mirrors/binutils-gdb
0
0
Fork 0
mirror of https://sourceware.org/git/binutils-gdb.git synced 2024-12-28 19:53:28 +08:00
Code Issues Actions Packages Projects Releases Wiki Activity
9f28686c2b
binutils-gdb/bfd/elfcode.h
Steve Chamberlain d1ec549d7b * elfcode.h (elf_sort_hdrs): Rewrite to be symmetrical.
1995-06-09 19:21:47 +00:00

6952 lines
203 KiB
C++
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* ELF executable support for BFD.
Copyright 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
Written by Fred Fish @ Cygnus Support, from information published
in "UNIX System V Release 4, Programmers Guide: ANSI C and
Programming Support Tools". Sufficient support for gdb.
Rewritten by Mark Eichin @ Cygnus Support, from information
published in "System V Application Binary Interface", chapters 4
and 5, as well as the various "Processor Supplement" documents
derived from it. Added support for assembler and other object file
utilities. Further work done by Ken Raeburn (Cygnus Support), Michael
Meissner (Open Software Foundation), and Peter Hoogenboom (University
of Utah) to finish and extend this.
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. */
/* Problems and other issues to resolve.
(1) BFD expects there to be some fixed number of "sections" in
the object file. I.E. there is a "section_count" variable in the
bfd structure which contains the number of sections. However, ELF
supports multiple "views" of a file. In particular, with current
implementations, executable files typically have two tables, a
program header table and a section header table, both of which
partition the executable.
In ELF-speak, the "linking view" of the file uses the section header
table to access "sections" within the file, and the "execution view"
uses the program header table to access "segments" within the file.
"Segments" typically may contain all the data from one or more
"sections".
Note that the section header table is optional in ELF executables,
but it is this information that is most useful to gdb. If the
section header table is missing, then gdb should probably try
to make do with the program header table. (FIXME)
(2) The code in this file is compiled twice, once in 32-bit mode and
once in 64-bit mode. More of it should be made size-independent
and moved into elf.c.
(3) ELF section symbols are handled rather sloppily now. This should
be cleaned up, and ELF section symbols reconciled with BFD section
symbols.
(4) We need a published spec for 64-bit ELF. We've got some stuff here
that we're using for SPARC V9 64-bit chips, but don't assume that
it's cast in stone.
*/
#include <string.h> /* For strrchr and friends */
#include "bfd.h"
#include "sysdep.h"
#include "bfdlink.h"
#include "libbfd.h"
#include "libelf.h"
/* Renaming structures, typedefs, macros and functions to be size-specific. */
#define Elf_External_Ehdr NAME(Elf,External_Ehdr)
#define Elf_External_Sym NAME(Elf,External_Sym)
#define Elf_External_Shdr NAME(Elf,External_Shdr)
#define Elf_External_Phdr NAME(Elf,External_Phdr)
#define Elf_External_Rel NAME(Elf,External_Rel)
#define Elf_External_Rela NAME(Elf,External_Rela)
#define Elf_External_Dyn NAME(Elf,External_Dyn)
#define elf_core_file_failing_command NAME(bfd_elf,core_file_failing_command)
#define elf_core_file_failing_signal NAME(bfd_elf,core_file_failing_signal)
#define elf_core_file_matches_executable_p \
NAME(bfd_elf,core_file_matches_executable_p)
#define elf_object_p NAME(bfd_elf,object_p)
#define elf_core_file_p NAME(bfd_elf,core_file_p)
#define elf_get_symtab_upper_bound NAME(bfd_elf,get_symtab_upper_bound)
#define elf_get_dynamic_symtab_upper_bound \
NAME(bfd_elf,get_dynamic_symtab_upper_bound)
#define elf_swap_reloc_in NAME(bfd_elf,swap_reloc_in)
#define elf_swap_reloca_in NAME(bfd_elf,swap_reloca_in)
#define elf_swap_reloc_out NAME(bfd_elf,swap_reloc_out)
#define elf_swap_reloca_out NAME(bfd_elf,swap_reloca_out)
#define elf_swap_symbol_in NAME(bfd_elf,swap_symbol_in)
#define elf_swap_symbol_out NAME(bfd_elf,swap_symbol_out)
#define elf_swap_dyn_in NAME(bfd_elf,swap_dyn_in)
#define elf_swap_dyn_out NAME(bfd_elf,swap_dyn_out)
#define elf_get_reloc_upper_bound NAME(bfd_elf,get_reloc_upper_bound)
#define elf_canonicalize_reloc NAME(bfd_elf,canonicalize_reloc)
#define elf_get_symtab NAME(bfd_elf,get_symtab)
#define elf_canonicalize_dynamic_symtab \
NAME(bfd_elf,canonicalize_dynamic_symtab)
#define elf_make_empty_symbol NAME(bfd_elf,make_empty_symbol)
#define elf_get_symbol_info NAME(bfd_elf,get_symbol_info)
#define elf_get_lineno NAME(bfd_elf,get_lineno)
#define elf_set_arch_mach NAME(bfd_elf,set_arch_mach)
#define elf_find_nearest_line NAME(bfd_elf,find_nearest_line)
#define elf_sizeof_headers NAME(bfd_elf,sizeof_headers)
#define elf_set_section_contents NAME(bfd_elf,set_section_contents)
#define elf_no_info_to_howto NAME(bfd_elf,no_info_to_howto)
#define elf_no_info_to_howto_rel NAME(bfd_elf,no_info_to_howto_rel)
#define elf_new_section_hook NAME(bfd_elf,new_section_hook)
#define elf_find_section NAME(bfd_elf,find_section)
#define elf_bfd_link_add_symbols NAME(bfd_elf,bfd_link_add_symbols)
#define elf_add_dynamic_entry NAME(bfd_elf,add_dynamic_entry)
#define elf_link_create_dynamic_sections \
NAME(bfd_elf,link_create_dynamic_sections)
#define elf_link_record_dynamic_symbol \
NAME(bfd_elf,link_record_dynamic_symbol)
#define elf_bfd_final_link NAME(bfd_elf,bfd_final_link)
#if ARCH_SIZE == 64
#define ELF_R_INFO(X,Y) ELF64_R_INFO(X,Y)
#define ELF_R_SYM(X) ELF64_R_SYM(X)
#define ELF_R_TYPE(X) ELF64_R_TYPE(X)
#define ELFCLASS ELFCLASS64
#define FILE_ALIGN 8
#define LOG_FILE_ALIGN 3
#endif
#if ARCH_SIZE == 32
#define ELF_R_INFO(X,Y) ELF32_R_INFO(X,Y)
#define ELF_R_SYM(X) ELF32_R_SYM(X)
#define ELF_R_TYPE(X) ELF32_R_TYPE(X)
#define ELFCLASS ELFCLASS32
#define FILE_ALIGN 4
#define LOG_FILE_ALIGN 2
#endif
/* Forward declarations of static functions */
static struct bfd_strtab_hash *elf_stringtab_init PARAMS ((void));
static asection *section_from_elf_index PARAMS ((bfd *, unsigned int));
static int elf_section_from_bfd_section PARAMS ((bfd *, struct sec *));
static long elf_slurp_symbol_table PARAMS ((bfd *, asymbol **, boolean));
static boolean elf_slurp_reloc_table PARAMS ((bfd *, asection *, asymbol **));
static int elf_symbol_from_bfd_symbol PARAMS ((bfd *,
struct symbol_cache_entry **));
static boolean elf_compute_section_file_positions
PARAMS ((bfd *, struct bfd_link_info *));
static boolean prep_headers PARAMS ((bfd *));
static void write_relocs PARAMS ((bfd *, asection *, PTR));
static void elf_fake_sections PARAMS ((bfd *, asection *, PTR));
static boolean assign_section_numbers PARAMS ((bfd *));
static file_ptr align_file_position PARAMS ((file_ptr));
static file_ptr assign_file_position_for_section
PARAMS ((Elf_Internal_Shdr *, file_ptr, boolean));
static boolean assign_file_positions_except_relocs PARAMS ((bfd *, boolean));
static int elf_sort_hdrs PARAMS ((const PTR, const PTR));
static void assign_file_positions_for_relocs PARAMS ((bfd *));
static bfd_size_type get_program_header_size PARAMS ((bfd *,
Elf_Internal_Shdr **,
unsigned int,
bfd_vma));
static file_ptr map_program_segments
PARAMS ((bfd *, file_ptr, Elf_Internal_Shdr *, Elf_Internal_Shdr **,
bfd_size_type));
static boolean elf_map_symbols PARAMS ((bfd *));
static boolean swap_out_syms PARAMS ((bfd *, struct bfd_strtab_hash **));
static boolean bfd_section_from_shdr PARAMS ((bfd *, unsigned int shindex));
#ifdef DEBUG
static void elf_debug_section PARAMS ((int, Elf_Internal_Shdr *));
static void elf_debug_file PARAMS ((Elf_Internal_Ehdr *));
static char *elf_symbol_flags PARAMS ((flagword));
#endif
#define elf_string_from_elf_strtab(abfd,strindex) \
elf_string_from_elf_section(abfd,elf_elfheader(abfd)->e_shstrndx,strindex)
/* Structure swapping routines */
/* Should perhaps use put_offset, put_word, etc. For now, the two versions
can be handled by explicitly specifying 32 bits or "the long type". */
#if ARCH_SIZE == 64
#define put_word bfd_h_put_64
#define get_word bfd_h_get_64
#endif
#if ARCH_SIZE == 32
#define put_word bfd_h_put_32
#define get_word bfd_h_get_32
#endif
/* Translate an ELF symbol in external format into an ELF symbol in internal
format. */
void
elf_swap_symbol_in (abfd, src, dst)
bfd *abfd;
Elf_External_Sym *src;
Elf_Internal_Sym *dst;
{
dst->st_name = bfd_h_get_32 (abfd, (bfd_byte *) src->st_name);
dst->st_value = get_word (abfd, (bfd_byte *) src->st_value);
dst->st_size = get_word (abfd, (bfd_byte *) src->st_size);
dst->st_info = bfd_h_get_8 (abfd, (bfd_byte *) src->st_info);
dst->st_other = bfd_h_get_8 (abfd, (bfd_byte *) src->st_other);
dst->st_shndx = bfd_h_get_16 (abfd, (bfd_byte *) src->st_shndx);
}
/* Translate an ELF symbol in internal format into an ELF symbol in external
format. */
void
elf_swap_symbol_out (abfd, src, dst)
bfd *abfd;
Elf_Internal_Sym *src;
Elf_External_Sym *dst;
{
bfd_h_put_32 (abfd, src->st_name, dst->st_name);
put_word (abfd, src->st_value, dst->st_value);
put_word (abfd, src->st_size, dst->st_size);
bfd_h_put_8 (abfd, src->st_info, dst->st_info);
bfd_h_put_8 (abfd, src->st_other, dst->st_other);
bfd_h_put_16 (abfd, src->st_shndx, dst->st_shndx);
}
/* Translate an ELF file header in external format into an ELF file header in
internal format. */
static void
elf_swap_ehdr_in (abfd, src, dst)
bfd *abfd;
Elf_External_Ehdr *src;
Elf_Internal_Ehdr *dst;
{
memcpy (dst->e_ident, src->e_ident, EI_NIDENT);
dst->e_type = bfd_h_get_16 (abfd, (bfd_byte *) src->e_type);
dst->e_machine = bfd_h_get_16 (abfd, (bfd_byte *) src->e_machine);
dst->e_version = bfd_h_get_32 (abfd, (bfd_byte *) src->e_version);
dst->e_entry = get_word (abfd, (bfd_byte *) src->e_entry);
dst->e_phoff = get_word (abfd, (bfd_byte *) src->e_phoff);
dst->e_shoff = get_word (abfd, (bfd_byte *) src->e_shoff);
dst->e_flags = bfd_h_get_32 (abfd, (bfd_byte *) src->e_flags);
dst->e_ehsize = bfd_h_get_16 (abfd, (bfd_byte *) src->e_ehsize);
dst->e_phentsize = bfd_h_get_16 (abfd, (bfd_byte *) src->e_phentsize);
dst->e_phnum = bfd_h_get_16 (abfd, (bfd_byte *) src->e_phnum);
dst->e_shentsize = bfd_h_get_16 (abfd, (bfd_byte *) src->e_shentsize);
dst->e_shnum = bfd_h_get_16 (abfd, (bfd_byte *) src->e_shnum);
dst->e_shstrndx = bfd_h_get_16 (abfd, (bfd_byte *) src->e_shstrndx);
}
/* Translate an ELF file header in internal format into an ELF file header in
external format. */
static void
elf_swap_ehdr_out (abfd, src, dst)
bfd *abfd;
Elf_Internal_Ehdr *src;
Elf_External_Ehdr *dst;
{
memcpy (dst->e_ident, src->e_ident, EI_NIDENT);
/* note that all elements of dst are *arrays of unsigned char* already... */
bfd_h_put_16 (abfd, src->e_type, dst->e_type);
bfd_h_put_16 (abfd, src->e_machine, dst->e_machine);
bfd_h_put_32 (abfd, src->e_version, dst->e_version);
put_word (abfd, src->e_entry, dst->e_entry);
put_word (abfd, src->e_phoff, dst->e_phoff);
put_word (abfd, src->e_shoff, dst->e_shoff);
bfd_h_put_32 (abfd, src->e_flags, dst->e_flags);
bfd_h_put_16 (abfd, src->e_ehsize, dst->e_ehsize);
bfd_h_put_16 (abfd, src->e_phentsize, dst->e_phentsize);
bfd_h_put_16 (abfd, src->e_phnum, dst->e_phnum);
bfd_h_put_16 (abfd, src->e_shentsize, dst->e_shentsize);
bfd_h_put_16 (abfd, src->e_shnum, dst->e_shnum);
bfd_h_put_16 (abfd, src->e_shstrndx, dst->e_shstrndx);
}
/* Translate an ELF section header table entry in external format into an
ELF section header table entry in internal format. */
static void
elf_swap_shdr_in (abfd, src, dst)
bfd *abfd;
Elf_External_Shdr *src;
Elf_Internal_Shdr *dst;
{
dst->sh_name = bfd_h_get_32 (abfd, (bfd_byte *) src->sh_name);
dst->sh_type = bfd_h_get_32 (abfd, (bfd_byte *) src->sh_type);
dst->sh_flags = get_word (abfd, (bfd_byte *) src->sh_flags);
dst->sh_addr = get_word (abfd, (bfd_byte *) src->sh_addr);
dst->sh_offset = get_word (abfd, (bfd_byte *) src->sh_offset);
dst->sh_size = get_word (abfd, (bfd_byte *) src->sh_size);
dst->sh_link = bfd_h_get_32 (abfd, (bfd_byte *) src->sh_link);
dst->sh_info = bfd_h_get_32 (abfd, (bfd_byte *) src->sh_info);
dst->sh_addralign = get_word (abfd, (bfd_byte *) src->sh_addralign);
dst->sh_entsize = get_word (abfd, (bfd_byte *) src->sh_entsize);
dst->bfd_section = NULL;
dst->contents = NULL;
}
/* Translate an ELF section header table entry in internal format into an
ELF section header table entry in external format. */
static void
elf_swap_shdr_out (abfd, src, dst)
bfd *abfd;
Elf_Internal_Shdr *src;
Elf_External_Shdr *dst;
{
/* note that all elements of dst are *arrays of unsigned char* already... */
bfd_h_put_32 (abfd, src->sh_name, dst->sh_name);
bfd_h_put_32 (abfd, src->sh_type, dst->sh_type);
put_word (abfd, src->sh_flags, dst->sh_flags);
put_word (abfd, src->sh_addr, dst->sh_addr);
put_word (abfd, src->sh_offset, dst->sh_offset);
put_word (abfd, src->sh_size, dst->sh_size);
bfd_h_put_32 (abfd, src->sh_link, dst->sh_link);
bfd_h_put_32 (abfd, src->sh_info, dst->sh_info);
put_word (abfd, src->sh_addralign, dst->sh_addralign);
put_word (abfd, src->sh_entsize, dst->sh_entsize);
}
/* Translate an ELF program header table entry in external format into an
ELF program header table entry in internal format. */
static void
elf_swap_phdr_in (abfd, src, dst)
bfd *abfd;
Elf_External_Phdr *src;
Elf_Internal_Phdr *dst;
{
dst->p_type = bfd_h_get_32 (abfd, (bfd_byte *) src->p_type);
dst->p_flags = bfd_h_get_32 (abfd, (bfd_byte *) src->p_flags);
dst->p_offset = get_word (abfd, (bfd_byte *) src->p_offset);
dst->p_vaddr = get_word (abfd, (bfd_byte *) src->p_vaddr);
dst->p_paddr = get_word (abfd, (bfd_byte *) src->p_paddr);
dst->p_filesz = get_word (abfd, (bfd_byte *) src->p_filesz);
dst->p_memsz = get_word (abfd, (bfd_byte *) src->p_memsz);
dst->p_align = get_word (abfd, (bfd_byte *) src->p_align);
}
static void
elf_swap_phdr_out (abfd, src, dst)
bfd *abfd;
Elf_Internal_Phdr *src;
Elf_External_Phdr *dst;
{
/* note that all elements of dst are *arrays of unsigned char* already... */
bfd_h_put_32 (abfd, src->p_type, dst->p_type);
put_word (abfd, src->p_offset, dst->p_offset);
put_word (abfd, src->p_vaddr, dst->p_vaddr);
put_word (abfd, src->p_paddr, dst->p_paddr);
put_word (abfd, src->p_filesz, dst->p_filesz);
put_word (abfd, src->p_memsz, dst->p_memsz);
bfd_h_put_32 (abfd, src->p_flags, dst->p_flags);
put_word (abfd, src->p_align, dst->p_align);
}
/* Translate an ELF reloc from external format to internal format. */
INLINE void
elf_swap_reloc_in (abfd, src, dst)
bfd *abfd;
Elf_External_Rel *src;
Elf_Internal_Rel *dst;
{
dst->r_offset = get_word (abfd, (bfd_byte *) src->r_offset);
dst->r_info = get_word (abfd, (bfd_byte *) src->r_info);
}
INLINE void
elf_swap_reloca_in (abfd, src, dst)
bfd *abfd;
Elf_External_Rela *src;
Elf_Internal_Rela *dst;
{
dst->r_offset = get_word (abfd, (bfd_byte *) src->r_offset);
dst->r_info = get_word (abfd, (bfd_byte *) src->r_info);
dst->r_addend = get_word (abfd, (bfd_byte *) src->r_addend);
}
/* Translate an ELF reloc from internal format to external format. */
INLINE void
elf_swap_reloc_out (abfd, src, dst)
bfd *abfd;
Elf_Internal_Rel *src;
Elf_External_Rel *dst;
{
put_word (abfd, src->r_offset, dst->r_offset);
put_word (abfd, src->r_info, dst->r_info);
}
INLINE void
elf_swap_reloca_out (abfd, src, dst)
bfd *abfd;
Elf_Internal_Rela *src;
Elf_External_Rela *dst;
{
put_word (abfd, src->r_offset, dst->r_offset);
put_word (abfd, src->r_info, dst->r_info);
put_word (abfd, src->r_addend, dst->r_addend);
}
INLINE void
elf_swap_dyn_in (abfd, src, dst)
bfd *abfd;
const Elf_External_Dyn *src;
Elf_Internal_Dyn *dst;
{
dst->d_tag = get_word (abfd, src->d_tag);
dst->d_un.d_val = get_word (abfd, src->d_un.d_val);
}
INLINE void
elf_swap_dyn_out (abfd, src, dst)
bfd *abfd;
const Elf_Internal_Dyn *src;
Elf_External_Dyn *dst;
{
put_word (abfd, src->d_tag, dst->d_tag);
put_word (abfd, src->d_un.d_val, dst->d_un.d_val);
}
/* Allocate an ELF string table--force the first byte to be zero. */
static struct bfd_strtab_hash *
elf_stringtab_init ()
{
struct bfd_strtab_hash *ret;
ret = _bfd_stringtab_init ();
if (ret != NULL)
{
bfd_size_type loc;
loc = _bfd_stringtab_add (ret, "", true, false);
BFD_ASSERT (loc == 0 || loc == (bfd_size_type) -1);
if (loc == (bfd_size_type) -1)
{
_bfd_stringtab_free (ret);
ret = NULL;
}
}
return ret;
}
/* ELF .o/exec file reading */
/* Create a new bfd section from an ELF section header. */
static boolean
bfd_section_from_shdr (abfd, shindex)
bfd *abfd;
unsigned int shindex;
{
Elf_Internal_Shdr *hdr = elf_elfsections (abfd)[shindex];
Elf_Internal_Ehdr *ehdr = elf_elfheader (abfd);
char *name;
name = elf_string_from_elf_strtab (abfd, hdr->sh_name);
switch (hdr->sh_type)
{
case SHT_NULL:
/* Inactive section. Throw it away. */
return true;
case SHT_PROGBITS: /* Normal section with contents. */
case SHT_DYNAMIC: /* Dynamic linking information. */
case SHT_NOBITS: /* .bss section. */
case SHT_HASH: /* .hash section. */
return _bfd_elf_make_section_from_shdr (abfd, hdr, name);
case SHT_SYMTAB: /* A symbol table */
if (elf_onesymtab (abfd) == shindex)
return true;
BFD_ASSERT (hdr->sh_entsize == sizeof (Elf_External_Sym));
BFD_ASSERT (elf_onesymtab (abfd) == 0);
elf_onesymtab (abfd) = shindex;
elf_tdata (abfd)->symtab_hdr = *hdr;
elf_elfsections (abfd)[shindex] = &elf_tdata (abfd)->symtab_hdr;
abfd->flags |= HAS_SYMS;
/* Sometimes a shared object will map in the symbol table. If
SHF_ALLOC is set, and this is a shared object, then we also
treat this section as a BFD section. We can not base the
decision purely on SHF_ALLOC, because that flag is sometimes
set in a relocateable object file, which would confuse the
linker. */
if ((hdr->sh_flags & SHF_ALLOC) != 0
&& (abfd->flags & DYNAMIC) != 0
&& ! _bfd_elf_make_section_from_shdr (abfd, hdr, name))
return false;
return true;
case SHT_DYNSYM: /* A dynamic symbol table */
if (elf_dynsymtab (abfd) == shindex)
return true;
BFD_ASSERT (hdr->sh_entsize == sizeof (Elf_External_Sym));
BFD_ASSERT (elf_dynsymtab (abfd) == 0);
elf_dynsymtab (abfd) = shindex;
elf_tdata (abfd)->dynsymtab_hdr = *hdr;
elf_elfsections (abfd)[shindex] = &elf_tdata (abfd)->dynsymtab_hdr;
abfd->flags |= HAS_SYMS;
/* Besides being a symbol table, we also treat this as a regular
section, so that objcopy can handle it. */
return _bfd_elf_make_section_from_shdr (abfd, hdr, name);
case SHT_STRTAB: /* A string table */
if (hdr->bfd_section != NULL)
return true;
if (ehdr->e_shstrndx == shindex)
{
elf_tdata (abfd)->shstrtab_hdr = *hdr;
elf_elfsections (abfd)[shindex] = &elf_tdata (abfd)->shstrtab_hdr;
return true;
}
{
unsigned int i;
for (i = 1; i < ehdr->e_shnum; i++)
{
Elf_Internal_Shdr *hdr2 = elf_elfsections (abfd)[i];
if (hdr2->sh_link == shindex)
{
if (! bfd_section_from_shdr (abfd, i))
return false;
if (elf_onesymtab (abfd) == i)
{
elf_tdata (abfd)->strtab_hdr = *hdr;
elf_elfsections (abfd)[shindex] =
&elf_tdata (abfd)->strtab_hdr;
return true;
}
if (elf_dynsymtab (abfd) == i)
{
elf_tdata (abfd)->dynstrtab_hdr = *hdr;
elf_elfsections (abfd)[shindex] =
&elf_tdata (abfd)->dynstrtab_hdr;
/* We also treat this as a regular section, so
that objcopy can handle it. */
break;
}
#if 0 /* Not handling other string tables specially right now. */
hdr2 = elf_elfsections (abfd)[i]; /* in case it moved */
/* We have a strtab for some random other section. */
newsect = (asection *) hdr2->bfd_section;
if (!newsect)
break;
hdr->bfd_section = newsect;
hdr2 = &elf_section_data (newsect)->str_hdr;
*hdr2 = *hdr;
elf_elfsections (abfd)[shindex] = hdr2;
#endif
}
}
}
return _bfd_elf_make_section_from_shdr (abfd, hdr, name);
case SHT_REL:
case SHT_RELA:
/* *These* do a lot of work -- but build no sections! */
{
asection *target_sect;
Elf_Internal_Shdr *hdr2;
int use_rela_p = get_elf_backend_data (abfd)->use_rela_p;
/* Get the symbol table. */
if (! bfd_section_from_shdr (abfd, hdr->sh_link))
return false;
/* If this reloc section does not use the main symbol table we
don't treat it as a reloc section. BFD can't adequately
represent such a section, so at least for now, we don't
try. We just present it as a normal section. */
if (hdr->sh_link != elf_onesymtab (abfd))
return _bfd_elf_make_section_from_shdr (abfd, hdr, name);
/* Don't allow REL relocations on a machine that uses RELA and
vice versa. */
/* @@ Actually, the generic ABI does suggest that both might be
used in one file. But the four ABI Processor Supplements I
have access to right now all specify that only one is used on
each of those architectures. It's conceivable that, e.g., a
bunch of absolute 32-bit relocs might be more compact in REL
form even on a RELA machine... */
BFD_ASSERT (use_rela_p
? (hdr->sh_type == SHT_RELA
&& hdr->sh_entsize == sizeof (Elf_External_Rela))
: (hdr->sh_type == SHT_REL
&& hdr->sh_entsize == sizeof (Elf_External_Rel)));
if (! bfd_section_from_shdr (abfd, hdr->sh_info))
return false;
target_sect = section_from_elf_index (abfd, hdr->sh_info);
if (target_sect == NULL)
return false;
hdr2 = &elf_section_data (target_sect)->rel_hdr;
*hdr2 = *hdr;
elf_elfsections (abfd)[shindex] = hdr2;
target_sect->reloc_count = hdr->sh_size / hdr->sh_entsize;
target_sect->flags |= SEC_RELOC;
target_sect->relocation = NULL;
target_sect->rel_filepos = hdr->sh_offset;
abfd->flags |= HAS_RELOC;
return true;
}
break;
case SHT_NOTE:
#if 0
fprintf (stderr, "Note Sections not yet supported.\n");
BFD_FAIL ();
#endif
break;
case SHT_SHLIB:
#if 0
fprintf (stderr, "SHLIB Sections not supported (and non conforming.)\n");
#endif
return true;
default:
/* Check for any processor-specific section types. */
{
struct elf_backend_data *bed = get_elf_backend_data (abfd);
if (bed->elf_backend_section_from_shdr)
(*bed->elf_backend_section_from_shdr) (abfd, hdr, name);
}
break;
}
return true;
}
boolean
elf_new_section_hook (abfd, sec)
bfd *abfd
;
asection *sec;
{
struct bfd_elf_section_data *sdata;
sdata = (struct bfd_elf_section_data *) bfd_alloc (abfd, sizeof (*sdata));
if (!sdata)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
sec->used_by_bfd = (PTR) sdata;
memset (sdata, 0, sizeof (*sdata));
return true;
}
/* Create a new bfd section from an ELF program header.
