1/* Support for reading /etc/ld.so.cache files written by Linux ldconfig.
2 Copyright (C) 1999-2020 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <stdint.h>
20
21#ifndef _DL_CACHE_DEFAULT_ID
22# define _DL_CACHE_DEFAULT_ID 3
23#endif
24
25#ifndef _dl_cache_check_flags
26# define _dl_cache_check_flags(flags) \
27 ((flags) == 1 || (flags) == _DL_CACHE_DEFAULT_ID)
28#endif
29
30#ifndef LD_SO_CACHE
31# define LD_SO_CACHE SYSCONFDIR "/ld.so.cache"
32#endif
33
34#ifndef add_system_dir
35# define add_system_dir(dir) add_dir (dir)
36#endif
37
38#define CACHEMAGIC "ld.so-1.7.0"
39
40/* libc5 and glibc 2.0/2.1 use the same format. For glibc 2.2 another
41 format has been added in a compatible way:
42 The beginning of the string table is used for the new table:
43 old_magic
44 nlibs
45 libs[0]
46 ...
47 libs[nlibs-1]
48 pad, new magic needs to be aligned
49 - this is string[0] for the old format
50 new magic - this is string[0] for the new format
51 newnlibs
52 ...
53 newlibs[0]
54 ...
55 newlibs[newnlibs-1]
56 string 1
57 string 2
58 ...
59*/
60struct file_entry
61{
62 int flags; /* This is 1 for an ELF library. */
63 unsigned int key, value; /* String table indices. */
64};
65
66struct cache_file
67{
68 char magic[sizeof CACHEMAGIC - 1];
69 unsigned int nlibs;
70 struct file_entry libs[0];
71};
72
73#define CACHEMAGIC_NEW "glibc-ld.so.cache"
74#define CACHE_VERSION "1.1"
75#define CACHEMAGIC_VERSION_NEW CACHEMAGIC_NEW CACHE_VERSION
76
77
78struct file_entry_new
79{
80 int32_t flags; /* This is 1 for an ELF library. */
81 uint32_t key, value; /* String table indices. */
82 uint32_t osversion; /* Required OS version. */
83 uint64_t hwcap; /* Hwcap entry. */
84};
85
86struct cache_file_new
87{
88 char magic[sizeof CACHEMAGIC_NEW - 1];
89 char version[sizeof CACHE_VERSION - 1];
90 uint32_t nlibs; /* Number of entries. */
91 uint32_t len_strings; /* Size of string table. */
92 uint32_t unused[5]; /* Leave space for future extensions
93 and align to 8 byte boundary. */
94 struct file_entry_new libs[0]; /* Entries describing libraries. */
95 /* After this the string table of size len_strings is found. */
96};
97
98/* Used to align cache_file_new. */
99#define ALIGN_CACHE(addr) \
100(((addr) + __alignof__ (struct cache_file_new) -1) \
101 & (~(__alignof__ (struct cache_file_new) - 1)))
102
103extern int _dl_cache_libcmp (const char *p1, const char *p2) attribute_hidden;
104