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Ben Cheng25b3c042013-11-20 14:45:36 -08001/* Convert from file to memory representation.
Elliott Hughes03333822015-02-18 22:19:45 -08002 Copyright (C) 1998, 1999, 2000, 2002, 2012 Red Hat, Inc.
3 This file is part of elfutils.
Ben Cheng25b3c042013-11-20 14:45:36 -08004 Written by Ulrich Drepper <drepper@redhat.com>, 1998.
5
Elliott Hughes03333822015-02-18 22:19:45 -08006 This file is free software; you can redistribute it and/or modify
7 it under the terms of either
Ben Cheng25b3c042013-11-20 14:45:36 -08008
Elliott Hughes03333822015-02-18 22:19:45 -08009 * the GNU Lesser General Public License as published by the Free
10 Software Foundation; either version 3 of the License, or (at
11 your option) any later version
12
13 or
14
15 * the GNU General Public License as published by the Free
16 Software Foundation; either version 2 of the License, or (at
17 your option) any later version
18
19 or both in parallel, as here.
20
21 elfutils is distributed in the hope that it will be useful, but
Ben Cheng25b3c042013-11-20 14:45:36 -080022 WITHOUT ANY WARRANTY; without even the implied warranty of
23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
24 General Public License for more details.
25
Elliott Hughes03333822015-02-18 22:19:45 -080026 You should have received copies of the GNU General Public License and
27 the GNU Lesser General Public License along with this program. If
28 not, see <http://www.gnu.org/licenses/>. */
Ben Cheng25b3c042013-11-20 14:45:36 -080029
30#ifdef HAVE_CONFIG_H
31# include <config.h>
32#endif
33
34#include <assert.h>
35#include <endian.h>
36#include <string.h>
37
38#include "libelfP.h"
39
40#ifndef LIBELFBITS
41# define LIBELFBITS 32
42#endif
43
44
45Elf_Data *
46elfw2(LIBELFBITS, xlatetom) (dest, src, encode)
47 Elf_Data *dest;
48 const Elf_Data *src;
49 unsigned int encode;
50{
51 /* First test whether the input data is really suitable for this
52 type. This means, whether there is an integer number of records.
53 Note that for this implementation the memory and file size of the
54 data types are identical. */
55#if EV_NUM != 2
56 size_t recsize = __libelf_type_sizes[src->d_version - 1][ELFW(ELFCLASS,LIBELFBITS) - 1][src->d_type];
57#else
58 size_t recsize = __libelf_type_sizes[0][ELFW(ELFCLASS,LIBELFBITS) - 1][src->d_type];
59#endif
60
61
Elliott Hughes03333822015-02-18 22:19:45 -080062 /* We shouldn't require integer number of records when processing
63 notes. Payload bytes follow the header immediately, it's not an
64 array of records as is the case otherwise. */
65 if (src->d_type != ELF_T_NHDR
66 && src->d_size % recsize != 0)
Ben Cheng25b3c042013-11-20 14:45:36 -080067 {
68 __libelf_seterrno (ELF_E_INVALID_DATA);
69 return NULL;
70 }
71
72 /* Next see whether the converted data fits in the output buffer. */
73 if (src->d_size > dest->d_size)
74 {
75 __libelf_seterrno (ELF_E_DEST_SIZE);
76 return NULL;
77 }
78
79 /* Test the encode parameter. */
80 if (encode != ELFDATA2LSB && encode != ELFDATA2MSB)
81 {
82 __libelf_seterrno (ELF_E_INVALID_ENCODING);
83 return NULL;
84 }
85
86 /* Determine the translation function to use.
87
88 At this point we make an assumption which is valid for all
89 existing implementations so far: the memory and file sizes are
90 the same. This has very important consequences:
91 a) The requirement that the source and destination buffer can
92 overlap can easily be fulfilled.
93 b) We need only one function to convert from and memory to file
94 and vice versa since the function only has to copy and/or
95 change the byte order.
96 */
97 if ((BYTE_ORDER == LITTLE_ENDIAN && encode == ELFDATA2LSB)
98 || (BYTE_ORDER == BIG_ENDIAN && encode == ELFDATA2MSB))
99 {
100 /* We simply have to copy since the byte order is the same. */
101 if (src->d_buf != dest->d_buf)
102 memmove (dest->d_buf, src->d_buf, src->d_size);
103 }
104 else
105 {
106 xfct_t fctp;
107
108 /* Get a pointer to the transformation functions. The `#ifdef' is
109 a small optimization since we don't anticipate another ELF
110 version and so would waste "precious" code. */
111#if EV_NUM != 2
112 fctp = __elf_xfctstom[src->d_version - 1][dest->d_version - 1][ELFW(ELFCLASS, LIBELFBITS) - 1][src->d_type];
113#else
114 fctp = __elf_xfctstom[0][0][ELFW(ELFCLASS, LIBELFBITS) - 1][src->d_type];
115#endif
116
117 /* Do the real work. */
118 (*fctp) (dest->d_buf, src->d_buf, src->d_size, 0);
119 }
120
121 /* Now set the real destination type and length since the operation was
122 successful. */
123 dest->d_type = src->d_type;
124 dest->d_size = src->d_size;
125
126 return dest;
127}
128INTDEF(elfw2(LIBELFBITS, xlatetom))