151 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			151 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*-
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|  * Copyright (c) 2006,2008 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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| 
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| #include <sys/cdefs.h>
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| 
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| #include <assert.h>
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| #include <libelf.h>
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| 
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| #include "_libelf.h"
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| 
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| LIBELF_VCSID("$Id$");
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| 
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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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| 
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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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| 
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| 	if (encoding == ELFDATANONE)
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| 		encoding = LIBELF_PRIVATE(byteorder);
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| 
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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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| 
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| 	assert(elfclass == ELFCLASS32 || elfclass == ELFCLASS64);
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| 	assert(direction == ELF_TOFILE || direction == ELF_TOMEMORY);
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| 	msz = _libelf_msize(src->d_type, elfclass, src->d_version);
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| 
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| 	assert(msz > 0);
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| 
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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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| 	/*
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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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| 
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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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| 
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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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| 	/*
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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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| 
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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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| 
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| 	dst->d_type = src->d_type;
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| 	dst->d_size = dsz;
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| 
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| 	byteswap = encoding != LIBELF_PRIVATE(byteorder);
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| 
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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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| 
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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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| 
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| 	return (dst);
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| }
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