|| h->weakdef != NULL
|| ((h->elf_link_hash_flags
& ELF_LINK_HASH_DEF_DYNAMIC) != 0
&& (h->elf_link_hash_flags
& ELF_LINK_HASH_REF_REGULAR) != 0
&& (h->elf_link_hash_flags
& ELF_LINK_HASH_DEF_REGULAR) == 0)));
/* If this is a function, put it in the procedure linkage table. We
will fill in the contents of the procedure linkage table later,
when we know the address of the .got section. */
if (h->type == STT_FUNC
|| (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0)
{
if (! info->shared
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
&& (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) == 0)
{
/* This case can occur if we saw a PLT32 reloc in an input
file, but the symbol was never referred to by a dynamic
object. In such a case, we don't actually need to build
a procedure linkage table, and we can just do a PC32
reloc instead. */
BFD_ASSERT ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0);
return true;
}
/* Make sure this symbol is output as a dynamic symbol. */
if (h->dynindx == -1)
{
if (! bfd_elf32_link_record_dynamic_symbol (info, h))
return false;
}
s = bfd_get_section_by_name (dynobj, ".plt");
BFD_ASSERT (s != NULL);
/* If this is the first .plt entry, make room for the special
first entry. */
if (s->_raw_size == 0)
s->_raw_size += PLT_ENTRY_SIZE;
/* If this symbol is not defined in a regular file, and we are
not generating a shared library, then set the symbol to this
location in the .plt. This is required to make function
pointers compare as equal between the normal executable and
the shared library. */
if (! info->shared
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
{
h->root.u.def.section = s;
h->root.u.def.value = s->_raw_size;
}
h->plt.offset = s->_raw_size;
/* Make room for this entry. */
s->_raw_size += PLT_ENTRY_SIZE;
/* We also need to make an entry in the .got.plt section, which
will be placed in the .got section by the linker script. */
s = bfd_get_section_by_name (dynobj, ".got.plt");
BFD_ASSERT (s != NULL);
s->_raw_size += 4;
/* We also need to make an entry in the .rel.plt section. */
s = bfd_get_section_by_name (dynobj, ".rel.plt");
BFD_ASSERT (s != NULL);
s->_raw_size += sizeof (Elf32_External_Rel);
return true;
}
/* If this is a weak symbol, and there is a real definition, the
processor independent code will have arranged for us to see the
real definition first, and we can just use the same value. */
if (h->weakdef != NULL)
{
BFD_ASSERT (h->weakdef->root.type == bfd_link_hash_defined
|| h->weakdef->root.type == bfd_link_hash_defweak);
h->root.u.def.section = h->weakdef->root.u.def.section;
h->root.u.def.value = h->weakdef->root.u.def.value;
return true;
}
/* This is a reference to a symbol defined by a dynamic object which
is not a function. */
/* If we are creating a shared library, we must presume that the
only references to the symbol are via the global offset table.
For such cases we need not do anything here; the relocations will
be handled correctly by relocate_section. */
if (info->shared)
return true;
/* We must allocate the symbol in our .dynbss section, which will
become part of the .bss section of the executable. There will be
an entry for this symbol in the .dynsym section. The dynamic
object will contain position independent code, so all references
from the dynamic object to this symbol will go through the global
offset table. The dynamic linker will use the .dynsym entry to
determine the address it must put in the global offset table, so
both the dynamic object and the regular object will refer to the
same memory location for the variable. */
s = bfd_get_section_by_name (dynobj, ".dynbss");
BFD_ASSERT (s != NULL);
/* We must generate a R_ARM_COPY reloc to tell the dynamic linker to
copy the initial value out of the dynamic object and into the
runtime process image. We need to remember the offset into the
.rel.bss section we are going to use. */
if ((h->root.u.def.section->flags & SEC_ALLOC) != 0)
{
asection *srel;
srel = bfd_get_section_by_name (dynobj, ".rel.bss");
BFD_ASSERT (srel != NULL);
srel->_raw_size += sizeof (Elf32_External_Rel);
h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_COPY;
}
/* We need to figure out the alignment required for this symbol. I
have no idea how ELF linkers handle this. */
power_of_two = bfd_log2 (h->size);
if (power_of_two > 3)
power_of_two = 3;
/* Apply the required alignment. */
s->_raw_size = BFD_ALIGN (s->_raw_size,
(bfd_size_type) (1 << power_of_two));
if (power_of_two > bfd_get_section_alignment (dynobj, s))
{
if (! bfd_set_section_alignment (dynobj, s, power_of_two))
return false;
}
/* Define the symbol as being at this point in the section. */
h->root.u.def.section = s;
h->root.u.def.value = s->_raw_size;
/* Increment the section size to make room for the symbol. */
s->_raw_size += h->size;
return true;
}
/* Set the sizes of the dynamic sections. */
static boolean
elf32_arm_size_dynamic_sections (output_bfd, info)
bfd * output_bfd;
struct bfd_link_info * info;
{
bfd * dynobj;
asection * s;
boolean plt;
boolean relocs;
boolean reltext;
dynobj = elf_hash_table (info)->dynobj;
BFD_ASSERT (dynobj != NULL);
if (elf_hash_table (info)->dynamic_sections_created)
{
/* Set the contents of the .interp section to the interpreter. */
if (! info->shared)
{
s = bfd_get_section_by_name (dynobj, ".interp");
BFD_ASSERT (s != NULL);
s->_raw_size = sizeof ELF_DYNAMIC_INTERPRETER;
s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER;
}
}
else
{
/* We may have created entries in the .rel.got section.
