f0f10541db
representations of ELF types. The ELF(3) API allows applications to request a conversion that is `in-place', i.e., with source and destinations data buffers being the same. However, the file and memory sizes of ELF sections that have additional internal structure, such as those of type `Elf_Note', or `Elf_GNU_Hash_Header', can be determined only known after the type-specific headers that comprise the first few words in these sections are read and translated. Pass in the size of destination buffer to type translation routines in "libelf_convert.m4" and have these routines return an error code if the translated data would not fit inside the destination buffer. Obtained from: elftoolchain MFC after: 1 month
150 lines
4.1 KiB
C
150 lines
4.1 KiB
C
/*-
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* Copyright (c) 2006 Joseph Koshy
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <assert.h>
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#include <libelf.h>
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#include "_libelf.h"
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/*
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* Translate to/from the file representation of ELF objects.
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*
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* Translation could potentially involve the following
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* transformations:
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*
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* - an endianness conversion,
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* - a change of layout, as the file representation of ELF objects
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* can differ from their in-memory representation.
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* - a change in representation due to a layout version change.
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*/
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Elf_Data *
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_libelf_xlate(Elf_Data *dst, const Elf_Data *src, unsigned int encoding,
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int elfclass, int direction)
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{
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int byteswap;
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size_t cnt, dsz, fsz, msz;
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uintptr_t sb, se, db, de;
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if (encoding == ELFDATANONE)
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encoding = LIBELF_PRIVATE(byteorder);
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if ((encoding != ELFDATA2LSB && encoding != ELFDATA2MSB) ||
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dst == NULL || src == NULL || dst == src) {
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LIBELF_SET_ERROR(ARGUMENT, 0);
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return (NULL);
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}
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assert(elfclass == ELFCLASS32 || elfclass == ELFCLASS64);
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assert(direction == ELF_TOFILE || direction == ELF_TOMEMORY);
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if (dst->d_version != src->d_version) {
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LIBELF_SET_ERROR(UNIMPL, 0);
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return (NULL);
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}
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if (src->d_buf == NULL || dst->d_buf == NULL) {
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LIBELF_SET_ERROR(DATA, 0);
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return (NULL);
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}
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if ((int) src->d_type < 0 || src->d_type >= ELF_T_NUM) {
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LIBELF_SET_ERROR(DATA, 0);
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return (NULL);
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}
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if ((fsz = (elfclass == ELFCLASS32 ? elf32_fsize : elf64_fsize)
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(src->d_type, (size_t) 1, src->d_version)) == 0)
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return (NULL);
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msz = _libelf_msize(src->d_type, elfclass, src->d_version);
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assert(msz > 0);
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if (src->d_size % (direction == ELF_TOMEMORY ? fsz : msz)) {
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LIBELF_SET_ERROR(DATA, 0);
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return (NULL);
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}
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/*
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* Determine the number of objects that need to be converted, and
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* the space required for the converted objects in the destination
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* buffer.
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*/
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if (direction == ELF_TOMEMORY) {
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cnt = src->d_size / fsz;
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dsz = cnt * msz;
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} else {
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cnt = src->d_size / msz;
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dsz = cnt * fsz;
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}
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if (dst->d_size < dsz) {
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LIBELF_SET_ERROR(DATA, 0);
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return (NULL);
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}
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sb = (uintptr_t) src->d_buf;
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se = sb + src->d_size;
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db = (uintptr_t) dst->d_buf;
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de = db + dst->d_size;
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/*
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* Check for overlapping buffers. Note that db == sb is
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* allowed.
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*/
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if (db != sb && de > sb && se > db) {
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LIBELF_SET_ERROR(DATA, 0);
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return (NULL);
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}
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if ((direction == ELF_TOMEMORY ? db : sb) %
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_libelf_malign(src->d_type, elfclass)) {
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LIBELF_SET_ERROR(DATA, 0);
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return (NULL);
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}
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dst->d_type = src->d_type;
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dst->d_size = dsz;
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byteswap = encoding != LIBELF_PRIVATE(byteorder);
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if (src->d_size == 0 ||
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(db == sb && !byteswap && fsz == msz))
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return (dst); /* nothing more to do */
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if (!(_libelf_get_translator(src->d_type, direction, elfclass))
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(dst->d_buf, dsz, src->d_buf, cnt, byteswap)) {
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LIBELF_SET_ERROR(DATA, 0);
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return (NULL);
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}
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return (dst);
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}
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