sysdeps/generic/dl-cache.h

   1 /* Support for reading /etc/ld.so.cache files written by Linux ldconfig.
   2    Copyright (C) 1999, 2000, 2002, 2003 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <stdint.h>
  21
  22 #ifndef _DL_CACHE_DEFAULT_ID
  23 # define _DL_CACHE_DEFAULT_ID   3
  24 #endif
  25
  26 #ifndef _dl_cache_check_flags
  27 # define _dl_cache_check_flags(flags)                   \
  28   ((flags) == 1 || (flags) == _DL_CACHE_DEFAULT_ID)
  29 #endif
  30
  31 #ifndef LD_SO_CACHE
  32 # define LD_SO_CACHE SYSCONFDIR "/ld.so.cache"
  33 #endif
  34
  35 #ifndef add_system_dir
  36 # define add_system_dir(dir) add_dir (dir)
  37 #endif
  38
  39 #define CACHEMAGIC "ld.so-1.7.0"
  40
  41 /* libc5 and glibc 2.0/2.1 use the same format.  For glibc 2.2 another
  42    format has been added in a compatible way:
  43    The beginning of the string table is used for the new table:
  44         old_magic
  45         nlibs
  46         libs[0]
  47         ...
  48         libs[nlibs-1]
  49         pad, new magic needs to be aligned
  50              - this is string[0] for the old format
  51         new magic - this is string[0] for the new format
  52         newnlibs
  53         ...
  54         newlibs[0]
  55         ...
  56         newlibs[newnlibs-1]
  57         string 1
  58         string 2
  59         ...
  60 */
  61 struct file_entry
  62 {
  63   int flags;            /* This is 1 for an ELF library.  */
  64   unsigned int key, value; /* String table indices.  */
  65 };
  66
  67 struct cache_file
  68 {
  69   char magic[sizeof CACHEMAGIC - 1];
  70   unsigned int nlibs;
  71   struct file_entry libs[0];
  72 };
  73
  74 #define CACHEMAGIC_NEW "glibc-ld.so.cache"
  75 #define CACHE_VERSION "1.1"
  76 #define CACHEMAGIC_VERSION_NEW CACHEMAGIC_NEW CACHE_VERSION
  77
  78
  79 struct file_entry_new
  80 {
  81   int32_t flags;                /* This is 1 for an ELF library.  */
  82   uint32_t key, value;          /* String table indices.  */
  83   uint32_t osversion;           /* Required OS version.  */
  84   uint64_t hwcap;               /* Hwcap entry.  */
  85 };
  86
  87 struct cache_file_new
  88 {
  89   char magic[sizeof CACHEMAGIC_NEW - 1];
  90   char version[sizeof CACHE_VERSION - 1];
  91   uint32_t nlibs;               /* Number of entries.  */
  92   uint32_t len_strings;         /* Size of string table. */
  93   uint32_t unused[5];           /* Leave space for future extensions
  94                                    and align to 8 byte boundary.  */
  95   struct file_entry_new libs[0]; /* Entries describing libraries.  */
  96   /* After this the string table of size len_strings is found.  */
  97 };
  98
  99 /* Used to align cache_file_new.  */
 100 #define ALIGN_CACHE(addr)                               \
 101 (((addr) + __alignof__ (struct cache_file_new) -1)      \
 102  & (~(__alignof__ (struct cache_file_new) - 1)))
 103
 104 extern int _dl_cache_libcmp (const char *p1, const char *p2)
 105      internal_function;