However, if we are not creating the dynamic sections, we will
not actually use these entries. Reset the size of .rel.got,
which will cause it to get stripped from the output file
below. */
s = bfd_get_section_by_name (dynobj, ".rel.got");
if (s != NULL)
s->_raw_size = 0;
}
/* If this is a -Bsymbolic shared link, then we need to discard all
PC relative relocs against symbols defined in a regular object.
We allocated space for them in the check_relocs routine, but we
will not fill them in in the relocate_section routine. */
if (info->shared && info->symbolic)
elf32_arm_link_hash_traverse (elf32_arm_hash_table (info),
elf32_arm_discard_copies,
(PTR) NULL);
/* The check_relocs and adjust_dynamic_symbol entry points have
determined the sizes of the various dynamic sections. Allocate
memory for them. */
plt = false;
relocs = false;
reltext = false;
for (s = dynobj->sections; s != NULL; s = s->next)
{
const char * name;
boolean strip;
if ((s->flags & SEC_LINKER_CREATED) == 0)
continue;
/* It's OK to base decisions on the section name, because none
of the dynobj section names depend upon the input files. */
name = bfd_get_section_name (dynobj, s);
strip = false;
if (strcmp (name, ".plt") == 0)
{
if (s->_raw_size == 0)
{
/* Strip this section if we don't need it; see the
comment below. */
strip = true;
}
else
{
/* Remember whether there is a PLT. */
plt = true;
}
}
else if (strncmp (name, ".rel", 4) == 0)
{
if (s->_raw_size == 0)
{
/* If we don't need this section, strip it from the
output file. This is mostly to handle .rel.bss and
.rel.plt. We must create both sections in
create_dynamic_sections, because they must be created
before the linker maps input sections to output
sections. The linker does that before
adjust_dynamic_symbol is called, and it is that
function which decides whether anything needs to go
into these sections. */
strip = true;
}
else
{
asection * target;
/* Remember whether there are any reloc sections other
than .rel.plt. */
if (strcmp (name, ".rel.plt") != 0)
{
const char *outname;
relocs = true;
/* If this relocation section applies to a read only
section, then we probably need a DT_TEXTREL
entry. The entries in the .rel.plt section
really apply to the .got section, which we
created ourselves and so know is not readonly. */
outname = bfd_get_section_name (output_bfd,
s->output_section);
target = bfd_get_section_by_name (output_bfd, outname + 4);
if (target != NULL
&& (target->flags & SEC_READONLY) != 0
&& (target->flags & SEC_ALLOC) != 0)
reltext = true;
}
/* We use the reloc_count field as a counter if we need
to copy relocs into the output file. */
s->reloc_count = 0;
}
}
else if (strncmp (name, ".got", 4) != 0)
{
/* It's not one of our sections, so don't allocate space. */
continue;
}
if (strip)
{
asection ** spp;
for (spp = &s->output_section->owner->sections;
*spp != s->output_section;
spp = &(*spp)->next)
;
*spp = s->output_section->next;
--s->output_section->owner->section_count;
continue;
}
/* Allocate memory for the section contents. */
s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->_raw_size);
if (s->contents == NULL && s->_raw_size != 0)
return false;
}
if (elf_hash_table (info)->dynamic_sections_created)
{
/* Add some entries to the .dynamic section. We fill in the
values later, in elf32_arm_finish_dynamic_sections, but we
must add the entries now so that we get the correct size for
the .dynamic section. The DT_DEBUG entry is filled in by the
dynamic linker and used by the debugger. */
if (! info->shared)
{
if (! bfd_elf32_add_dynamic_entry (info, DT_DEBUG, 0))
return false;
}
if (plt)
{
if ( ! bfd_elf32_add_dynamic_entry (info, DT_PLTGOT, 0)
|| ! bfd_elf32_add_dynamic_entry (info, DT_PLTRELSZ, 0)
