glibc/sysdeps/generic/dl-cache.h
Florian Weimer de1a9197af elf: Unify old and new format cache handling code in ld.so
struct file_entry_new starts with the fields of struct file_entry,
so the code can be shared if the size computation is made dynamic.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-30 14:12:14 +01:00

113 lines
3.1 KiB
C

/* Support for reading /etc/ld.so.cache files written by Linux ldconfig.
Copyright (C) 1999-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <stdint.h>
#ifndef _DL_CACHE_DEFAULT_ID
# define _DL_CACHE_DEFAULT_ID 3
#endif
#ifndef _dl_cache_check_flags
# define _dl_cache_check_flags(flags) \
((flags) == 1 || (flags) == _DL_CACHE_DEFAULT_ID)
#endif
#ifndef LD_SO_CACHE
# define LD_SO_CACHE SYSCONFDIR "/ld.so.cache"
#endif
#ifndef add_system_dir
# define add_system_dir(dir) add_dir (dir)
#endif
#define CACHEMAGIC "ld.so-1.7.0"
/* libc5 and glibc 2.0/2.1 use the same format. For glibc 2.2 another
format has been added in a compatible way:
The beginning of the string table is used for the new table:
old_magic
nlibs
libs[0]
...
libs[nlibs-1]
pad, new magic needs to be aligned
- this is string[0] for the old format
new magic - this is string[0] for the new format
newnlibs
...
newlibs[0]
...
newlibs[newnlibs-1]
string 1
string 2
...
*/
struct file_entry
{
int32_t flags; /* This is 1 for an ELF library. */
uint32_t key, value; /* String table indices. */
};
struct cache_file
{
char magic[sizeof CACHEMAGIC - 1];
unsigned int nlibs;
struct file_entry libs[0];
};
#define CACHEMAGIC_NEW "glibc-ld.so.cache"
#define CACHE_VERSION "1.1"
#define CACHEMAGIC_VERSION_NEW CACHEMAGIC_NEW CACHE_VERSION
struct file_entry_new
{
union
{
/* Fields shared with struct file_entry. */
struct file_entry entry;
/* Also expose these fields directly. */
struct
{
int32_t flags; /* This is 1 for an ELF library. */
uint32_t key, value; /* String table indices. */
};
};
uint32_t osversion; /* Required OS version. */
uint64_t hwcap; /* Hwcap entry. */
};
struct cache_file_new
{
char magic[sizeof CACHEMAGIC_NEW - 1];
char version[sizeof CACHE_VERSION - 1];
uint32_t nlibs; /* Number of entries. */
uint32_t len_strings; /* Size of string table. */
uint32_t unused[5]; /* Leave space for future extensions
and align to 8 byte boundary. */
struct file_entry_new libs[0]; /* Entries describing libraries. */
/* After this the string table of size len_strings is found. */
};
/* Used to align cache_file_new. */
#define ALIGN_CACHE(addr) \
(((addr) + __alignof__ (struct cache_file_new) -1) \
& (~(__alignof__ (struct cache_file_new) - 1)))
extern int _dl_cache_libcmp (const char *p1, const char *p2) attribute_hidden;