Since program segments have no names, we generate a synthetic name
of the form segment<NUM>, where NUM is generally the index in the
program header table. For segments that are split (see below) we
generate the names segment<NUM>a and segment<NUM>b.
Note that some program segments may have a file size that is different than
(less than) the memory size. All this means is that at execution the
system must allocate the amount of memory specified by the memory size,
but only initialize it with the first "file size" bytes read from the
file. This would occur for example, with program segments consisting
of combined data+bss.
To handle the above situation, this routine generates TWO bfd sections
for the single program segment. The first has the length specified by
the file size of the segment, and the second has the length specified
by the difference between the two sizes. In effect, the segment is split
into it's initialized and uninitialized parts.
*/
static boolean
bfd_section_from_phdr (abfd, hdr, index)
bfd *abfd;
Elf_Internal_Phdr *hdr;
int index;
{
asection *newsect;
char *name;
char namebuf[64];
int split;
split = ((hdr->p_memsz > 0) &&
(hdr->p_filesz > 0) &&
(hdr->p_memsz > hdr->p_filesz));
sprintf (namebuf, split ? "segment%da" : "segment%d", index);
name = bfd_alloc (abfd, strlen (namebuf) + 1);
if (!name)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
strcpy (name, namebuf);
newsect = bfd_make_section (abfd, name);
if (newsect == NULL)
return false;
newsect->vma = hdr->p_vaddr;
newsect->_raw_size = hdr->p_filesz;
newsect->filepos = hdr->p_offset;
newsect->flags |= SEC_HAS_CONTENTS;
if (hdr->p_type == PT_LOAD)
{
newsect->flags |= SEC_ALLOC;
newsect->flags |= SEC_LOAD;
if (hdr->p_flags & PF_X)
{
/* FIXME: all we known is that it has execute PERMISSION,
may be data. */
newsect->flags |= SEC_CODE;
}
}
if (!(hdr->p_flags & PF_W))
{
newsect->flags |= SEC_READONLY;
}
if (split)
{
sprintf (namebuf, "segment%db", index);
name = bfd_alloc (abfd, strlen (namebuf) + 1);
if (!name)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
strcpy (name, namebuf);
newsect = bfd_make_section (abfd, name);
if (newsect == NULL)
return false;
newsect->vma = hdr->p_vaddr + hdr->p_filesz;
newsect->_raw_size = hdr->p_memsz - hdr->p_filesz;
if (hdr->p_type == PT_LOAD)
{
newsect->flags |= SEC_ALLOC;
if (hdr->p_flags & PF_X)
newsect->flags |= SEC_CODE;
}
if (!(hdr->p_flags & PF_W))
newsect->flags |= SEC_READONLY;
}
return true;
}
/* Begin processing a given object.
First we validate the file by reading in the ELF header and checking
the magic number. */
static INLINE boolean
elf_file_p (x_ehdrp)
Elf_External_Ehdr *x_ehdrp;
{
return ((x_ehdrp->e_ident[EI_MAG0] == ELFMAG0)
&& (x_ehdrp->e_ident[EI_MAG1] == ELFMAG1)
&& (x_ehdrp->e_ident[EI_MAG2] == ELFMAG2)
&& (x_ehdrp->e_ident[EI_MAG3] == ELFMAG3));
}
/* Check to see if the file associated with ABFD matches the target vector
that ABFD points to.
Note that we may be called several times with the same ABFD, but different
target vectors, most of which will not match. We have to avoid leaving
any side effects in ABFD, or any data it points to (like tdata), if the
file does not match the target vector. */
const bfd_target *
elf_object_p (abfd)
bfd *abfd;
{
Elf_External_Ehdr x_ehdr; /* Elf file header, external form */
Elf_Internal_Ehdr *i_ehdrp; /* Elf file header, internal form */
Elf_External_Shdr x_shdr; /* Section header table entry, external form */
Elf_Internal_Shdr *i_shdrp = NULL; /* Section header table, internal form */
unsigned int shindex;
char *shstrtab; /* Internal copy of section header stringtab */
struct elf_backend_data *ebd;
struct elf_obj_tdata *preserved_tdata = elf_tdata (abfd);
struct elf_obj_tdata *new_tdata = NULL;
/* Read in the ELF header in external format. */
if (bfd_read ((PTR) & x_ehdr, sizeof (x_ehdr), 1, abfd) != sizeof (x_ehdr))
{
if (bfd_get_error () != bfd_error_system_call)
goto got_wrong_format_error;
else
goto got_no_match;
}
/* Now check to see if we have a valid ELF file, and one that BFD can
make use of. The magic number must match, the address size ('class')
and byte-swapping must match our XVEC entry, and it must have a
section header table (FIXME: See comments re sections at top of this
file). */
if ((elf_file_p (&x_ehdr) == false) ||
(x_ehdr.e_ident[EI_VERSION] != EV_CURRENT) ||
(x_ehdr.e_ident[EI_CLASS] != ELFCLASS))
goto got_wrong_format_error;
/* Check that file's byte order matches xvec's */
switch (x_ehdr.e_ident[EI_DATA])
{
case ELFDATA2MSB: /* Big-endian */
if (!abfd->xvec->header_byteorder_big_p)
goto got_wrong_format_error;
break;
case ELFDATA2LSB: /* Little-endian */
if (abfd->xvec->header_byteorder_big_p)
goto got_wrong_format_error;
break;
case ELFDATANONE: /* No data encoding specified */
default: /* Unknown data encoding specified */
goto got_wrong_format_error;
}
/* Allocate an instance of the elf_obj_tdata structure and hook it up to
the tdata pointer in the bfd. */
new_tdata = ((struct elf_obj_tdata *)
bfd_zalloc (abfd, sizeof (struct elf_obj_tdata)));
if (new_tdata == NULL)
goto got_no_memory_error;
elf_tdata (abfd) = new_tdata;
/* Now that we know the byte order, swap in the rest of the header */
i_ehdrp = elf_elfheader (abfd);
elf_swap_ehdr_in (abfd, &x_ehdr, i_ehdrp);
#if DEBUG & 1
elf_debug_file (i_ehdrp);
#endif
/* If there is no section header table, we're hosed. */
if (i_ehdrp->e_shoff == 0)
goto got_wrong_format_error;
/* As a simple sanity check, verify that the what BFD thinks is the
size of each section header table entry actually matches the size
recorded in the file. */
if (i_ehdrp->e_shentsize != sizeof (x_shdr))
goto got_wrong_format_error;
ebd = get_elf_backend_data (abfd);
/* Check that the ELF e_machine field matches what this particular
BFD format expects. */
if (ebd->elf_machine_code != i_ehdrp->e_machine
&& (ebd->elf_machine_alt1 == 0 || i_ehdrp->e_machine != ebd->elf_machine_alt1)
&& (ebd->elf_machine_alt2 == 0 || i_ehdrp->e_machine != ebd->elf_machine_alt2))
{
const bfd_target * const *target_ptr;
if (ebd->elf_machine_code != EM_NONE)
goto got_wrong_format_error;
/* This is the generic ELF target. Let it match any ELF target
for which we do not have a specific backend. */
for (target_ptr = bfd_target_vector; *target_ptr != NULL; target_ptr++)
{
struct elf_backend_data *back;
if ((*target_ptr)->flavour != bfd_target_elf_flavour)
continue;
back = (struct elf_backend_data *) (*target_ptr)->backend_data;
if (back->elf_machine_code == i_ehdrp->e_machine)
{
/* target_ptr is an ELF backend which matches this
object file, so reject the generic ELF target. */
goto got_wrong_format_error;
}
}
}
if (i_ehdrp->e_type == ET_EXEC)
abfd->flags |= EXEC_P;
else if (i_ehdrp->e_type == ET_DYN)
abfd->flags |= DYNAMIC;
if (i_ehdrp->e_phnum > 0)
abfd->flags |= D_PAGED;
if (! bfd_default_set_arch_mach (abfd, ebd->arch, 0))
goto got_no_match;
/* Remember the entry point specified in the ELF file header. */
bfd_get_start_address (abfd) = i_ehdrp->e_entry;
/* Allocate space for a copy of the section header table in
internal form, seek to the section header table in the file,
read it in, and convert it to internal form. */
i_shdrp = ((Elf_Internal_Shdr *)
bfd_alloc (abfd, sizeof (*i_shdrp) * i_ehdrp->e_shnum));
elf_elfsections (abfd) = ((Elf_Internal_Shdr **)
bfd_alloc (abfd,
sizeof (i_shdrp) * i_ehdrp->e_shnum));
if (!i_shdrp || !elf_elfsections (abfd))
goto got_no_memory_error;
if (bfd_seek (abfd, i_ehdrp->e_shoff, SEEK_SET) != 0)
goto got_no_match;
for (shindex = 0; shindex < i_ehdrp->e_shnum; shindex++)
{
if (bfd_read ((PTR) & x_shdr, sizeof x_shdr, 1, abfd) != sizeof (x_shdr))
goto got_no_match;
elf_swap_shdr_in (abfd, &x_shdr, i_shdrp + shindex);
elf_elfsections (abfd)[shindex] = i_shdrp + shindex;
}
if (i_ehdrp->e_shstrndx)
{
if (! bfd_section_from_shdr (abfd, i_ehdrp->e_shstrndx))
goto got_no_match;
}
/* Read in the string table containing the names of the sections. We
will need the base pointer to this table later. */
/* We read this inline now, so that we don't have to go through
bfd_section_from_shdr with it (since this particular strtab is
used to find all of the ELF section names.) */
shstrtab = elf_get_str_section (abfd, i_ehdrp->e_shstrndx);
if (!shstrtab)
goto got_no_match;
/* Once all of the section headers have been read and converted, we
can start processing them. Note that the first section header is
a dummy placeholder entry, so we ignore it. */
for (shindex = 1; shindex < i_ehdrp->e_shnum; shindex++)
{
if (! bfd_section_from_shdr (abfd, shindex))
goto got_no_match;
}
/* Let the backend double check the format and override global
information. */
if (ebd->elf_backend_object_p)
{
if ((*ebd->elf_backend_object_p) (abfd) == false)
goto got_wrong_format_error;
}
return (abfd->xvec);
got_wrong_format_error:
bfd_set_error (bfd_error_wrong_format);
goto got_no_match;
got_no_memory_error:
bfd_set_error (bfd_error_no_memory);
goto got_no_match;
got_no_match:
if (new_tdata != NULL
&& new_tdata->elf_sect_ptr != NULL)
bfd_release (abfd, new_tdata->elf_sect_ptr);
if (i_shdrp != NULL)
bfd_release (abfd, i_shdrp);
if (new_tdata != NULL)
bfd_release (abfd, new_tdata);
elf_tdata (abfd) = preserved_tdata;
return (NULL);
}
/* ELF .o/exec file writing */
/* Takes a bfd and a symbol, returns a pointer to the elf specific area
of the symbol if there is one. */
static INLINE elf_symbol_type *
elf_symbol_from (ignore_abfd, symbol)
bfd *ignore_abfd;
asymbol *symbol;
{
if (symbol->the_bfd->xvec->flavour != bfd_target_elf_flavour)
return 0;
if (symbol->the_bfd->tdata.elf_obj_data == (struct elf_obj_tdata *) NULL)
return 0;
return (elf_symbol_type *) symbol;
}
static void
write_relocs (abfd, sec, data)
bfd *abfd;
asection *sec;
PTR data;
{
boolean *failedp = (boolean *) data;
Elf_Internal_Shdr *rela_hdr;
Elf_External_Rela *outbound_relocas;
Elf_External_Rel *outbound_relocs;
int idx;
int use_rela_p = get_elf_backend_data (abfd)->use_rela_p;
asymbol *last_sym = 0;
int last_sym_idx = 9999999; /* should always be written before use */
/* If we have already failed, don't do anything. */
if (*failedp)
return;
if ((sec->flags & SEC_RELOC) == 0)
return;
/* The linker backend writes the relocs out itself, and sets the
reloc_count field to zero to inhibit writing them here. Also,
sometimes the SEC_RELOC flag gets set even when there aren't any
relocs. */
if (sec->reloc_count == 0)
return;
rela_hdr = &elf_section_data (sec)->rel_hdr;
rela_hdr->sh_size = rela_hdr->sh_entsize * sec->reloc_count;
rela_hdr->contents = (PTR) bfd_alloc (abfd, rela_hdr->sh_size);
if (rela_hdr->contents == NULL)
{
bfd_set_error (bfd_error_no_memory);
*failedp = true;
return;
}
/* orelocation has the data, reloc_count has the count... */
if (use_rela_p)
{
outbound_relocas = (Elf_External_Rela *) rela_hdr->contents;
for (idx = 0; idx < sec->reloc_count; idx++)
{
Elf_Internal_Rela dst_rela;
Elf_External_Rela *src_rela;
arelent *ptr;
asymbol *sym;
int n;
ptr = sec->orelocation[idx];
src_rela = outbound_relocas + idx;
/* The address of an ELF reloc is section relative for an object
file, and absolute for an executable file or shared library.
The address of a BFD reloc is always section relative. */
if ((abfd->flags & (EXEC_P | DYNAMIC)) == 0)
dst_rela.r_offset = ptr->address;
else
dst_rela.r_offset = ptr->address + sec->vma;
sym = *ptr->sym_ptr_ptr;
if (sym == last_sym)
n = last_sym_idx;
else
{
last_sym = sym;
last_sym_idx = n = elf_symbol_from_bfd_symbol (abfd, &sym);
}
dst_rela.r_info = ELF_R_INFO (n, ptr->howto->type);
dst_rela.r_addend = ptr->addend;
elf_swap_reloca_out (abfd, &dst_rela, src_rela);
}
}
else
/* REL relocations */
{
outbound_relocs = (Elf_External_Rel *) rela_hdr->contents;
for (idx = 0; idx < sec->reloc_count; idx++)
{
Elf_Internal_Rel dst_rel;
Elf_External_Rel *src_rel;
arelent *ptr;
int n;
asymbol *sym;
ptr = sec->orelocation[idx];
sym = *ptr->sym_ptr_ptr;
src_rel = outbound_relocs + idx;
/* The address of an ELF reloc is section relative for an object
file, and absolute for an executable file or shared library.
The address of a BFD reloc is always section relative. */
if ((abfd->flags & (EXEC_P | DYNAMIC)) == 0)
dst_rel.r_offset = ptr->address;
else
dst_rel.r_offset = ptr->address + sec->vma;
if (sym == last_sym)
n = last_sym_idx;
else
{
last_sym = sym;
last_sym_idx = n = elf_symbol_from_bfd_symbol (abfd, &sym);
}
dst_rel.r_info = ELF_R_INFO (n, ptr->howto->type);
elf_swap_reloc_out (abfd, &dst_rel, src_rel);
}
}
}
/* Set up an ELF internal section header for a section. */
/*ARGSUSED*/
static void
elf_fake_sections (abfd, asect, failedptrarg)
bfd *abfd;
asection *asect;
PTR failedptrarg;
{
boolean *failedptr = (boolean *) failedptrarg;
Elf_Internal_Shdr *this_hdr;
if (*failedptr)
{
/* We already failed; just get out of the bfd_map_over_sections
loop. */
return;
}
this_hdr = &elf_section_data (asect)->this_hdr;
this_hdr->sh_name = (unsigned long) _bfd_stringtab_add (elf_shstrtab (abfd),
asect->name,
true, false);
if (this_hdr->sh_name == (unsigned long) -1)
{
*failedptr = true;
return;
}
this_hdr->sh_flags = 0;
if ((asect->flags & SEC_ALLOC) != 0)
this_hdr->sh_addr = asect->vma;
else
this_hdr->sh_addr = 0;
this_hdr->sh_offset = 0;
this_hdr->sh_size = asect->_raw_size;
this_hdr->sh_link = 0;
this_hdr->sh_info = 0;
this_hdr->sh_addralign = 1 << asect->alignment_power;
this_hdr->sh_entsize = 0;
this_hdr->bfd_section = asect;
this_hdr->contents = NULL;
/* FIXME: This should not be based on section names. */
if (strcmp (asect->name, ".dynstr") == 0)
this_hdr->sh_type = SHT_STRTAB;
else if (strcmp (asect->name, ".hash") == 0)
{
this_hdr->sh_type = SHT_HASH;
this_hdr->sh_entsize = ARCH_SIZE / 8;
}
else if (strcmp (asect->name, ".dynsym") == 0)
{
this_hdr->sh_type = SHT_DYNSYM;
this_hdr->sh_entsize = sizeof (Elf_External_Sym);
}
else if (strcmp (asect->name, ".dynamic") == 0)
{
this_hdr->sh_type = SHT_DYNAMIC;
this_hdr->sh_entsize = sizeof (Elf_External_Dyn);
}
else if (strncmp (asect->name, ".rela", 5) == 0
&& get_elf_backend_data (abfd)->use_rela_p)
{
this_hdr->sh_type = SHT_RELA;
this_hdr->sh_entsize = sizeof (Elf_External_Rela);
}
else if (strncmp (asect->name, ".rel", 4) == 0
&& ! get_elf_backend_data (abfd)->use_rela_p)
{
this_hdr->sh_type = SHT_REL;
this_hdr->sh_entsize = sizeof (Elf_External_Rel);
}
else if (strcmp (asect->name, ".note") == 0)
this_hdr->sh_type = SHT_NOTE;
else if (strncmp (asect->name, ".stab", 5) == 0
&& strcmp (asect->name + strlen (asect->name) - 3, "str") == 0)
this_hdr->sh_type = SHT_STRTAB;
else if ((asect->flags & SEC_ALLOC) != 0
&& (asect->flags & SEC_LOAD) != 0)
this_hdr->sh_type = SHT_PROGBITS;
else if ((asect->flags & SEC_ALLOC) != 0
&& ((asect->flags & SEC_LOAD) == 0))
{
BFD_ASSERT (strcmp (asect->name, ".bss") == 0
|| strcmp (asect->name, ".sbss") == 0
|| strcmp (asect->name, ".scommon") == 0
|| strcmp (asect->name, "COMMON") == 0);
this_hdr->sh_type = SHT_NOBITS;
}
else
{
/* Who knows? */
this_hdr->sh_type = SHT_PROGBITS;
}
if ((asect->flags & SEC_ALLOC) != 0)
this_hdr->sh_flags |= SHF_ALLOC;
if ((asect->flags & SEC_READONLY) == 0)
this_hdr->sh_flags |= SHF_WRITE;
if ((asect->flags & SEC_CODE) != 0)
this_hdr->sh_flags |= SHF_EXECINSTR;
/* Check for processor-specific section types. */
{
struct elf_backend_data *bed = get_elf_backend_data (abfd);
if (bed->elf_backend_fake_sections)
(*bed->elf_backend_fake_sections) (abfd, this_hdr, asect);
}
/* If the section has relocs, set up a section header for the
SHT_REL[A] section. */
if ((asect->flags & SEC_RELOC) != 0)
{
Elf_Internal_Shdr *rela_hdr;
int use_rela_p = get_elf_backend_data (abfd)->use_rela_p;
char *name;
rela_hdr = &elf_section_data (asect)->rel_hdr;
name = bfd_alloc (abfd, sizeof ".rela" + strlen (asect->name));
if (name == NULL)
{
bfd_set_error (bfd_error_no_memory);
*failedptr = true;
return;
}
sprintf (name, "%s%s", use_rela_p ? ".rela" : ".rel", asect->name);
rela_hdr->sh_name =
(unsigned int) _bfd_stringtab_add (elf_shstrtab (abfd), name,
true, false);
if (rela_hdr->sh_name == (unsigned int) -1)
{
*failedptr = true;
return;
}
rela_hdr->sh_type = use_rela_p ? SHT_RELA : SHT_REL;
rela_hdr->sh_entsize = (use_rela_p
? sizeof (Elf_External_Rela)
: sizeof (Elf_External_Rel));
rela_hdr->sh_addralign = FILE_ALIGN;
rela_hdr->sh_flags = 0;
rela_hdr->sh_addr = 0;
rela_hdr->sh_size = 0;
rela_hdr->sh_offset = 0;
}
}
/* Assign all ELF section numbers. The dummy first section is handled here
too. The link/info pointers for the standard section types are filled
in here too, while we're at it. */
static boolean
assign_section_numbers (abfd)
bfd *abfd;
{
struct elf_obj_tdata *t = elf_tdata (abfd);
asection *sec;
unsigned int section_number;
Elf_Internal_Shdr **i_shdrp;
section_number = 1;
for (sec = abfd->sections; sec; sec = sec->next)
{
struct bfd_elf_section_data *d = elf_section_data (sec);
d->this_idx = section_number++;
if ((sec->flags & SEC_RELOC) == 0)
d->rel_idx = 0;
else
d->rel_idx = section_number++;
}
t->shstrtab_section = section_number++;
elf_elfheader (abfd)->e_shstrndx = t->shstrtab_section;
t->shstrtab_hdr.sh_size = _bfd_stringtab_size (elf_shstrtab (abfd));
if (abfd->symcount > 0)
{
t->symtab_section = section_number++;
t->strtab_section = section_number++;
}
elf_elfheader (abfd)->e_shnum = section_number;
/* Set up the list of section header pointers, in agreement with the
indices. */
i_shdrp = ((Elf_Internal_Shdr **)
bfd_alloc (abfd, section_number * sizeof (Elf_Internal_Shdr *)));
if (i_shdrp == NULL)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
i_shdrp[0] = ((Elf_Internal_Shdr *)
bfd_alloc (abfd, sizeof (Elf_Internal_Shdr)));
if (i_shdrp[0] == NULL)
{
bfd_release (abfd, i_shdrp);
bfd_set_error (bfd_error_no_memory);
return false;
}
memset (i_shdrp[0], 0, sizeof (Elf_Internal_Shdr));
elf_elfsections (abfd) = i_shdrp;
i_shdrp[t->shstrtab_section] = &t->shstrtab_hdr;
if (abfd->symcount > 0)
{
i_shdrp[t->symtab_section] = &t->symtab_hdr;
i_shdrp[t->strtab_section] = &t->strtab_hdr;
t->symtab_hdr.sh_link = t->strtab_section;
}
for (sec = abfd->sections; sec; sec = sec->next)
{
struct bfd_elf_section_data *d = elf_section_data (sec);
asection *s;
const char *name;
i_shdrp[d->this_idx] = &d->this_hdr;
if (d->rel_idx != 0)
i_shdrp[d->rel_idx] = &d->rel_hdr;
/* Fill in the sh_link and sh_info fields while we're at it. */
/* sh_link of a reloc section is the section index of the symbol
table. sh_info is the section index of the section to which
the relocation entries apply. */
if (d->rel_idx != 0)
{
d->rel_hdr.sh_link = t->symtab_section;
d->rel_hdr.sh_info = d->this_idx;
}
switch (d->this_hdr.sh_type)
{
case SHT_REL:
case SHT_RELA:
/* A reloc section which we are treating as a normal BFD
section. sh_link is the section index of the symbol
table. sh_info is the section index of the section to
which the relocation entries apply. We assume that an
allocated reloc section uses the dynamic symbol table.
