932 lines
29 KiB
C
932 lines
29 KiB
C
/* Intel 80386/80486-specific support for 32-bit ELF
|
||
Copyright 1993 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
|
||
|
||
#include "bfd.h"
|
||
#include "sysdep.h"
|
||
#include "bfdlink.h"
|
||
#include "libbfd.h"
|
||
#include "libelf.h"
|
||
|
||
static CONST struct reloc_howto_struct *elf_i386_reloc_type_lookup
|
||
PARAMS ((bfd *, bfd_reloc_code_real_type));
|
||
static void elf_i386_info_to_howto
|
||
PARAMS ((bfd *, arelent *, Elf32_Internal_Rela *));
|
||
static void elf_i386_info_to_howto_rel
|
||
PARAMS ((bfd *, arelent *, Elf32_Internal_Rel *));
|
||
static boolean elf_i386_create_dynamic_sections
|
||
PARAMS ((bfd *, struct bfd_link_info *));
|
||
static boolean elf_i386_adjust_dynamic_symbol
|
||
PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *));
|
||
static boolean elf_i386_allocate_dynamic_section
|
||
PARAMS ((bfd *, const char *));
|
||
static boolean elf_i386_size_dynamic_sections
|
||
PARAMS ((bfd *, struct bfd_link_info *));
|
||
static boolean elf_i386_relocate_section
|
||
PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
|
||
Elf_Internal_Rela *, Elf_Internal_Sym *, asection **, char *));
|
||
static boolean elf_i386_finish_dynamic_symbol
|
||
PARAMS ((bfd *, struct bfd_link_info *, struct elf_link_hash_entry *,
|
||
Elf_Internal_Sym *));
|
||
static boolean elf_i386_finish_dynamic_sections
|
||
PARAMS ((bfd *, struct bfd_link_info *));
|
||
|
||
#define USE_REL 1 /* 386 uses REL relocations instead of RELA */
|
||
|
||
enum reloc_type
|
||
{
|
||
R_386_NONE = 0,
|
||
R_386_32,
|
||
R_386_PC32,
|
||
R_386_GOT32,
|
||
R_386_PLT32,
|
||
R_386_COPY,
|
||
R_386_GLOB_DAT,
|
||
R_386_JUMP_SLOT,
|
||
R_386_RELATIVE,
|
||
R_386_GOTOFF,
|
||
R_386_GOTPC,
|
||
R_386_max
|
||
};
|
||
|
||
#if 0
|
||
static CONST char *CONST reloc_type_names[] =
|
||
{
|
||
"R_386_NONE",
|
||
"R_386_32",
|
||
"R_386_PC32",
|
||
"R_386_GOT32",
|
||
"R_386_PLT32",
|
||
"R_386_COPY",
|
||
"R_386_GLOB_DAT",
|
||
"R_386_JUMP_SLOT",
|
||
"R_386_RELATIVE",
|
||
"R_386_GOTOFF",
|
||
"R_386_GOTPC",
|
||
};
|
||
#endif
|
||
|
||
static reloc_howto_type elf_howto_table[]=
|
||
{
|
||
HOWTO(R_386_NONE, 0,0, 0,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_NONE", true,0x00000000,0x00000000,false),
|
||
HOWTO(R_386_32, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_32", true,0xffffffff,0xffffffff,false),
|
||
HOWTO(R_386_PC32, 0,2,32,true, 0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_PC32", true,0xffffffff,0xffffffff,true),
|
||
HOWTO(R_386_GOT32, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_GOT32", true,0xffffffff,0xffffffff,false),
|
||
HOWTO(R_386_PLT32, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_PLT32", true,0xffffffff,0xffffffff,false),
|
||
HOWTO(R_386_COPY, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_COPY", true,0xffffffff,0xffffffff,false),
|
||
HOWTO(R_386_GLOB_DAT, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_GLOB_DAT", true,0xffffffff,0xffffffff,false),
|
||
HOWTO(R_386_JUMP_SLOT, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_JUMP_SLOT",true,0xffffffff,0xffffffff,false),
|
||
HOWTO(R_386_RELATIVE, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_RELATIVE", true,0xffffffff,0xffffffff,false),
|
||
HOWTO(R_386_GOTOFF, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_GOTOFF", true,0xffffffff,0xffffffff,false),
|
||
