2 * Copyright (c) 2006 Joseph Koshy
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
36 * Translate to/from the file representation of ELF objects.
38 * Translation could potentially involve the following
41 * - an endianness conversion,
42 * - a change of layout, as the file representation of ELF objects
43 * can differ from their in-memory representation.
44 * - a change in representation due to a layout version change.
48 _libelf_xlate(Elf_Data *dst, const Elf_Data *src, unsigned int encoding,
49 int elfclass, int direction)
52 size_t cnt, dsz, fsz, msz;
53 uintptr_t sb, se, db, de;
55 if (encoding == ELFDATANONE)
56 encoding = LIBELF_PRIVATE(byteorder);
58 if ((encoding != ELFDATA2LSB && encoding != ELFDATA2MSB) ||
59 dst == NULL || src == NULL || dst == src) {
60 LIBELF_SET_ERROR(ARGUMENT, 0);
64 assert(elfclass == ELFCLASS32 || elfclass == ELFCLASS64);
65 assert(direction == ELF_TOFILE || direction == ELF_TOMEMORY);
67 if (dst->d_version != src->d_version) {
68 LIBELF_SET_ERROR(UNIMPL, 0);
72 if (src->d_buf == NULL || dst->d_buf == NULL) {
73 LIBELF_SET_ERROR(DATA, 0);
77 if ((int) src->d_type < 0 || src->d_type >= ELF_T_NUM) {
78 LIBELF_SET_ERROR(DATA, 0);
82 if ((fsz = (elfclass == ELFCLASS32 ? elf32_fsize : elf64_fsize)
83 (src->d_type, (size_t) 1, src->d_version)) == 0)
86 msz = _libelf_msize(src->d_type, elfclass, src->d_version);
90 if (src->d_size % (direction == ELF_TOMEMORY ? fsz : msz)) {
91 LIBELF_SET_ERROR(DATA, 0);
96 * Determine the number of objects that need to be converted, and
97 * the space required for the converted objects in the destination
100 if (direction == ELF_TOMEMORY) {
101 cnt = src->d_size / fsz;
104 cnt = src->d_size / msz;
108 if (dst->d_size < dsz) {
109 LIBELF_SET_ERROR(DATA, 0);
113 sb = (uintptr_t) src->d_buf;
114 se = sb + src->d_size;
115 db = (uintptr_t) dst->d_buf;
116 de = db + dst->d_size;
119 * Check for overlapping buffers. Note that db == sb is
122 if (db != sb && de > sb && se > db) {
123 LIBELF_SET_ERROR(DATA, 0);
127 if ((direction == ELF_TOMEMORY ? db : sb) %
128 _libelf_malign(src->d_type, elfclass)) {
129 LIBELF_SET_ERROR(DATA, 0);
133 dst->d_type = src->d_type;
136 byteswap = encoding != LIBELF_PRIVATE(byteorder);
138 if (src->d_size == 0 ||
139 (db == sb && !byteswap && fsz == msz))
140 return (dst); /* nothing more to do */
142 if (!(_libelf_get_translator(src->d_type, direction, elfclass))
143 (dst->d_buf, dsz, src->d_buf, cnt, byteswap)) {
144 LIBELF_SET_ERROR(DATA, 0);