Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 1 | /* Update data structures for changes and write them out. |
Ulrich Drepper | 697d8d2 | 2006-04-04 21:07:28 +0000 | [diff] [blame] | 2 | Copyright (C) 1999, 2000, 2001, 2002, 2004, 2005, 2006 Red Hat, Inc. |
Ulrich Drepper | 361df7d | 2006-04-04 21:38:57 +0000 | [diff] [blame] | 3 | This file is part of Red Hat elfutils. |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 4 | Contributed by Ulrich Drepper <drepper@redhat.com>, 1999. |
| 5 | |
Ulrich Drepper | 361df7d | 2006-04-04 21:38:57 +0000 | [diff] [blame] | 6 | Red Hat elfutils is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by the |
| 8 | Free Software Foundation; version 2 of the License. |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 9 | |
Ulrich Drepper | 361df7d | 2006-04-04 21:38:57 +0000 | [diff] [blame] | 10 | Red Hat elfutils is distributed in the hope that it will be useful, but |
| 11 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | General Public License for more details. |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 14 | |
Ulrich Drepper | 361df7d | 2006-04-04 21:38:57 +0000 | [diff] [blame] | 15 | You should have received a copy of the GNU General Public License along |
| 16 | with Red Hat elfutils; if not, write to the Free Software Foundation, |
Ulrich Drepper | 1e9ef50 | 2006-04-04 22:29:06 +0000 | [diff] [blame] | 17 | Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. |
Ulrich Drepper | 361df7d | 2006-04-04 21:38:57 +0000 | [diff] [blame] | 18 | |
| 19 | In addition, as a special exception, Red Hat, Inc. gives You the |
| 20 | additional right to link the code of Red Hat elfutils with code licensed |
| 21 | under any Open Source Initiative certified open source license |
| 22 | (http://www.opensource.org/licenses/index.php) which requires the |
| 23 | distribution of source code with any binary distribution and to |
| 24 | distribute linked combinations of the two. Non-GPL Code permitted under |
| 25 | this exception must only link to the code of Red Hat elfutils through |
| 26 | those well defined interfaces identified in the file named EXCEPTION |
| 27 | found in the source code files (the "Approved Interfaces"). The files |
| 28 | of Non-GPL Code may instantiate templates or use macros or inline |
| 29 | functions from the Approved Interfaces without causing the resulting |
| 30 | work to be covered by the GNU General Public License. Only Red Hat, |
| 31 | Inc. may make changes or additions to the list of Approved Interfaces. |
| 32 | Red Hat's grant of this exception is conditioned upon your not adding |
| 33 | any new exceptions. If you wish to add a new Approved Interface or |
| 34 | exception, please contact Red Hat. You must obey the GNU General Public |
| 35 | License in all respects for all of the Red Hat elfutils code and other |
| 36 | code used in conjunction with Red Hat elfutils except the Non-GPL Code |
| 37 | covered by this exception. If you modify this file, you may extend this |
| 38 | exception to your version of the file, but you are not obligated to do |
| 39 | so. If you do not wish to provide this exception without modification, |
| 40 | you must delete this exception statement from your version and license |
| 41 | this file solely under the GPL without exception. |
| 42 | |
| 43 | Red Hat elfutils is an included package of the Open Invention Network. |
| 44 | An included package of the Open Invention Network is a package for which |