HOWTO(R_386_GOTPC, 0,2,32,false,0,complain_overflow_bitfield, bfd_elf_generic_reloc,"R_386_GOTPC", true,0xffffffff,0xffffffff,false),
|
||
};
|
||
|
||
#ifdef DEBUG_GEN_RELOC
|
||
#define TRACE(str) fprintf (stderr, "i386 bfd reloc lookup %d (%s)\n", code, str)
|
||
#else
|
||
#define TRACE(str)
|
||
#endif
|
||
|
||
static CONST struct reloc_howto_struct *
|
||
elf_i386_reloc_type_lookup (abfd, code)
|
||
bfd *abfd;
|
||
bfd_reloc_code_real_type code;
|
||
{
|
||
switch (code)
|
||
{
|
||
case BFD_RELOC_NONE:
|
||
TRACE ("BFD_RELOC_NONE");
|
||
return &elf_howto_table[ (int)R_386_NONE ];
|
||
|
||
case BFD_RELOC_32:
|
||
TRACE ("BFD_RELOC_32");
|
||
return &elf_howto_table[ (int)R_386_32 ];
|
||
|
||
case BFD_RELOC_32_PCREL:
|
||
TRACE ("BFD_RELOC_PC32");
|
||
return &elf_howto_table[ (int)R_386_PC32 ];
|
||
|
||
case BFD_RELOC_386_GOT32:
|
||
TRACE ("BFD_RELOC_386_GOT32");
|
||
return &elf_howto_table[ (int)R_386_GOT32 ];
|
||
|
||
case BFD_RELOC_386_PLT32:
|
||
TRACE ("BFD_RELOC_386_PLT32");
|
||
return &elf_howto_table[ (int)R_386_PLT32 ];
|
||
|
||
case BFD_RELOC_386_COPY:
|
||
TRACE ("BFD_RELOC_386_COPY");
|
||
return &elf_howto_table[ (int)R_386_COPY ];
|
||
|
||
case BFD_RELOC_386_GLOB_DAT:
|
||
TRACE ("BFD_RELOC_386_GLOB_DAT");
|
||
return &elf_howto_table[ (int)R_386_GLOB_DAT ];
|
||
|
||
case BFD_RELOC_386_JUMP_SLOT:
|
||
TRACE ("BFD_RELOC_386_JUMP_SLOT");
|
||
return &elf_howto_table[ (int)R_386_JUMP_SLOT ];
|
||
|
||
case BFD_RELOC_386_RELATIVE:
|
||
TRACE ("BFD_RELOC_386_RELATIVE");
|
||
return &elf_howto_table[ (int)R_386_RELATIVE ];
|
||
|
||
case BFD_RELOC_386_GOTOFF:
|
||
TRACE ("BFD_RELOC_386_GOTOFF");
|
||
return &elf_howto_table[ (int)R_386_GOTOFF ];
|
||
|
||
case BFD_RELOC_386_GOTPC:
|
||
TRACE ("BFD_RELOC_386_GOTPC");
|
||
return &elf_howto_table[ (int)R_386_GOTPC ];
|
||
|
||
default:
|
||
break;
|
||
}
|
||
|
||
TRACE ("Unknown");
|
||
return 0;
|
||
}
|
||
|
||
static void
|
||
elf_i386_info_to_howto (abfd, cache_ptr, dst)
|
||
bfd *abfd;
|
||
arelent *cache_ptr;
|
||
Elf32_Internal_Rela *dst;
|
||
{
|
||
BFD_ASSERT (ELF32_R_TYPE(dst->r_info) < (unsigned int) R_386_max);
|
||
|
||
cache_ptr->howto = &elf_howto_table[ELF32_R_TYPE(dst->r_info)];
|
||
}
|
||
|
||
static void
|
||
elf_i386_info_to_howto_rel (abfd, cache_ptr, dst)
|
||
bfd *abfd;
|
||
arelent *cache_ptr;
|
||
Elf32_Internal_Rel *dst;
|
||
{
|
||
BFD_ASSERT (ELF32_R_TYPE(dst->r_info) < (unsigned int) R_386_max);
|
||
|
||
cache_ptr->howto = &elf_howto_table[ELF32_R_TYPE(dst->r_info)];
|
||
}
|
||
|
||
/* Functions for the i386 ELF linker. */
|
||
|
||
/* The name of the dynamic interpreter. This is put in the .interp
|
||
section. */
|
||
|
||
#define ELF_DYNAMIC_INTERPRETER "/usr/lib/libc.so.1"
|
||
|
||
/* The size in bytes of an entry in the procedure linkage table. */
|
||
|
||
#define PLT_ENTRY_SIZE 16
|
||
|
||
/* The first entry in an absolute procedure linkage table looks like
|
||
this. See the SVR4 ABI i386 supplement to see how this works. */
|
||
|
||
static bfd_byte elf_i386_plt0_entry[PLT_ENTRY_SIZE] =
|
||
{
|
||
0xff, 0x35, /* pushl contents of address */
|
||
0, 0, 0, 0, /* replaced with address of .got + 4. */
|
||
0xff, 0x25, /* jmp indirect */
|
||
0, 0, 0, 0, /* replaced with address of .got + 8. */
|
||
0, 0, 0, 0 /* pad out to 16 bytes. */
|
||
};
|
||
|
||
/* Subsequent entries in an absolute procedure linkage table look like
|
||
this. */
|
||
|
||
static bfd_byte elf_i386_plt_entry[PLT_ENTRY_SIZE] =
|
||
{
|
||