|| ! bfd_elf32_add_dynamic_entry (info, DT_PLTREL, DT_REL)
|| ! bfd_elf32_add_dynamic_entry (info, DT_JMPREL, 0))
return false;
}
if (relocs)
{
if ( ! bfd_elf32_add_dynamic_entry (info, DT_REL, 0)
|| ! bfd_elf32_add_dynamic_entry (info, DT_RELSZ, 0)
|| ! bfd_elf32_add_dynamic_entry (info, DT_RELENT,
sizeof (Elf32_External_Rel)))
return false;
}
if (reltext)
{
if (! bfd_elf32_add_dynamic_entry (info, DT_TEXTREL, 0))
return false;
info->flags |= DF_TEXTREL;
}
}
return true;
}
/* This function is called via elf32_arm_link_hash_traverse if we are
creating a shared object with -Bsymbolic. It discards the space
allocated to copy PC relative relocs against symbols which are
defined in regular objects. We allocated space for them in the
check_relocs routine, but we won't fill them in in the
relocate_section routine. */
static boolean
elf32_arm_discard_copies (h, ignore)
struct elf32_arm_link_hash_entry * h;
PTR ignore ATTRIBUTE_UNUSED;
{
struct elf32_arm_pcrel_relocs_copied * s;
/* We only discard relocs for symbols defined in a regular object. */
if ((h->root.elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
return true;
for (s = h->pcrel_relocs_copied; s != NULL; s = s->next)
s->section->_raw_size -= s->count * sizeof (Elf32_External_Rel);
return true;
}
/* Finish up dynamic symbol handling. We set the contents of various
dynamic sections here. */
static boolean
elf32_arm_finish_dynamic_symbol (output_bfd, info, h, sym)
bfd * output_bfd;
struct bfd_link_info * info;
struct elf_link_hash_entry * h;
Elf_Internal_Sym * sym;
{
bfd * dynobj;
dynobj = elf_hash_table (info)->dynobj;
if (h->plt.offset != (bfd_vma) -1)
{
asection * splt;
asection * sgot;
asection * srel;
bfd_vma plt_index;
bfd_vma got_offset;
Elf_Internal_Rel rel;
/* This symbol has an entry in the procedure linkage table. Set
it up. */
BFD_ASSERT (h->dynindx != -1);
splt = bfd_get_section_by_name (dynobj, ".plt");
sgot = bfd_get_section_by_name (dynobj, ".got.plt");
srel = bfd_get_section_by_name (dynobj, ".rel.plt");
BFD_ASSERT (splt != NULL && sgot != NULL && srel != NULL);
/* Get the index in the procedure linkage table which
corresponds to this symbol. This is the index of this symbol
in all the symbols for which we are making plt entries. The
first entry in the procedure linkage table is reserved. */
plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1;
/* Get the offset into the .got table of the entry that
corresponds to this function. Each .got entry is 4 bytes.
The first three are reserved. */
got_offset = (plt_index + 3) * 4;
/* Fill in the entry in the procedure linkage table. */
bfd_put_32 (output_bfd, elf32_arm_plt_entry[0],
splt->contents + h->plt.offset + 0);
bfd_put_32 (output_bfd, elf32_arm_plt_entry[1],
splt->contents + h->plt.offset + 4);
bfd_put_32 (output_bfd, elf32_arm_plt_entry[2],
splt->contents + h->plt.offset + 8);
bfd_put_32 (output_bfd,
(sgot->output_section->vma
+ sgot->output_offset
+ got_offset
- splt->output_section->vma
- splt->output_offset
- h->plt.offset - 12),
splt->contents + h->plt.offset + 12);
/* Fill in the entry in the global offset table. */
bfd_put_32 (output_bfd,
(splt->output_section->vma
+ splt->output_offset),
sgot->contents + got_offset);
/* Fill in the entry in the .rel.plt section. */
rel.r_offset = (sgot->output_section->vma
+ sgot->output_offset
+ got_offset);
rel.r_info = ELF32_R_INFO (h->dynindx, R_ARM_JUMP_SLOT);
bfd_elf32_swap_reloc_out (output_bfd, &rel,
((Elf32_External_Rel *) srel->contents
+ plt_index));
if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
{
/* Mark the symbol as undefined, rather than as defined in
the .plt section. Leave the value alone. */
sym->st_shndx = SHN_UNDEF;
/* If the symbol is weak, we do need to clear the value.
