1 /* Conversion functions for versioning information.
2 Copyright (C) 2006, 2007 Red Hat, Inc.
3 This file is part of elfutils.
4 Written by Ulrich Drepper <drepper@redhat.com>, 2006.
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 #include <assert.h>
31 #include <gelf.h>
32
33 #include "libelfP.h"
34
35
36 static void
elf_cvt_gnuhash(void * dest,const void * src,size_t len,int encode)37 elf_cvt_gnuhash (void *dest, const void *src, size_t len, int encode)
38 {
39 /* The GNU hash table format on 64 bit machines mixes 32 bit and 64 bit
40 words. We must detangle them here. */
41 Elf32_Word *dest32 = dest;
42 const Elf32_Word *src32 = src;
43
44 /* First four control words, 32 bits. */
45 for (unsigned int cnt = 0; cnt < 4; ++cnt)
46 {
47 if (len < 4)
48 return;
49 dest32[cnt] = bswap_32 (src32[cnt]);
50 len -= 4;
51 }
52
53 Elf32_Word bitmask_words = encode ? src32[2] : dest32[2];
54
55 /* Now the 64 bit words. */
56 Elf64_Xword *dest64 = (Elf64_Xword *) &dest32[4];
57 const Elf64_Xword *src64 = (const Elf64_Xword *) &src32[4];
58 for (unsigned int cnt = 0; cnt < bitmask_words; ++cnt)
59 {
60 if (len < 8)
61 return;
62 dest64[cnt] = bswap_64 (src64[cnt]);
63 len -= 8;
64 }
65
66 /* The rest are 32 bit words again. */
67 src32 = (const Elf32_Word *) &src64[bitmask_words];
68 dest32 = (Elf32_Word *) &dest64[bitmask_words];
69 while (len >= 4)
70 {
71 *dest32++ = bswap_32 (*src32++);
72 len -= 4;
73 }
74 }
75