0xff, 0x25, /* jmp indirect */
|
||
0, 0, 0, 0, /* replaced with address of this symbol in .got. */
|
||
0x68, /* pushl immediate */
|
||
0, 0, 0, 0, /* replaced with offset into relocation table. */
|
||
0xe9, /* jmp relative */
|
||
0, 0, 0, 0 /* replaced with offset to start of .plt. */
|
||
};
|
||
|
||
/* Create dynamic sections when linking against a dynamic object. */
|
||
|
||
static boolean
|
||
elf_i386_create_dynamic_sections (abfd, info)
|
||
bfd *abfd;
|
||
struct bfd_link_info *info;
|
||
{
|
||
flagword flags;
|
||
register asection *s;
|
||
struct elf_link_hash_entry *h;
|
||
|
||
/* We need to create .plt, .rel.plt, .got, .dynbss, and .rel.bss
|
||
sections. */
|
||
|
||
flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY;
|
||
|
||
s = bfd_make_section (abfd, ".plt");
|
||
if (s == NULL
|
||
|| ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY | SEC_CODE)
|
||
|| ! bfd_set_section_alignment (abfd, s, 2))
|
||
return false;
|
||
|
||
s = bfd_make_section (abfd, ".rel.plt");
|
||
if (s == NULL
|
||
|| ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
|
||
|| ! bfd_set_section_alignment (abfd, s, 2))
|
||
return false;
|
||
|
||
s = bfd_make_section (abfd, ".got");
|
||
if (s == NULL
|
||
|| ! bfd_set_section_flags (abfd, s, flags)
|
||
|| ! bfd_set_section_alignment (abfd, s, 2))
|
||
return false;
|
||
|
||
/* Define the symbol _GLOBAL_OFFSET_TABLE_ at the start of the .got
|
||
section. We don't do this in the linker script because we don't
|
||
want to define the symbol if we are not creating a global offset
|
||
table. */
|
||
h = NULL;
|
||
if (! (_bfd_generic_link_add_one_symbol
|
||
(info, abfd, "_GLOBAL_OFFSET_TABLE_", BSF_GLOBAL, s, (bfd_vma) 0,
|
||
(const char *) NULL, false, get_elf_backend_data (abfd)->collect,
|
||
(struct bfd_link_hash_entry **) &h)))
|
||
return false;
|
||
h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
|
||
|
||
/* The first three global offset table entries are reserved. */
|
||
s->_raw_size += 3 * 4;
|
||
|
||
/* The .dynbss section is a place to put symbols which are defined
|
||
by dynamic objects, are referenced by regular objects, and are
|
||
not functions. We must allocate space for them in the process
|
||
image and use a R_386_COPY reloc to tell the dynamic linker to
|
||
initialize them at run time. The linker script puts the .dynbss
|
||
section into the .bss section of the final image. */
|
||
s = bfd_make_section (abfd, ".dynbss");
|
||
if (s == NULL
|
||
|| ! bfd_set_section_flags (abfd, s, SEC_ALLOC))
|
||
return false;
|
||
|
||
/* The .rel.bss section holds copy relocs. This section is not
|
||
normally needed. We need to create it here, though, so that the
|
||
linker will map it to an output section. If it turns out not to
|
||
be needed, we can discard it later. */
|
||
s = bfd_make_section (abfd, ".rel.bss");
|
||
if (s == NULL
|
||
|| ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
|
||
|| ! bfd_set_section_alignment (abfd, s, 2))
|
||
return false;
|
||
|
||
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
|
||
elf_i386_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;
|
||
size_t align;
|
||
|
||
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_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
|
||
&& h->root.type == bfd_link_hash_defined
|
||
&& (bfd_get_flavour (h->root.u.def.section->owner)
|
||
== bfd_target_elf_flavour)
|
||
&& (elf_elfheader (h->root.u.def.section->owner)->e_type
