125b3c049e70834cf33790a28643ab058b507b35cBen Cheng/* Update data structures for changes and write them out. 225b3c049e70834cf33790a28643ab058b507b35cBen Cheng Copyright (C) 1999, 2000, 2001, 2002, 2004, 2005, 2006 Red Hat, Inc. 325b3c049e70834cf33790a28643ab058b507b35cBen Cheng This file is part of Red Hat elfutils. 425b3c049e70834cf33790a28643ab058b507b35cBen Cheng Contributed by Ulrich Drepper <drepper@redhat.com>, 1999. 525b3c049e70834cf33790a28643ab058b507b35cBen Cheng 625b3c049e70834cf33790a28643ab058b507b35cBen Cheng Red Hat elfutils is free software; you can redistribute it and/or modify 725b3c049e70834cf33790a28643ab058b507b35cBen Cheng it under the terms of the GNU General Public License as published by the 825b3c049e70834cf33790a28643ab058b507b35cBen Cheng Free Software Foundation; version 2 of the License. 925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 1025b3c049e70834cf33790a28643ab058b507b35cBen Cheng Red Hat elfutils is distributed in the hope that it will be useful, but 1125b3c049e70834cf33790a28643ab058b507b35cBen Cheng WITHOUT ANY WARRANTY; without even the implied warranty of 1225b3c049e70834cf33790a28643ab058b507b35cBen Cheng MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 1325b3c049e70834cf33790a28643ab058b507b35cBen Cheng General Public License for more details. 1425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 1525b3c049e70834cf33790a28643ab058b507b35cBen Cheng You should have received a copy of the GNU General Public License along 1625b3c049e70834cf33790a28643ab058b507b35cBen Cheng with Red Hat elfutils; if not, write to the Free Software Foundation, 1725b3c049e70834cf33790a28643ab058b507b35cBen Cheng Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 1825b3c049e70834cf33790a28643ab058b507b35cBen Cheng 1925b3c049e70834cf33790a28643ab058b507b35cBen Cheng In addition, as a special exception, Red Hat, Inc. gives You the 2025b3c049e70834cf33790a28643ab058b507b35cBen Cheng additional right to link the code of Red Hat elfutils with code licensed 2125b3c049e70834cf33790a28643ab058b507b35cBen Cheng under any Open Source Initiative certified open source license 2225b3c049e70834cf33790a28643ab058b507b35cBen Cheng (http://www.opensource.org/licenses/index.php) which requires the 2325b3c049e70834cf33790a28643ab058b507b35cBen Cheng distribution of source code with any binary distribution and to 2425b3c049e70834cf33790a28643ab058b507b35cBen Cheng distribute linked combinations of the two. Non-GPL Code permitted under 2525b3c049e70834cf33790a28643ab058b507b35cBen Cheng this exception must only link to the code of Red Hat elfutils through 2625b3c049e70834cf33790a28643ab058b507b35cBen Cheng those well defined interfaces identified in the file named EXCEPTION 2725b3c049e70834cf33790a28643ab058b507b35cBen Cheng found in the source code files (the "Approved Interfaces"). The files 2825b3c049e70834cf33790a28643ab058b507b35cBen Cheng of Non-GPL Code may instantiate templates or use macros or inline 2925b3c049e70834cf33790a28643ab058b507b35cBen Cheng functions from the Approved Interfaces without causing the resulting 3025b3c049e70834cf33790a28643ab058b507b35cBen Cheng work to be covered by the GNU General Public License. Only Red Hat, 3125b3c049e70834cf33790a28643ab058b507b35cBen Cheng Inc. may make changes or additions to the list of Approved Interfaces. 