FIXME: How can we be sure? */
s = bfd_get_section_by_name (abfd, ".dynsym");
if (s != NULL)
d->this_hdr.sh_link = elf_section_data (s)->this_idx;
/* We look up the section the relocs apply to by name. */
name = sec->name;
if (d->this_hdr.sh_type == SHT_REL)
name += 4;
else
name += 5;
s = bfd_get_section_by_name (abfd, name);
if (s != NULL)
d->this_hdr.sh_info = elf_section_data (s)->this_idx;
break;
case SHT_STRTAB:
/* We assume that a section named .stab*str is a stabs
string section. We look for a section with the same name
but without the trailing ``str'', and set its sh_link
field to point to this section. */
if (strncmp (sec->name, ".stab", sizeof ".stab" - 1) == 0
&& strcmp (sec->name + strlen (sec->name) - 3, "str") == 0)
{
size_t len;
char *alc;
len = strlen (sec->name);
alc = (char *) malloc (len - 2);
if (alc == NULL)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
strncpy (alc, sec->name, len - 3);
alc[len - 3] = '\0';
s = bfd_get_section_by_name (abfd, alc);
free (alc);
if (s != NULL)
{
elf_section_data (s)->this_hdr.sh_link = d->this_idx;
/* This is a .stab section. */
elf_section_data (s)->this_hdr.sh_entsize =
4 + 2 * (ARCH_SIZE / 8);
}
}
break;
case SHT_DYNAMIC:
case SHT_DYNSYM:
/* sh_link is the section header index of the string table
used for the dynamic entries or symbol table. */
s = bfd_get_section_by_name (abfd, ".dynstr");
if (s != NULL)
d->this_hdr.sh_link = elf_section_data (s)->this_idx;
break;
case SHT_HASH:
/* sh_link is the section header index of the symbol table
this hash table is for. */
s = bfd_get_section_by_name (abfd, ".dynsym");
if (s != NULL)
d->this_hdr.sh_link = elf_section_data (s)->this_idx;
break;
}
}
return true;
}
/* Map symbol from it's internal number to the external number, moving
all local symbols to be at the head of the list. */
static INLINE int
sym_is_global (abfd, sym)
bfd *abfd;
asymbol *sym;
{
/* If the backend has a special mapping, use it. */
if (get_elf_backend_data (abfd)->elf_backend_sym_is_global)
return ((*get_elf_backend_data (abfd)->elf_backend_sym_is_global)
(abfd, sym));
return ((sym->flags & (BSF_GLOBAL | BSF_WEAK)) != 0
|| bfd_is_und_section (bfd_get_section (sym))
|| bfd_is_com_section (bfd_get_section (sym)));
}
static boolean
elf_map_symbols (abfd)
bfd *abfd;
{
int symcount = bfd_get_symcount (abfd);
asymbol **syms = bfd_get_outsymbols (abfd);
asymbol **sect_syms;
int num_locals = 0;
int num_globals = 0;
int num_locals2 = 0;
int num_globals2 = 0;
int max_index = 0;
int num_sections = 0;
int idx;
asection *asect;
asymbol **new_syms;
#ifdef DEBUG
fprintf (stderr, "elf_map_symbols\n");
fflush (stderr);
#endif
/* Add a section symbol for each BFD section. FIXME: Is this really
necessary? */
for (asect = abfd->sections; asect; asect = asect->next)
{
if (max_index < asect->index)
max_index = asect->index;
}
max_index++;
sect_syms = (asymbol **) bfd_zalloc (abfd, max_index * sizeof (asymbol *));
if (sect_syms == NULL)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
elf_section_syms (abfd) = sect_syms;
for (idx = 0; idx < symcount; idx++)
{
if ((syms[idx]->flags & BSF_SECTION_SYM) != 0
&& syms[idx]->value == 0)
{
asection *sec;
sec = syms[idx]->section;
if (sec->owner != NULL)
{
if (sec->owner != abfd)
{
if (sec->output_offset != 0)
continue;
sec = sec->output_section;
BFD_ASSERT (sec->owner == abfd);
}
sect_syms[sec->index] = syms[idx];
}
}
}
for (asect = abfd->sections; asect; asect = asect->next)
{
asymbol *sym;
if (sect_syms[asect->index] != NULL)
continue;
sym = bfd_make_empty_symbol (abfd);
if (sym == NULL)
return false;
sym->the_bfd = abfd;
sym->name = asect->name;
sym->value = 0;
/* Set the flags to 0 to indicate that this one was newly added. */
sym->flags = 0;
sym->section = asect;
sect_syms[asect->index] = sym;
num_sections++;
#ifdef DEBUG
fprintf (stderr,
"creating section symbol, name = %s, value = 0x%.8lx, index = %d, section = 0x%.8lx\n",
asect->name, (long) asect->vma, asect->index, (long) asect);
#endif
}
/* Classify all of the symbols. */
for (idx = 0; idx < symcount; idx++)
{
if (!sym_is_global (abfd, syms[idx]))
num_locals++;
else
num_globals++;
}
for (asect = abfd->sections; asect; asect = asect->next)
{
if (sect_syms[asect->index] != NULL
&& sect_syms[asect->index]->flags == 0)
{
sect_syms[asect->index]->flags = BSF_SECTION_SYM;
if (!sym_is_global (abfd, sect_syms[asect->index]))
num_locals++;
else
num_globals++;
sect_syms[asect->index]->flags = 0;
}
}
/* Now sort the symbols so the local symbols are first. */
new_syms = ((asymbol **)
bfd_alloc (abfd,
(num_locals + num_globals) * sizeof (asymbol *)));
if (new_syms == NULL)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
for (idx = 0; idx < symcount; idx++)
{
asymbol *sym = syms[idx];
int i;
if (!sym_is_global (abfd, sym))
i = num_locals2++;
else
i = num_locals + num_globals2++;
new_syms[i] = sym;
sym->udata.i = i + 1;
}
for (asect = abfd->sections; asect; asect = asect->next)
{
if (sect_syms[asect->index] != NULL
&& sect_syms[asect->index]->flags == 0)
{
asymbol *sym = sect_syms[asect->index];
int i;
sym->flags = BSF_SECTION_SYM;
if (!sym_is_global (abfd, sym))
i = num_locals2++;
else
i = num_locals + num_globals2++;
new_syms[i] = sym;
sym->udata.i = i + 1;
}
}
bfd_set_symtab (abfd, new_syms, num_locals + num_globals);
elf_num_locals (abfd) = num_locals;
elf_num_globals (abfd) = num_globals;
return true;
}
/* Compute the file positions we are going to put the sections at, and
otherwise prepare to begin writing out the ELF file. If LINK_INFO
is not NULL, this is being called by the ELF backend linker. */
static boolean
elf_compute_section_file_positions (abfd, link_info)
bfd *abfd;
struct bfd_link_info *link_info;
{
struct elf_backend_data *bed = get_elf_backend_data (abfd);
boolean failed;
struct bfd_strtab_hash *strtab;
Elf_Internal_Shdr *shstrtab_hdr;
if (abfd->output_has_begun)
return true;
/* Do any elf backend specific processing first. */
if (bed->elf_backend_begin_write_processing)
(*bed->elf_backend_begin_write_processing) (abfd, link_info);
if (! prep_headers (abfd))
return false;
failed = false;
bfd_map_over_sections (abfd, elf_fake_sections, &failed);
if (failed)
return false;
if (!assign_section_numbers (abfd))
return false;
/* The backend linker builds symbol table information itself. */
if (link_info == NULL)
{
if (! swap_out_syms (abfd, &strtab))
return false;
}
shstrtab_hdr = &elf_tdata (abfd)->shstrtab_hdr;
/* sh_name was set in prep_headers. */
shstrtab_hdr->sh_type = SHT_STRTAB;
shstrtab_hdr->sh_flags = 0;
shstrtab_hdr->sh_addr = 0;
shstrtab_hdr->sh_size = _bfd_stringtab_size (elf_shstrtab (abfd));
shstrtab_hdr->sh_entsize = 0;
shstrtab_hdr->sh_link = 0;
shstrtab_hdr->sh_info = 0;
/* sh_offset is set in assign_file_positions_for_symtabs_and_strtabs. */
shstrtab_hdr->sh_addralign = 1;
if (!assign_file_positions_except_relocs (abfd,
link_info == NULL ? true : false))
return false;
if (link_info == NULL)
{
/* Now that we know where the .strtab section goes, write it
out. */
if ((bfd_seek (abfd, elf_tdata (abfd)->strtab_hdr.sh_offset, SEEK_SET)
!= 0)
|| ! _bfd_stringtab_emit (abfd, strtab))
return false;
_bfd_stringtab_free (strtab);
}
abfd->output_has_begun = true;
return true;
}
/* Align to the maximum file alignment that could be required for any
ELF data structure. */
static INLINE file_ptr
align_file_position (off)
file_ptr off;
{
return (off + FILE_ALIGN - 1) & ~(FILE_ALIGN - 1);
}
/* Assign a file position to a section, optionally aligning to the
required section alignment. */
static INLINE file_ptr
assign_file_position_for_section (i_shdrp, offset, align)
Elf_Internal_Shdr *i_shdrp;
file_ptr offset;
boolean align;
{
if (align)
{
unsigned int al;
al = i_shdrp->sh_addralign;
if (al > 1)
offset = BFD_ALIGN (offset, al);
}
i_shdrp->sh_offset = offset;
if (i_shdrp->bfd_section != NULL)
i_shdrp->bfd_section->filepos = offset;
if (i_shdrp->sh_type != SHT_NOBITS)
offset += i_shdrp->sh_size;
return offset;
}
/* Get the size of the program header.
SORTED_HDRS, if non-NULL, is an array of COUNT pointers to headers sorted
by VMA. Non-allocated sections (!SHF_ALLOC) must appear last. All
section VMAs and sizes are known so we can compute the correct value.
(??? This may not be perfectly true. What cases do we miss?)
If SORTED_HDRS is NULL we assume there are two segments: text and data
(exclusive of .interp and .dynamic).
If this is called by the linker before any of the section VMA's are set, it
can't calculate the correct value for a strange memory layout. This only
happens when SIZEOF_HEADERS is used in a linker script. In this case,
SORTED_HDRS is NULL and we assume the normal scenario of one text and one
data segment (exclusive of .interp and .dynamic).
??? User written scripts must either not use SIZEOF_HEADERS, or assume there
will be two segments. */
static bfd_size_type
get_program_header_size (abfd, sorted_hdrs, count, maxpagesize)
bfd *abfd;
Elf_Internal_Shdr **sorted_hdrs;
unsigned int count;
bfd_vma maxpagesize;
{
size_t segs;
asection *s;
/* We can't return a different result each time we're called. */
if (elf_tdata (abfd)->program_header_size != 0)
return elf_tdata (abfd)->program_header_size;
if (sorted_hdrs != NULL)
{
unsigned int i;
unsigned int last_type;
Elf_Internal_Shdr **hdrpp;
/* What we think the current segment's offset is. */
bfd_vma p_offset;
/* What we think the current segment's address is. */
bfd_vma p_vaddr;
/* How big we think the current segment is. */
bfd_vma p_memsz;
/* What we think the current file offset is. */
bfd_vma file_offset;
bfd_vma next_offset;
/* Scan the headers and compute the number of segments required. This
code is intentionally similar to the code in map_program_segments.
The `sh_offset' field isn't valid at this point, so we keep our own
running total in `file_offset'.
This works because section VMAs are already known. */
segs = 1;
/* Make sure the first section goes in the first segment. */
file_offset = p_offset = sorted_hdrs[0]->sh_addr % maxpagesize;
p_vaddr = sorted_hdrs[0]->sh_addr;
p_memsz = 0;
last_type = SHT_PROGBITS;
for (i = 0, hdrpp = sorted_hdrs; i < count; i++, hdrpp++)
{
Elf_Internal_Shdr *hdr;
hdr = *hdrpp;
/* Ignore any section which will not be part of the process
image. */
if ((hdr->sh_flags & SHF_ALLOC) == 0)
continue;
/* Keep track of where this and the next sections go.
The section VMA must equal the file position modulo
the page size. */
file_offset += (hdr->sh_addr - file_offset) % maxpagesize;
next_offset = file_offset;
if (hdr->sh_type != SHT_NOBITS)
next_offset = file_offset + hdr->sh_size;
/* If this section fits in the segment we are constructing, add
it in. */
if ((file_offset - (p_offset + p_memsz)
== hdr->sh_addr - (p_vaddr + p_memsz))
&& (last_type != SHT_NOBITS || hdr->sh_type == SHT_NOBITS))
{
bfd_size_type adjust;
adjust = hdr->sh_addr - (p_vaddr + p_memsz);
p_memsz += hdr->sh_size + adjust;
file_offset = next_offset;
last_type = hdr->sh_type;
continue;
}
/* The section won't fit, start a new segment. */
++segs;
/* Initialize the segment. */
p_vaddr = hdr->sh_addr;
p_memsz = hdr->sh_size;
p_offset = file_offset;
file_offset = next_offset;
last_type = hdr->sh_type;
}
}
else
{
/* Assume we will need exactly two PT_LOAD segments: one for text
and one for data. */
segs = 2;
}
s = bfd_get_section_by_name (abfd, ".interp");
if (s != NULL && (s->flags & SEC_LOAD) != 0)
{
/* If we have a loadable interpreter section, we need a
PT_INTERP segment. In this case, assume we also need a
PT_PHDR segment, although that may not be true for all
targets. */
segs += 2;
}
if (bfd_get_section_by_name (abfd, ".dynamic") != NULL)
{
/* We need a PT_DYNAMIC segment. */
++segs;
}
elf_tdata (abfd)->program_header_size = segs * sizeof (Elf_External_Phdr);
return elf_tdata (abfd)->program_header_size;
}
/* Create the program header. OFF is the file offset where the
program header should be written. FIRST is the first loadable ELF
section. SORTED_HDRS is the ELF sections sorted by section
address. PHDR_SIZE is the size of the program header as returned
by get_program_header_size. */
static file_ptr
map_program_segments (abfd, off, first, sorted_hdrs, phdr_size)
bfd *abfd;
file_ptr off;
Elf_Internal_Shdr *first;
Elf_Internal_Shdr **sorted_hdrs;
bfd_size_type phdr_size;
{
Elf_Internal_Phdr phdrs[10];
unsigned int phdr_count;
Elf_Internal_Phdr *phdr;
int phdr_size_adjust;
unsigned int i;
Elf_Internal_Shdr **hdrpp;
asection *sinterp, *sdyn;
unsigned int last_type;
Elf_Internal_Ehdr *i_ehdrp;
BFD_ASSERT ((abfd->flags & (EXEC_P | DYNAMIC)) != 0);
BFD_ASSERT (phdr_size / sizeof (Elf_Internal_Phdr)
<= sizeof phdrs / sizeof (phdrs[0]));
phdr_count = 0;
phdr = phdrs;
phdr_size_adjust = 0;
/* If we have a loadable .interp section, we must create a PT_INTERP
segment which must precede all PT_LOAD segments. We assume that
we must also create a PT_PHDR segment, although that may not be
true for all targets. */
sinterp = bfd_get_section_by_name (abfd, ".interp");
if (sinterp != NULL && (sinterp->flags & SEC_LOAD) != 0)
{
BFD_ASSERT (first != NULL);
phdr->p_type = PT_PHDR;
phdr->p_offset = off;
/* Account for any adjustment made because of the alignment of
the first loadable section. */
phdr_size_adjust = (first->sh_offset - phdr_size) - off;
BFD_ASSERT (phdr_size_adjust >= 0 && phdr_size_adjust < 128);
/* The program header precedes all loadable sections. This lets
us compute its loadable address. This depends on the linker
script. */
phdr->p_vaddr = first->sh_addr - (phdr_size + phdr_size_adjust);
phdr->p_paddr = 0;
phdr->p_filesz = phdr_size;
phdr->p_memsz = phdr_size;
/* FIXME: UnixWare and Solaris set PF_X, Irix 5 does not. */
phdr->p_flags = PF_R | PF_X;
phdr->p_align = FILE_ALIGN;
BFD_ASSERT ((phdr->p_vaddr - phdr->p_offset) % FILE_ALIGN == 0);
/* Include the ELF header in the first loadable segment. */
phdr_size_adjust += off;
++phdr_count;
++phdr;
phdr->p_type = PT_INTERP;
phdr->p_offset = sinterp->filepos;
phdr->p_vaddr = sinterp->vma;
phdr->p_paddr = 0;
phdr->p_filesz = sinterp->_raw_size;
phdr->p_memsz = sinterp->_raw_size;
phdr->p_flags = PF_R;
phdr->p_align = 1 << bfd_get_section_alignment (abfd, sinterp);
++phdr_count;
++phdr;
}
/* Look through the sections to see how they will be divided into
program segments. The sections must be arranged in order by
sh_addr for this to work correctly. */
phdr->p_type = PT_NULL;
last_type = SHT_PROGBITS;
for (i = 1, hdrpp = sorted_hdrs;
i < elf_elfheader (abfd)->e_shnum;
i++, hdrpp++)
{
Elf_Internal_Shdr *hdr;
hdr = *hdrpp;
/* Ignore any section which will not be part of the process
image. */
if ((hdr->sh_flags & SHF_ALLOC) == 0)
continue;
/* If this section fits in the segment we are constructing, add
it in. */
if (phdr->p_type != PT_NULL
&& (hdr->sh_offset - (phdr->p_offset + phdr->p_memsz)
== hdr->sh_addr - (phdr->p_vaddr + phdr->p_memsz))
&& (last_type != SHT_NOBITS || hdr->sh_type == SHT_NOBITS))
{
bfd_size_type adjust;
adjust = hdr->sh_addr - (phdr->p_vaddr + phdr->p_memsz);
phdr->p_memsz += hdr->sh_size + adjust;
if (hdr->sh_type != SHT_NOBITS)
phdr->p_filesz += hdr->sh_size + adjust;
if ((hdr->sh_flags & SHF_WRITE) != 0)
phdr->p_flags |= PF_W;
if ((hdr->sh_flags & SHF_EXECINSTR) != 0)
phdr->p_flags |= PF_X;
last_type = hdr->sh_type;
continue;
}
/* The section won't fit, start a new segment. If we're already in one,
move to the next one. */
if (phdr->p_type != PT_NULL)
{
++phdr;
++phdr_count;
}
/* Initialize the segment. */
phdr->p_type = PT_LOAD;
phdr->p_offset = hdr->sh_offset;
phdr->p_vaddr = hdr->sh_addr;
phdr->p_paddr = 0;
if (hdr->sh_type == SHT_NOBITS)
phdr->p_filesz = 0;
else
phdr->p_filesz = hdr->sh_size;
phdr->p_memsz = hdr->sh_size;
phdr->p_flags = PF_R;
if ((hdr->sh_flags & SHF_WRITE) != 0)
phdr->p_flags |= PF_W;
if ((hdr->sh_flags & SHF_EXECINSTR) != 0)
phdr->p_flags |= PF_X;
phdr->p_align = get_elf_backend_data (abfd)->maxpagesize;
if (hdr == first
&& sinterp != NULL
&& (sinterp->flags & SEC_LOAD) != 0)
{
phdr->p_offset -= phdr_size + phdr_size_adjust;
phdr->p_vaddr -= phdr_size + phdr_size_adjust;
phdr->p_filesz += phdr_size + phdr_size_adjust;
phdr->p_memsz += phdr_size + phdr_size_adjust;
}
last_type = hdr->sh_type;
}
if (phdr->p_type != PT_NULL)
{
++phdr;
++phdr_count;
}
/* If we have a .dynamic section, create a PT_DYNAMIC segment. */
sdyn = bfd_get_section_by_name (abfd, ".dynamic");
if (sdyn != NULL && (sdyn->flags & SEC_LOAD) != 0)
{
phdr->p_type = PT_DYNAMIC;
phdr->p_offset = sdyn->filepos;
phdr->p_vaddr = sdyn->vma;
phdr->p_paddr = 0;
phdr->p_filesz = sdyn->_raw_size;
phdr->p_memsz = sdyn->_raw_size;
phdr->p_flags = PF_R;
if ((sdyn->flags & SEC_READONLY) == 0)
phdr->p_flags |= PF_W;
if ((sdyn->flags & SEC_CODE) != 0)
phdr->p_flags |= PF_X;
phdr->p_align = 1 << bfd_get_section_alignment (abfd, sdyn);
++phdr;
++phdr_count;
}
/* Make sure the return value from get_program_header_size matches
what we computed here. Actually, it's OK if we allocated too
much space in the program header. */
if (phdr_count > phdr_size / sizeof (Elf_External_Phdr))
{
((*_bfd_error_handler)
("%s: Not enough room for program headers (allocated %lu, need %u)",
bfd_get_filename (abfd),
(unsigned long) (phdr_size / sizeof (Elf_External_Phdr)),
phdr_count));
bfd_set_error (bfd_error_bad_value);
return (file_ptr) -1;
}
/* Set up program header information. */
i_ehdrp = elf_elfheader (abfd);
i_ehdrp->e_phentsize = sizeof (Elf_External_Phdr);
i_ehdrp->e_phoff = off;
i_ehdrp->e_phnum = phdr_count;
/* Save the program headers away. I don't think anybody uses this
information right now. */
elf_tdata (abfd)->phdr = ((Elf_Internal_Phdr *)
bfd_alloc (abfd,
(phdr_count
* sizeof (Elf_Internal_Phdr))));
if (elf_tdata (abfd)->phdr == NULL && phdr_count != 0)
{
bfd_set_error (bfd_error_no_memory);
return (file_ptr) -1;
}
memcpy (elf_tdata (abfd)->phdr, phdrs,
phdr_count * sizeof (Elf_Internal_Phdr));
/* Write out the program headers. */
if (bfd_seek (abfd, off, SEEK_SET) != 0)
return (file_ptr) -1;
for (i = 0, phdr = phdrs; i < phdr_count; i++, phdr++)
{
Elf_External_Phdr extphdr;
elf_swap_phdr_out (abfd, phdr, &extphdr);
if (bfd_write (&extphdr, sizeof (Elf_External_Phdr), 1, abfd)
!= sizeof (Elf_External_Phdr))
return (file_ptr) -1;
}
return off + phdr_count * sizeof (Elf_External_Phdr);
}
/* Work out the file positions of all the sections. This is called by
elf_compute_section_file_positions. All the section sizes and VMAs
must be known before this is called.
We do not consider reloc sections at this point, unless they form
part of the loadable image. Reloc sections are assigned file
positions in assign_file_positions_for_relocs, which is called by
write_object_contents and final_link.
If DOSYMS is false, we do not assign file positions for the symbol
table or the string table. */
static boolean
assign_file_positions_except_relocs (abfd, dosyms)
bfd *abfd;
boolean dosyms;
{
struct elf_obj_tdata * const tdata = elf_tdata (abfd);
Elf_Internal_Ehdr * const i_ehdrp = elf_elfheader (abfd);
Elf_Internal_Shdr ** const i_shdrpp = elf_elfsections (abfd);
file_ptr off;
/* Start after the ELF header. */
off = i_ehdrp->e_ehsize;
if ((abfd->flags & (EXEC_P | DYNAMIC)) == 0)
{
Elf_Internal_Shdr **hdrpp;
unsigned int i;
/* We are not creating an executable, which means that we are
not creating a program header, and that the actual order of
the sections in the file is unimportant. */
for (i = 1, hdrpp = i_shdrpp + 1; i < i_ehdrp->e_shnum; i++, hdrpp++)
{
Elf_Internal_Shdr *hdr;
hdr = *hdrpp;
if (hdr->sh_type == SHT_REL || hdr->sh_type == SHT_RELA)
{
hdr->sh_offset = -1;
continue;
}
if (! dosyms
&& (i == tdata->symtab_section
|| i == tdata->strtab_section))
{
hdr->sh_offset = -1;
continue;
}
off = assign_file_position_for_section (hdr, off, true);
}
}
else
{
file_ptr phdr_off;
bfd_size_type phdr_size;
bfd_vma maxpagesize;
size_t hdrppsize;
Elf_Internal_Shdr **sorted_hdrs;
Elf_Internal_Shdr **hdrpp;
unsigned int i;
Elf_Internal_Shdr *first;
file_ptr phdr_map;
/* We are creating an executable. */
maxpagesize = get_elf_backend_data (abfd)->maxpagesize;
if (maxpagesize == 0)
maxpagesize = 1;
/* We must sort the sections. The GNU linker will always create
the sections in an appropriate order, but the Irix 5 linker
will not. We don't include the dummy first section in the
sort. We sort sections which are not SHF_ALLOC to the end. */
hdrppsize = (i_ehdrp->e_shnum - 1) * sizeof (Elf_Internal_Shdr *);
sorted_hdrs = (Elf_Internal_Shdr **) malloc (hdrppsize);
if (sorted_hdrs == NULL)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
memcpy (sorted_hdrs, i_shdrpp + 1, hdrppsize);
qsort (sorted_hdrs, i_ehdrp->e_shnum - 1, sizeof (Elf_Internal_Shdr *),
elf_sort_hdrs);
/* We can't actually create the program header until we have set the
file positions for the sections, and we can't do that until we know
how big the header is going to be. */
off = align_file_position (off);
phdr_size = get_program_header_size (abfd,
sorted_hdrs, i_ehdrp->e_shnum - 1,
maxpagesize);
if (phdr_size == (file_ptr) -1)
return false;
/* Compute the file offsets of each section. */
phdr_off = off;
off += phdr_size;
first = NULL;
for (i = 1, hdrpp = sorted_hdrs; i < i_ehdrp->e_shnum; i++, hdrpp++)
{
Elf_Internal_Shdr *hdr;
hdr = *hdrpp;
if ((hdr->sh_flags & SHF_ALLOC) == 0)
{
if (hdr->sh_type == SHT_REL || hdr->sh_type == SHT_RELA)
{
hdr->sh_offset = -1;
continue;
}
if (! dosyms
&& (hdr == i_shdrpp[tdata->symtab_section]
|| hdr == i_shdrpp[tdata->strtab_section]))
{
hdr->sh_offset = -1;
continue;
}
}
else
{
if (first == NULL)
first = hdr;
/* The section VMA must equal the file position modulo
the page size. This is required by the program
header. */
off += (hdr->sh_addr - off) % maxpagesize;
}
off = assign_file_position_for_section (hdr, off, false);
}
/* Create the program header. */
phdr_map = map_program_segments (abfd, phdr_off, first, sorted_hdrs,
phdr_size);
if (phdr_map == (file_ptr) -1)
return false;
BFD_ASSERT ((bfd_size_type) phdr_map <= (bfd_size_type) phdr_off + phdr_size);
free (sorted_hdrs);
}
/* Place the section headers. */
off = align_file_position (off);
i_ehdrp->e_shoff = off;
off += i_ehdrp->e_shnum * i_ehdrp->e_shentsize;
elf_tdata (abfd)->next_file_pos = off;
return true;
}
/* Sort the ELF headers by VMA. We sort headers which are not
SHF_ALLOC to the end. */
static int
elf_sort_hdrs (arg1, arg2)
const PTR arg1;
const PTR arg2;
{
int ret;
const Elf_Internal_Shdr *hdr1 = *(const Elf_Internal_Shdr **) arg1;
const Elf_Internal_Shdr *hdr2 = *(const Elf_Internal_Shdr **) arg2;
#define TOEND(x) (((x)->sh_flags & SHF_ALLOC)==0)
if (TOEND(hdr1))
if (TOEND(hdr2))
return 0;
else
return 1;
if (TOEND(hdr2))
return -1;
if (hdr1->sh_addr < hdr2->sh_addr)
return -1;
else if (hdr1->sh_addr > hdr2->sh_addr)
return 1;
/* Put !SHT_NOBITS sections before SHT_NOBITS ones.