| 45 | Open Invention Network licensees cross-license their patents. No patent |
| 46 | license is granted, either expressly or impliedly, by designation as an |
| 47 | included package. Should you wish to participate in the Open Invention |
| 48 | Network licensing program, please visit www.openinventionnetwork.com |
| 49 | <http://www.openinventionnetwork.com>. */ |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 50 | |
| 51 | #ifdef HAVE_CONFIG_H |
| 52 | # include <config.h> |
| 53 | #endif |
| 54 | |
| 55 | #include <libelf.h> |
| 56 | #include <unistd.h> |
| 57 | #include <sys/mman.h> |
Roland McGrath | 8975744 | 2005-09-11 09:05:20 +0000 | [diff] [blame] | 58 | #include <sys/stat.h> |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 59 | |
| 60 | #include "libelfP.h" |
| 61 | |
| 62 | |
| 63 | static off_t |
| 64 | write_file (Elf *elf, off_t size, int change_bo, size_t shnum) |
| 65 | { |
| 66 | int class = elf->class; |
| 67 | |
Roland McGrath | 8975744 | 2005-09-11 09:05:20 +0000 | [diff] [blame] | 68 | /* Check the mode bits now, before modification might change them. */ |
| 69 | struct stat st; |
| 70 | if (unlikely (fstat (elf->fildes, &st) != 0)) |
| 71 | { |
| 72 | __libelf_seterrno (ELF_E_WRITE_ERROR); |
| 73 | return -1; |
| 74 | } |
| 75 | |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 76 | /* Adjust the size in any case. We do this even if we use `write'. |
| 77 | We cannot do this if this file is in an archive. We also don't |
| 78 | do it *now* if we are shortening the file since this would |
| 79 | prevent programs to use the data of the file in generating the |
| 80 | new file. We truncate the file later in this case. */ |
| 81 | if (elf->parent == NULL |
| 82 | && (elf->maximum_size == ~((size_t) 0) |
| 83 | || (size_t) size > elf->maximum_size) |
| 84 | && unlikely (ftruncate (elf->fildes, size) != 0)) |
| 85 | { |
| 86 | __libelf_seterrno (ELF_E_WRITE_ERROR); |
| 87 | return -1; |
| 88 | } |
| 89 | |
| 90 | /* Try to map the file if this isn't done yet. */ |
| 91 | if (elf->map_address == NULL && elf->cmd == ELF_C_WRITE_MMAP) |
| 92 | { |
| 93 | #if _MUDFLAP |
| 94 | /* Mudflap doesn't grok that our mmap'd data is ok. */ |
| 95 | #else |
| 96 | elf->map_address = mmap (NULL, size, PROT_READ | PROT_WRITE, |
| 97 | MAP_SHARED, elf->fildes, 0); |
| 98 | if (unlikely (elf->map_address == MAP_FAILED)) |
| 99 | elf->map_address = NULL; |
| 100 | #endif |
| 101 | } |
| 102 | |
| 103 | if (elf->map_address != NULL) |
| 104 | { |
| 105 | /* The file is mmaped. */ |
| 106 | if ((class == ELFCLASS32 |
| 107 | ? __elf32_updatemmap (elf, change_bo, shnum) |
| 108 | : __elf64_updatemmap (elf, change_bo, shnum)) != 0) |
| 109 | /* Some problem while writing. */ |
| 110 | size = -1; |
| 111 | } |
| 112 | else |
| 113 | { |
| 114 | /* The file is not mmaped. */ |
| 115 | if ((class == ELFCLASS32 |
| 116 | ? __elf32_updatefile (elf, change_bo, shnum) |
| 117 | : __elf64_updatefile (elf, change_bo, shnum)) != 0) |
| 118 | /* Some problem while writing. */ |
| 119 | size = -1; |
| 120 | } |
| 121 | |
| 122 | if (size != -1 |
| 123 | && elf->parent == NULL |
| 124 | && elf->maximum_size != ~((size_t) 0) |
| 125 | && (size_t) size < elf->maximum_size |
| 126 | && unlikely (ftruncate (elf->fildes, size) != 0)) |
| 127 | { |
| 128 | __libelf_seterrno (ELF_E_WRITE_ERROR); |
| 129 | size = -1; |
| 130 | } |
| 131 | |
Roland McGrath | 8975744 | 2005-09-11 09:05:20 +0000 | [diff] [blame] | 132 | /* POSIX says that ftruncate and write may clear the S_ISUID and S_ISGID |