Otherwise, the PLT entry would provide a definition for
the symbol even if the symbol wasn't defined anywhere,
and so the symbol would never be NULL. */
if ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR_NONWEAK)
== 0)
sym->st_value = 0;
}
}
if (h->got.offset != (bfd_vma) -1)
{
asection * sgot;
asection * srel;
Elf_Internal_Rel rel;
/* This symbol has an entry in the global offset table. Set it
up. */
sgot = bfd_get_section_by_name (dynobj, ".got");
srel = bfd_get_section_by_name (dynobj, ".rel.got");
BFD_ASSERT (sgot != NULL && srel != NULL);
rel.r_offset = (sgot->output_section->vma
+ sgot->output_offset
+ (h->got.offset &~ 1));
/* If this is a -Bsymbolic link, and the symbol is defined
locally, we just want to emit a RELATIVE reloc. The entry in
the global offset table will already have been initialized in
the relocate_section function. */
if (info->shared
&& (info->symbolic || h->dynindx == -1)
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))
rel.r_info = ELF32_R_INFO (0, R_ARM_RELATIVE);
else
{
bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + h->got.offset);
rel.r_info = ELF32_R_INFO (h->dynindx, R_ARM_GLOB_DAT);
}
bfd_elf32_swap_reloc_out (output_bfd, &rel,
((Elf32_External_Rel *) srel->contents
+ srel->reloc_count));
++srel->reloc_count;
}
if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_COPY) != 0)
{
asection * s;
Elf_Internal_Rel rel;
/* This symbol needs a copy reloc. Set it up. */
BFD_ASSERT (h->dynindx != -1
&& (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak));
s = bfd_get_section_by_name (h->root.u.def.section->owner,
".rel.bss");
BFD_ASSERT (s != NULL);
rel.r_offset = (h->root.u.def.value
+ h->root.u.def.section->output_section->vma
+ h->root.u.def.section->output_offset);
rel.r_info = ELF32_R_INFO (h->dynindx, R_ARM_COPY);
bfd_elf32_swap_reloc_out (output_bfd, &rel,
((Elf32_External_Rel *) s->contents
+ s->reloc_count));
++s->reloc_count;
}
/* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */
if (strcmp (h->root.root.string, "_DYNAMIC") == 0
|| strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0)
sym->st_shndx = SHN_ABS;
return true;
}
/* Finish up the dynamic sections. */
static boolean
elf32_arm_finish_dynamic_sections (output_bfd, info)
bfd * output_bfd;
struct bfd_link_info * info;
{
bfd * dynobj;
asection * sgot;
asection * sdyn;
dynobj = elf_hash_table (info)->dynobj;
sgot = bfd_get_section_by_name (dynobj, ".got.plt");
BFD_ASSERT (sgot != NULL);
sdyn = bfd_get_section_by_name (dynobj, ".dynamic");
if (elf_hash_table (info)->dynamic_sections_created)
{
asection *splt;
Elf32_External_Dyn *dyncon, *dynconend;
splt = bfd_get_section_by_name (dynobj, ".plt");
BFD_ASSERT (splt != NULL && sdyn != NULL);
dyncon = (Elf32_External_Dyn *) sdyn->contents;
dynconend = (Elf32_External_Dyn *) (sdyn->contents + sdyn->_raw_size);
for (; dyncon < dynconend; dyncon++)
{
Elf_Internal_Dyn dyn;
const char * name;
asection * s;
bfd_elf32_swap_dyn_in (dynobj, dyncon, &dyn);
switch (dyn.d_tag)
{
default:
break;
case DT_PLTGOT:
name = ".got";
goto get_vma;
case DT_JMPREL:
name = ".rel.plt";
get_vma:
s = bfd_get_section_by_name (output_bfd, name);
BFD_ASSERT (s != NULL);
dyn.d_un.d_ptr = s->vma;
bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
break;
case DT_PLTRELSZ:
s = bfd_get_section_by_name (output_bfd, ".rel.plt");
BFD_ASSERT (s != NULL);
if (s->_cooked_size != 0)
dyn.d_un.d_val = s->_cooked_size;
else
dyn.d_un.d_val = s->_raw_size;
bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
break;
case DT_RELSZ:
/* My reading of the SVR4 ABI indicates that the
procedure linkage table relocs (DT_JMPREL) should be