3225b3c049e70834cf33790a28643ab058b507b35cBen Cheng Red Hat's grant of this exception is conditioned upon your not adding 3325b3c049e70834cf33790a28643ab058b507b35cBen Cheng any new exceptions. If you wish to add a new Approved Interface or 3425b3c049e70834cf33790a28643ab058b507b35cBen Cheng exception, please contact Red Hat. You must obey the GNU General Public 3525b3c049e70834cf33790a28643ab058b507b35cBen Cheng License in all respects for all of the Red Hat elfutils code and other 3625b3c049e70834cf33790a28643ab058b507b35cBen Cheng code used in conjunction with Red Hat elfutils except the Non-GPL Code 3725b3c049e70834cf33790a28643ab058b507b35cBen Cheng covered by this exception. If you modify this file, you may extend this 3825b3c049e70834cf33790a28643ab058b507b35cBen Cheng exception to your version of the file, but you are not obligated to do 3925b3c049e70834cf33790a28643ab058b507b35cBen Cheng so. If you do not wish to provide this exception without modification, 4025b3c049e70834cf33790a28643ab058b507b35cBen Cheng you must delete this exception statement from your version and license 4125b3c049e70834cf33790a28643ab058b507b35cBen Cheng this file solely under the GPL without exception. 4225b3c049e70834cf33790a28643ab058b507b35cBen Cheng 4325b3c049e70834cf33790a28643ab058b507b35cBen Cheng Red Hat elfutils is an included package of the Open Invention Network. 4425b3c049e70834cf33790a28643ab058b507b35cBen Cheng An included package of the Open Invention Network is a package for which 4525b3c049e70834cf33790a28643ab058b507b35cBen Cheng Open Invention Network licensees cross-license their patents. No patent 4625b3c049e70834cf33790a28643ab058b507b35cBen Cheng license is granted, either expressly or impliedly, by designation as an 4725b3c049e70834cf33790a28643ab058b507b35cBen Cheng included package. Should you wish to participate in the Open Invention 4825b3c049e70834cf33790a28643ab058b507b35cBen Cheng Network licensing program, please visit www.openinventionnetwork.com 4925b3c049e70834cf33790a28643ab058b507b35cBen Cheng <http://www.openinventionnetwork.com>. */ 5025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 5125b3c049e70834cf33790a28643ab058b507b35cBen Cheng#ifdef HAVE_CONFIG_H 5225b3c049e70834cf33790a28643ab058b507b35cBen Cheng# include <config.h> 5325b3c049e70834cf33790a28643ab058b507b35cBen Cheng#endif 5425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 5525b3c049e70834cf33790a28643ab058b507b35cBen Cheng#include <libelf.h> 5625b3c049e70834cf33790a28643ab058b507b35cBen Cheng#include <unistd.h> 5725b3c049e70834cf33790a28643ab058b507b35cBen Cheng#include <sys/mman.h> 5825b3c049e70834cf33790a28643ab058b507b35cBen Cheng#include <sys/stat.h> 5925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 6025b3c049e70834cf33790a28643ab058b507b35cBen Cheng#include "libelfP.h" 6125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 6225b3c049e70834cf33790a28643ab058b507b35cBen Cheng 6325b3c049e70834cf33790a28643ab058b507b35cBen Chengstatic off_t 6425b3c049e70834cf33790a28643ab058b507b35cBen Chengwrite_file (Elf *elf, off_t size, int change_bo, size_t shnum) 6525b3c049e70834cf33790a28643ab058b507b35cBen Cheng{ 6625b3c049e70834cf33790a28643ab058b507b35cBen Cheng int class = elf->class; 6725b3c049e70834cf33790a28643ab058b507b35cBen Cheng 6825b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Check the mode bits now, before modification might change them. */ 6925b3c049e70834cf33790a28643ab058b507b35cBen Cheng struct stat st; 7025b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (fstat (elf->fildes, &st) != 0)) 7125b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 7225b3c049e70834cf33790a28643ab058b507b35cBen Cheng __libelf_seterrno (ELF_E_WRITE_ERROR); 7325b3c049e70834cf33790a28643ab058b507b35cBen Cheng return -1; 7425b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 7525b3c049e70834cf33790a28643ab058b507b35cBen Cheng 7625b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Adjust the size in any case. We do this even if we use `write'. 