dlfcn/dlopen.c

   1 /* Load a shared object at run time.
   2    Copyright (C) 1995,96,97,98,99,2000,2003,2004 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 <dlfcn.h>
  21 #include <stddef.h>
  22
  23 #if !defined SHARED && defined IS_IN_libdl
  24
  25 void *
  26 dlopen (const char *file, int mode)
  27 {
  28   return __dlopen (file, mode, RETURN_ADDRESS (0));
  29 }
  30 static_link_warning (dlopen)
  31
  32 #else
  33
  34 struct dlopen_args
  35 {
  36   /* The arguments for dlopen_doit.  */
  37   const char *file;
  38   int mode;
  39   /* The return value of dlopen_doit.  */
  40   void *new;
  41   /* Address of the caller.  */
  42   const void *caller;
  43 };
  44
  45
  46 /* Non-shared code has no support for multiple namespaces.  */
  47 # ifdef SHARED
  48 #  define NS __LM_ID_CALLER
  49 # else
  50 #  define NS LM_ID_BASE
  51 # endif
  52
  53
  54 static void
  55 dlopen_doit (void *a)
  56 {
  57   struct dlopen_args *args = (struct dlopen_args *) a;
  58
  59   args->new = _dl_open (args->file ?: "", args->mode | __RTLD_DLOPEN,
  60                         args->caller, args->file == NULL ? LM_ID_BASE : NS);
  61 }
  62
  63
  64 void *
  65 __dlopen (const char *file, int mode DL_CALLER_DECL)
  66 {
  67 # ifdef SHARED
  68   if (__builtin_expect (_dlfcn_hook != NULL, 0))
  69     return _dlfcn_hook->dlopen (file, mode, DL_CALLER);
  70 # endif
  71
  72   struct dlopen_args args;
  73   args.file = file;
  74   args.mode = mode;
  75   args.caller = DL_CALLER;
  76
  77 # ifdef SHARED
  78   return _dlerror_run (dlopen_doit, &args) ? NULL : args.new;
  79 # else
  80   if (_dlerror_run (dlopen_doit, &args))
  81     return NULL;
  82
  83   __libc_register_dl_open_hook ((struct link_map *) args.new);
  84   __libc_register_dlfcn_hook ((struct link_map *) args.new);
  85
  86   return args.new;
  87 # endif
  88 }
  89 # ifdef SHARED
  90 #  include <shlib-compat.h>
  91 strong_alias (__dlopen, __dlopen_check)
  92 versioned_symbol (libdl, __dlopen_check, dlopen, GLIBC_2_1);
  93 # endif
  94 #endif