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/* Update data structures for changes and write them out.
Copyright (C) 1999, 2000, 2001, 2002 Red Hat, Inc.
Contributed by Ulrich Drepper <drepper@redhat.com>, 1999.
This program is Open Source software; you can redistribute it and/or
modify it under the terms of the Open Software License version 1.0 as
published by the Open Source Initiative.
You should have received a copy of the Open Software License along
with this program; if not, you may obtain a copy of the Open Software
License version 1.0 from http://www.opensource.org/license/osl.php or
by writing the Open Source Initiative c/o Lawrence Rosen, Esq.,
3001 King Ranch Road, Ukiah, CA 95482. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <libelf.h>
#include <unistd.h>
#include <sys/mman.h>
#include "libelfP.h"
static off_t
write_file (Elf *elf, off_t size, int change_bo, size_t shnum)
/*@modifies elf @*/
{
int class = elf->class;
/* Adjust the size in any case. We do this even if we use `write'.
We cannot do this if this file is in an archive. We also don't
do it *now* if we are shortening the file since this woudl
prevent programs to use the data of the file in generating the
new file. We truncate the file later in this case. */
if (elf->parent == NULL
&& (elf->maximum_size == ~((size_t) 0) || size > elf->maximum_size)
&& unlikely (ftruncate (elf->fildes, size) != 0))
{
__libelf_seterrno (ELF_E_WRITE_ERROR);
return -1;
}
/* Try to map the file if this isn't done yet. */
if (elf->map_address == NULL && elf->cmd == ELF_C_WRITE_MMAP)
{
elf->map_address = mmap (NULL, size, PROT_READ | PROT_WRITE,
MAP_SHARED, elf->fildes, 0);
if (unlikely (elf->map_address == MAP_FAILED))
elf->map_address = NULL;
}
if (elf->map_address != NULL)
{
/* The file is mmaped. */
if ((class == ELFCLASS32
? __elf32_updatemmap (elf, change_bo, shnum)
: __elf64_updatemmap (elf, change_bo, shnum)) != 0)
/* Some problem while writing. */
size = -1;
}
else
{
/* The file is not mmaped. */
if ((class == ELFCLASS32
? __elf32_updatefile (elf, change_bo, shnum)
: __elf64_updatefile (elf, change_bo, shnum)) != 0)
/* Some problem while writing. */
size = -1;
}
if (size != -1
&& elf->parent == NULL
&& elf->maximum_size != ~((size_t) 0)
&& size < elf->maximum_size
&& unlikely (ftruncate (elf->fildes, size) != 0))
{
__libelf_seterrno (ELF_E_WRITE_ERROR);
size = -1;
}
if (size != -1 && elf->parent == NULL)
elf->maximum_size = size;
return size;
}
off_t
elf_update (Elf *elf, Elf_Cmd cmd)
{
size_t shnum;
off_t size;
int change_bo = 0;
if (cmd != ELF_C_NULL
&& cmd != ELF_C_WRITE
&& unlikely (cmd != ELF_C_WRITE_MMAP))
{
__libelf_seterrno (ELF_E_INVALID_CMD);
return -1;
}
if (elf == NULL)
return -1;
if (elf->kind != ELF_K_ELF)
{
__libelf_seterrno (ELF_E_INVALID_HANDLE);
return -1;
}
rwlock_rdlock (elf->lock);
/* Make sure we have an ELF header. */
if (elf->state.elf.ehdr == NULL)
{
__libelf_seterrno (ELF_E_WRONG_ORDER_EHDR);
size = -1;
goto out;
}
/* Determine the number of sections. */
shnum = (elf->state.elf.scns_last->cnt == 0
? 0
: 1 + elf->state.elf.scns_last->data[elf->state.elf.scns_last->cnt - 1].index);
/* Update the ELF descriptor. First, place the program header. It
will come right after the ELF header. The count the size of all
sections and finally place the section table. */
size = (elf->class == ELFCLASS32
? __elf32_updatenull (elf, &change_bo, shnum)
: __elf64_updatenull (elf, &change_bo, shnum));
if (likely (size != -1)
/* See whether we actually have to write out the data. */
&& (cmd == ELF_C_WRITE || cmd == ELF_C_WRITE_MMAP))
{
if (elf->cmd != ELF_C_RDWR
&& elf->cmd != ELF_C_RDWR_MMAP
&& elf->cmd != ELF_C_WRITE
&& unlikely (elf->cmd != ELF_C_WRITE_MMAP))
{
__libelf_seterrno (ELF_E_UPDATE_RO);
size = -1;
}
else if (unlikely (elf->fildes == -1))
{
/* We closed the file already. */
__libelf_seterrno (ELF_E_FD_DISABLED);
size = -1;
}
else
size = write_file (elf, size, change_bo, shnum);
}
out:
rwlock_unlock (elf->unlock);
return size;
}
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