dlfcn/dlopen.c

   1 /* Load a shared object at run time.
   2    Copyright (C) 1995-2016 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    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <dlfcn.h>
  20 #include <libintl.h>
  21 #include <stddef.h>
  22 #include <unistd.h>
  23 #include <ldsodefs.h>
  24
  25 #if !defined SHARED && IS_IN (libdl)
  26
  27 void *
  28 dlopen (const char *file, int mode)
  29 {
  30   return __dlopen (file, mode, RETURN_ADDRESS (0));
  31 }
  32 static_link_warning (dlopen)
  33
  34 #else
  35
  36 struct dlopen_args
  37 {
  38   /* The arguments for dlopen_doit.  */
  39   const char *file;
  40   int mode;
  41   /* The return value of dlopen_doit.  */
  42   void *new;
  43   /* Address of the caller.  */
  44   const void *caller;
  45 };
  46
  47
  48 /* Non-shared code has no support for multiple namespaces.  */
  49 # ifdef SHARED
  50 #  define NS __LM_ID_CALLER
  51 # else
  52 #  define NS LM_ID_BASE
  53 # endif
  54
  55
  56 static void
  57 dlopen_doit (void *a)
  58 {
  59   struct dlopen_args *args = (struct dlopen_args *) a;
  60
  61   if (args->mode & ~(RTLD_BINDING_MASK | RTLD_NOLOAD | RTLD_DEEPBIND
  62                      | RTLD_GLOBAL | RTLD_LOCAL | RTLD_NODELETE
  63                      | __RTLD_SPROF))
  64     GLRO(dl_signal_error) (0, NULL, NULL, _("invalid mode parameter"));
  65
  66   args->new = GLRO(dl_open) (args->file ?: "", args->mode | __RTLD_DLOPEN,
  67                              args->caller,
  68                              args->file == NULL ? LM_ID_BASE : NS,
  69                              __dlfcn_argc, __dlfcn_argv, __environ);
  70 }
  71
  72
  73 void *
  74 __dlopen (const char *file, int mode DL_CALLER_DECL)
  75 {
  76 # ifdef SHARED
  77   if (__glibc_unlikely (_dlfcn_hook != NULL))
  78     return _dlfcn_hook->dlopen (file, mode, DL_CALLER);
  79 # endif
  80
  81   struct dlopen_args args;
  82   args.file = file;
  83   args.mode = mode;
  84   args.caller = DL_CALLER;
  85
  86 # ifdef SHARED
  87   return _dlerror_run (dlopen_doit, &args) ? NULL : args.new;
  88 # else
  89   if (_dlerror_run (dlopen_doit, &args))
  90     return NULL;
  91
  92   __libc_register_dl_open_hook ((struct link_map *) args.new);
  93   __libc_register_dlfcn_hook ((struct link_map *) args.new);
  94
  95   return args.new;
  96 # endif
  97 }
  98 # ifdef SHARED
  99 #  include <shlib-compat.h>
 100 strong_alias (__dlopen, __dlopen_check)
 101 versioned_symbol (libdl, __dlopen_check, dlopen, GLIBC_2_1);
 102 # endif
 103 #endif