• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /* Convert from file to memory representation.
2    Copyright (C) 1998, 1999, 2000, 2002, 2012, 2015 Red Hat, Inc.
3    This file is part of elfutils.
4    Written by Ulrich Drepper <drepper@redhat.com>, 1998.
5 
6    This file is free software; you can redistribute it and/or modify
7    it under the terms of either
8 
9      * 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
22    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 
26    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/>.  */
29 
30 #ifdef HAVE_CONFIG_H
31 # include <config.h>
32 #endif
33 
34 #include <assert.h>
35 #include <string.h>
36 
37 #include "libelfP.h"
38 
39 #ifndef LIBELFBITS
40 # define LIBELFBITS	32
41 #endif
42 
43 
44 Elf_Data *
elfw2(LIBELFBITS,xlatetom)45 elfw2(LIBELFBITS, xlatetom) (Elf_Data *dest, const Elf_Data *src,
46 			     unsigned int encode)
47 {
48   /* First test whether the input data is really suitable for this
49      type.  This means, whether there is an integer number of records.
50      Note that for this implementation the memory and file size of the
51      data types are identical.  */
52   size_t recsize = __libelf_type_sizes[ELFW(ELFCLASS,LIBELFBITS) - 1][src->d_type];
53 
54 
55   /* We shouldn't require integer number of records when processing
56      notes.  Payload bytes follow the header immediately, it's not an
57      array of records as is the case otherwise.  */
58   if (src->d_type != ELF_T_NHDR && src->d_type != ELF_T_NHDR8
59       && src->d_size % recsize != 0)
60     {
61       __libelf_seterrno (ELF_E_INVALID_DATA);
62       return NULL;
63     }
64 
65   /* Next see whether the converted data fits in the output buffer.  */
66   if (src->d_size > dest->d_size)
67     {
68       __libelf_seterrno (ELF_E_DEST_SIZE);
69       return NULL;
70     }
71 
72   /* Test the encode parameter.  */
73   if (encode != ELFDATA2LSB && encode != ELFDATA2MSB)
74     {
75       __libelf_seterrno (ELF_E_INVALID_ENCODING);
76       return NULL;
77     }
78 
79   /* Determine the translation function to use.
80 
81      At this point we make an assumption which is valid for all
82      existing implementations so far: the memory and file sizes are
83      the same.  This has very important consequences:
84      a) The requirement that the source and destination buffer can
85 	overlap can easily be fulfilled.
86      b) We need only one function to convert from and memory to file
87 	and vice versa since the function only has to copy and/or
88 	change the byte order.
89   */
90   if ((BYTE_ORDER == LITTLE_ENDIAN && encode == ELFDATA2LSB)
91       || (BYTE_ORDER == BIG_ENDIAN && encode == ELFDATA2MSB))
92     {
93       /* We simply have to copy since the byte order is the same.  */
94       if (src->d_buf != dest->d_buf)
95 	memmove (dest->d_buf, src->d_buf, src->d_size);
96     }
97   else
98     {
99       xfct_t fctp;
100       fctp = __elf_xfctstom[ELFW(ELFCLASS, LIBELFBITS) - 1][src->d_type];
101 
102       /* Do the real work.  */
103       (*fctp) (dest->d_buf, src->d_buf, src->d_size, 0);
104     }
105 
106   /* Now set the real destination type and length since the operation was
107      successful.  */
108   dest->d_type = src->d_type;
109   dest->d_size = src->d_size;
110 
111   return dest;
112 }
113 INTDEF(elfw2(LIBELFBITS, xlatetom))
114