The main loop in map_program_segments requires this. */
ret = (hdr1->sh_type == SHT_NOBITS) - (hdr2->sh_type == SHT_NOBITS);
if (ret != 0)
return ret;
if (hdr1->sh_size < hdr2->sh_size)
return -1;
if (hdr1->sh_size > hdr2->sh_size)
return 1;
return 0;
}
static boolean
prep_headers (abfd)
bfd *abfd;
{
Elf_Internal_Ehdr *i_ehdrp; /* Elf file header, internal form */
Elf_Internal_Phdr *i_phdrp = 0; /* Program header table, internal form */
Elf_Internal_Shdr **i_shdrp; /* Section header table, internal form */
int count;
struct bfd_strtab_hash *shstrtab;
i_ehdrp = elf_elfheader (abfd);
i_shdrp = elf_elfsections (abfd);
shstrtab = elf_stringtab_init ();
if (shstrtab == NULL)
return false;
elf_shstrtab (abfd) = shstrtab;
i_ehdrp->e_ident[EI_MAG0] = ELFMAG0;
i_ehdrp->e_ident[EI_MAG1] = ELFMAG1;
i_ehdrp->e_ident[EI_MAG2] = ELFMAG2;
i_ehdrp->e_ident[EI_MAG3] = ELFMAG3;
i_ehdrp->e_ident[EI_CLASS] = ELFCLASS;
i_ehdrp->e_ident[EI_DATA] =
abfd->xvec->byteorder_big_p ? ELFDATA2MSB : ELFDATA2LSB;
i_ehdrp->e_ident[EI_VERSION] = EV_CURRENT;
for (count = EI_PAD; count < EI_NIDENT; count++)
i_ehdrp->e_ident[count] = 0;
if ((abfd->flags & DYNAMIC) != 0)
i_ehdrp->e_type = ET_DYN;
else if ((abfd->flags & EXEC_P) != 0)
i_ehdrp->e_type = ET_EXEC;
else
i_ehdrp->e_type = ET_REL;
switch (bfd_get_arch (abfd))
{
case bfd_arch_unknown:
i_ehdrp->e_machine = EM_NONE;
break;
case bfd_arch_sparc:
#if ARCH_SIZE == 64
i_ehdrp->e_machine = EM_SPARC64;
#else
i_ehdrp->e_machine = EM_SPARC;
#endif
break;
case bfd_arch_i386:
i_ehdrp->e_machine = EM_386;
break;
case bfd_arch_m68k:
i_ehdrp->e_machine = EM_68K;
break;
case bfd_arch_m88k:
i_ehdrp->e_machine = EM_88K;
break;
case bfd_arch_i860:
i_ehdrp->e_machine = EM_860;
break;
case bfd_arch_mips: /* MIPS Rxxxx */
i_ehdrp->e_machine = EM_MIPS; /* only MIPS R3000 */
break;
case bfd_arch_hppa:
i_ehdrp->e_machine = EM_PARISC;
break;
case bfd_arch_powerpc:
i_ehdrp->e_machine = EM_PPC;
break;
/* start-sanitize-arc */
case bfd_arch_arc:
i_ehdrp->e_machine = EM_CYGNUS_ARC;
break;
/* end-sanitize-arc */
/* also note that EM_M32, AT&T WE32100 is unknown to bfd */
default:
i_ehdrp->e_machine = EM_NONE;
}
i_ehdrp->e_version = EV_CURRENT;
i_ehdrp->e_ehsize = sizeof (Elf_External_Ehdr);
/* no program header, for now. */
i_ehdrp->e_phoff = 0;
i_ehdrp->e_phentsize = 0;
i_ehdrp->e_phnum = 0;
/* each bfd section is section header entry */
i_ehdrp->e_entry = bfd_get_start_address (abfd);
i_ehdrp->e_shentsize = sizeof (Elf_External_Shdr);
/* if we're building an executable, we'll need a program header table */
if (abfd->flags & EXEC_P)
{
/* it all happens later */
#if 0
i_ehdrp->e_phentsize = sizeof (Elf_External_Phdr);
/* elf_build_phdrs() returns a (NULL-terminated) array of
Elf_Internal_Phdrs */
i_phdrp = elf_build_phdrs (abfd, i_ehdrp, i_shdrp, &i_ehdrp->e_phnum);
i_ehdrp->e_phoff = outbase;
outbase += i_ehdrp->e_phentsize * i_ehdrp->e_phnum;
#endif
}
else
{
i_ehdrp->e_phentsize = 0;
i_phdrp = 0;
i_ehdrp->e_phoff = 0;
}
elf_tdata (abfd)->symtab_hdr.sh_name =
(unsigned int) _bfd_stringtab_add (shstrtab, ".symtab", true, false);
elf_tdata (abfd)->strtab_hdr.sh_name =
(unsigned int) _bfd_stringtab_add (shstrtab, ".strtab", true, false);
elf_tdata (abfd)->shstrtab_hdr.sh_name =
(unsigned int) _bfd_stringtab_add (shstrtab, ".shstrtab", true, false);
if (elf_tdata (abfd)->symtab_hdr.sh_name == (unsigned int) -1
|| elf_tdata (abfd)->symtab_hdr.sh_name == (unsigned int) -1
|| elf_tdata (abfd)->shstrtab_hdr.sh_name == (unsigned int) -1)
return false;
return true;
}
static boolean
swap_out_syms (abfd, sttp)
bfd *abfd;
struct bfd_strtab_hash **sttp;
{
if (!elf_map_symbols (abfd))
return false;
/* Dump out the symtabs. */
{
int symcount = bfd_get_symcount (abfd);
asymbol **syms = bfd_get_outsymbols (abfd);
struct bfd_strtab_hash *stt;
Elf_Internal_Shdr *symtab_hdr;
Elf_Internal_Shdr *symstrtab_hdr;
Elf_External_Sym *outbound_syms;
int idx;
stt = elf_stringtab_init ();
if (stt == NULL)
return false;
symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
symtab_hdr->sh_type = SHT_SYMTAB;
symtab_hdr->sh_entsize = sizeof (Elf_External_Sym);
symtab_hdr->sh_size = symtab_hdr->sh_entsize * (symcount + 1);
symtab_hdr->sh_info = elf_num_locals (abfd) + 1;
symtab_hdr->sh_addralign = FILE_ALIGN;
symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr;
symstrtab_hdr->sh_type = SHT_STRTAB;
outbound_syms = ((Elf_External_Sym *)
bfd_alloc (abfd,
(1 + symcount) * sizeof (Elf_External_Sym)));
if (outbound_syms == NULL)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
symtab_hdr->contents = (PTR) outbound_syms;
/* now generate the data (for "contents") */
{
/* Fill in zeroth symbol and swap it out. */
Elf_Internal_Sym sym;
sym.st_name = 0;
sym.st_value = 0;
sym.st_size = 0;
sym.st_info = 0;
sym.st_other = 0;
sym.st_shndx = SHN_UNDEF;
elf_swap_symbol_out (abfd, &sym, outbound_syms);
++outbound_syms;
}
for (idx = 0; idx < symcount; idx++)
{
Elf_Internal_Sym sym;
bfd_vma value = syms[idx]->value;
elf_symbol_type *type_ptr;
flagword flags = syms[idx]->flags;
if (flags & BSF_SECTION_SYM)
/* Section symbols have no names. */
sym.st_name = 0;
else
{
sym.st_name = (unsigned long) _bfd_stringtab_add (stt,
syms[idx]->name,
true, false);
if (sym.st_name == (unsigned long) -1)
return false;
}
type_ptr = elf_symbol_from (abfd, syms[idx]);
if (bfd_is_com_section (syms[idx]->section))
{
/* ELF common symbols put the alignment into the `value' field,
and the size into the `size' field. This is backwards from
how BFD handles it, so reverse it here. */
sym.st_size = value;
if (type_ptr == NULL
|| type_ptr->internal_elf_sym.st_value == 0)
sym.st_value = value >= 16 ? 16 : (1 << bfd_log2 (value));
else
sym.st_value = type_ptr->internal_elf_sym.st_value;
sym.st_shndx = elf_section_from_bfd_section (abfd,
syms[idx]->section);
}
else
{
asection *sec = syms[idx]->section;
int shndx;
if (sec->output_section)
{
value += sec->output_offset;
sec = sec->output_section;
}
value += sec->vma;
sym.st_value = value;
sym.st_size = type_ptr ? type_ptr->internal_elf_sym.st_size : 0;
sym.st_shndx = shndx = elf_section_from_bfd_section (abfd, sec);
if (shndx == -1)
{
asection *sec2;
/* Writing this would be a hell of a lot easier if we had
some decent documentation on bfd, and knew what to expect
of the library, and what to demand of applications. For
example, it appears that `objcopy' might not set the
section of a symbol to be a section that is actually in
the output file. */
sec2 = bfd_get_section_by_name (abfd, sec->name);
BFD_ASSERT (sec2 != 0);
sym.st_shndx = shndx = elf_section_from_bfd_section (abfd, sec2);
BFD_ASSERT (shndx != -1);
}
}
if (bfd_is_com_section (syms[idx]->section))
sym.st_info = ELF_ST_INFO (STB_GLOBAL, STT_OBJECT);
else if (bfd_is_und_section (syms[idx]->section))
sym.st_info = ELF_ST_INFO (((flags & BSF_WEAK)
? STB_WEAK
: STB_GLOBAL),
((flags & BSF_FUNCTION)
? STT_FUNC
: STT_NOTYPE));
else if (flags & BSF_SECTION_SYM)
sym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
else if (flags & BSF_FILE)
sym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE);
else
{
int bind = STB_LOCAL;
int type = STT_OBJECT;
if (flags & BSF_LOCAL)
bind = STB_LOCAL;
else if (flags & BSF_WEAK)
bind = STB_WEAK;
else if (flags & BSF_GLOBAL)
bind = STB_GLOBAL;
if (flags & BSF_FUNCTION)
type = STT_FUNC;
sym.st_info = ELF_ST_INFO (bind, type);
}
sym.st_other = 0;
elf_swap_symbol_out (abfd, &sym, outbound_syms);
++outbound_syms;
}
*sttp = stt;
symstrtab_hdr->sh_size = _bfd_stringtab_size (stt);
symstrtab_hdr->sh_type = SHT_STRTAB;
symstrtab_hdr->sh_flags = 0;
symstrtab_hdr->sh_addr = 0;
symstrtab_hdr->sh_entsize = 0;
symstrtab_hdr->sh_link = 0;
symstrtab_hdr->sh_info = 0;
symstrtab_hdr->sh_addralign = 1;
}
return true;
}
static boolean
write_shdrs_and_ehdr (abfd)
bfd *abfd;
{
Elf_External_Ehdr x_ehdr; /* Elf file header, external form */
Elf_Internal_Ehdr *i_ehdrp; /* Elf file header, internal form */
Elf_External_Shdr *x_shdrp; /* Section header table, external form */
Elf_Internal_Shdr **i_shdrp; /* Section header table, internal form */
unsigned int count;
i_ehdrp = elf_elfheader (abfd);
i_shdrp = elf_elfsections (abfd);
/* swap the header before spitting it out... */
#if DEBUG & 1
elf_debug_file (i_ehdrp);
#endif
elf_swap_ehdr_out (abfd, i_ehdrp, &x_ehdr);
if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0
|| (bfd_write ((PTR) & x_ehdr, sizeof (x_ehdr), 1, abfd)
!= sizeof (x_ehdr)))
return false;
/* at this point we've concocted all the ELF sections... */
x_shdrp = (Elf_External_Shdr *)
bfd_alloc (abfd, sizeof (*x_shdrp) * (i_ehdrp->e_shnum));
if (!x_shdrp)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
for (count = 0; count < i_ehdrp->e_shnum; count++)
{
#if DEBUG & 2
elf_debug_section (count, i_shdrp[count]);
#endif
elf_swap_shdr_out (abfd, i_shdrp[count], x_shdrp + count);
}
if (bfd_seek (abfd, (file_ptr) i_ehdrp->e_shoff, SEEK_SET) != 0
|| (bfd_write ((PTR) x_shdrp, sizeof (*x_shdrp), i_ehdrp->e_shnum, abfd)
!= sizeof (*x_shdrp) * i_ehdrp->e_shnum))
return false;
/* need to dump the string table too... */
return true;
}
/* Assign file positions for all the reloc sections which are not part
of the loadable file image. */
static void
assign_file_positions_for_relocs (abfd)
bfd *abfd;
{
file_ptr off;
unsigned int i;
Elf_Internal_Shdr **shdrpp;
off = elf_tdata (abfd)->next_file_pos;
for (i = 1, shdrpp = elf_elfsections (abfd) + 1;
i < elf_elfheader (abfd)->e_shnum;
i++, shdrpp++)
{
Elf_Internal_Shdr *shdrp;
shdrp = *shdrpp;
if ((shdrp->sh_type == SHT_REL || shdrp->sh_type == SHT_RELA)
&& shdrp->sh_offset == -1)
off = assign_file_position_for_section (shdrp, off, true);
}
elf_tdata (abfd)->next_file_pos = off;
}
boolean
NAME(bfd_elf,write_object_contents) (abfd)
bfd *abfd;
{
struct elf_backend_data *bed = get_elf_backend_data (abfd);
Elf_Internal_Ehdr *i_ehdrp;
Elf_Internal_Shdr **i_shdrp;
boolean failed;
unsigned int count;
if (! abfd->output_has_begun
&& ! elf_compute_section_file_positions (abfd,
(struct bfd_link_info *) NULL))
return false;
i_shdrp = elf_elfsections (abfd);
i_ehdrp = elf_elfheader (abfd);
failed = false;
bfd_map_over_sections (abfd, write_relocs, &failed);
if (failed)
return false;
assign_file_positions_for_relocs (abfd);
/* After writing the headers, we need to write the sections too... */
for (count = 1; count < i_ehdrp->e_shnum; count++)
{
if (bed->elf_backend_section_processing)
(*bed->elf_backend_section_processing) (abfd, i_shdrp[count]);
if (i_shdrp[count]->contents)
{
if (bfd_seek (abfd, i_shdrp[count]->sh_offset, SEEK_SET) != 0
|| (bfd_write (i_shdrp[count]->contents, i_shdrp[count]->sh_size,
1, abfd)
!= i_shdrp[count]->sh_size))
return false;
}
}
/* Write out the section header names. */
if (bfd_seek (abfd, elf_tdata (abfd)->shstrtab_hdr.sh_offset, SEEK_SET) != 0
|| ! _bfd_stringtab_emit (abfd, elf_shstrtab (abfd)))
return false;
if (bed->elf_backend_final_write_processing)
(*bed->elf_backend_final_write_processing) (abfd,
elf_tdata (abfd)->linker);
return write_shdrs_and_ehdr (abfd);
}
/* Given an ELF section number, retrieve the corresponding BFD
section. */
static asection *
section_from_elf_index (abfd, index)
bfd *abfd;
unsigned int index;
{
BFD_ASSERT (index > 0 && index < SHN_LORESERVE);
if (index >= elf_elfheader (abfd)->e_shnum)
return NULL;
return elf_elfsections (abfd)[index]->bfd_section;
}
/* given a section, search the header to find them... */
static int
elf_section_from_bfd_section (abfd, asect)
bfd *abfd;
struct sec *asect;
{
struct elf_backend_data *bed = get_elf_backend_data (abfd);
Elf_Internal_Shdr **i_shdrp = elf_elfsections (abfd);
int index;
Elf_Internal_Shdr *hdr;
int maxindex = elf_elfheader (abfd)->e_shnum;
for (index = 0; index < maxindex; index++)
{
hdr = i_shdrp[index];
if (hdr->bfd_section == asect)
return index;
}
if (bed->elf_backend_section_from_bfd_section)
{
for (index = 0; index < maxindex; index++)
{
int retval;
hdr = i_shdrp[index];
retval = index;
if ((*bed->elf_backend_section_from_bfd_section)
(abfd, hdr, asect, &retval))
return retval;
}
}
if (bfd_is_abs_section (asect))
return SHN_ABS;
if (bfd_is_com_section (asect))
return SHN_COMMON;
if (bfd_is_und_section (asect))
return SHN_UNDEF;
return -1;
}
/* given a symbol, return the bfd index for that symbol. */
static int
elf_symbol_from_bfd_symbol (abfd, asym_ptr_ptr)
bfd *abfd;
struct symbol_cache_entry **asym_ptr_ptr;
{
struct symbol_cache_entry *asym_ptr = *asym_ptr_ptr;
int idx;
flagword flags = asym_ptr->flags;
/* When gas creates relocations against local labels, it creates its
own symbol for the section, but does put the symbol into the
symbol chain, so udata is 0. When the linker is generating
relocatable output, this section symbol may be for one of the
input sections rather than the output section. */
if (asym_ptr->udata.i == 0
&& (flags & BSF_SECTION_SYM)
&& asym_ptr->section)
{
int indx;
if (asym_ptr->section->output_section != NULL)
indx = asym_ptr->section->output_section->index;
else
indx = asym_ptr->section->index;
if (elf_section_syms (abfd)[indx])
asym_ptr->udata.i = elf_section_syms (abfd)[indx]->udata.i;
}
idx = asym_ptr->udata.i;
BFD_ASSERT (idx != 0);
#if DEBUG & 4
{
fprintf (stderr,
"elf_symbol_from_bfd_symbol 0x%.8lx, name = %s, sym num = %d, flags = 0x%.8lx%s\n",
(long) asym_ptr, asym_ptr->name, idx, flags, elf_symbol_flags (flags));
fflush (stderr);
}
#endif
return idx;
}
static long
elf_slurp_symbol_table (abfd, symptrs, dynamic)
bfd *abfd;
asymbol **symptrs; /* Buffer for generated bfd symbols */
boolean dynamic;
{
Elf_Internal_Shdr *hdr;
long symcount; /* Number of external ELF symbols */
elf_symbol_type *sym; /* Pointer to current bfd symbol */
elf_symbol_type *symbase; /* Buffer for generated bfd symbols */
Elf_Internal_Sym i_sym;
Elf_External_Sym *x_symp = NULL;
/* Read each raw ELF symbol, converting from external ELF form to
internal ELF form, and then using the information to create a
canonical bfd symbol table entry.
Note that we allocate the initial bfd canonical symbol buffer
based on a one-to-one mapping of the ELF symbols to canonical
symbols. We actually use all the ELF symbols, so there will be no
space left over at the end. When we have all the symbols, we
build the caller's pointer vector. */
if (dynamic)
hdr = &elf_tdata (abfd)->dynsymtab_hdr;
else
hdr = &elf_tdata (abfd)->symtab_hdr;
if (bfd_seek (abfd, hdr->sh_offset, SEEK_SET) == -1)
return -1;
symcount = hdr->sh_size / sizeof (Elf_External_Sym);
if (symcount == 0)
sym = symbase = NULL;
else
{
long i;
if (bfd_seek (abfd, hdr->sh_offset, SEEK_SET) == -1)
return -1;
symbase = ((elf_symbol_type *)
bfd_zalloc (abfd, symcount * sizeof (elf_symbol_type)));
if (symbase == (elf_symbol_type *) NULL)
{
bfd_set_error (bfd_error_no_memory);
return -1;
}
sym = symbase;
/* Temporarily allocate room for the raw ELF symbols. */
x_symp = ((Elf_External_Sym *)
malloc (symcount * sizeof (Elf_External_Sym)));
if (x_symp == NULL && symcount != 0)
{
bfd_set_error (bfd_error_no_memory);
goto error_return;
}
if (bfd_read ((PTR) x_symp, sizeof (Elf_External_Sym), symcount, abfd)
!= symcount * sizeof (Elf_External_Sym))
goto error_return;
/* Skip first symbol, which is a null dummy. */
for (i = 1; i < symcount; i++)
{
elf_swap_symbol_in (abfd, x_symp + i, &i_sym);
memcpy (&sym->internal_elf_sym, &i_sym, sizeof (Elf_Internal_Sym));
#ifdef ELF_KEEP_EXTSYM
memcpy (&sym->native_elf_sym, x_symp + i, sizeof (Elf_External_Sym));
#endif
sym->symbol.the_bfd = abfd;
sym->symbol.name = elf_string_from_elf_section (abfd, hdr->sh_link,
i_sym.st_name);
sym->symbol.value = i_sym.st_value;
if (i_sym.st_shndx > 0 && i_sym.st_shndx < SHN_LORESERVE)
{
sym->symbol.section = section_from_elf_index (abfd,
i_sym.st_shndx);
if (sym->symbol.section == NULL)
{
/* This symbol is in a section for which we did not
create a BFD section. Just use bfd_abs_section,
although it is wrong. FIXME. */
sym->symbol.section = bfd_abs_section_ptr;
}
}
else if (i_sym.st_shndx == SHN_ABS)
{
sym->symbol.section = bfd_abs_section_ptr;
}
else if (i_sym.st_shndx == SHN_COMMON)
{
sym->symbol.section = bfd_com_section_ptr;
/* Elf puts the alignment into the `value' field, and
the size into the `size' field. BFD wants to see the
size in the value field, and doesn't care (at the
moment) about the alignment. */
sym->symbol.value = i_sym.st_size;
}
else if (i_sym.st_shndx == SHN_UNDEF)
{
sym->symbol.section = bfd_und_section_ptr;
}
else
sym->symbol.section = bfd_abs_section_ptr;
sym->symbol.value -= sym->symbol.section->vma;
switch (ELF_ST_BIND (i_sym.st_info))
{
case STB_LOCAL:
sym->symbol.flags |= BSF_LOCAL;
break;
case STB_GLOBAL:
if (i_sym.st_shndx != SHN_UNDEF
&& i_sym.st_shndx != SHN_COMMON)
sym->symbol.flags |= BSF_GLOBAL;
break;
case STB_WEAK:
sym->symbol.flags |= BSF_WEAK;
break;
}
switch (ELF_ST_TYPE (i_sym.st_info))
{
case STT_SECTION:
sym->symbol.flags |= BSF_SECTION_SYM | BSF_DEBUGGING;
break;
case STT_FILE:
sym->symbol.flags |= BSF_FILE | BSF_DEBUGGING;
break;
case STT_FUNC:
sym->symbol.flags |= BSF_FUNCTION;
break;
}
if (dynamic)
sym->symbol.flags |= BSF_DYNAMIC;
/* Do some backend-specific processing on this symbol. */
{
struct elf_backend_data *ebd = get_elf_backend_data (abfd);
if (ebd->elf_backend_symbol_processing)
(*ebd->elf_backend_symbol_processing) (abfd, &sym->symbol);
}
sym++;
}
}
/* Do some backend-specific processing on this symbol table. */
{
struct elf_backend_data *ebd = get_elf_backend_data (abfd);
if (ebd->elf_backend_symbol_table_processing)
(*ebd->elf_backend_symbol_table_processing) (abfd, symbase, symcount);
}
/* We rely on the zalloc to clear out the final symbol entry. */
symcount = sym - symbase;
/* Fill in the user's symbol pointer vector if needed. */
if (symptrs)
{
long l = symcount;
sym = symbase;
while (l-- > 0)
{
*symptrs++ = &sym->symbol;
sym++;
}
*symptrs = 0; /* Final null pointer */
}
if (x_symp != NULL)
free (x_symp);
return symcount;
error_return:
if (x_symp != NULL)
free (x_symp);
return -1;
}
/* Return the number of bytes required to hold the symtab vector.
Note that we base it on the count plus 1, since we will null terminate
the vector allocated based on this size. However, the ELF symbol table
always has a dummy entry as symbol #0, so it ends up even. */
long
elf_get_symtab_upper_bound (abfd)
bfd *abfd;
{
long symcount;
long symtab_size;
Elf_Internal_Shdr *hdr = &elf_tdata (abfd)->symtab_hdr;
symcount = hdr->sh_size / sizeof (Elf_External_Sym);
symtab_size = (symcount - 1 + 1) * (sizeof (asymbol *));
return symtab_size;
}
long
elf_get_dynamic_symtab_upper_bound (abfd)
bfd *abfd;
{
long symcount;
long symtab_size;
Elf_Internal_Shdr *hdr = &elf_tdata (abfd)->dynsymtab_hdr;
if (elf_dynsymtab (abfd) == 0)
{
bfd_set_error (bfd_error_invalid_operation);
return -1;
}
symcount = hdr->sh_size / sizeof (Elf_External_Sym);
symtab_size = (symcount - 1 + 1) * (sizeof (asymbol *));
return symtab_size;
}
long
elf_get_reloc_upper_bound (abfd, asect)
bfd *abfd;
sec_ptr asect;
{
return (asect->reloc_count + 1) * sizeof (arelent *);
}
/* Read in and swap the external relocs. */
static boolean
elf_slurp_reloc_table (abfd, asect, symbols)
bfd *abfd;
asection *asect;
asymbol **symbols;
{
struct elf_backend_data * const ebd = get_elf_backend_data (abfd);
struct bfd_elf_section_data * const d = elf_section_data (asect);
PTR allocated = NULL;
bfd_byte *native_relocs;
arelent *relents;
arelent *relent;
unsigned int i;
int entsize;
if (asect->relocation != NULL
|| (asect->flags & SEC_RELOC) == 0
|| asect->reloc_count == 0)
return true;
BFD_ASSERT (asect->rel_filepos == d->rel_hdr.sh_offset
&& (asect->reloc_count
== d->rel_hdr.sh_size / d->rel_hdr.sh_entsize));
allocated = (PTR) malloc (d->rel_hdr.sh_size);
if (allocated == NULL)
{
bfd_set_error (bfd_error_no_memory);
goto error_return;
}
if (bfd_seek (abfd, asect->rel_filepos, SEEK_SET) != 0
|| (bfd_read (allocated, 1, d->rel_hdr.sh_size, abfd)
!= d->rel_hdr.sh_size))
goto error_return;
native_relocs = (bfd_byte *) allocated;
relents = ((arelent *)
bfd_alloc (abfd, asect->reloc_count * sizeof (arelent)));
if (relents == NULL)
{
bfd_set_error (bfd_error_no_memory);
goto error_return;
}
entsize = d->rel_hdr.sh_entsize;
BFD_ASSERT (entsize == sizeof (Elf_External_Rel)
|| entsize == sizeof (Elf_External_Rela));
for (i = 0, relent = relents;
i < asect->reloc_count;
i++, relent++, native_relocs += entsize)
{
Elf_Internal_Rela rela;
Elf_Internal_Rel rel;
if (entsize == sizeof (Elf_External_Rela))
elf_swap_reloca_in (abfd, (Elf_External_Rela *) native_relocs, &rela);
else
{
elf_swap_reloc_in (abfd, (Elf_External_Rel *) native_relocs, &rel);
rela.r_offset = rel.r_offset;
rela.r_info = rel.r_info;
rela.r_addend = 0;
}
/* The address of an ELF reloc is section relative for an object
file, and absolute for an executable file or shared library.