7725b3c049e70834cf33790a28643ab058b507b35cBen Cheng We cannot do this if this file is in an archive. We also don't 7825b3c049e70834cf33790a28643ab058b507b35cBen Cheng do it *now* if we are shortening the file since this would 7925b3c049e70834cf33790a28643ab058b507b35cBen Cheng prevent programs to use the data of the file in generating the 8025b3c049e70834cf33790a28643ab058b507b35cBen Cheng new file. We truncate the file later in this case. */ 8125b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (elf->parent == NULL 8225b3c049e70834cf33790a28643ab058b507b35cBen Cheng && (elf->maximum_size == ~((size_t) 0) 8325b3c049e70834cf33790a28643ab058b507b35cBen Cheng || (size_t) size > elf->maximum_size) 8425b3c049e70834cf33790a28643ab058b507b35cBen Cheng && unlikely (ftruncate (elf->fildes, size) != 0)) 8525b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 8625b3c049e70834cf33790a28643ab058b507b35cBen Cheng __libelf_seterrno (ELF_E_WRITE_ERROR); 8725b3c049e70834cf33790a28643ab058b507b35cBen Cheng return -1; 8825b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 8925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 9025b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Try to map the file if this isn't done yet. */ 9125b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (elf->map_address == NULL && elf->cmd == ELF_C_WRITE_MMAP) 9225b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 9325b3c049e70834cf33790a28643ab058b507b35cBen Cheng#if _MUDFLAP 9425b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Mudflap doesn't grok that our mmap'd data is ok. */ 9525b3c049e70834cf33790a28643ab058b507b35cBen Cheng#else 9625b3c049e70834cf33790a28643ab058b507b35cBen Cheng elf->map_address = mmap (NULL, size, PROT_READ | PROT_WRITE, 9725b3c049e70834cf33790a28643ab058b507b35cBen Cheng MAP_SHARED, elf->fildes, 0); 9825b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (elf->map_address == MAP_FAILED)) 9925b3c049e70834cf33790a28643ab058b507b35cBen Cheng elf->map_address = NULL; 10025b3c049e70834cf33790a28643ab058b507b35cBen Cheng#endif 10125b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 10225b3c049e70834cf33790a28643ab058b507b35cBen Cheng 10325b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (elf->map_address != NULL) 10425b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 10525b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* The file is mmaped. */ 10625b3c049e70834cf33790a28643ab058b507b35cBen Cheng if ((class == ELFCLASS32 10725b3c049e70834cf33790a28643ab058b507b35cBen Cheng ? __elf32_updatemmap (elf, change_bo, shnum) 10825b3c049e70834cf33790a28643ab058b507b35cBen Cheng : __elf64_updatemmap (elf, change_bo, shnum)) != 0) 10925b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Some problem while writing. */ 11025b3c049e70834cf33790a28643ab058b507b35cBen Cheng size = -1; 11125b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 11225b3c049e70834cf33790a28643ab058b507b35cBen Cheng else 11325b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 11425b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* The file is not mmaped. */ 11525b3c049e70834cf33790a28643ab058b507b35cBen Cheng if ((class == ELFCLASS32 11625b3c049e70834cf33790a28643ab058b507b35cBen Cheng ? __elf32_updatefile (elf, change_bo, shnum) 11725b3c049e70834cf33790a28643ab058b507b35cBen Cheng : __elf64_updatefile (elf, change_bo, shnum)) != 0) 11825b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Some problem while writing. */ 11925b3c049e70834cf33790a28643ab058b507b35cBen Cheng size = -1; 12025b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 12125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 12225b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (size != -1 12325b3c049e70834cf33790a28643ab058b507b35cBen Cheng && elf->parent == NULL 12425b3c049e70834cf33790a28643ab058b507b35cBen Cheng && elf->maximum_size != ~((size_t) 0) 12525b3c049e70834cf33790a28643ab058b507b35cBen Cheng && (size_t) size < elf->maximum_size 