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/* Update data structures for changes and write them out.
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Copyright (C) 1999, 2000, 2001, 2002, 2004, 2005, 2006 Red Hat, Inc.
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This file is part of Red Hat elfutils.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 1999.
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Red Hat elfutils is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by the
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Free Software Foundation; version 2 of the License.
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Red Hat elfutils is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License along
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with Red Hat elfutils; if not, write to the Free Software Foundation,
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Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
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In addition, as a special exception, Red Hat, Inc. gives You the
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additional right to link the code of Red Hat elfutils with code licensed
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under any Open Source Initiative certified open source license
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(http://www.opensource.org/licenses/index.php) which requires the
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distribution of source code with any binary distribution and to
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distribute linked combinations of the two. Non-GPL Code permitted under
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this exception must only link to the code of Red Hat elfutils through
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those well defined interfaces identified in the file named EXCEPTION
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found in the source code files (the "Approved Interfaces"). The files
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of Non-GPL Code may instantiate templates or use macros or inline
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functions from the Approved Interfaces without causing the resulting
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work to be covered by the GNU General Public License. Only Red Hat,
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Inc. may make changes or additions to the list of Approved Interfaces.
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Red Hat's grant of this exception is conditioned upon your not adding
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any new exceptions. If you wish to add a new Approved Interface or
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exception, please contact Red Hat. You must obey the GNU General Public
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License in all respects for all of the Red Hat elfutils code and other
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code used in conjunction with Red Hat elfutils except the Non-GPL Code
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covered by this exception. If you modify this file, you may extend this
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exception to your version of the file, but you are not obligated to do
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so. If you do not wish to provide this exception without modification,
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you must delete this exception statement from your version and license
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this file solely under the GPL without exception.
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Red Hat elfutils is an included package of the Open Invention Network.
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An included package of the Open Invention Network is a package for which
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Open Invention Network licensees cross-license their patents. No patent
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license is granted, either expressly or impliedly, by designation as an
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included package. Should you wish to participate in the Open Invention
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Network licensing program, please visit www.openinventionnetwork.com
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<http://www.openinventionnetwork.com>. */
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write_file (Elf *elf, off_t size, int change_bo, size_t shnum)
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int class = elf->class;
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/* Check the mode bits now, before modification might change them. */
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if (unlikely (fstat (elf->fildes, &st) != 0))
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__libelf_seterrno (ELF_E_WRITE_ERROR);
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/* Adjust the size in any case. We do this even if we use `write'.
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We cannot do this if this file is in an archive. We also don't
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do it *now* if we are shortening the file since this would
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prevent programs to use the data of the file in generating the
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new file. We truncate the file later in this case. */
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if (elf->parent == NULL
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&& (elf->maximum_size == ~((size_t) 0)
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|| (size_t) size > elf->maximum_size)
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&& unlikely (ftruncate (elf->fildes, size) != 0))
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__libelf_seterrno (ELF_E_WRITE_ERROR);
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/* Try to map the file if this isn't done yet. */
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if (elf->map_address == NULL && elf->cmd == ELF_C_WRITE_MMAP)
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/* Mudflap doesn't grok that our mmap'd data is ok. */
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elf->map_address = mmap (NULL, size, PROT_READ | PROT_WRITE,
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MAP_SHARED, elf->fildes, 0);
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if (unlikely (elf->map_address == MAP_FAILED))
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elf->map_address = NULL;
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if (elf->map_address != NULL)
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/* The file is mmaped. */
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if ((class == ELFCLASS32
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? __elf32_updatemmap (elf, change_bo, shnum)
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: __elf64_updatemmap (elf, change_bo, shnum)) != 0)
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/* Some problem while writing. */
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/* The file is not mmaped. */
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if ((class == ELFCLASS32
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? __elf32_updatefile (elf, change_bo, shnum)
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: __elf64_updatefile (elf, change_bo, shnum)) != 0)
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/* Some problem while writing. */
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&& elf->parent == NULL
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&& elf->maximum_size != ~((size_t) 0)
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&& (size_t) size < elf->maximum_size
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&& unlikely (ftruncate (elf->fildes, size) != 0))
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__libelf_seterrno (ELF_E_WRITE_ERROR);
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/* POSIX says that ftruncate and write may clear the S_ISUID and S_ISGID
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mode bits. So make sure we restore them afterwards if they were set.
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This is not atomic if someone else chmod's the file while we operate. */
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&& unlikely (st.st_mode & (S_ISUID | S_ISGID))
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/* fchmod ignores the bits we cannot change. */
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&& unlikely (fchmod (elf->fildes, st.st_mode) != 0))
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__libelf_seterrno (ELF_E_WRITE_ERROR);
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if (size != -1 && elf->parent == NULL)
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elf->maximum_size = size;
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elf_update (elf, cmd)
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if (cmd != ELF_C_NULL
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&& cmd != ELF_C_WRITE
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&& unlikely (cmd != ELF_C_WRITE_MMAP))
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__libelf_seterrno (ELF_E_INVALID_CMD);
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if (elf->kind != ELF_K_ELF)
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__libelf_seterrno (ELF_E_INVALID_HANDLE);
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rwlock_wrlock (elf->lock);
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/* Make sure we have an ELF header. */
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if (elf->state.elf.ehdr == NULL)
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__libelf_seterrno (ELF_E_WRONG_ORDER_EHDR);
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/* Determine the number of sections. */
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shnum = (elf->state.elf.scns_last->cnt == 0
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: 1 + elf->state.elf.scns_last->data[elf->state.elf.scns_last->cnt - 1].index);
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/* Update the ELF descriptor. First, place the program header. It
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will come right after the ELF header. The count the size of all
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sections and finally place the section table. */
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size = (elf->class == ELFCLASS32
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? __elf32_updatenull (elf, &change_bo, shnum)
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: __elf64_updatenull (elf, &change_bo, shnum));
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if (likely (size != -1)
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/* See whether we actually have to write out the data. */
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&& (cmd == ELF_C_WRITE || cmd == ELF_C_WRITE_MMAP))
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if (elf->cmd != ELF_C_RDWR
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&& elf->cmd != ELF_C_RDWR_MMAP
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&& elf->cmd != ELF_C_WRITE
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&& unlikely (elf->cmd != ELF_C_WRITE_MMAP))
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__libelf_seterrno (ELF_E_UPDATE_RO);
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else if (unlikely (elf->fildes == -1))
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/* We closed the file already. */
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__libelf_seterrno (ELF_E_FD_DISABLED);
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size = write_file (elf, size, change_bo, shnum);
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rwlock_unlock (elf->lock);
added
removed
libelf/elf_update.c