The address of a BFD reloc is always section relative. */
if ((abfd->flags & (EXEC_P | DYNAMIC)) == 0)
relent->address = rela.r_offset;
else
relent->address = rela.r_offset - asect->vma;
if (ELF_R_SYM (rela.r_info) == 0)
relent->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr;
else
{
asymbol **ps, *s;
ps = symbols + ELF_R_SYM (rela.r_info) - 1;
s = *ps;
/* Canonicalize ELF section symbols. FIXME: Why? */
if ((s->flags & BSF_SECTION_SYM) == 0)
relent->sym_ptr_ptr = ps;
else
relent->sym_ptr_ptr = s->section->symbol_ptr_ptr;
}
relent->addend = rela.r_addend;
if (entsize == sizeof (Elf_External_Rela))
(*ebd->elf_info_to_howto) (abfd, relent, &rela);
else
(*ebd->elf_info_to_howto_rel) (abfd, relent, &rel);
}
asect->relocation = relents;
if (allocated != NULL)
free (allocated);
return true;
error_return:
if (allocated != NULL)
free (allocated);
return false;
}
#ifdef DEBUG
static void
elf_debug_section (num, hdr)
int num;
Elf_Internal_Shdr *hdr;
{
fprintf (stderr, "\nSection#%d '%s' 0x%.8lx\n", num,
hdr->bfd_section != NULL ? hdr->bfd_section->name : "",
(long) hdr);
fprintf (stderr,
"sh_name = %ld\tsh_type = %ld\tsh_flags = %ld\n",
(long) hdr->sh_name,
(long) hdr->sh_type,
(long) hdr->sh_flags);
fprintf (stderr,
"sh_addr = %ld\tsh_offset = %ld\tsh_size = %ld\n",
(long) hdr->sh_addr,
(long) hdr->sh_offset,
(long) hdr->sh_size);
fprintf (stderr,
"sh_link = %ld\tsh_info = %ld\tsh_addralign = %ld\n",
(long) hdr->sh_link,
(long) hdr->sh_info,
(long) hdr->sh_addralign);
fprintf (stderr, "sh_entsize = %ld\n",
(long) hdr->sh_entsize);
fflush (stderr);
}
static void
elf_debug_file (ehdrp)
Elf_Internal_Ehdr *ehdrp;
{
fprintf (stderr, "e_entry = 0x%.8lx\n", (long) ehdrp->e_entry);
fprintf (stderr, "e_phoff = %ld\n", (long) ehdrp->e_phoff);
fprintf (stderr, "e_phnum = %ld\n", (long) ehdrp->e_phnum);
fprintf (stderr, "e_phentsize = %ld\n", (long) ehdrp->e_phentsize);
fprintf (stderr, "e_shoff = %ld\n", (long) ehdrp->e_shoff);
fprintf (stderr, "e_shnum = %ld\n", (long) ehdrp->e_shnum);
fprintf (stderr, "e_shentsize = %ld\n", (long) ehdrp->e_shentsize);
}
static char *
elf_symbol_flags (flags)
flagword flags;
{
static char buffer[1024];
buffer[0] = '\0';
if (flags & BSF_LOCAL)
strcat (buffer, " local");
if (flags & BSF_GLOBAL)
strcat (buffer, " global");
if (flags & BSF_DEBUGGING)
strcat (buffer, " debug");
if (flags & BSF_FUNCTION)
strcat (buffer, " function");
if (flags & BSF_KEEP)
strcat (buffer, " keep");
if (flags & BSF_KEEP_G)
strcat (buffer, " keep_g");
if (flags & BSF_WEAK)
strcat (buffer, " weak");
if (flags & BSF_SECTION_SYM)
strcat (buffer, " section-sym");
if (flags & BSF_OLD_COMMON)
strcat (buffer, " old-common");
if (flags & BSF_NOT_AT_END)
strcat (buffer, " not-at-end");
if (flags & BSF_CONSTRUCTOR)
strcat (buffer, " constructor");
if (flags & BSF_WARNING)
strcat (buffer, " warning");
if (flags & BSF_INDIRECT)
strcat (buffer, " indirect");
if (flags & BSF_FILE)
strcat (buffer, " file");
if (flags & DYNAMIC)
strcat (buffer, " dynamic");
if (flags & ~(BSF_LOCAL
| BSF_GLOBAL
| BSF_DEBUGGING
| BSF_FUNCTION
| BSF_KEEP
| BSF_KEEP_G
| BSF_WEAK
| BSF_SECTION_SYM
| BSF_OLD_COMMON
| BSF_NOT_AT_END
| BSF_CONSTRUCTOR
| BSF_WARNING
| BSF_INDIRECT
| BSF_FILE
| BSF_DYNAMIC))
strcat (buffer, " unknown-bits");
return buffer;
}
#endif
/* Canonicalize the relocs. */
long
elf_canonicalize_reloc (abfd, section, relptr, symbols)
bfd *abfd;
sec_ptr section;
arelent **relptr;
asymbol **symbols;
{
arelent *tblptr;
unsigned int i;
if (! elf_slurp_reloc_table (abfd, section, symbols))
return -1;
tblptr = section->relocation;
for (i = 0; i < section->reloc_count; i++)
*relptr++ = tblptr++;
*relptr = NULL;
return section->reloc_count;
}
long
elf_get_symtab (abfd, alocation)
bfd *abfd;
asymbol **alocation;
{
long symcount = elf_slurp_symbol_table (abfd, alocation, false);
if (symcount >= 0)
bfd_get_symcount (abfd) = symcount;
return symcount;
}
long
elf_canonicalize_dynamic_symtab (abfd, alocation)
bfd *abfd;
asymbol **alocation;
{
return elf_slurp_symbol_table (abfd, alocation, true);
}
asymbol *
elf_make_empty_symbol (abfd)
bfd *abfd;
{
elf_symbol_type *newsym;
newsym = (elf_symbol_type *) bfd_zalloc (abfd, sizeof (elf_symbol_type));
if (!newsym)
{
bfd_set_error (bfd_error_no_memory);
return NULL;
}
else
{
newsym->symbol.the_bfd = abfd;
return &newsym->symbol;
}
}
void
elf_get_symbol_info (ignore_abfd, symbol, ret)
bfd *ignore_abfd;
asymbol *symbol;
symbol_info *ret;
{
bfd_symbol_info (symbol, ret);
}
alent *
elf_get_lineno (ignore_abfd, symbol)
bfd *ignore_abfd;
asymbol *symbol;
{
fprintf (stderr, "elf_get_lineno unimplemented\n");
fflush (stderr);
BFD_FAIL ();
return NULL;
}
boolean
elf_set_arch_mach (abfd, arch, machine)
bfd *abfd;
enum bfd_architecture arch;
unsigned long machine;
{
/* If this isn't the right architecture for this backend, and this
isn't the generic backend, fail. */
if (arch != get_elf_backend_data (abfd)->arch
&& arch != bfd_arch_unknown
&& get_elf_backend_data (abfd)->arch != bfd_arch_unknown)
return false;
return bfd_default_set_arch_mach (abfd, arch, machine);
}
boolean
elf_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;
{
return false;
}
int
elf_sizeof_headers (abfd, reloc)
bfd *abfd;
boolean reloc;
{
int ret;
ret = sizeof (Elf_External_Ehdr);
if (! reloc)
ret += get_program_header_size (abfd, (Elf_Internal_Shdr **) NULL, 0,
(bfd_vma) 0);
return ret;
}
boolean
elf_set_section_contents (abfd, section, location, offset, count)
bfd *abfd;
sec_ptr section;
PTR location;
file_ptr offset;
bfd_size_type count;
{
Elf_Internal_Shdr *hdr;
if (! abfd->output_has_begun
&& ! elf_compute_section_file_positions (abfd,
(struct bfd_link_info *) NULL))
return false;
hdr = &elf_section_data (section)->this_hdr;
if (bfd_seek (abfd, hdr->sh_offset + offset, SEEK_SET) == -1)
return false;
if (bfd_write (location, 1, count, abfd) != count)
return false;
return true;
}
void
elf_no_info_to_howto (abfd, cache_ptr, dst)
bfd *abfd;
arelent *cache_ptr;
Elf_Internal_Rela *dst;
{
fprintf (stderr, "elf RELA relocation support for target machine unimplemented\n");
fflush (stderr);
BFD_FAIL ();
}
void
elf_no_info_to_howto_rel (abfd, cache_ptr, dst)
bfd *abfd;
arelent *cache_ptr;
Elf_Internal_Rel *dst;
{
fprintf (stderr, "elf REL relocation support for target machine unimplemented\n");
fflush (stderr);
BFD_FAIL ();
}
/* Core file support */
#ifdef HAVE_PROCFS /* Some core file support requires host /proc files */
#include <sys/procfs.h>
#else
#define bfd_prstatus(abfd, descdata, descsz, filepos) true
#define bfd_fpregset(abfd, descdata, descsz, filepos) true
#define bfd_prpsinfo(abfd, descdata, descsz, filepos) true
#endif
#ifdef HAVE_PROCFS
static boolean
bfd_prstatus (abfd, descdata, descsz, filepos)
bfd *abfd;
char *descdata;
int descsz;
long filepos;
{
asection *newsect;
prstatus_t *status = (prstatus_t *) 0;
if (descsz == sizeof (prstatus_t))
{
newsect = bfd_make_section (abfd, ".reg");
if (newsect == NULL)
return false;
newsect->_raw_size = sizeof (status->pr_reg);
newsect->filepos = filepos + (long) &status->pr_reg;
newsect->flags = SEC_HAS_CONTENTS;
newsect->alignment_power = 2;
if ((core_prstatus (abfd) = bfd_alloc (abfd, descsz)) != NULL)
{
memcpy (core_prstatus (abfd), descdata, descsz);
}
}
return true;
}
/* Stash a copy of the prpsinfo structure away for future use. */
static boolean
bfd_prpsinfo (abfd, descdata, descsz, filepos)
bfd *abfd;
char *descdata;
int descsz;
long filepos;
{
if (descsz == sizeof (prpsinfo_t))
{
if ((core_prpsinfo (abfd) = bfd_alloc (abfd, descsz)) == NULL)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
memcpy (core_prpsinfo (abfd), descdata, descsz);
}
return true;
}
static boolean
bfd_fpregset (abfd, descdata, descsz, filepos)
bfd *abfd;
char *descdata;
int descsz;
long filepos;
{
asection *newsect;
newsect = bfd_make_section (abfd, ".reg2");
if (newsect == NULL)
return false;
newsect->_raw_size = descsz;
newsect->filepos = filepos;
newsect->flags = SEC_HAS_CONTENTS;
newsect->alignment_power = 2;
return true;
}
#endif /* HAVE_PROCFS */
/* Return a pointer to the args (including the command name) that were
seen by the program that generated the core dump. Note that for
some reason, a spurious space is tacked onto the end of the args
in some (at least one anyway) implementations, so strip it off if
it exists. */
char *
elf_core_file_failing_command (abfd)
bfd *abfd;
{
#ifdef HAVE_PROCFS
if (core_prpsinfo (abfd))
{
prpsinfo_t *p = core_prpsinfo (abfd);
char *scan = p->pr_psargs;
while (*scan++)
{;
}
scan -= 2;
if ((scan > p->pr_psargs) && (*scan == ' '))
{
*scan = '\000';
}
return p->pr_psargs;
}
#endif
return NULL;
}
/* Return the number of the signal that caused the core dump. Presumably,
since we have a core file, we got a signal of some kind, so don't bother
checking the other process status fields, just return the signal number.
*/
int
elf_core_file_failing_signal (abfd)
bfd *abfd;
{
#ifdef HAVE_PROCFS
if (core_prstatus (abfd))
{
return ((prstatus_t *) (core_prstatus (abfd)))->pr_cursig;
}
#endif
return -1;
}
/* Check to see if the core file could reasonably be expected to have
come for the current executable file. Note that by default we return
true unless we find something that indicates that there might be a
problem.
*/
boolean
elf_core_file_matches_executable_p (core_bfd, exec_bfd)
bfd *core_bfd;
bfd *exec_bfd;
{
#ifdef HAVE_PROCFS
char *corename;
char *execname;
#endif
/* First, xvecs must match since both are ELF files for the same target. */
if (core_bfd->xvec != exec_bfd->xvec)
{
bfd_set_error (bfd_error_system_call);
return false;
}
#ifdef HAVE_PROCFS
/* If no prpsinfo, just return true. Otherwise, grab the last component
of the exec'd pathname from the prpsinfo. */
if (core_prpsinfo (core_bfd))
{
corename = (((prpsinfo_t *) core_prpsinfo (core_bfd))->pr_fname);
}
else
{
return true;
}
/* Find the last component of the executable pathname. */
if ((execname = strrchr (exec_bfd->filename, '/')) != NULL)
{
execname++;
}
else
{
execname = (char *) exec_bfd->filename;
}
/* See if they match */
return strcmp (execname, corename) ? false : true;
#else
return true;
#endif /* HAVE_PROCFS */
}
/* ELF core files contain a segment of type PT_NOTE, that holds much of
the information that would normally be available from the /proc interface
for the process, at the time the process dumped core. Currently this
includes copies of the prstatus, prpsinfo, and fpregset structures.
Since these structures are potentially machine dependent in size and
ordering, bfd provides two levels of support for them. The first level,
available on all machines since it does not require that the host
have /proc support or the relevant include files, is to create a bfd
section for each of the prstatus, prpsinfo, and fpregset structures,
without any interpretation of their contents. With just this support,
the bfd client will have to interpret the structures itself. Even with
/proc support, it might want these full structures for it's own reasons.
In the second level of support, where HAVE_PROCFS is defined, bfd will
pick apart the structures to gather some additional information that
clients may want, such as the general register set, the name of the
exec'ed file and its arguments, the signal (if any) that caused the
core dump, etc.
*/
static boolean
elf_corefile_note (abfd, hdr)
bfd *abfd;
Elf_Internal_Phdr *hdr;
{
Elf_External_Note *x_note_p; /* Elf note, external form */
Elf_Internal_Note i_note; /* Elf note, internal form */
char *buf = NULL; /* Entire note segment contents */
char *namedata; /* Name portion of the note */
char *descdata; /* Descriptor portion of the note */
char *sectname; /* Name to use for new section */
long filepos; /* File offset to descriptor data */
asection *newsect;
if (hdr->p_filesz > 0
&& (buf = (char *) malloc (hdr->p_filesz)) != NULL
&& bfd_seek (abfd, hdr->p_offset, SEEK_SET) != -1
&& bfd_read ((PTR) buf, hdr->p_filesz, 1, abfd) == hdr->p_filesz)
{
x_note_p = (Elf_External_Note *) buf;
while ((char *) x_note_p < (buf + hdr->p_filesz))
{
i_note.namesz = bfd_h_get_32 (abfd, (bfd_byte *) x_note_p->namesz);
i_note.descsz = bfd_h_get_32 (abfd, (bfd_byte *) x_note_p->descsz);
i_note.type = bfd_h_get_32 (abfd, (bfd_byte *) x_note_p->type);
namedata = x_note_p->name;
descdata = namedata + BFD_ALIGN (i_note.namesz, 4);
filepos = hdr->p_offset + (descdata - buf);
switch (i_note.type)
{
case NT_PRSTATUS:
/* process descdata as prstatus info */
if (! bfd_prstatus (abfd, descdata, i_note.descsz, filepos))
return false;
sectname = ".prstatus";
break;
case NT_FPREGSET:
/* process descdata as fpregset info */
if (! bfd_fpregset (abfd, descdata, i_note.descsz, filepos))
return false;
sectname = ".fpregset";
break;
case NT_PRPSINFO:
/* process descdata as prpsinfo */
if (! bfd_prpsinfo (abfd, descdata, i_note.descsz, filepos))
return false;
sectname = ".prpsinfo";
break;
default:
/* Unknown descriptor, just ignore it. */
sectname = NULL;
break;
}
if (sectname != NULL)
{
newsect = bfd_make_section (abfd, sectname);
if (newsect == NULL)
return false;
newsect->_raw_size = i_note.descsz;
newsect->filepos = filepos;
newsect->flags = SEC_ALLOC | SEC_HAS_CONTENTS;
newsect->alignment_power = 2;
}
x_note_p = (Elf_External_Note *)
(descdata + BFD_ALIGN (i_note.descsz, 4));
}
}
if (buf != NULL)
{
free (buf);
}
else if (hdr->p_filesz > 0)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
return true;
}
/* Core files are simply standard ELF formatted files that partition
the file using the execution view of the file (program header table)
rather than the linking view. In fact, there is no section header
table in a core file.
The process status information (including the contents of the general
register set) and the floating point register set are stored in a
segment of type PT_NOTE. We handcraft a couple of extra bfd sections
that allow standard bfd access to the general registers (.reg) and the
floating point registers (.reg2).
*/
const bfd_target *
elf_core_file_p (abfd)
bfd *abfd;
{
Elf_External_Ehdr x_ehdr; /* Elf file header, external form */
Elf_Internal_Ehdr *i_ehdrp; /* Elf file header, internal form */
Elf_External_Phdr x_phdr; /* Program header table entry, external form */
Elf_Internal_Phdr *i_phdrp; /* Program header table, internal form */
unsigned int phindex;
struct elf_backend_data *ebd;
/* Read in the ELF header in external format. */
if (bfd_read ((PTR) & x_ehdr, sizeof (x_ehdr), 1, abfd) != sizeof (x_ehdr))
{
if (bfd_get_error () != bfd_error_system_call)
bfd_set_error (bfd_error_wrong_format);
return NULL;
}
/* Now check to see if we have a valid ELF file, and one that BFD can
make use of. The magic number must match, the address size ('class')
and byte-swapping must match our XVEC entry, and it must have a
program header table (FIXME: See comments re segments at top of this
file). */
if (elf_file_p (&x_ehdr) == false)
{
wrong:
bfd_set_error (bfd_error_wrong_format);
return NULL;
}
/* FIXME, Check EI_VERSION here ! */
{
#if ARCH_SIZE == 32
int desired_address_size = ELFCLASS32;
#endif
#if ARCH_SIZE == 64
int desired_address_size = ELFCLASS64;
#endif
if (x_ehdr.e_ident[EI_CLASS] != desired_address_size)
goto wrong;
}
/* Switch xvec to match the specified byte order. */
switch (x_ehdr.e_ident[EI_DATA])
{
case ELFDATA2MSB: /* Big-endian */
if (abfd->xvec->byteorder_big_p == false)
goto wrong;
break;
case ELFDATA2LSB: /* Little-endian */
if (abfd->xvec->byteorder_big_p == true)
goto wrong;
break;
case ELFDATANONE: /* No data encoding specified */
default: /* Unknown data encoding specified */
goto wrong;
}
/* Allocate an instance of the elf_obj_tdata structure and hook it up to
the tdata pointer in the bfd. */
elf_tdata (abfd) =
(struct elf_obj_tdata *) bfd_zalloc (abfd, sizeof (struct elf_obj_tdata));
if (elf_tdata (abfd) == NULL)
{
bfd_set_error (bfd_error_no_memory);
return NULL;
}
/* FIXME, `wrong' returns from this point onward, leak memory. */
/* Now that we know the byte order, swap in the rest of the header */
i_ehdrp = elf_elfheader (abfd);
elf_swap_ehdr_in (abfd, &x_ehdr, i_ehdrp);
#if DEBUG & 1
elf_debug_file (i_ehdrp);
#endif
ebd = get_elf_backend_data (abfd);
/* Check that the ELF e_machine field matches what this particular
BFD format expects. */
if (ebd->elf_machine_code != i_ehdrp->e_machine
&& (ebd->elf_machine_alt1 == 0 || i_ehdrp->e_machine != ebd->elf_machine_alt1)
&& (ebd->elf_machine_alt2 == 0 || i_ehdrp->e_machine != ebd->elf_machine_alt2))
{
const bfd_target * const *target_ptr;
if (ebd->elf_machine_code != EM_NONE)
goto wrong;
/* This is the generic ELF target. Let it match any ELF target
for which we do not have a specific backend. */
for (target_ptr = bfd_target_vector; *target_ptr != NULL; target_ptr++)
{
struct elf_backend_data *back;
if ((*target_ptr)->flavour != bfd_target_elf_flavour)
continue;
back = (struct elf_backend_data *) (*target_ptr)->backend_data;
if (back->elf_machine_code == i_ehdrp->e_machine)
{
/* target_ptr is an ELF backend which matches this
object file, so reject the generic ELF target. */
goto wrong;
}
}
}
/* If there is no program header, or the type is not a core file, then
we are hosed. */
if (i_ehdrp->e_phoff == 0 || i_ehdrp->e_type != ET_CORE)
goto wrong;
/* Allocate space for a copy of the program header table in
internal form, seek to the program header table in the file,
read it in, and convert it to internal form. As a simple sanity
check, verify that the what BFD thinks is the size of each program
header table entry actually matches the size recorded in the file. */
if (i_ehdrp->e_phentsize != sizeof (x_phdr))
goto wrong;
i_phdrp = (Elf_Internal_Phdr *)
bfd_alloc (abfd, sizeof (*i_phdrp) * i_ehdrp->e_phnum);
if (!i_phdrp)
{
bfd_set_error (bfd_error_no_memory);
return NULL;
}
if (bfd_seek (abfd, i_ehdrp->e_phoff, SEEK_SET) == -1)
return NULL;
for (phindex = 0; phindex < i_ehdrp->e_phnum; phindex++)
{
if (bfd_read ((PTR) & x_phdr, sizeof (x_phdr), 1, abfd)
!= sizeof (x_phdr))
return NULL;
elf_swap_phdr_in (abfd, &x_phdr, i_phdrp + phindex);
}
/* Once all of the program headers have been read and converted, we
can start processing them. */
for (phindex = 0; phindex < i_ehdrp->e_phnum; phindex++)
{
bfd_section_from_phdr (abfd, i_phdrp + phindex, phindex);
if ((i_phdrp + phindex)->p_type == PT_NOTE)
{
if (! elf_corefile_note (abfd, i_phdrp + phindex))
return NULL;
}
}
/* Remember the entry point specified in the ELF file header. */
bfd_get_start_address (abfd) = i_ehdrp->e_entry;
return abfd->xvec;
}
/* ELF linker code. */
static boolean elf_link_add_object_symbols
PARAMS ((bfd *, struct bfd_link_info *));
static boolean elf_link_add_archive_symbols
PARAMS ((bfd *, struct bfd_link_info *));
static Elf_Internal_Rela *elf_link_read_relocs
PARAMS ((bfd *, asection *, PTR, Elf_Internal_Rela *, boolean));
static boolean elf_export_symbol
PARAMS ((struct elf_link_hash_entry *, PTR));
static boolean elf_adjust_dynamic_symbol
PARAMS ((struct elf_link_hash_entry *, PTR));
/* This struct is used to pass information to routines called via
elf_link_hash_traverse which must return failure. */
struct elf_info_failed
{
boolean failed;
struct bfd_link_info *info;
};
/* Given an ELF BFD, add symbols to the global hash table as
appropriate. */
boolean
elf_bfd_link_add_symbols (abfd, info)
bfd *abfd;
struct bfd_link_info *info;
{
bfd *first;
switch (bfd_get_format (abfd))
{
case bfd_object:
return elf_link_add_object_symbols (abfd, info);
case bfd_archive:
first = bfd_openr_next_archived_file (abfd, (bfd *) NULL);
if (first == NULL)
{
/* It's OK to have an empty archive. */
return true;
}
if (! bfd_check_format (first, bfd_object))
return false;
if (bfd_get_flavour (first) != bfd_target_elf_flavour)
{
/* On Linux, we may have an a.out archive which got
recognized as an ELF archive. Therefore, we treat all
archives as though they were actually of the flavour of
their first element. */
return (*first->xvec->_bfd_link_add_symbols) (abfd, info);
}
return elf_link_add_archive_symbols (abfd, info);
default:
bfd_set_error (bfd_error_wrong_format);
return false;
}
}
/* Add symbols from an ELF archive file to the linker hash table. We
don't use _bfd_generic_link_add_archive_symbols because of a
problem which arises on UnixWare. The UnixWare libc.so is an
archive which includes an entry libc.so.1 which defines a bunch of
symbols. The libc.so archive also includes a number of other
object files, which also define symbols, some of which are the same
as those defined in libc.so.1. Correct linking requires that we
consider each object file in turn, and include it if it defines any
symbols we need. _bfd_generic_link_add_archive_symbols does not do
this; it looks through the list of undefined symbols, and includes
any object file which defines them. When this algorithm is used on
UnixWare, it winds up pulling in libc.so.1 early and defining a
bunch of symbols. This means that some of the other objects in the
archive are not included in the link, which is incorrect since they
precede libc.so.1 in the archive.
Fortunately, ELF archive handling is simpler than that done by
_bfd_generic_link_add_archive_symbols, which has to allow for a.out
oddities. In ELF, if we find a symbol in the archive map, and the
symbol is currently undefined, we know that we must pull in that
object file.
Unfortunately, we do have to make multiple passes over the symbol
table until nothing further is resolved. */
static boolean
elf_link_add_archive_symbols (abfd, info)
bfd *abfd;
struct bfd_link_info *info;
{
symindex c;
boolean *defined = NULL;
boolean *included = NULL;
carsym *symdefs;
boolean loop;
if (! bfd_has_map (abfd))
{
/* An empty archive is a special case. */
if (bfd_openr_next_archived_file (abfd, (bfd *) NULL) == NULL)
return true;
bfd_set_error (bfd_error_no_symbols);
return false;
}
/* Keep track of all symbols we know to be already defined, and all
files we know to be already included. This is to speed up the
second and subsequent passes. */
c = bfd_ardata (abfd)->symdef_count;
if (c == 0)
return true;
defined = (boolean *) malloc (c * sizeof (boolean));
included = (boolean *) malloc (c * sizeof (boolean));
if (defined == (boolean *) NULL || included == (boolean *) NULL)
{
bfd_set_error (bfd_error_no_memory);
goto error_return;
}
memset (defined, 0, c * sizeof (boolean));
memset (included, 0, c * sizeof (boolean));
symdefs = bfd_ardata (abfd)->symdefs;
do
{
file_ptr last;
symindex i;
carsym *symdef;
carsym *symdefend;
loop = false;
last = -1;
symdef = symdefs;
symdefend = symdef + c;
for (i = 0; symdef < symdefend; symdef++, i++)
{
struct elf_link_hash_entry *h;
bfd *element;
struct bfd_link_hash_entry *undefs_tail;
symindex mark;
if (defined[i] || included[i])
continue;
if (symdef->file_offset == last)
{
included[i] = true;
continue;
}
h = elf_link_hash_lookup (elf_hash_table (info), symdef->name,
false, false, false);
if (h == (struct elf_link_hash_entry *) NULL)
continue;
if (h->root.type != bfd_link_hash_undefined)
{
defined[i] = true;
continue;
}
/* We need to include this archive member. */
element = _bfd_get_elt_at_filepos (abfd, symdef->file_offset);
if (element == (bfd *) NULL)
goto error_return;
if (! bfd_check_format (element, bfd_object))
goto error_return;
/* Doublecheck that we have not included this object
already--it should be impossible, but there may be
something wrong with the archive. */
if (element->archive_pass != 0)
{
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
element->archive_pass = 1;
undefs_tail = info->hash->undefs_tail;
if (! (*info->callbacks->add_archive_element) (info, element,
symdef->name))
goto error_return;
if (! elf_link_add_object_symbols (element, info))
goto error_return;
/* If there are any new undefined symbols, we need to make
another pass through the archive in order to see whether
they can be defined. FIXME: This isn't perfect, because
common symbols wind up on undefs_tail and because an
undefined symbol which is defined later on in this pass
does not require another pass. This isn't a bug, but it
does make the code less efficient than it could be. */
if (undefs_tail != info->hash->undefs_tail)
loop = true;
/* Look backward to mark all symbols from this object file
which we have already seen in this pass. */
mark = i;
do
{
included[mark] = true;
if (mark == 0)
break;
--mark;
}
while (symdefs[mark].file_offset == symdef->file_offset);
/* We mark subsequent symbols from this object file as we go
on through the loop. */
last = symdef->file_offset;
}
}
while (loop);
free (defined);
free (included);
return true;
error_return:
if (defined != (boolean *) NULL)
free (defined);
if (included != (boolean *) NULL)
free (included);
return false;
}
/* Record a new dynamic symbol. We record the dynamic symbols as we
read the input files, since we need to have a list of all of them
before we can determine the final sizes of the output sections.
