1  /* Load a shared object at run time.
       2     Copyright (C) 1995-2023 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     <https://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 OTHER_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  			     __libc_argc, __libc_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 (GLRO (dl_dlfcn_hook) != NULL)
      74      return GLRO (dl_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