dlfcn/dlopenold.c

   1 /* Load a shared object at run time.
   2    Copyright (C) 1995-2017 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 <stddef.h>
  21 #include <unistd.h>
  22 #include <ldsodefs.h>
  23
  24 /* This file is for compatibility with glibc 2.0.  Compile it only if
  25    versioning is used.  */
  26 #include <shlib-compat.h>
  27 #if SHLIB_COMPAT (libdl, GLIBC_2_0, GLIBC_2_1)
  28
  29 struct dlopen_args
  30 {
  31   /* The arguments for dlopen_doit.  */
  32   const char *file;
  33   int mode;
  34   /* The return value of dlopen_doit.  */
  35   void *new;
  36   /* Address of the caller.  */
  37   const void *caller;
  38 };
  39
  40
  41 /* Non-shared code has no support for multiple namespaces.  */
  42 #ifdef SHARED
  43 # define NS __LM_ID_CALLER
  44 #else
  45 # define NS LM_ID_BASE
  46 #endif
  47
  48
  49 static void
  50 dlopen_doit (void *a)
  51 {
  52   struct dlopen_args *args = (struct dlopen_args *) a;
  53
  54   args->new = GLRO(dl_open) (args->file ?: "", args->mode | __RTLD_DLOPEN,
  55                              args->caller,
  56                              args->file == NULL ? LM_ID_BASE : NS,
  57                              __dlfcn_argc, __dlfcn_argv, __environ);
  58 }
  59
  60 extern void *__dlopen_nocheck (const char *file, int mode);
  61 void *
  62 __dlopen_nocheck (const char *file, int mode)
  63 {
  64   struct dlopen_args args;
  65   args.file = file;
  66   args.caller = RETURN_ADDRESS (0);
  67
  68   if ((mode & RTLD_BINDING_MASK) == 0)
  69     /* By default assume RTLD_LAZY.  */
  70     mode |= RTLD_LAZY;
  71   args.mode = mode;
  72
  73   if (__glibc_unlikely (_dlfcn_hook != NULL))
  74     return _dlfcn_hook->dlopen (file, mode, RETURN_ADDRESS (0));
  75
  76   return _dlerror_run (dlopen_doit, &args) ? NULL : args.new;
  77 }
  78 compat_symbol (libdl, __dlopen_nocheck, dlopen, GLIBC_2_0);
  79 #endif