| 133 | mode bits. So make sure we restore them afterwards if they were set. |
| 134 | This is not atomic if someone else chmod's the file while we operate. */ |
| 135 | if (size != -1 |
| 136 | && unlikely (st.st_mode & (S_ISUID | S_ISGID)) |
| 137 | /* fchmod ignores the bits we cannot change. */ |
| 138 | && unlikely (fchmod (elf->fildes, st.st_mode) != 0)) |
| 139 | { |
| 140 | __libelf_seterrno (ELF_E_WRITE_ERROR); |
| 141 | size = -1; |
| 142 | } |
| 143 | |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 144 | if (size != -1 && elf->parent == NULL) |
| 145 | elf->maximum_size = size; |
| 146 | |
| 147 | return size; |
| 148 | } |
| 149 | |
| 150 | |
| 151 | off_t |
| 152 | elf_update (elf, cmd) |
| 153 | Elf *elf; |
| 154 | Elf_Cmd cmd; |
| 155 | { |
| 156 | size_t shnum; |
| 157 | off_t size; |
| 158 | int change_bo = 0; |
| 159 | |
| 160 | if (cmd != ELF_C_NULL |
| 161 | && cmd != ELF_C_WRITE |
| 162 | && unlikely (cmd != ELF_C_WRITE_MMAP)) |
| 163 | { |
| 164 | __libelf_seterrno (ELF_E_INVALID_CMD); |
| 165 | return -1; |
| 166 | } |
| 167 | |
| 168 | if (elf == NULL) |
| 169 | return -1; |
| 170 | |
| 171 | if (elf->kind != ELF_K_ELF) |
| 172 | { |
| 173 | __libelf_seterrno (ELF_E_INVALID_HANDLE); |
| 174 | return -1; |
| 175 | } |
| 176 | |
Roland McGrath | b4d6f0f | 2008-08-25 22:55:17 +0000 | [diff] [blame] | 177 | rwlock_wrlock (elf->lock); |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 178 | |
| 179 | /* Make sure we have an ELF header. */ |
| 180 | if (elf->state.elf.ehdr == NULL) |
| 181 | { |
| 182 | __libelf_seterrno (ELF_E_WRONG_ORDER_EHDR); |
| 183 | size = -1; |
| 184 | goto out; |
| 185 | } |
| 186 | |
| 187 | /* Determine the number of sections. */ |
| 188 | shnum = (elf->state.elf.scns_last->cnt == 0 |
| 189 | ? 0 |
| 190 | : 1 + elf->state.elf.scns_last->data[elf->state.elf.scns_last->cnt - 1].index); |
| 191 | |
| 192 | /* Update the ELF descriptor. First, place the program header. It |
| 193 | will come right after the ELF header. The count the size of all |
| 194 | sections and finally place the section table. */ |
| 195 | size = (elf->class == ELFCLASS32 |
Roland McGrath | b4d6f0f | 2008-08-25 22:55:17 +0000 | [diff] [blame] | 196 | ? __elf32_updatenull_wrlock (elf, &change_bo, shnum) |
| 197 | : __elf64_updatenull_wrlock (elf, &change_bo, shnum)); |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 198 | if (likely (size != -1) |
| 199 | /* See whether we actually have to write out the data. */ |
| 200 | && (cmd == ELF_C_WRITE || cmd == ELF_C_WRITE_MMAP)) |
| 201 | { |
| 202 | if (elf->cmd != ELF_C_RDWR |
| 203 | && elf->cmd != ELF_C_RDWR_MMAP |
| 204 | && elf->cmd != ELF_C_WRITE |
| 205 | && unlikely (elf->cmd != ELF_C_WRITE_MMAP)) |
| 206 | { |
| 207 | __libelf_seterrno (ELF_E_UPDATE_RO); |
| 208 | size = -1; |
| 209 | } |
| 210 | else if (unlikely (elf->fildes == -1)) |
| 211 | { |
| 212 | /* We closed the file already. */ |
| 213 | __libelf_seterrno (ELF_E_FD_DISABLED); |
| 214 | size = -1; |
| 215 | } |
| 216 | else |
Ulrich Drepper | 697d8d2 | 2006-04-04 21:07:28 +0000 | [diff] [blame] | 217 | size = write_file (elf, size, change_bo, shnum); |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 218 | } |
| 219 | |
| 220 | out: |
Roland McGrath | b4d6f0f | 2008-08-25 22:55:17 +0000 | [diff] [blame] | 221 | rwlock_unlock (elf->lock); |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 222 | |
| 223 | return size; |
| 224 | } |