|
||
== ET_DYN)
|
||
&& h->root.u.def.section->output_section == NULL);
|
||
|
||
/* 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)
|
||
{
|
||
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;
|
||
|
||
/* Set the symbol to this location in the .plt. */
|
||
h->root.u.def.section = s;
|
||
h->root.u.def.value = s->_raw_size;
|
||
|
||
/* Make room for this entry. */
|
||
s->_raw_size += PLT_ENTRY_SIZE;
|
||
|
||
/* We also need to make an entry in the .got section. */
|
||
|
||
s = bfd_get_section_by_name (dynobj, ".got");
|
||
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->root.u.def.section = h->weakdef->root.u.def.section;
|
||
h->root.u.def.value = h->weakdef->root.u.def.value;
|
||
h->align = (bfd_size_type) -1;
|
||
return true;
|
||
}
|
||
|
||
/* This is a reference to a symbol defined by a dynamic object which
|
||
is not a function. We must allocate it 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);
|
||
|
||
/* If the symbol is currently defined in the .bss section of the
|
||
dynamic object, then it is OK to simply initialize it to zero.
|
||
If the symbol is in some other section, we must generate a
|
||
R_386_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, and we coopt the align field for this
|
||
purpose (the align field is only used for common symbols, and
|
||
these symbols are always defined). It would be cleaner to use a
|
||
new field, but that would waste memory. */
|
||
if ((h->root.u.def.section->flags & SEC_LOAD) == 0)
|
||
h->align = (bfd_size_type) -1;
|
||
else
|
||
{
|
||
asection *srel;
|
||
|
||
srel = bfd_get_section_by_name (dynobj, ".rel.bss");
|
||
BFD_ASSERT (srel != NULL);
|
||
h->align = srel->_raw_size;
|
||
srel->_raw_size += sizeof (Elf32_External_Rel);
|
||
}
|
||
|
||
/* We need to figure out the alignment required for this symbol. I
|
||
have no idea how ELF linkers handle this. */
|
||
switch (h->size)
|
||
{
|
||
case 0:
|
||
case 1:
|
||
power_of_two = 0;
|
||
align = 1;
|
||
break;
|
||
case 2:
|
||
power_of_two = 1;
|
||
align = 2;
|
||
break;
|
||
case 3:
|
||
case 4:
|
||
power_of_two = 2;
|
||
align = 4;
|
||
break;
|
||
case 5:
|
||
case 6:
|
||
case 7:
|
||
case 8:
|
||
power_of_two = 3;
|
||
align = 8;
|
||
break;
|
||
default:
|
||
power_of_two = 4;
|
||
align = 16;
|
||
break;
|
||
}
|
||
|
||
/* Apply the required alignment. */
|
||
s->_raw_size = BFD_ALIGN (s->_raw_size, align);
|
||
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;
|
||
}
|
||
|
||
/* Allocate contents for a section. */
|
||
|
||
static INLINE boolean
|
||
elf_i386_allocate_dynamic_section (dynobj, name)
|
||
bfd *dynobj;
|
||
const char *name;
|
||
{
|
||
register asection *s;
|
||
|
||
s = bfd_get_section_by_name (dynobj, name);
|
||
BFD_ASSERT (s != NULL);
|
||
s->contents = (bfd_byte *) bfd_alloc (dynobj, s->_raw_size);
|
||
if (s->contents == NULL && s->_raw_size != 0)
|
||
{
|
||
bfd_set_error (bfd_error_no_memory);
|
||
return false;
|
||
}
|
||
return true;
|
||
}
|
||
|
||
/* Set the sizes of the dynamic sections. */
|
||
|
||
static boolean
|
||
elf_i386_size_dynamic_sections (output_bfd, info)
|
||
bfd *output_bfd;
|
||
struct bfd_link_info *info;
|
||
{
|
||
bfd *dynobj;
|
||
asection *s;
|
||
|
||
dynobj = elf_hash_table (info)->dynobj;
|
||
BFD_ASSERT (dynobj != NULL);
|
||
|
||
/* 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;
|
||
}
|
||
|
||
/* The adjust_dynamic_symbol entry point has determined the sizes of