Note that we may actually call this function even though we are not
going to output any dynamic symbols; in some cases we know that a
symbol should be in the dynamic symbol table, but only if there is
one. */
boolean
elf_link_record_dynamic_symbol (info, h)
struct bfd_link_info *info;
struct elf_link_hash_entry *h;
{
if (h->dynindx == -1)
{
struct bfd_strtab_hash *dynstr;
h->dynindx = elf_hash_table (info)->dynsymcount;
++elf_hash_table (info)->dynsymcount;
dynstr = elf_hash_table (info)->dynstr;
if (dynstr == NULL)
{
/* Create a strtab to hold the dynamic symbol names. */
elf_hash_table (info)->dynstr = dynstr = elf_stringtab_init ();
if (dynstr == NULL)
return false;
}
h->dynstr_index = ((unsigned long)
_bfd_stringtab_add (dynstr, h->root.root.string,
true, false));
if (h->dynstr_index == (unsigned long) -1)
return false;
}
return true;
}
/* Add symbols from an ELF object file to the linker hash table. */
static boolean
elf_link_add_object_symbols (abfd, info)
bfd *abfd;
struct bfd_link_info *info;
{
boolean (*add_symbol_hook) PARAMS ((bfd *, struct bfd_link_info *,
const Elf_Internal_Sym *,
const char **, flagword *,
asection **, bfd_vma *));
boolean (*check_relocs) PARAMS ((bfd *, struct bfd_link_info *,
asection *, const Elf_Internal_Rela *));
boolean collect;
Elf_Internal_Shdr *hdr;
size_t symcount;
size_t extsymcount;
size_t extsymoff;
Elf_External_Sym *buf = NULL;
struct elf_link_hash_entry **sym_hash;
boolean dynamic;
Elf_External_Dyn *dynbuf = NULL;
struct elf_link_hash_entry *weaks;
Elf_External_Sym *esym;
Elf_External_Sym *esymend;
add_symbol_hook = get_elf_backend_data (abfd)->elf_add_symbol_hook;
collect = get_elf_backend_data (abfd)->collect;
/* A stripped shared library might only have a dynamic symbol table,
not a regular symbol table. In that case we can still go ahead
and link using the dynamic symbol table. */
if (elf_onesymtab (abfd) == 0
&& elf_dynsymtab (abfd) != 0)
{
elf_onesymtab (abfd) = elf_dynsymtab (abfd);
elf_tdata (abfd)->symtab_hdr = elf_tdata (abfd)->dynsymtab_hdr;
}
hdr = &elf_tdata (abfd)->symtab_hdr;
symcount = hdr->sh_size / sizeof (Elf_External_Sym);
/* The sh_info field of the symtab header tells us where the
external symbols start. We don't care about the local symbols at
this point. */
if (elf_bad_symtab (abfd))
{
extsymcount = symcount;
extsymoff = 0;
}
else
{
extsymcount = symcount - hdr->sh_info;
extsymoff = hdr->sh_info;
}
buf = (Elf_External_Sym *) malloc (extsymcount * sizeof (Elf_External_Sym));
if (buf == NULL && extsymcount != 0)
{
bfd_set_error (bfd_error_no_memory);
goto error_return;
}
/* We store a pointer to the hash table entry for each external
symbol. */
sym_hash = ((struct elf_link_hash_entry **)
bfd_alloc (abfd,
extsymcount * sizeof (struct elf_link_hash_entry *)));
if (sym_hash == NULL)
{
bfd_set_error (bfd_error_no_memory);
goto error_return;
}
elf_sym_hashes (abfd) = sym_hash;
if (elf_elfheader (abfd)->e_type != ET_DYN)
{
dynamic = false;
/* If we are creating a shared library, create all the dynamic
sections immediately. We need to attach them to something,
so we attach them to this BFD, provided it is the right
format. FIXME: If there are no input BFD's of the same
format as the output, we can't make a shared library. */
if (info->shared
&& ! elf_hash_table (info)->dynamic_sections_created
&& abfd->xvec == info->hash->creator)
{
if (! elf_link_create_dynamic_sections (abfd, info))
goto error_return;
}
}
else
{
asection *s;
const char *name;
bfd_size_type oldsize;
bfd_size_type strindex;
dynamic = true;
/* You can't use -r against a dynamic object. Also, there's no
hope of using a dynamic object which does not exactly match
the format of the output file. */
if (info->relocateable
|| info->hash->creator != abfd->xvec)
{
bfd_set_error (bfd_error_invalid_operation);
goto error_return;
}
/* Find the name to use in a DT_NEEDED entry that refers to this
object. If the object has a DT_SONAME entry, we use it.
Otherwise, if the generic linker stuck something in
elf_dt_needed_name, we use that. Otherwise, we just use the
file name. */
name = bfd_get_filename (abfd);
if (elf_dt_needed_name (abfd) != NULL)
name = elf_dt_needed_name (abfd);
s = bfd_get_section_by_name (abfd, ".dynamic");
if (s != NULL)
{
Elf_External_Dyn *extdyn;
Elf_External_Dyn *extdynend;
dynbuf = (Elf_External_Dyn *) malloc (s->_raw_size);
if (dynbuf == NULL)
{
bfd_set_error (bfd_error_no_memory);
goto error_return;
}
if (! bfd_get_section_contents (abfd, s, (PTR) dynbuf,
(file_ptr) 0, s->_raw_size))
goto error_return;
extdyn = dynbuf;
extdynend = extdyn + s->_raw_size / sizeof (Elf_External_Dyn);
for (; extdyn < extdynend; extdyn++)
{
Elf_Internal_Dyn dyn;
elf_swap_dyn_in (abfd, extdyn, &dyn);
if (dyn.d_tag == DT_SONAME)
{
int elfsec;
unsigned long link;
elfsec = elf_section_from_bfd_section (abfd, s);
if (elfsec == -1)
goto error_return;
link = elf_elfsections (abfd)[elfsec]->sh_link;
name = elf_string_from_elf_section (abfd, link,
dyn.d_un.d_val);
if (name == NULL)
goto error_return;
}
if (dyn.d_tag == DT_NEEDED)
elf_hash_table (info)->saw_needed = true;
}
free (dynbuf);
dynbuf = NULL;
}
/* We do not want to include any of the sections in a dynamic
object in the output file. We hack by simply clobbering the
list of sections in the BFD. This could be handled more
cleanly by, say, a new section flag; the existing
SEC_NEVER_LOAD flag is not the one we want, because that one
still implies that the section takes up space in the output
file. */
abfd->sections = NULL;
/* If this is the first dynamic object found in the link, create
the special sections required for dynamic linking. */
if (! elf_hash_table (info)->dynamic_sections_created)
{
if (! elf_link_create_dynamic_sections (abfd, info))
goto error_return;
}
/* Add a DT_NEEDED entry for this dynamic object. */
oldsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
strindex = _bfd_stringtab_add (elf_hash_table (info)->dynstr, name,
true, false);
if (strindex == (bfd_size_type) -1)
goto error_return;
if (oldsize == _bfd_stringtab_size (elf_hash_table (info)->dynstr))
{
asection *sdyn;
Elf_External_Dyn *dyncon, *dynconend;
/* The hash table size did not change, which means that the
dynamic object name was already entered. If we have
already included this dynamic object in the link, just
ignore it. There is no reason to include a particular
dynamic object more than once. */
sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
".dynamic");
BFD_ASSERT (sdyn != NULL);
dyncon = (Elf_External_Dyn *) sdyn->contents;
dynconend = (Elf_External_Dyn *) (sdyn->contents + sdyn->_raw_size);
for (; dyncon < dynconend; dyncon++)
{
Elf_Internal_Dyn dyn;
elf_swap_dyn_in (elf_hash_table (info)->dynobj, dyncon, &dyn);
if (dyn.d_tag == DT_NEEDED
&& dyn.d_un.d_val == strindex)
{
if (buf != NULL)
free (buf);
return true;
}
}
}
if (! elf_add_dynamic_entry (info, DT_NEEDED, strindex))
goto error_return;
}
if (bfd_seek (abfd,
hdr->sh_offset + extsymoff * sizeof (Elf_External_Sym),
SEEK_SET) != 0
|| (bfd_read ((PTR) buf, sizeof (Elf_External_Sym), extsymcount, abfd)
!= extsymcount * sizeof (Elf_External_Sym)))
goto error_return;
weaks = NULL;
esymend = buf + extsymcount;
for (esym = buf; esym < esymend; esym++, sym_hash++)
{
Elf_Internal_Sym sym;
int bind;
bfd_vma value;
asection *sec;
flagword flags;
const char *name;
struct elf_link_hash_entry *h = NULL;
boolean definition;
elf_swap_symbol_in (abfd, esym, &sym);
flags = BSF_NO_FLAGS;
sec = NULL;
value = sym.st_value;
*sym_hash = NULL;
bind = ELF_ST_BIND (sym.st_info);
if (bind == STB_LOCAL)
{
/* This should be impossible, since ELF requires that all
global symbols follow all local symbols, and that sh_info
point to the first global symbol. Unfortunatealy, Irix 5
screws this up. */
continue;
}
else if (bind == STB_GLOBAL)
{
if (sym.st_shndx != SHN_UNDEF
&& sym.st_shndx != SHN_COMMON)
flags = BSF_GLOBAL;
else
flags = 0;
}
else if (bind == STB_WEAK)
flags = BSF_WEAK;
else
{
/* Leave it up to the processor backend. */
}
if (sym.st_shndx == SHN_UNDEF)
sec = bfd_und_section_ptr;
else if (sym.st_shndx > 0 && sym.st_shndx < SHN_LORESERVE)
{
sec = section_from_elf_index (abfd, sym.st_shndx);
if (sec != NULL)
value -= sec->vma;
else
sec = bfd_abs_section_ptr;
}
else if (sym.st_shndx == SHN_ABS)
sec = bfd_abs_section_ptr;
else if (sym.st_shndx == SHN_COMMON)
{
sec = bfd_com_section_ptr;
/* What ELF calls the size we call the value. What ELF
calls the value we call the alignment. */
value = sym.st_size;
}
else
{
/* Leave it up to the processor backend. */
}
name = elf_string_from_elf_section (abfd, hdr->sh_link, sym.st_name);
if (name == (const char *) NULL)
goto error_return;
if (add_symbol_hook)
{
if (! (*add_symbol_hook) (abfd, info, &sym, &name, &flags, &sec,
&value))
goto error_return;
/* The hook function sets the name to NULL if this symbol
should be skipped for some reason. */
if (name == (const char *) NULL)
continue;
}
/* Sanity check that all possibilities were handled. */
if (sec == (asection *) NULL)
{
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
if (bfd_is_und_section (sec)
|| bfd_is_com_section (sec))
definition = false;
else
definition = true;
if (info->hash->creator->flavour == bfd_target_elf_flavour)
{
/* We need to look up the symbol now in order to get some of
the dynamic object handling right. We pass the hash
table entry in to _bfd_generic_link_add_one_symbol so
that it does not have to look it up again. */
h = elf_link_hash_lookup (elf_hash_table (info), name,
true, false, false);
if (h == NULL)
goto error_return;
*sym_hash = h;
/* If we are looking at a dynamic object, and this is a
definition, we need to see if it has already been defined
by some other object. If it has, we want to use the
existing definition, and we do not want to report a
multiple symbol definition error; we do this by
clobbering sec to be bfd_und_section_ptr. */
if (dynamic && definition)
{
if (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
sec = bfd_und_section_ptr;
}
/* Similarly, if we are not looking at a dynamic object, and
we have a definition, we want to override any definition
we may have from a dynamic object. Symbols from regular
files always take precedence over symbols from dynamic
objects, even if they are defined after the dynamic
object in the link. */
if (! dynamic
&& definition
&& (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
&& (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))
{
/* Change the hash table entry to undefined, and let
_bfd_generic_link_add_one_symbol do the right thing
with the new definition. */
h->root.type = bfd_link_hash_undefined;
h->root.u.undef.abfd = h->root.u.def.section->owner;
}
}
if (! (_bfd_generic_link_add_one_symbol
(info, abfd, name, flags, sec, value, (const char *) NULL,
false, collect, (struct bfd_link_hash_entry **) sym_hash)))
goto error_return;
if (dynamic
&& definition
&& (flags & BSF_WEAK) != 0
&& ELF_ST_TYPE (sym.st_info) != STT_FUNC
&& info->hash->creator->flavour == bfd_target_elf_flavour
&& (*sym_hash)->weakdef == NULL)
{
/* Keep a list of all weak defined non function symbols from
a dynamic object, using the weakdef field. Later in this
function we will set the weakdef field to the correct
value. We only put non-function symbols from dynamic
objects on this list, because that happens to be the only
time we need to know the normal symbol corresponding to a
weak symbol, and the information is time consuming to
figure out. If the weakdef field is not already NULL,
then this symbol was already defined by some previous
dynamic object, and we will be using that previous
definition anyhow. */
(*sym_hash)->weakdef = weaks;
weaks = *sym_hash;
}
/* Get the alignment of a common symbol. */
if (sym.st_shndx == SHN_COMMON
&& (*sym_hash)->root.type == bfd_link_hash_common)
(*sym_hash)->root.u.c.p->alignment_power = bfd_log2 (sym.st_value);
if (info->hash->creator->flavour == bfd_target_elf_flavour)
{
int old_flags;
boolean dynsym;
int new_flag;
/* Remember the symbol size and type. */
if (sym.st_size != 0)
{
/* FIXME: We should probably somehow give a warning if
the symbol size changes. */
h->size = sym.st_size;
}
if (ELF_ST_TYPE (sym.st_info) != STT_NOTYPE)
{
/* FIXME: We should probably somehow give a warning if
the symbol type changes. */
h->type = ELF_ST_TYPE (sym.st_info);
}
/* Set a flag in the hash table entry indicating the type of
reference or definition we just found. Keep a count of
the number of dynamic symbols we find. A dynamic symbol
is one which is referenced or defined by both a regular
object and a shared object, or one which is referenced or
defined by more than one shared object. */
old_flags = h->elf_link_hash_flags;
dynsym = false;
if (! dynamic)
{
if (! definition)
new_flag = ELF_LINK_HASH_REF_REGULAR;
else
new_flag = ELF_LINK_HASH_DEF_REGULAR;
if (info->shared
|| (old_flags & (ELF_LINK_HASH_DEF_DYNAMIC
| ELF_LINK_HASH_REF_DYNAMIC)) != 0)
dynsym = true;
}
else
{
if (! definition)
new_flag = ELF_LINK_HASH_REF_DYNAMIC;
else
new_flag = ELF_LINK_HASH_DEF_DYNAMIC;
if ((old_flags & new_flag) != 0
|| (old_flags & (ELF_LINK_HASH_DEF_REGULAR
| ELF_LINK_HASH_REF_REGULAR)) != 0)
dynsym = true;
}
h->elf_link_hash_flags |= new_flag;
if (dynsym && h->dynindx == -1)
{
if (! elf_link_record_dynamic_symbol (info, h))
goto error_return;
}
}
}
/* Now set the weakdefs field correctly for all the weak defined
symbols we found. The only way to do this is to search all the
symbols. Since we only need the information for non functions in
dynamic objects, that's the only time we actually put anything on
the list WEAKS. We need this information so that if a regular
object refers to a symbol defined weakly in a dynamic object, the
real symbol in the dynamic object is also put in the dynamic
symbols; we also must arrange for both symbols to point to the
same memory location. We could handle the general case of symbol
aliasing, but a general symbol alias can only be generated in
assembler code, handling it correctly would be very time
consuming, and other ELF linkers don't handle general aliasing
either. */
while (weaks != NULL)
{
struct elf_link_hash_entry *hlook;
asection *slook;
bfd_vma vlook;
struct elf_link_hash_entry **hpp;
struct elf_link_hash_entry **hppend;
hlook = weaks;
weaks = hlook->weakdef;
hlook->weakdef = NULL;
BFD_ASSERT (hlook->root.type == bfd_link_hash_defined
|| hlook->root.type == bfd_link_hash_defweak);
slook = hlook->root.u.def.section;
vlook = hlook->root.u.def.value;
hpp = elf_sym_hashes (abfd);
hppend = hpp + extsymcount;
for (; hpp < hppend; hpp++)
{
struct elf_link_hash_entry *h;
h = *hpp;
if (h != NULL && h != hlook
&& (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
&& h->root.u.def.section == slook
&& h->root.u.def.value == vlook)
{
hlook->weakdef = h;
/* If the weak definition is in the list of dynamic
symbols, make sure the real definition is put there
as well. */
if (hlook->dynindx != -1
&& h->dynindx == -1)
{
if (! elf_link_record_dynamic_symbol (info, h))
goto error_return;
}
break;
}
}
}
if (buf != NULL)
{
free (buf);
buf = NULL;
}
/* If this object is the same format as the output object, and it is
not a shared library, then let the backend look through the
relocs.
This is required to build global offset table entries and to
arrange for dynamic relocs. It is not required for the
particular common case of linking non PIC code, even when linking
against shared libraries, but unfortunately there is no way of
knowing whether an object file has been compiled PIC or not.
Looking through the relocs is not particularly time consuming.
The problem is that we must either (1) keep the relocs in memory,
which causes the linker to require additional runtime memory or
(2) read the relocs twice from the input file, which wastes time.
This would be a good case for using mmap.
I have no idea how to handle linking PIC code into a file of a
different format. It probably can't be done. */
check_relocs = get_elf_backend_data (abfd)->check_relocs;
if (! dynamic
&& abfd->xvec == info->hash->creator
&& check_relocs != NULL)
{
asection *o;
for (o = abfd->sections; o != NULL; o = o->next)
{
Elf_Internal_Rela *internal_relocs;
boolean ok;
if ((o->flags & SEC_RELOC) == 0
|| o->reloc_count == 0)
continue;
/* I believe we can ignore the relocs for any section which
does not form part of the final process image, such as a
debugging section. */
if ((o->flags & SEC_ALLOC) == 0)
continue;
internal_relocs = elf_link_read_relocs (abfd, o, (PTR) NULL,
(Elf_Internal_Rela *) NULL,
info->keep_memory);
if (internal_relocs == NULL)
goto error_return;
ok = (*check_relocs) (abfd, info, o, internal_relocs);
if (! info->keep_memory)
free (internal_relocs);
if (! ok)
goto error_return;
}
}
return true;
error_return:
if (buf != NULL)
free (buf);
if (dynbuf != NULL)
free (dynbuf);
return false;
}
/* Create some sections which will be filled in with dynamic linking
information. ABFD is an input file which requires dynamic sections
to be created. The dynamic sections take up virtual memory space
when the final executable is run, so we need to create them before
addresses are assigned to the output sections. We work out the
actual contents and size of these sections later. */
boolean
elf_link_create_dynamic_sections (abfd, info)
bfd *abfd;
struct bfd_link_info *info;
{
flagword flags;
register asection *s;
struct elf_link_hash_entry *h;
struct elf_backend_data *bed;
if (elf_hash_table (info)->dynamic_sections_created)
return true;
/* Make sure that all dynamic sections use the same input BFD. */
if (elf_hash_table (info)->dynobj == NULL)
elf_hash_table (info)->dynobj = abfd;
else
abfd = elf_hash_table (info)->dynobj;
/* Note that we set the SEC_IN_MEMORY flag for all of these
sections. */
flags = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY;
/* A dynamically linked executable has a .interp section, but a
shared library does not. */
if (! info->shared)
{
s = bfd_make_section (abfd, ".interp");
if (s == NULL
|| ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
return false;
}
s = bfd_make_section (abfd, ".dynsym");
if (s == NULL
|| ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
|| ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
return false;
s = bfd_make_section (abfd, ".dynstr");
if (s == NULL
|| ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
return false;
/* Create a strtab to hold the dynamic symbol names. */
if (elf_hash_table (info)->dynstr == NULL)
{
elf_hash_table (info)->dynstr = elf_stringtab_init ();
if (elf_hash_table (info)->dynstr == NULL)
return false;
}
s = bfd_make_section (abfd, ".dynamic");
if (s == NULL
|| ! bfd_set_section_flags (abfd, s, flags)
|| ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
return false;
/* The special symbol _DYNAMIC is always set to the start of the
.dynamic section. This call occurs before we have processed the
symbols for any dynamic object, so we don't have to worry about
overriding a dynamic definition. We could set _DYNAMIC in a
linker script, but we only want to define it if we are, in fact,
creating a .dynamic section. We don't want to define it if there
is no .dynamic section, since on some ELF platforms the start up
code examines it to decide how to initialize the process. */
h = NULL;
if (! (_bfd_generic_link_add_one_symbol
(info, abfd, "_DYNAMIC", 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;
h->type = STT_OBJECT;
if (info->shared
&& ! elf_link_record_dynamic_symbol (info, h))
return false;
s = bfd_make_section (abfd, ".hash");
if (s == NULL
|| ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
|| ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
return false;
/* Let the backend create the rest of the sections. This lets the
backend set the right flags. The backend will normally create
the .got and .plt sections. */
bed = get_elf_backend_data (abfd);
if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info))
return false;
elf_hash_table (info)->dynamic_sections_created = true;
return true;
}
/* Add an entry to the .dynamic table. */
boolean
elf_add_dynamic_entry (info, tag, val)
struct bfd_link_info *info;
bfd_vma tag;
bfd_vma val;
{
Elf_Internal_Dyn dyn;
bfd *dynobj;
asection *s;
size_t newsize;
bfd_byte *newcontents;
dynobj = elf_hash_table (info)->dynobj;
s = bfd_get_section_by_name (dynobj, ".dynamic");
BFD_ASSERT (s != NULL);
newsize = s->_raw_size + sizeof (Elf_External_Dyn);
if (s->contents == NULL)
newcontents = (bfd_byte *) malloc (newsize);
else
newcontents = (bfd_byte *) realloc (s->contents, newsize);
if (newcontents == NULL)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
dyn.d_tag = tag;
dyn.d_un.d_val = val;
elf_swap_dyn_out (dynobj, &dyn,
(Elf_External_Dyn *) (newcontents + s->_raw_size));
s->_raw_size = newsize;
s->contents = newcontents;
return true;
}
/* Read and swap the relocs for a section. They may have been cached.
If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are not NULL,
they are used as buffers to read into. They are known to be large
enough. If the INTERNAL_RELOCS relocs argument is NULL, the return
value is allocated using either malloc or bfd_alloc, according to
the KEEP_MEMORY argument. */
static Elf_Internal_Rela *
elf_link_read_relocs (abfd, o, external_relocs, internal_relocs, keep_memory)
bfd *abfd;
asection *o;
PTR external_relocs;
Elf_Internal_Rela *internal_relocs;
boolean keep_memory;
{
Elf_Internal_Shdr *rel_hdr;
PTR alloc1 = NULL;
Elf_Internal_Rela *alloc2 = NULL;
if (elf_section_data (o)->relocs != NULL)
return elf_section_data (o)->relocs;
if (o->reloc_count == 0)
return NULL;
rel_hdr = &elf_section_data (o)->rel_hdr;
if (internal_relocs == NULL)
{
size_t size;
size = o->reloc_count * sizeof (Elf_Internal_Rela);
if (keep_memory)
internal_relocs = (Elf_Internal_Rela *) bfd_alloc (abfd, size);
else
internal_relocs = alloc2 = (Elf_Internal_Rela *) malloc (size);
if (internal_relocs == NULL)
{
bfd_set_error (bfd_error_no_memory);
goto error_return;
}
}
if (external_relocs == NULL)
{
alloc1 = (PTR) malloc (rel_hdr->sh_size);
if (alloc1 == NULL)
{
bfd_set_error (bfd_error_no_memory);
goto error_return;
}
external_relocs = alloc1;
}
if ((bfd_seek (abfd, rel_hdr->sh_offset, SEEK_SET) != 0)
|| (bfd_read (external_relocs, 1, rel_hdr->sh_size, abfd)
!= rel_hdr->sh_size))
goto error_return;
/* Swap in the relocs. For convenience, we always produce an
Elf_Internal_Rela array; if the relocs are Rel, we set the addend
to 0. */
if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
{
Elf_External_Rel *erel;
Elf_External_Rel *erelend;
Elf_Internal_Rela *irela;
erel = (Elf_External_Rel *) external_relocs;
erelend = erel + o->reloc_count;
irela = internal_relocs;
for (; erel < erelend; erel++, irela++)
{
Elf_Internal_Rel irel;
elf_swap_reloc_in (abfd, erel, &irel);
irela->r_offset = irel.r_offset;
irela->r_info = irel.r_info;
irela->r_addend = 0;
}
}
else
{
Elf_External_Rela *erela;
Elf_External_Rela *erelaend;
Elf_Internal_Rela *irela;
BFD_ASSERT (rel_hdr->sh_entsize == sizeof (Elf_External_Rela));
erela = (Elf_External_Rela *) external_relocs;
erelaend = erela + o->reloc_count;
irela = internal_relocs;
for (; erela < erelaend; erela++, irela++)
elf_swap_reloca_in (abfd, erela, irela);
}
/* Cache the results for next time, if we can. */
if (keep_memory)
elf_section_data (o)->relocs = internal_relocs;
if (alloc1 != NULL)
free (alloc1);
/* Don't free alloc2, since if it was allocated we are passing it
back (under the name of internal_relocs). */
return internal_relocs;
error_return:
if (alloc1 != NULL)
free (alloc1);
if (alloc2 != NULL)
free (alloc2);
return NULL;
}
/* Record an assignment to a symbol made by a linker script. We need
this in case some dynamic object refers to this symbol. */
/*ARGSUSED*/
boolean
NAME(bfd_elf,record_link_assignment) (output_bfd, info, name)
bfd *output_bfd;
struct bfd_link_info *info;
const char *name;
{
struct elf_link_hash_entry *h;
if (info->hash->creator->flavour != bfd_target_elf_flavour)
return true;
h = elf_link_hash_lookup (elf_hash_table (info), name, true, true, false);
if (h == NULL)
return false;
h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
h->type = STT_OBJECT;
if (((h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_DYNAMIC
| ELF_LINK_HASH_REF_DYNAMIC)) != 0
|| info->shared)
&& h->dynindx == -1)
{
if (! elf_link_record_dynamic_symbol (info, h))
return false;
/* If this is a weak defined symbol, and we know a corresponding
real symbol from the same dynamic object, make sure the real
symbol is also made into a dynamic symbol. */
if (h->weakdef != NULL
&& h->weakdef->dynindx == -1)
{
if (! elf_link_record_dynamic_symbol (info, h->weakdef))
return false;
}
}
return true;
}
/* Array used to determine the number of hash table buckets to use
based on the number of symbols there are. If there are fewer than
3 symbols we use 1 bucket, fewer than 17 symbols we use 3 buckets,
fewer than 37 we use 17 buckets, and so forth. We never use more
than 521 buckets. */
static const size_t elf_buckets[] =
{
1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 0
};
/* Set up the sizes and contents of the ELF dynamic sections. This is
called by the ELF linker emulation before_allocation routine. We
must set the sizes of the sections before the linker sets the
addresses of the various sections. */
boolean
NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath,
export_dynamic, info, sinterpptr)
bfd *output_bfd;
const char *soname;
const char *rpath;
boolean export_dynamic;
struct bfd_link_info *info;
asection **sinterpptr;
{
bfd *dynobj;
struct elf_backend_data *bed;
*sinterpptr = NULL;
if (info->hash->creator->flavour != bfd_target_elf_flavour)
return true;
dynobj = elf_hash_table (info)->dynobj;
/* If there were no dynamic objects in the link, there is nothing to
do here. */
if (dynobj == NULL)
return true;
/* If we are supposed to export all symbols into the dynamic symbol
table (this is not the normal case), then do so. */
if (export_dynamic)
{
struct elf_info_failed eif;
eif.failed = false;
eif.info = info;
elf_link_hash_traverse (elf_hash_table (info), elf_export_symbol,
(PTR) &eif);
if (eif.failed)
return false;
}
if (elf_hash_table (info)->dynamic_sections_created)
{
struct elf_info_failed eif;
bfd_size_type strsize;
*sinterpptr = bfd_get_section_by_name (dynobj, ".interp");
BFD_ASSERT (*sinterpptr != NULL || info->shared);
if (soname != NULL)
{
bfd_size_type indx;
indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, soname,
true, true);
if (indx == (bfd_size_type) -1
|| ! elf_add_dynamic_entry (info, DT_SONAME, indx))
return false;
}
if (rpath != NULL)
{
bfd_size_type indx;
indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, rpath,
true, true);
if (indx == (bfd_size_type) -1
|| ! elf_add_dynamic_entry (info, DT_RPATH, indx))
return false;
}
/* Find all symbols which were defined in a dynamic object and make
the backend pick a reasonable value for them. */
eif.failed = false;
eif.info = info;
elf_link_hash_traverse (elf_hash_table (info),
elf_adjust_dynamic_symbol,
(PTR) &eif);
if (eif.failed)
return false;
/* Add some entries to the .dynamic section. We fill in some of the
values later, in elf_bfd_final_link, but we must add the entries
now so that we know the final size of the .dynamic section. */
if (elf_link_hash_lookup (elf_hash_table (info), "_init", false,
false, false) != NULL)
{
if (! elf_add_dynamic_entry (info, DT_INIT, 0))
return false;
}
if (elf_link_hash_lookup (elf_hash_table (info), "_fini", false,
false, false) != NULL)
{
if (! elf_add_dynamic_entry (info, DT_FINI, 0))
return false;
}
strsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
if (! elf_add_dynamic_entry (info, DT_HASH, 0)
|| ! elf_add_dynamic_entry (info, DT_STRTAB, 0)
|| ! elf_add_dynamic_entry (info, DT_SYMTAB, 0)
|| ! elf_add_dynamic_entry (info, DT_STRSZ, strsize)
|| ! elf_add_dynamic_entry (info, DT_SYMENT,
sizeof (Elf_External_Sym)))
return false;
}
/* The backend must work out the sizes of all the other dynamic
sections. */
bed = get_elf_backend_data (output_bfd);
if (! (*bed->elf_backend_size_dynamic_sections) (output_bfd, info))
return false;
if (elf_hash_table (info)->dynamic_sections_created)
{
size_t dynsymcount;
asection *s;
size_t i;
size_t bucketcount;
Elf_Internal_Sym isym;
/* Set the size of the .dynsym and .hash sections. We counted
the number of dynamic symbols in elf_link_add_object_symbols.