12625b3c049e70834cf33790a28643ab058b507b35cBen Cheng && unlikely (ftruncate (elf->fildes, size) != 0)) 12725b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 12825b3c049e70834cf33790a28643ab058b507b35cBen Cheng __libelf_seterrno (ELF_E_WRITE_ERROR); 12925b3c049e70834cf33790a28643ab058b507b35cBen Cheng size = -1; 13025b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 13125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 13225b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* POSIX says that ftruncate and write may clear the S_ISUID and S_ISGID 13325b3c049e70834cf33790a28643ab058b507b35cBen Cheng mode bits. So make sure we restore them afterwards if they were set. 13425b3c049e70834cf33790a28643ab058b507b35cBen Cheng This is not atomic if someone else chmod's the file while we operate. */ 13525b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (size != -1 13625b3c049e70834cf33790a28643ab058b507b35cBen Cheng && unlikely (st.st_mode & (S_ISUID | S_ISGID)) 13725b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* fchmod ignores the bits we cannot change. */ 13825b3c049e70834cf33790a28643ab058b507b35cBen Cheng && unlikely (fchmod (elf->fildes, st.st_mode) != 0)) 13925b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 14025b3c049e70834cf33790a28643ab058b507b35cBen Cheng __libelf_seterrno (ELF_E_WRITE_ERROR); 14125b3c049e70834cf33790a28643ab058b507b35cBen Cheng size = -1; 14225b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 14325b3c049e70834cf33790a28643ab058b507b35cBen Cheng 14425b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (size != -1 && elf->parent == NULL) 14525b3c049e70834cf33790a28643ab058b507b35cBen Cheng elf->maximum_size = size; 14625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 14725b3c049e70834cf33790a28643ab058b507b35cBen Cheng return size; 14825b3c049e70834cf33790a28643ab058b507b35cBen Cheng} 14925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 15025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 15125b3c049e70834cf33790a28643ab058b507b35cBen Chengoff_t 15225b3c049e70834cf33790a28643ab058b507b35cBen Chengelf_update (elf, cmd) 15325b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf *elf; 15425b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Cmd cmd; 15525b3c049e70834cf33790a28643ab058b507b35cBen Cheng{ 15625b3c049e70834cf33790a28643ab058b507b35cBen Cheng size_t shnum; 15725b3c049e70834cf33790a28643ab058b507b35cBen Cheng off_t size; 15825b3c049e70834cf33790a28643ab058b507b35cBen Cheng int change_bo = 0; 15925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 16025b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (cmd != ELF_C_NULL 16125b3c049e70834cf33790a28643ab058b507b35cBen Cheng && cmd != ELF_C_WRITE 16225b3c049e70834cf33790a28643ab058b507b35cBen Cheng && unlikely (cmd != ELF_C_WRITE_MMAP)) 16325b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 16425b3c049e70834cf33790a28643ab058b507b35cBen Cheng __libelf_seterrno (ELF_E_INVALID_CMD); 16525b3c049e70834cf33790a28643ab058b507b35cBen Cheng return -1; 16625b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 16725b3c049e70834cf33790a28643ab058b507b35cBen Cheng 16825b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (elf == NULL) 16925b3c049e70834cf33790a28643ab058b507b35cBen Cheng return -1; 17025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 17125b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (elf->kind != ELF_K_ELF) 17225b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 17325b3c049e70834cf33790a28643ab058b507b35cBen Cheng __libelf_seterrno (ELF_E_INVALID_HANDLE); 17425b3c049e70834cf33790a28643ab058b507b35cBen Cheng return -1; 17525b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 17625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 17725b3c049e70834cf33790a28643ab058b507b35cBen