|
||
the various dynamic sections. Allocate some memory for them to
|
||
hold contents. */
|
||
if (! elf_i386_allocate_dynamic_section (dynobj, ".plt")
|
||
|| ! elf_i386_allocate_dynamic_section (dynobj, ".rel.plt")
|
||
|| ! elf_i386_allocate_dynamic_section (dynobj, ".got")
|
||
|| ! elf_i386_allocate_dynamic_section (dynobj, ".rel.bss"))
|
||
return false;
|
||
|
||
/* Add some entries to the .dynamic section. We fill in the values
|
||
later, in elf_i386_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 (! bfd_elf32_add_dynamic_entry (info, DT_DEBUG, 0)
|
||
|| ! bfd_elf32_add_dynamic_entry (info, DT_PLTGOT, 0))
|
||
return false;
|
||
|
||
s = bfd_get_section_by_name (dynobj, ".plt");
|
||
BFD_ASSERT (s != NULL);
|
||
if (s->_raw_size != 0)
|
||
{
|
||
if (! 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 we didn't need the .rel.bss section, then discard it from the
|
||
output file. This is a hack. We don't bother to do it for the
|
||
other sections because they normally are needed. */
|
||
s = bfd_get_section_by_name (dynobj, ".rel.bss");
|
||
BFD_ASSERT (s != NULL);
|
||
if (s->_raw_size == 0)
|
||
{
|
||
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;
|
||
}
|
||
else
|
||
{
|
||
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;
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
/* Relocate an i386 ELF section. */
|
||
|
||
static boolean
|
||
elf_i386_relocate_section (output_bfd, info, input_bfd, input_section,
|
||
contents, relocs, local_syms, local_sections,
|
||
output_names)
|
||
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;
|
||
char *output_names;
|
||
{
|
||
Elf_Internal_Shdr *symtab_hdr;
|
||
Elf_Internal_Rela *rel;
|
||
Elf_Internal_Rela *relend;
|
||
|
||
symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
|
||
|
||
rel = relocs;
|
||
relend = relocs + input_section->reloc_count;
|
||
for (; rel < relend; rel++)
|
||
{
|
||
int r_type;
|
||
const reloc_howto_type *howto;
|
||
long r_symndx;
|
||
struct elf_link_hash_entry *h;
|
||
Elf_Internal_Sym *sym;
|
||
asection *sec;
|
||
bfd_vma relocation;
|
||
bfd_reloc_status_type r;
|
||
|
||
r_type = ELF32_R_TYPE (rel->r_info);
|
||
if (r_type < 0 || r_type >= (int) R_386_max)
|
||
{
|
||
bfd_set_error (bfd_error_bad_value);
|
||
return false;
|
||
}
|
||
howto = elf_howto_table + r_type;
|
||
|
||
r_symndx = ELF32_R_SYM (rel->r_info);
|
||
|
||
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)
|
||
{
|
||
bfd_vma val;
|
||
|
||
sec = local_sections[r_symndx];
|
||
val = bfd_get_32 (input_bfd, contents + rel->r_offset);
|
||
val += sec->output_offset + sym->st_value;
|
||
bfd_put_32 (input_bfd, val, contents + rel->r_offset);
|
||
}
|
||
}
|
||
|
||
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
|
||
{
|
||
long indx;
|
||
|
||
indx = r_symndx - symtab_hdr->sh_info;
|
||
h = elf_sym_hashes (input_bfd)[indx];
|
||
if (h->root.type == bfd_link_hash_defined)
|
||
{
|
||
sec = h->root.u.def.section;
|
||
relocation = (h->root.u.def.value
|
||
+ sec->output_section->vma
|
||
+ sec->output_offset);
|
||
}
|
||
else if (h->root.type == bfd_link_hash_weak)
|
||
relocation = 0;
|
||
else
|
||
{
|
||
if (! ((*info->callbacks->undefined_symbol)
|
||
(info, h->root.root.string, input_bfd,
|
||
input_section, rel->r_offset)))
|
||
return false;
|
||
relocation = 0;
|
||
}
|
||
}
|
||
|
||
r = _bfd_final_link_relocate (howto, input_bfd, input_section,
|
||