We will build the contents of .dynsym and .hash when we build
the final symbol table, because until then we do not know the
correct value to give the symbols. We built the .dynstr
section as we went along in elf_link_add_object_symbols. */
dynsymcount = elf_hash_table (info)->dynsymcount;
s = bfd_get_section_by_name (dynobj, ".dynsym");
BFD_ASSERT (s != NULL);
s->_raw_size = dynsymcount * sizeof (Elf_External_Sym);
s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
if (s->contents == NULL && s->_raw_size != 0)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
/* The first entry in .dynsym is a dummy symbol. */
isym.st_value = 0;
isym.st_size = 0;
isym.st_name = 0;
isym.st_info = 0;
isym.st_other = 0;
isym.st_shndx = 0;
elf_swap_symbol_out (output_bfd, &isym,
(Elf_External_Sym *) s->contents);
for (i = 0; elf_buckets[i] != 0; i++)
{
bucketcount = elf_buckets[i];
if (dynsymcount < elf_buckets[i + 1])
break;
}
s = bfd_get_section_by_name (dynobj, ".hash");
BFD_ASSERT (s != NULL);
s->_raw_size = (2 + bucketcount + dynsymcount) * (ARCH_SIZE / 8);
s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
if (s->contents == NULL)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
memset (s->contents, 0, s->_raw_size);
put_word (output_bfd, bucketcount, s->contents);
put_word (output_bfd, dynsymcount, s->contents + (ARCH_SIZE / 8));
elf_hash_table (info)->bucketcount = bucketcount;
s = bfd_get_section_by_name (dynobj, ".dynstr");
BFD_ASSERT (s != NULL);
s->_raw_size = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
if (! elf_add_dynamic_entry (info, DT_NULL, 0))
return false;
}
return true;
}
/* This routine is used to export all defined symbols into the dynamic
symbol table. It is called via elf_link_hash_traverse. */
static boolean
elf_export_symbol (h, data)
struct elf_link_hash_entry *h;
PTR data;
{
struct elf_info_failed *eif = (struct elf_info_failed *) data;
if (h->dynindx == -1
&& (h->elf_link_hash_flags
& (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0)
{
if (! elf_link_record_dynamic_symbol (eif->info, h))
{
eif->failed = true;
return false;
}
}
return true;
}
/* Make the backend pick a good value for a dynamic symbol. This is
called via elf_link_hash_traverse, and also calls itself
recursively. */
static boolean
elf_adjust_dynamic_symbol (h, data)
struct elf_link_hash_entry *h;
PTR data;
{
struct elf_info_failed *eif = (struct elf_info_failed *) data;
bfd *dynobj;
struct elf_backend_data *bed;
/* If this symbol does not require a PLT entry, and it is not
defined by a dynamic object, or is not referenced by a regular
object, ignore it. FIXME: Do we need to worry about symbols
which are defined by one dynamic object and referenced by another
one? */
if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0
&& ((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))
return true;
/* If we've already adjusted this symbol, don't do it again. This
can happen via a recursive call. */
if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0)
return true;
/* Don't look at this symbol again. Note that we must set this
after checking the above conditions, because we may look at a
symbol once, decide not to do anything, and then get called
recursively later after REF_REGULAR is set below. */
h->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED;
/* If this is a weak definition, and we know a real definition, and
the real symbol is not itself defined by a regular object file,
then get a good value for the real definition. We handle the
real symbol first, for the convenience of the backend routine.
Note that there is a confusing case here. If the real definition
is defined by a regular object file, we don't get the real symbol
from the dynamic object, but we do get the weak symbol. If the
processor backend uses a COPY reloc, then if some routine in the
dynamic object changes the real symbol, we will not see that
change in the corresponding weak symbol. This is the way other
ELF linkers work as well, and seems to be a result of the shared
library model.
I will clarify this issue. Most SVR4 shared libraries define the
variable _timezone and define timezone as a weak synonym. The
tzset call changes _timezone. If you write
extern int timezone;
int _timezone = 5;
int main () { tzset (); printf ("%d %d\n", timezone, _timezone); }
you might expect that, since timezone is a synonym for _timezone,
the same number will print both times. However, if the processor
backend uses a COPY reloc, then actually timezone will be copied
into your process image, and, since you define _timezone
yourself, _timezone will not. Thus timezone and _timezone will
wind up at different memory locations. The tzset call will set
_timezone, leaving timezone unchanged. */
if (h->weakdef != NULL)
{
struct elf_link_hash_entry *weakdef;
BFD_ASSERT (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak);
weakdef = h->weakdef;
BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined
|| weakdef->root.type == bfd_link_hash_defweak);
BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC);
if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
{
/* This symbol is defined by a regular object file, so we
will not do anything special. Clear weakdef for the
convenience of the processor backend. */
h->weakdef = NULL;
}
else
{
/* There is an implicit reference by a regular object file
via the weak symbol. */
weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
if (! elf_adjust_dynamic_symbol (weakdef, (PTR) eif))
return false;
}
}
dynobj = elf_hash_table (eif->info)->dynobj;
bed = get_elf_backend_data (dynobj);
if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h))
{
eif->failed = true;
return false;
}
return true;
}
/* Final phase of ELF linker. */
/* A structure we use to avoid passing large numbers of arguments. */
struct elf_final_link_info
{
/* General link information. */
struct bfd_link_info *info;
/* Output BFD. */
bfd *output_bfd;
/* Symbol string table. */
struct bfd_strtab_hash *symstrtab;
/* .dynsym section. */
asection *dynsym_sec;
/* .hash section. */
asection *hash_sec;
/* Buffer large enough to hold contents of any section. */
bfd_byte *contents;
/* Buffer large enough to hold external relocs of any section. */
PTR external_relocs;
/* Buffer large enough to hold internal relocs of any section. */
Elf_Internal_Rela *internal_relocs;
/* Buffer large enough to hold external local symbols of any input
BFD. */
Elf_External_Sym *external_syms;
/* Buffer large enough to hold internal local symbols of any input
BFD. */
Elf_Internal_Sym *internal_syms;
/* Array large enough to hold a symbol index for each local symbol
of any input BFD. */
long *indices;
/* Array large enough to hold a section pointer for each local
symbol of any input BFD. */
asection **sections;
/* Buffer to hold swapped out symbols. */
Elf_External_Sym *symbuf;
/* Number of swapped out symbols in buffer. */
size_t symbuf_count;
/* Number of symbols which fit in symbuf. */
size_t symbuf_size;
};
static boolean elf_link_output_sym
PARAMS ((struct elf_final_link_info *, const char *,
Elf_Internal_Sym *, asection *));
static boolean elf_link_flush_output_syms
PARAMS ((struct elf_final_link_info *));
static boolean elf_link_output_extsym
PARAMS ((struct elf_link_hash_entry *, PTR));
static boolean elf_link_input_bfd
PARAMS ((struct elf_final_link_info *, bfd *));
static boolean elf_reloc_link_order
PARAMS ((bfd *, struct bfd_link_info *, asection *,
struct bfd_link_order *));
/* This struct is used to pass information to routines called via
elf_link_hash_traverse which must return failure. */
struct elf_finfo_failed
{
boolean failed;
struct elf_final_link_info *finfo;
};
/* Do the final step of an ELF link. */
boolean
elf_bfd_final_link (abfd, info)
bfd *abfd;
struct bfd_link_info *info;
{
boolean dynamic;
bfd *dynobj;
struct elf_final_link_info finfo;
register asection *o;
register struct bfd_link_order *p;
register bfd *sub;
size_t max_contents_size;
size_t max_external_reloc_size;
size_t max_internal_reloc_count;
size_t max_sym_count;
file_ptr off;
Elf_Internal_Sym elfsym;
unsigned int i;
Elf_Internal_Shdr *symtab_hdr;
Elf_Internal_Shdr *symstrtab_hdr;
struct elf_backend_data *bed = get_elf_backend_data (abfd);
struct elf_finfo_failed eif;
if (info->shared)
abfd->flags |= DYNAMIC;
dynamic = elf_hash_table (info)->dynamic_sections_created;
dynobj = elf_hash_table (info)->dynobj;
finfo.info = info;
finfo.output_bfd = abfd;
finfo.symstrtab = elf_stringtab_init ();
if (finfo.symstrtab == NULL)
return false;
if (! dynamic)
{
finfo.dynsym_sec = NULL;
finfo.hash_sec = NULL;
}
else
{
finfo.dynsym_sec = bfd_get_section_by_name (dynobj, ".dynsym");
finfo.hash_sec = bfd_get_section_by_name (dynobj, ".hash");
BFD_ASSERT (finfo.dynsym_sec != NULL && finfo.hash_sec != NULL);
}
finfo.contents = NULL;
finfo.external_relocs = NULL;
finfo.internal_relocs = NULL;
finfo.external_syms = NULL;
finfo.internal_syms = NULL;
finfo.indices = NULL;
finfo.sections = NULL;
finfo.symbuf = NULL;
finfo.symbuf_count = 0;
/* Count up the number of relocations we will output for each output
section, so that we know the sizes of the reloc sections. We
also figure out some maximum sizes. */
max_contents_size = 0;
max_external_reloc_size = 0;
max_internal_reloc_count = 0;
max_sym_count = 0;
for (o = abfd->sections; o != (asection *) NULL; o = o->next)
{
o->reloc_count = 0;
for (p = o->link_order_head; p != NULL; p = p->next)
{
if (p->type == bfd_section_reloc_link_order
|| p->type == bfd_symbol_reloc_link_order)
++o->reloc_count;
else if (p->type == bfd_indirect_link_order)
{
asection *sec;
sec = p->u.indirect.section;
if (info->relocateable)
o->reloc_count += sec->reloc_count;
if (sec->_raw_size > max_contents_size)
max_contents_size = sec->_raw_size;
if (sec->_cooked_size > max_contents_size)
max_contents_size = sec->_cooked_size;
/* We are interested in just local symbols, not all
symbols. */
if (bfd_get_flavour (sec->owner) == bfd_target_elf_flavour)
{
size_t sym_count;
if (elf_bad_symtab (sec->owner))
sym_count = (elf_tdata (sec->owner)->symtab_hdr.sh_size
/ sizeof (Elf_External_Sym));
else
sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info;
if (sym_count > max_sym_count)
max_sym_count = sym_count;
if ((sec->flags & SEC_RELOC) != 0)
{
size_t ext_size;
ext_size = elf_section_data (sec)->rel_hdr.sh_size;
if (ext_size > max_external_reloc_size)
max_external_reloc_size = ext_size;
if (sec->reloc_count > max_internal_reloc_count)
max_internal_reloc_count = sec->reloc_count;
}
}
}
}
if (o->reloc_count > 0)
o->flags |= SEC_RELOC;
else
{
/* Explicitly clear the SEC_RELOC flag. The linker tends to
set it (this is probably a bug) and if it is set
assign_section_numbers will create a reloc section. */
o->flags &=~ SEC_RELOC;
}
/* If the SEC_ALLOC flag is not set, force the section VMA to
zero. This is done in elf_fake_sections as well, but forcing
the VMA to 0 here will ensure that relocs against these
sections are handled correctly. */
if ((o->flags & SEC_ALLOC) == 0)
o->vma = 0;
}
/* Figure out the file positions for everything but the symbol table
and the relocs. We set symcount to force assign_section_numbers
to create a symbol table. */
abfd->symcount = info->strip == strip_all ? 0 : 1;
BFD_ASSERT (! abfd->output_has_begun);
if (! elf_compute_section_file_positions (abfd, info))
goto error_return;
/* That created the reloc sections. Set their sizes, and assign
them file positions, and allocate some buffers. */
for (o = abfd->sections; o != NULL; o = o->next)
{
if ((o->flags & SEC_RELOC) != 0)
{
Elf_Internal_Shdr *rel_hdr;
register struct elf_link_hash_entry **p, **pend;
rel_hdr = &elf_section_data (o)->rel_hdr;
rel_hdr->sh_size = rel_hdr->sh_entsize * o->reloc_count;
/* The contents field must last into write_object_contents,
so we allocate it with bfd_alloc rather than malloc. */
rel_hdr->contents = (PTR) bfd_alloc (abfd, rel_hdr->sh_size);
if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0)
{
bfd_set_error (bfd_error_no_memory);
goto error_return;
}
p = ((struct elf_link_hash_entry **)
malloc (o->reloc_count
* sizeof (struct elf_link_hash_entry *)));
if (p == NULL && o->reloc_count != 0)
{
bfd_set_error (bfd_error_no_memory);
goto error_return;
}
elf_section_data (o)->rel_hashes = p;
pend = p + o->reloc_count;
for (; p < pend; p++)
*p = NULL;
/* Use the reloc_count field as an index when outputting the
relocs. */
o->reloc_count = 0;
}
}
assign_file_positions_for_relocs (abfd);
/* We have now assigned file positions for all the sections except
.symtab and .strtab. We start the .symtab section at the current
file position, and write directly to it. We build the .strtab
section in memory. When we add .dynsym support, we will build
that in memory as well (.dynsym is smaller than .symtab). */
abfd->symcount = 0;
symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
/* sh_name is set in prep_headers. */
symtab_hdr->sh_type = SHT_SYMTAB;
symtab_hdr->sh_flags = 0;
symtab_hdr->sh_addr = 0;
symtab_hdr->sh_size = 0;
symtab_hdr->sh_entsize = sizeof (Elf_External_Sym);
/* sh_link is set in assign_section_numbers. */
/* sh_info is set below. */
/* sh_offset is set just below. */
symtab_hdr->sh_addralign = 4; /* FIXME: system dependent? */
off = elf_tdata (abfd)->next_file_pos;
off = assign_file_position_for_section (symtab_hdr, off, true);
/* Note that at this point elf_tdata (abfd)->next_file_pos is
incorrect. We do not yet know the size of the .symtab section.
We correct next_file_pos below, after we do know the size. */
/* Allocate a buffer to hold swapped out symbols. This is to avoid
continuously seeking to the right position in the file. */
if (! info->keep_memory || max_sym_count < 20)
finfo.symbuf_size = 20;
else
finfo.symbuf_size = max_sym_count;
finfo.symbuf = ((Elf_External_Sym *)
malloc (finfo.symbuf_size * sizeof (Elf_External_Sym)));
if (finfo.symbuf == NULL)
{
bfd_set_error (bfd_error_no_memory);
goto error_return;
}
/* Start writing out the symbol table. The first symbol is always a
dummy symbol. */
elfsym.st_value = 0;
elfsym.st_size = 0;
elfsym.st_info = 0;
elfsym.st_other = 0;
elfsym.st_shndx = SHN_UNDEF;
if (! elf_link_output_sym (&finfo, (const char *) NULL,
&elfsym, bfd_und_section_ptr))
goto error_return;
#if 0
/* Some standard ELF linkers do this, but we don't because it causes
bootstrap comparison failures. */
/* Output a file symbol for the output file as the second symbol.
We output this even if we are discarding local symbols, although
I'm not sure if this is correct. */
elfsym.st_value = 0;
elfsym.st_size = 0;
elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE);
elfsym.st_other = 0;
elfsym.st_shndx = SHN_ABS;
if (! elf_link_output_sym (&finfo, bfd_get_filename (abfd),
&elfsym, bfd_abs_section_ptr))
goto error_return;
#endif
/* Output a symbol for each section. We output these even if we are
discarding local symbols, since they are used for relocs. These
symbols have no names. We store the index of each one in the
index field of the section, so that we can find it again when
outputting relocs. */
elfsym.st_value = 0;
elfsym.st_size = 0;
elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
elfsym.st_other = 0;
for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
{
o = section_from_elf_index (abfd, i);
if (o != NULL)
o->target_index = abfd->symcount;
elfsym.st_shndx = i;
if (! elf_link_output_sym (&finfo, (const char *) NULL,
&elfsym, o))
goto error_return;
}
/* Allocate some memory to hold information read in from the input
files. */
finfo.contents = (bfd_byte *) malloc (max_contents_size);
finfo.external_relocs = (PTR) malloc (max_external_reloc_size);
finfo.internal_relocs = ((Elf_Internal_Rela *)
malloc (max_internal_reloc_count
* sizeof (Elf_Internal_Rela)));
finfo.external_syms = ((Elf_External_Sym *)
malloc (max_sym_count * sizeof (Elf_External_Sym)));
finfo.internal_syms = ((Elf_Internal_Sym *)
malloc (max_sym_count * sizeof (Elf_Internal_Sym)));
finfo.indices = (long *) malloc (max_sym_count * sizeof (long));
finfo.sections = (asection **) malloc (max_sym_count * sizeof (asection *));
if ((finfo.contents == NULL && max_contents_size != 0)
|| (finfo.external_relocs == NULL && max_external_reloc_size != 0)
|| (finfo.internal_relocs == NULL && max_internal_reloc_count != 0)
|| (finfo.external_syms == NULL && max_sym_count != 0)
|| (finfo.internal_syms == NULL && max_sym_count != 0)
|| (finfo.indices == NULL && max_sym_count != 0)
|| (finfo.sections == NULL && max_sym_count != 0))
{
bfd_set_error (bfd_error_no_memory);
goto error_return;
}
/* Since ELF permits relocations to be against local symbols, we
must have the local symbols available when we do the relocations.
Since we would rather only read the local symbols once, and we
would rather not keep them in memory, we handle all the
relocations for a single input file at the same time.