included in the overall relocs (DT_REL). This is
what Solaris does. However, UnixWare can not handle
that case. Therefore, we override the DT_RELSZ entry
here to make it not include the JMPREL relocs. Since
the linker script arranges for .rel.plt to follow all
other relocation sections, we don't have to worry
about changing the DT_REL entry. */
s = bfd_get_section_by_name (output_bfd, ".rel.plt");
if (s != NULL)
{
if (s->_cooked_size != 0)
dyn.d_un.d_val -= s->_cooked_size;
else
dyn.d_un.d_val -= s->_raw_size;
}
bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
break;
}
}
/* Fill in the first entry in the procedure linkage table. */
if (splt->_raw_size > 0)
{
bfd_put_32 (output_bfd, elf32_arm_plt0_entry[0], splt->contents + 0);
bfd_put_32 (output_bfd, elf32_arm_plt0_entry[1], splt->contents + 4);
bfd_put_32 (output_bfd, elf32_arm_plt0_entry[2], splt->contents + 8);
bfd_put_32 (output_bfd, elf32_arm_plt0_entry[3], splt->contents + 12);
}
/* UnixWare sets the entsize of .plt to 4, although that doesn't
really seem like the right value. */
elf_section_data (splt->output_section)->this_hdr.sh_entsize = 4;
}
/* Fill in the first three entries in the global offset table. */
if (sgot->_raw_size > 0)
{
if (sdyn == NULL)
bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents);
else
bfd_put_32 (output_bfd,
sdyn->output_section->vma + sdyn->output_offset,
sgot->contents);
bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + 4);
bfd_put_32 (output_bfd, (bfd_vma) 0, sgot->contents + 8);
}
elf_section_data (sgot->output_section)->this_hdr.sh_entsize = 4;
return true;
}
static void
elf32_arm_post_process_headers (abfd, link_info)
bfd * abfd;
struct bfd_link_info * link_info ATTRIBUTE_UNUSED;
{
Elf_Internal_Ehdr * i_ehdrp; /* ELF file header, internal form. */
i_ehdrp = elf_elfheader (abfd);
i_ehdrp->e_ident[EI_OSABI] = ARM_ELF_OS_ABI_VERSION;
i_ehdrp->e_ident[EI_ABIVERSION] = ARM_ELF_ABI_VERSION;
}
#define ELF_ARCH bfd_arch_arm
#define ELF_MACHINE_CODE EM_ARM
#define ELF_MAXPAGESIZE 0x8000
#define bfd_elf32_bfd_copy_private_bfd_data elf32_arm_copy_private_bfd_data
#define bfd_elf32_bfd_merge_private_bfd_data elf32_arm_merge_private_bfd_data
#define bfd_elf32_bfd_set_private_flags elf32_arm_set_private_flags
#define bfd_elf32_bfd_print_private_bfd_data elf32_arm_print_private_bfd_data
#define bfd_elf32_bfd_link_hash_table_create elf32_arm_link_hash_table_create
#define bfd_elf32_bfd_reloc_type_lookup elf32_arm_reloc_type_lookup
#define bfd_elf32_find_nearest_line elf32_arm_find_nearest_line
#define elf_backend_get_symbol_type elf32_arm_get_symbol_type
#define elf_backend_gc_mark_hook elf32_arm_gc_mark_hook
#define elf_backend_gc_sweep_hook elf32_arm_gc_sweep_hook
#define elf_backend_check_relocs elf32_arm_check_relocs
#define elf_backend_relocate_section elf32_arm_relocate_section
#define elf_backend_adjust_dynamic_symbol elf32_arm_adjust_dynamic_symbol
#define elf_backend_create_dynamic_sections _bfd_elf_create_dynamic_sections
#define elf_backend_finish_dynamic_symbol elf32_arm_finish_dynamic_symbol
#define elf_backend_finish_dynamic_sections elf32_arm_finish_dynamic_sections
#define elf_backend_size_dynamic_sections elf32_arm_size_dynamic_sections
#define elf_backend_post_process_headers elf32_arm_post_process_headers
#define elf_backend_can_gc_sections 1
#define elf_backend_plt_readonly 1
#define elf_backend_want_got_plt 1
#define elf_backend_want_plt_sym 0
#define elf_backend_got_header_size 12
#define elf_backend_plt_header_size PLT_ENTRY_SIZE
#include "elf32-target.h"
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