contents, rel->r_offset,
|
||
relocation, (bfd_vma) 0);
|
||
|
||
if (r != bfd_reloc_ok)
|
||
{
|
||
switch (r)
|
||
{
|
||
default:
|
||
case bfd_reloc_outofrange:
|
||
abort ();
|
||
case bfd_reloc_overflow:
|
||
{
|
||
const char *name;
|
||
|
||
if (h != NULL)
|
||
name = h->root.root.string;
|
||
else
|
||
{
|
||
name = output_names + sym->st_name;
|
||
if (name == NULL)
|
||
return false;
|
||
if (*name == '\0')
|
||
name = bfd_section_name (input_bfd, sec);
|
||
}
|
||
if (! ((*info->callbacks->reloc_overflow)
|
||
(info, name, howto->name, (bfd_vma) 0,
|
||
input_bfd, input_section, rel->r_offset)))
|
||
return false;
|
||
}
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
/* Finish up dynamic symbol handling. We set the contents of various
|
||
dynamic sections here. */
|
||
|
||
static boolean
|
||
elf_i386_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;
|
||
{
|
||
/* If this symbol is not defined by a dynamic object, or is not
|
||
referenced by a regular object, ignore it. */
|
||
if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
|
||
|| (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
|
||
|| (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
|
||
{
|
||
/* 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;
|
||
}
|
||
|
||
BFD_ASSERT (h->root.type == bfd_link_hash_defined);
|
||
BFD_ASSERT (h->dynindx != -1);
|
||
|
||
if (h->type == STT_FUNC)
|
||
{
|
||
asection *splt;
|
||
asection *sgot;
|
||
asection *srel;
|
||
bfd_vma plt_index;
|
||
bfd_vma got_offset;
|
||
Elf_Internal_Rel rel;
|
||
|
||
splt = h->root.u.def.section;
|
||
BFD_ASSERT (strcmp (bfd_get_section_name (splt->owner, splt), ".plt")
|
||
== 0);
|
||
sgot = bfd_get_section_by_name (splt->owner, ".got");
|
||
BFD_ASSERT (sgot != NULL);
|
||
srel = bfd_get_section_by_name (splt->owner, ".rel.plt");
|
||
BFD_ASSERT (srel != NULL);
|
||
|
||
/* FIXME: This only handles an absolute procedure linkage table.
|
||
When producing a dynamic object, we need to generate a
|
||
position independent procedure linkage table. */
|
||
|
||
/* 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->root.u.def.value / 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. */
|
||
memcpy (splt->contents + h->root.u.def.value, elf_i386_plt_entry,
|
||
PLT_ENTRY_SIZE);
|
||
bfd_put_32 (output_bfd,
|
||
(sgot->output_section->vma
|
||
+ sgot->output_offset
|
||
+ got_offset),
|
||
splt->contents + h->root.u.def.value + 2);
|
||
bfd_put_32 (output_bfd, plt_index * sizeof (Elf32_External_Rel),
|
||
splt->contents + h->root.u.def.value + 7);
|
||
bfd_put_32 (output_bfd, - (h->root.u.def.value + PLT_ENTRY_SIZE),
|
||
splt->contents + h->root.u.def.value + 12);
|
||
|
||
/* Fill in the entry in the global offset table. */
|
||
bfd_put_32 (output_bfd,
|
||
(splt->output_section->vma
|
||
+ splt->output_offset
|
||
+ h->root.u.def.value
|
||
+ 6),
|
||
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_386_JUMP_SLOT);
|
||
bfd_elf32_swap_reloc_out (output_bfd, &rel,
|
||
((Elf32_External_Rel *) srel->contents
|
||
+ plt_index));
|
||
|
||
/* Mark the symbol as undefined, rather than as defined in the
|
||
.plt section. Leave the value alone. */
|
||
sym->st_shndx = SHN_UNDEF;
|
||
}
|
||
else
|
||
{
|
||
/* This is not a function. We have already allocated memory for
|
||
it in the .bss section (via .dynbss). All we have to do here
|
||
is create a COPY reloc if required. */
|
||
if (h->align != (bfd_size_type) -1)