Cheng rwlock_wrlock (elf->lock); 17825b3c049e70834cf33790a28643ab058b507b35cBen Cheng 17925b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Make sure we have an ELF header. */ 18025b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (elf->state.elf.ehdr == NULL) 18125b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 18225b3c049e70834cf33790a28643ab058b507b35cBen Cheng __libelf_seterrno (ELF_E_WRONG_ORDER_EHDR); 18325b3c049e70834cf33790a28643ab058b507b35cBen Cheng size = -1; 18425b3c049e70834cf33790a28643ab058b507b35cBen Cheng goto out; 18525b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 18625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 18725b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Determine the number of sections. */ 18825b3c049e70834cf33790a28643ab058b507b35cBen Cheng shnum = (elf->state.elf.scns_last->cnt == 0 18925b3c049e70834cf33790a28643ab058b507b35cBen Cheng ? 0 19025b3c049e70834cf33790a28643ab058b507b35cBen Cheng : 1 + elf->state.elf.scns_last->data[elf->state.elf.scns_last->cnt - 1].index); 19125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 19225b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Update the ELF descriptor. First, place the program header. It 19325b3c049e70834cf33790a28643ab058b507b35cBen Cheng will come right after the ELF header. The count the size of all 19425b3c049e70834cf33790a28643ab058b507b35cBen Cheng sections and finally place the section table. */ 19525b3c049e70834cf33790a28643ab058b507b35cBen Cheng size = (elf->class == ELFCLASS32 19625b3c049e70834cf33790a28643ab058b507b35cBen Cheng ? __elf32_updatenull_wrlock (elf, &change_bo, shnum) 19725b3c049e70834cf33790a28643ab058b507b35cBen Cheng : __elf64_updatenull_wrlock (elf, &change_bo, shnum)); 19825b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (likely (size != -1) 19925b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* See whether we actually have to write out the data. */ 20025b3c049e70834cf33790a28643ab058b507b35cBen Cheng && (cmd == ELF_C_WRITE || cmd == ELF_C_WRITE_MMAP)) 20125b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 20225b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (elf->cmd != ELF_C_RDWR 20325b3c049e70834cf33790a28643ab058b507b35cBen Cheng && elf->cmd != ELF_C_RDWR_MMAP 20425b3c049e70834cf33790a28643ab058b507b35cBen Cheng && elf->cmd != ELF_C_WRITE 20525b3c049e70834cf33790a28643ab058b507b35cBen Cheng && unlikely (elf->cmd != ELF_C_WRITE_MMAP)) 20625b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 20725b3c049e70834cf33790a28643ab058b507b35cBen Cheng __libelf_seterrno (ELF_E_UPDATE_RO); 20825b3c049e70834cf33790a28643ab058b507b35cBen Cheng size = -1; 20925b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 21025b3c049e70834cf33790a28643ab058b507b35cBen Cheng else if (unlikely (elf->fildes == -1)) 21125b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 21225b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* We closed the file already. */ 21325b3c049e70834cf33790a28643ab058b507b35cBen Cheng __libelf_seterrno (ELF_E_FD_DISABLED); 21425b3c049e70834cf33790a28643ab058b507b35cBen Cheng size = -1; 21525b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 21625b3c049e70834cf33790a28643ab058b507b35cBen Cheng else 21725b3c049e70834cf33790a28643ab058b507b35cBen Cheng size = write_file (elf, size, change_bo, shnum); 21825b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 21925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 22025b3c049e70834cf33790a28643ab058b507b35cBen Cheng out: 22125b3c049e70834cf33790a28643ab058b507b35cBen Cheng rwlock_unlock (elf->lock); 22225b3c049e70834cf33790a28643ab058b507b35cBen Cheng 22325b3c049e70834cf33790a28643ab058b507b35cBen Cheng return size; 22425b3c049e70834cf33790a28643ab058b507b35cBen Cheng} 225