Unfortunately, there is no way to know the total number of local
symbols until we have seen all of them, and the local symbol
indices precede the global symbol indices. This means that when
we are generating relocateable output, and we see a reloc against
a global symbol, we can not know the symbol index until we have
finished examining all the local symbols to see which ones we are
going to output. To deal with this, we keep the relocations in
memory, and don't output them until the end of the link. This is
an unfortunate waste of memory, but I don't see a good way around
it. Fortunately, it only happens when performing a relocateable
link, which is not the common case. FIXME: If keep_memory is set
we could write the relocs out and then read them again; I don't
know how bad the memory loss will be. */
for (sub = info->input_bfds; sub != NULL; sub = sub->next)
sub->output_has_begun = false;
for (o = abfd->sections; o != NULL; o = o->next)
{
for (p = o->link_order_head; p != NULL; p = p->next)
{
if (p->type == bfd_indirect_link_order
&& (bfd_get_flavour (p->u.indirect.section->owner)
== bfd_target_elf_flavour))
{
sub = p->u.indirect.section->owner;
if (! sub->output_has_begun)
{
if (! elf_link_input_bfd (&finfo, sub))
goto error_return;
sub->output_has_begun = true;
}
}
else if (p->type == bfd_section_reloc_link_order
|| p->type == bfd_symbol_reloc_link_order)
{
if (! elf_reloc_link_order (abfd, info, o, p))
goto error_return;
}
else
{
if (! _bfd_default_link_order (abfd, info, o, p))
goto error_return;
}
}
}
/* That wrote out all the local symbols. Finish up the symbol table
with the global symbols. */
/* The sh_info field records the index of the first non local
symbol. */
symtab_hdr->sh_info = abfd->symcount;
if (dynamic)
elf_section_data (finfo.dynsym_sec->output_section)->this_hdr.sh_info = 1;
/* We get the global symbols from the hash table. */
eif.failed = false;
eif.finfo = &finfo;
elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
(PTR) &eif);
if (eif.failed)
return false;
/* Flush all symbols to the file. */
if (! elf_link_flush_output_syms (&finfo))
return false;
/* Now we know the size of the symtab section. */
off += symtab_hdr->sh_size;
/* Finish up and write out the symbol string table (.strtab)
section. */
symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr;
/* sh_name was set in prep_headers. */
symstrtab_hdr->sh_type = SHT_STRTAB;
symstrtab_hdr->sh_flags = 0;
symstrtab_hdr->sh_addr = 0;
symstrtab_hdr->sh_size = _bfd_stringtab_size (finfo.symstrtab);
symstrtab_hdr->sh_entsize = 0;
symstrtab_hdr->sh_link = 0;
symstrtab_hdr->sh_info = 0;
/* sh_offset is set just below. */
symstrtab_hdr->sh_addralign = 1;
off = assign_file_position_for_section (symstrtab_hdr, off, true);
elf_tdata (abfd)->next_file_pos = off;
if (bfd_seek (abfd, symstrtab_hdr->sh_offset, SEEK_SET) != 0
|| ! _bfd_stringtab_emit (abfd, finfo.symstrtab))
return false;
/* Adjust the relocs to have the correct symbol indices. */
for (o = abfd->sections; o != NULL; o = o->next)
{
struct elf_link_hash_entry **rel_hash;
Elf_Internal_Shdr *rel_hdr;
if ((o->flags & SEC_RELOC) == 0)
continue;
rel_hash = elf_section_data (o)->rel_hashes;
rel_hdr = &elf_section_data (o)->rel_hdr;
for (i = 0; i < o->reloc_count; i++, rel_hash++)
{
if (*rel_hash == NULL)
continue;
BFD_ASSERT ((*rel_hash)->indx >= 0);
if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
{
Elf_External_Rel *erel;
Elf_Internal_Rel irel;
erel = (Elf_External_Rel *) rel_hdr->contents + i;
elf_swap_reloc_in (abfd, erel, &irel);
irel.r_info = ELF_R_INFO ((*rel_hash)->indx,
ELF_R_TYPE (irel.r_info));
elf_swap_reloc_out (abfd, &irel, erel);
}
else
{
Elf_External_Rela *erela;
Elf_Internal_Rela irela;
BFD_ASSERT (rel_hdr->sh_entsize
== sizeof (Elf_External_Rela));
erela = (Elf_External_Rela *) rel_hdr->contents + i;
elf_swap_reloca_in (abfd, erela, &irela);
irela.r_info = ELF_R_INFO ((*rel_hash)->indx,
ELF_R_TYPE (irela.r_info));
elf_swap_reloca_out (abfd, &irela, erela);
}
}
/* Set the reloc_count field to 0 to prevent write_relocs from
trying to swap the relocs out itself. */
o->reloc_count = 0;
}
/* If we are linking against a dynamic object, or generating a
shared library, finish up the dynamic linking information. */
if (dynamic)
{
Elf_External_Dyn *dyncon, *dynconend;
/* Fix up .dynamic entries. */
o = bfd_get_section_by_name (dynobj, ".dynamic");
BFD_ASSERT (o != NULL);
dyncon = (Elf_External_Dyn *) o->contents;
dynconend = (Elf_External_Dyn *) (o->contents + o->_raw_size);
for (; dyncon < dynconend; dyncon++)
{
Elf_Internal_Dyn dyn;
const char *name;
unsigned int type;
elf_swap_dyn_in (dynobj, dyncon, &dyn);
switch (dyn.d_tag)
{
default:
break;
/* SVR4 linkers seem to set DT_INIT and DT_FINI based on
magic _init and _fini symbols. This is pretty ugly,
but we are compatible. */
case DT_INIT:
name = "_init";
goto get_sym;
case DT_FINI:
name = "_fini";
get_sym:
{
struct elf_link_hash_entry *h;
h = elf_link_hash_lookup (elf_hash_table (info), name,
false, false, true);
BFD_ASSERT (h != NULL);
if (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
{
dyn.d_un.d_val = h->root.u.def.value;
o = h->root.u.def.section;
if (o->output_section != NULL)
dyn.d_un.d_val += (o->output_section->vma
+ o->output_offset);
else
/* The symbol is imported from another shared
library and does not apply to this one. */
dyn.d_un.d_val = 0;
}
elf_swap_dyn_out (dynobj, &dyn, dyncon);
}
break;
case DT_HASH:
name = ".hash";
goto get_vma;
case DT_STRTAB:
name = ".dynstr";
goto get_vma;
case DT_SYMTAB:
name = ".dynsym";
get_vma:
o = bfd_get_section_by_name (abfd, name);
BFD_ASSERT (o != NULL);
dyn.d_un.d_ptr = o->vma;
elf_swap_dyn_out (dynobj, &dyn, dyncon);
break;
case DT_REL:
case DT_RELA:
case DT_RELSZ:
case DT_RELASZ:
if (dyn.d_tag == DT_REL || dyn.d_tag == DT_RELSZ)
type = SHT_REL;
else
type = SHT_RELA;
dyn.d_un.d_val = 0;
for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
{
Elf_Internal_Shdr *hdr;
hdr = elf_elfsections (abfd)[i];
if (hdr->sh_type == type
&& (hdr->sh_flags & SHF_ALLOC) != 0)
{
if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ)
dyn.d_un.d_val += hdr->sh_size;
else
{
if (dyn.d_un.d_val == 0
|| hdr->sh_addr < dyn.d_un.d_val)
dyn.d_un.d_val = hdr->sh_addr;
}
}
}
elf_swap_dyn_out (dynobj, &dyn, dyncon);
break;
}
}
}
/* If we have created any dynamic sections, then output them. */
if (dynobj != NULL)
{
if (! (*bed->elf_backend_finish_dynamic_sections) (abfd, info))
goto error_return;
for (o = dynobj->sections; o != NULL; o = o->next)
{
if ((o->flags & SEC_HAS_CONTENTS) == 0
|| o->_raw_size == 0)
continue;
if ((o->flags & SEC_IN_MEMORY) == 0)
{
/* At this point, we are only interested in sections
created by elf_link_create_dynamic_sections. FIXME:
This test is fragile. */
continue;
}
if ((elf_section_data (o->output_section)->this_hdr.sh_type
!= SHT_STRTAB)
|| strcmp (bfd_get_section_name (abfd, o), ".dynstr") != 0)
{
if (! bfd_set_section_contents (abfd, o->output_section,
o->contents, o->output_offset,
o->_raw_size))
goto error_return;
}
else
{
file_ptr off;
/* The contents of the .dynstr section are actually in a
stringtab. */
off = elf_section_data (o->output_section)->this_hdr.sh_offset;
if (bfd_seek (abfd, off, SEEK_SET) != 0
|| ! _bfd_stringtab_emit (abfd,
elf_hash_table (info)->dynstr))
goto error_return;
}
}
}
if (finfo.symstrtab != NULL)
_bfd_stringtab_free (finfo.symstrtab);
if (finfo.contents != NULL)
free (finfo.contents);
if (finfo.external_relocs != NULL)
free (finfo.external_relocs);
if (finfo.internal_relocs != NULL)
free (finfo.internal_relocs);
if (finfo.external_syms != NULL)
free (finfo.external_syms);
if (finfo.internal_syms != NULL)
free (finfo.internal_syms);
if (finfo.indices != NULL)
free (finfo.indices);
if (finfo.sections != NULL)
free (finfo.sections);
if (finfo.symbuf != NULL)
free (finfo.symbuf);
for (o = abfd->sections; o != NULL; o = o->next)
{
if ((o->flags & SEC_RELOC) != 0
&& elf_section_data (o)->rel_hashes != NULL)
free (elf_section_data (o)->rel_hashes);
}
elf_tdata (abfd)->linker = true;
return true;
error_return:
if (finfo.symstrtab != NULL)
_bfd_stringtab_free (finfo.symstrtab);
if (finfo.contents != NULL)
free (finfo.contents);
if (finfo.external_relocs != NULL)
free (finfo.external_relocs);
if (finfo.internal_relocs != NULL)
free (finfo.internal_relocs);
if (finfo.external_syms != NULL)
free (finfo.external_syms);
if (finfo.internal_syms != NULL)
free (finfo.internal_syms);
if (finfo.indices != NULL)
free (finfo.indices);
if (finfo.sections != NULL)
free (finfo.sections);
if (finfo.symbuf != NULL)
free (finfo.symbuf);
for (o = abfd->sections; o != NULL; o = o->next)
{
if ((o->flags & SEC_RELOC) != 0
&& elf_section_data (o)->rel_hashes != NULL)
free (elf_section_data (o)->rel_hashes);
}
return false;
}
/* Add a symbol to the output symbol table. */
static boolean
elf_link_output_sym (finfo, name, elfsym, input_sec)
struct elf_final_link_info *finfo;
const char *name;
Elf_Internal_Sym *elfsym;
asection *input_sec;
{
boolean (*output_symbol_hook) PARAMS ((bfd *,
struct bfd_link_info *info,
const char *,
Elf_Internal_Sym *,
asection *));
output_symbol_hook = get_elf_backend_data (finfo->output_bfd)->
elf_backend_link_output_symbol_hook;
if (output_symbol_hook != NULL)
{
if (! ((*output_symbol_hook)
(finfo->output_bfd, finfo->info, name, elfsym, input_sec)))
return false;
}
if (name == (const char *) NULL || *name == '\0')
elfsym->st_name = 0;
else
{
elfsym->st_name = (unsigned long) _bfd_stringtab_add (finfo->symstrtab,
name, true,
false);
if (elfsym->st_name == (unsigned long) -1)
return false;
}
if (finfo->symbuf_count >= finfo->symbuf_size)
{
if (! elf_link_flush_output_syms (finfo))
return false;
}
elf_swap_symbol_out (finfo->output_bfd, elfsym,
finfo->symbuf + finfo->symbuf_count);
++finfo->symbuf_count;
++finfo->output_bfd->symcount;
return true;
}
/* Flush the output symbols to the file. */
static boolean
elf_link_flush_output_syms (finfo)
struct elf_final_link_info *finfo;
{
Elf_Internal_Shdr *symtab;
symtab = &elf_tdata (finfo->output_bfd)->symtab_hdr;
if (bfd_seek (finfo->output_bfd, symtab->sh_offset + symtab->sh_size,
SEEK_SET) != 0
|| (bfd_write ((PTR) finfo->symbuf, finfo->symbuf_count,
sizeof (Elf_External_Sym), finfo->output_bfd)
!= finfo->symbuf_count * sizeof (Elf_External_Sym)))
return false;
symtab->sh_size += finfo->symbuf_count * sizeof (Elf_External_Sym);
finfo->symbuf_count = 0;
return true;
}
/* Add an external symbol to the symbol table. This is called from
the hash table traversal routine. */
static boolean
elf_link_output_extsym (h, data)
struct elf_link_hash_entry *h;
PTR data;
{
struct elf_finfo_failed *eif = (struct elf_finfo_failed *) data;
struct elf_final_link_info *finfo = eif->finfo;
boolean strip;
Elf_Internal_Sym sym;
asection *input_sec;
/* If we are not creating a shared library, and this symbol is
referenced by a shared library but is not defined anywhere, then
warn that it is undefined. If we do not do this, the runtime
linker will complain that the symbol is undefined when the
program is run. We don't have to worry about symbols that are
referenced by regular files, because we will already have issued
warnings for them.
FIXME: If we are linking against an object which uses DT_NEEDED,
we don't give this warning, because it might be the case that the
needed dynamic object will define the symbols. Unfortunately,
this makes this type of check much less useful, but the only way
to fix it would be to locate the needed object and read its
symbol table. That seems like a real waste of time just to give
better error messages. */
if (! finfo->info->relocateable
&& ! finfo->info->shared
&& ! elf_hash_table (finfo->info)->saw_needed
&& h->root.type == bfd_link_hash_undefined
&& (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0
&& (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
{
if (! ((*finfo->info->callbacks->undefined_symbol)
(finfo->info, h->root.root.string, h->root.u.undef.abfd,
(asection *) NULL, 0)))
{
eif->failed = true;
return false;
}
}
/* We don't want to output symbols that have never been mentioned by
a regular file, or that we have been told to strip. However, if
h->indx is set to -2, the symbol is used by a reloc and we must
output it. */
if (h->indx == -2)
strip = false;
else if (((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
|| (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0)
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
&& (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
strip = true;
else if (finfo->info->strip == strip_all
|| (finfo->info->strip == strip_some
&& bfd_hash_lookup (finfo->info->keep_hash,
h->root.root.string,
false, false) == NULL))
strip = true;
else
strip = false;
/* If we're stripping it, and it's not a dynamic symbol, there's
nothing else to do. */
if (strip && h->dynindx == -1)
return true;
sym.st_value = 0;
sym.st_size = h->size;
sym.st_other = 0;
if (h->root.type == bfd_link_hash_undefweak
|| h->root.type == bfd_link_hash_defweak)
sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
else
sym.st_info = ELF_ST_INFO (STB_GLOBAL, h->type);
switch (h->root.type)
{
default:
case bfd_link_hash_new:
abort ();
return false;
case bfd_link_hash_undefined:
input_sec = bfd_und_section_ptr;
sym.st_shndx = SHN_UNDEF;
break;
case bfd_link_hash_undefweak:
input_sec = bfd_und_section_ptr;
sym.st_shndx = SHN_UNDEF;
break;
case bfd_link_hash_defined:
case bfd_link_hash_defweak:
{
input_sec = h->root.u.def.section;
if (input_sec->output_section != NULL)
{
sym.st_shndx =
elf_section_from_bfd_section (finfo->output_bfd,
input_sec->output_section);
if (sym.st_shndx == (unsigned short) -1)
{
eif->failed = true;
return false;
}
/* ELF symbols in relocateable files are section relative,
but in nonrelocateable files they are virtual
addresses. */
sym.st_value = h->root.u.def.value + input_sec->output_offset;
if (! finfo->info->relocateable)
sym.st_value += input_sec->output_section->vma;
}
else
{
BFD_ASSERT ((bfd_get_flavour (input_sec->owner)
== bfd_target_elf_flavour)
&& elf_elfheader (input_sec->owner)->e_type == ET_DYN);
sym.st_shndx = SHN_UNDEF;
input_sec = bfd_und_section_ptr;
}
}
break;
case bfd_link_hash_common:
input_sec = bfd_com_section_ptr;
sym.st_shndx = SHN_COMMON;
sym.st_value = 1 << h->root.u.c.p->alignment_power;
break;
case bfd_link_hash_indirect:
case bfd_link_hash_warning:
/* I have no idea how these should be handled. */
return true;
}
/* If this symbol should be put in the .dynsym section, then put it
there now. We have already know the symbol index. We also fill
in the entry in the .hash section. */
if (h->dynindx != -1
&& elf_hash_table (finfo->info)->dynamic_sections_created)
{
struct elf_backend_data *bed;
size_t bucketcount;
size_t bucket;
bfd_byte *bucketpos;
bfd_vma chain;
sym.st_name = h->dynstr_index;
/* Give the processor backend a chance to tweak the symbol
value, and also to finish up anything that needs to be done
for this symbol. */
bed = get_elf_backend_data (finfo->output_bfd);
if (! ((*bed->elf_backend_finish_dynamic_symbol)
(finfo->output_bfd, finfo->info, h, &sym)))
{
eif->failed = true;
return false;
}
elf_swap_symbol_out (finfo->output_bfd, &sym,
((Elf_External_Sym *) finfo->dynsym_sec->contents
+ h->dynindx));
bucketcount = elf_hash_table (finfo->info)->bucketcount;
bucket = (bfd_elf_hash ((const unsigned char *) h->root.root.string)
% bucketcount);
bucketpos = ((bfd_byte *) finfo->hash_sec->contents
+ (bucket + 2) * (ARCH_SIZE / 8));
chain = get_word (finfo->output_bfd, bucketpos);
put_word (finfo->output_bfd, h->dynindx, bucketpos);
put_word (finfo->output_bfd, chain,
((bfd_byte *) finfo->hash_sec->contents
+ (bucketcount + 2 + h->dynindx) * (ARCH_SIZE / 8)));
}
/* If we're stripping it, then it was just a dynamic symbol, and
there's nothing else to do. */
if (strip)
return true;
h->indx = finfo->output_bfd->symcount;
if (! elf_link_output_sym (finfo, h->root.root.string, &sym, input_sec))
{
eif->failed = true;
return false;
}
return true;
}
/* Link an input file into the linker output file. This function
handles all the sections and relocations of the input file at once.
This is so that we only have to read the local symbols once, and
don't have to keep them in memory. */
static boolean
elf_link_input_bfd (finfo, input_bfd)
struct elf_final_link_info *finfo;
bfd *input_bfd;
{
boolean (*relocate_section) PARAMS ((bfd *, struct bfd_link_info *,
bfd *, asection *, bfd_byte *,
Elf_Internal_Rela *,
Elf_Internal_Sym *, asection **));
bfd *output_bfd;
Elf_Internal_Shdr *symtab_hdr;
size_t locsymcount;
size_t extsymoff;
Elf_External_Sym *esym;
Elf_External_Sym *esymend;
Elf_Internal_Sym *isym;
long *pindex;
asection **ppsection;
asection *o;
output_bfd = finfo->output_bfd;
relocate_section =
get_elf_backend_data (output_bfd)->elf_backend_relocate_section;
/* If this is a dynamic object, we don't want to do anything here:
we don't want the local symbols, and we don't want the section
contents. */
if (elf_elfheader (input_bfd)->e_type == ET_DYN)
return true;
symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
if (elf_bad_symtab (input_bfd))
{
locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
extsymoff = 0;
}
else
{
locsymcount = symtab_hdr->sh_info;
extsymoff = symtab_hdr->sh_info;
}
/* Read the local symbols. */
if (locsymcount > 0
&& (bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
|| (bfd_read (finfo->external_syms, sizeof (Elf_External_Sym),
locsymcount, input_bfd)
!= locsymcount * sizeof (Elf_External_Sym))))
return false;
/* Swap in the local symbols and write out the ones which we know
are going into the output file. */
esym = finfo->external_syms;
esymend = esym + locsymcount;
isym = finfo->internal_syms;
pindex = finfo->indices;
ppsection = finfo->sections;
for (; esym < esymend; esym++, isym++, pindex++, ppsection++)
{
asection *isec;
const char *name;
Elf_Internal_Sym osym;
elf_swap_symbol_in (input_bfd, esym, isym);
*pindex = -1;
if (elf_bad_symtab (input_bfd))
{
if (ELF_ST_BIND (isym->st_info) != STB_LOCAL)
{
*ppsection = NULL;
continue;
}
}
if (isym->st_shndx == SHN_UNDEF)
isec = bfd_und_section_ptr;
else if (isym->st_shndx > 0 && isym->st_shndx < SHN_LORESERVE)
isec = section_from_elf_index (input_bfd, isym->st_shndx);
else if (isym->st_shndx == SHN_ABS)
isec = bfd_abs_section_ptr;
else if (isym->st_shndx == SHN_COMMON)
isec = bfd_com_section_ptr;
else
{
/* Who knows? */
isec = NULL;
}
*ppsection = isec;
/* Don't output the first, undefined, symbol. */
if (esym == finfo->external_syms)
continue;
/* If we are stripping all symbols, we don't want to output this
one. */
if (finfo->info->strip == strip_all)
continue;
/* We never output section symbols. Instead, we use the section
symbol of the corresponding section in the output file. */
if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
continue;
/* If we are discarding all local symbols, we don't want to
output this one. If we are generating a relocateable output
file, then some of the local symbols may be required by
relocs; we output them below as we discover that they are
needed. */
if (finfo->info->discard == discard_all)
continue;
/* Get the name of the symbol. */
name = elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link,
isym->st_name);
if (name == NULL)
return false;
/* See if we are discarding symbols with this name. */
if ((finfo->info->strip == strip_some
&& (bfd_hash_lookup (finfo->info->keep_hash, name, false, false)
== NULL))
|| (finfo->info->discard == discard_l
&& strncmp (name, finfo->info->lprefix,
finfo->info->lprefix_len) == 0))
continue;
/* If we get here, we are going to output this symbol. */
osym = *isym;
/* Adjust the section index for the output file. */
osym.st_shndx = elf_section_from_bfd_section (output_bfd,
isec->output_section);
if (osym.st_shndx == (unsigned short) -1)
return false;
*pindex = output_bfd->symcount;
/* ELF symbols in relocateable files are section relative, but
in executable files they are virtual addresses. Note that
this code assumes that all ELF sections have an associated
BFD section with a reasonable value for output_offset; below
we assume that they also have a reasonable value for
output_section. Any special sections must be set up to meet
these requirements. */
osym.st_value += isec->output_offset;
if (! finfo->info->relocateable)
osym.st_value += isec->output_section->vma;
if (! elf_link_output_sym (finfo, name, &osym, isec))
return false;
}
/* Relocate the contents of each section. */
for (o = input_bfd->sections; o != NULL; o = o->next)
{
if ((o->flags & SEC_HAS_CONTENTS) == 0)
continue;
if ((o->flags & SEC_IN_MEMORY) != 0
&& input_bfd == elf_hash_table (finfo->info)->dynobj)
{
/* Section was created by elf_link_create_dynamic_sections.
FIXME: This test is fragile. */
continue;
}
/* Read the contents of the section. */
if (! bfd_get_section_contents (input_bfd, o, finfo->contents,
(file_ptr) 0, o->_raw_size))
return false;
if ((o->flags & SEC_RELOC) != 0)
{
Elf_Internal_Rela *internal_relocs;
/* Get the swapped relocs. */
internal_relocs = elf_link_read_relocs (input_bfd, o,
finfo->external_relocs,
finfo->internal_relocs,
false);
if (internal_relocs == NULL
&& o->reloc_count > 0)
return false;
/* Relocate the section by invoking a back end routine.
The back end routine is responsible for adjusting the
section contents as necessary, and (if using Rela relocs
and generating a relocateable output file) adjusting the
reloc addend as necessary.
The back end routine does not have to worry about setting
the reloc address or the reloc symbol index.
The back end routine is given a pointer to the swapped in
internal symbols, and can access the hash table entries
for the external symbols via elf_sym_hashes (input_bfd).
When generating relocateable output, the back end routine
must handle STB_LOCAL/STT_SECTION symbols specially. The
output symbol is going to be a section symbol
corresponding to the output section, which will require
the addend to be adjusted. */
if (! (*relocate_section) (output_bfd, finfo->info,
input_bfd, o,
finfo->contents,
internal_relocs,
finfo->internal_syms,
finfo->sections))
return false;
if (finfo->info->relocateable)
{
Elf_Internal_Rela *irela;
Elf_Internal_Rela *irelaend;
struct elf_link_hash_entry **rel_hash;
Elf_Internal_Shdr *input_rel_hdr;
Elf_Internal_Shdr *output_rel_hdr;
/* Adjust the reloc addresses and symbol indices. */
irela = internal_relocs;
irelaend = irela + o->reloc_count;
rel_hash = (elf_section_data (o->output_section)->rel_hashes
+ o->output_section->reloc_count);
for (; irela < irelaend; irela++, rel_hash++)
{
long r_symndx;
Elf_Internal_Sym *isym;
asection *sec;
irela->r_offset += o->output_offset;
r_symndx = ELF_R_SYM (irela->r_info);
if (r_symndx == 0)
continue;
if (r_symndx >= locsymcount
|| (elf_bad_symtab (input_bfd)
&& finfo->sections[r_symndx] == NULL))
{
long indx;
/* This is a reloc against a global symbol. We
have not yet output all the local symbols, so
we do not know the symbol index of any global
symbol. We set the rel_hash entry for this
reloc to point to the global hash table entry
for this symbol. The symbol index is then
set at the end of elf_bfd_final_link. */
indx = r_symndx - extsymoff;
*rel_hash = elf_sym_hashes (input_bfd)[indx];
/* Setting the index to -2 tells
elf_link_output_extsym that this symbol is
used by a reloc. */
BFD_ASSERT ((*rel_hash)->indx < 0);
(*rel_hash)->indx = -2;
continue;
}
/* This is a reloc against a local symbol. */
*rel_hash = NULL;
isym = finfo->internal_syms + r_symndx;
sec = finfo->sections[r_symndx];
if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
{
/* I suppose the backend ought to fill in the
section of any STT_SECTION symbol against a
processor specific section. */
if (sec != NULL && bfd_is_abs_section (sec))
r_symndx = 0;
else if (sec == NULL || sec->owner == NULL)
{
bfd_set_error (bfd_error_bad_value);
return false;
}
else
{
r_symndx = sec->output_section->target_index;
BFD_ASSERT (r_symndx != 0);
}
}
else
{
if (finfo->indices[r_symndx] == -1)
{
unsigned long link;
const char *name;
asection *osec;
if (finfo->info->strip == strip_all)
{
/* You can't do ld -r -s. */
bfd_set_error (bfd_error_invalid_operation);
return false;
}
/* This symbol was skipped earlier, but
since it is needed by a reloc, we
must output it now. */
link = symtab_hdr->sh_link;
name = elf_string_from_elf_section (input_bfd,
link,
isym->st_name);
if (name == NULL)
return false;
osec = sec->output_section;
isym->st_shndx =
elf_section_from_bfd_section (output_bfd,
osec);
if (isym->st_shndx == (unsigned short) -1)
return false;
isym->st_value += sec->output_offset;
if (! finfo->info->relocateable)
isym->st_value += osec->vma;
finfo->indices[r_symndx] = output_bfd->symcount;
if (! elf_link_output_sym (finfo, name, isym, sec))
return false;
}
r_symndx = finfo->indices[r_symndx];
}
irela->r_info = ELF_R_INFO (r_symndx,
ELF_R_TYPE (irela->r_info));
}
/* Swap out the relocs. */
input_rel_hdr = &elf_section_data (o)->rel_hdr;
output_rel_hdr = &elf_section_data (o->output_section)->rel_hdr;
BFD_ASSERT (output_rel_hdr->sh_entsize
== input_rel_hdr->sh_entsize);
irela = internal_relocs;
irelaend = irela + o->reloc_count;
if (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
{
Elf_External_Rel *erel;
erel = ((Elf_External_Rel *) output_rel_hdr->contents
+ o->output_section->reloc_count);
for (; irela < irelaend; irela++, erel++)
{
Elf_Internal_Rel irel;
irel.r_offset = irela->r_offset;
irel.r_info = irela->r_info;
BFD_ASSERT (irela->r_addend == 0);
elf_swap_reloc_out (output_bfd, &irel, erel);
}
}
else
{
Elf_External_Rela *erela;
BFD_ASSERT (input_rel_hdr->sh_entsize
== sizeof (Elf_External_Rela));
erela = ((Elf_External_Rela *) output_rel_hdr->contents
+ o->output_section->reloc_count);
for (; irela < irelaend; irela++, erela++)
elf_swap_reloca_out (output_bfd, irela, erela);
}
o->output_section->reloc_count += o->reloc_count;
}
}
/* Write out the modified section contents. */
if (! bfd_set_section_contents (output_bfd, o->output_section,
finfo->contents, o->output_offset,
(o->_cooked_size != 0
? o->_cooked_size
: o->_raw_size)))
return false;
}
return true;
}
/* Generate a reloc when linking an ELF file. This is a reloc
requested by the linker, and does come from any input file. This
is used to build constructor and destructor tables when linking
with -Ur. */
static boolean
elf_reloc_link_order (output_bfd, info, output_section, link_order)
bfd *output_bfd;
struct bfd_link_info *info;
asection *output_section;
struct bfd_link_order *link_order;
{
reloc_howto_type *howto;
long indx;
bfd_vma offset;
struct elf_link_hash_entry **rel_hash_ptr;
Elf_Internal_Shdr *rel_hdr;
howto = bfd_reloc_type_lookup (output_bfd, link_order->u.reloc.p->reloc);
if (howto == NULL)
{
bfd_set_error (bfd_error_bad_value);
return false;
}
/* If this is an inplace reloc, we must write the addend into the
object file. */
if (howto->partial_inplace
&& link_order->u.reloc.p->addend != 0)
{
bfd_size_type size;
bfd_reloc_status_type rstat;
bfd_byte *buf;
boolean ok;
size = bfd_get_reloc_size (howto);
buf = (bfd_byte *) bfd_zmalloc (size);
if (buf == (bfd_byte *) NULL)
{
bfd_set_error (bfd_error_no_memory);
return false;
}
rstat = _bfd_relocate_contents (howto, output_bfd,
link_order->u.reloc.p->addend, buf);
switch (rstat)
{
case bfd_reloc_ok:
break;
default:
case bfd_reloc_outofrange:
abort ();
case bfd_reloc_overflow:
if (! ((*info->callbacks->reloc_overflow)
(info,
(link_order->type == bfd_section_reloc_link_order
? bfd_section_name (output_bfd,
link_order->u.reloc.p->u.section)
: link_order->u.reloc.p->u.name),
howto->name, link_order->u.reloc.p->addend,
(bfd *) NULL, (asection *) NULL, (bfd_vma) 0)))
{
free (buf);
return false;
}
break;
}
ok = bfd_set_section_contents (output_bfd, output_section, (PTR) buf,
(file_ptr) link_order->offset, size);
free (buf);
if (! ok)
return false;
}
/* Figure out the symbol index. */
rel_hash_ptr = (elf_section_data (output_section)->rel_hashes
+ output_section->reloc_count);
if (link_order->type == bfd_section_reloc_link_order)
{
indx = link_order->u.reloc.p->u.section->target_index;
BFD_ASSERT (indx != 0);
*rel_hash_ptr = NULL;
}
else
{
struct elf_link_hash_entry *h;
h = elf_link_hash_lookup (elf_hash_table (info),
link_order->u.reloc.p->u.name,
false, false, true);
if (h != NULL)
{
/* Setting the index to -2 tells elf_link_output_extsym that
this symbol is used by a reloc. */
h->indx = -2;
*rel_hash_ptr = h;
indx = 0;
}
else
{
if (! ((*info->callbacks->unattached_reloc)
(info, link_order->u.reloc.p->u.name, (bfd *) NULL,
(asection *) NULL, (bfd_vma) 0)))
return false;
indx = 0;
}
}
/* The address of a reloc is relative to the section in a
relocateable file, and is a virtual address in an executable
file. */
offset = link_order->offset;
if (! info->relocateable)
offset += output_section->vma;
rel_hdr = &elf_section_data (output_section)->rel_hdr;
if (rel_hdr->sh_type == SHT_REL)
{
Elf_Internal_Rel irel;
Elf_External_Rel *erel;
irel.r_offset = offset;
irel.r_info = ELF_R_INFO (indx, howto->type);
erel = ((Elf_External_Rel *) rel_hdr->contents
+ output_section->reloc_count);
elf_swap_reloc_out (output_bfd, &irel, erel);
}
else
{
Elf_Internal_Rela irela;
Elf_External_Rela *erela;
irela.r_offset = offset;
irela.r_info = ELF_R_INFO (indx, howto->type);
irela.r_addend = link_order->u.reloc.p->addend;
erela = ((Elf_External_Rela *) rel_hdr->contents
+ output_section->reloc_count);
elf_swap_reloca_out (output_bfd, &irela, erela);
}
++output_section->reloc_count;
return true;
}
Reference in New Issue View Git Blame Copy Permalink