|
||
{
|
||
asection *s;
|
||
Elf_Internal_Rel rel;
|
||
|
||
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_386_COPY);
|
||
bfd_elf32_swap_reloc_out (output_bfd, &rel,
|
||
((Elf32_External_Rel *)
|
||
(s->contents + h->align)));
|
||
}
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
/* Finish up the dynamic sections. */
|
||
|
||
static boolean
|
||
elf_i386_finish_dynamic_sections (output_bfd, info)
|
||
bfd *output_bfd;
|
||
struct bfd_link_info *info;
|
||
{
|
||
asection *splt;
|
||
asection *sgot;
|
||
asection *sdyn;
|
||
Elf32_External_Dyn *dyncon, *dynconend;
|
||
|
||
splt = bfd_get_section_by_name (elf_hash_table (info)->dynobj, ".plt");
|
||
sgot = bfd_get_section_by_name (elf_hash_table (info)->dynobj, ".got");
|
||
sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj, ".dynamic");
|
||
BFD_ASSERT (splt != NULL && sgot != 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;
|
||
boolean size;
|
||
|
||
bfd_elf32_swap_dyn_in (elf_hash_table (info)->dynobj, dyncon, &dyn);
|
||
|
||
/* 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_REL and DT_RELSZ entries here to make them
|
||
not include the JMPREL relocs. */
|
||
|
||
switch (dyn.d_tag)
|
||
{
|
||
case DT_PLTGOT: name = ".got"; size = false; break;
|
||
case DT_PLTRELSZ: name = ".rel.plt"; size = true; break;
|
||
case DT_JMPREL: name = ".rel.plt"; size = false; break;
|
||
case DT_REL: name = ".rel.bss"; size = false; break;
|
||
case DT_RELSZ: name = ".rel.bss"; size = true; break;
|
||
default: name = NULL; size = false; break;
|
||
}
|
||
|
||
if (name != NULL)
|
||
{
|
||
asection *s;
|
||
|
||
s = bfd_get_section_by_name (output_bfd, name);
|
||
BFD_ASSERT (s != NULL);
|
||
if (! size)
|
||
dyn.d_un.d_ptr = s->vma;
|
||
else
|
||
{
|
||
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);
|
||
}
|
||
}
|
||
|
||
/* Fill in the first entry in the procedure linkage table. */
|
||
if (splt->_raw_size > 0)
|
||
{
|
||
memcpy (splt->contents, elf_i386_plt0_entry, PLT_ENTRY_SIZE);
|
||
bfd_put_32 (output_bfd,
|
||
sgot->output_section->vma + sgot->output_offset + 4,
|
||
splt->contents + 2);
|
||
bfd_put_32 (output_bfd,
|
||
sgot->output_section->vma + sgot->output_offset + 8,
|
||
splt->contents + 8);
|
||
}
|
||
|
||
/* Fill in the first three entries in the global offset table. */
|
||
if (sgot->_raw_size > 0)
|
||
{
|
||
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;
|
||
|
||
/* 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;
|
||
|
||
return true;
|
||
}
|
||
|
||
#define TARGET_LITTLE_SYM bfd_elf32_i386_vec
|
||
#define TARGET_LITTLE_NAME "elf32-i386"
|
||
#define ELF_ARCH bfd_arch_i386
|
||
#define ELF_MACHINE_CODE EM_386
|
||
#define elf_info_to_howto elf_i386_info_to_howto
|
||
#define elf_info_to_howto_rel elf_i386_info_to_howto_rel
|
||
#define bfd_elf32_bfd_reloc_type_lookup elf_i386_reloc_type_lookup
|
||
#define ELF_MAXPAGESIZE 0x1000
|
||
#define elf_backend_create_dynamic_sections \
|
||
elf_i386_create_dynamic_sections
|
||
#define elf_backend_adjust_dynamic_symbol \
|
||
elf_i386_adjust_dynamic_symbol
|
||
#define elf_backend_size_dynamic_sections \
|
||
elf_i386_size_dynamic_sections
|
||
#define elf_backend_relocate_section elf_i386_relocate_section
|
||
#define elf_backend_finish_dynamic_symbol \
|
||
elf_i386_finish_dynamic_symbol
|
||
#define elf_backend_finish_dynamic_sections \
|
||
elf_i386_finish_dynamic_sections
|
||
|
||
#include "elf32-target.h"
|