dlfcn/dlmopen.c

   1 /* Load a shared object at run time.
   2    Copyright (C) 1995-2021 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 <errno.h>
  21 #include <libintl.h>
  22 #include <stddef.h>
  23 #include <unistd.h>
  24 #include <ldsodefs.h>
  25
  26 #if !defined SHARED && IS_IN (libdl)
  27
  28 void *
  29 dlmopen (Lmid_t nsid, const char *file, int mode)
  30 {
  31   return __dlmopen (nsid, file, mode, RETURN_ADDRESS (0));
  32 }
  33 static_link_warning (dlmopen)
  34
  35 #else
  36
  37 struct dlmopen_args
  38 {
  39   /* Namespace ID.  */
  40   Lmid_t nsid;
  41   /* The arguments for dlopen_doit.  */
  42   const char *file;
  43   int mode;
  44   /* The return value of dlopen_doit.  */
  45   void *new;
  46   /* Address of the caller.  */
  47   const void *caller;
  48 };
  49
  50 static void
  51 dlmopen_doit (void *a)
  52 {
  53   struct dlmopen_args *args = (struct dlmopen_args *) a;
  54
  55   /* Non-shared code has no support for multiple namespaces.  */
  56   if (args->nsid != LM_ID_BASE)
  57     {
  58 # ifdef SHARED
  59       /* If trying to open the link map for the main executable the namespace
  60          must be the main one.  */
  61       if (args->file == NULL)
  62 # endif
  63         _dl_signal_error (EINVAL, NULL, NULL, N_("invalid namespace"));
  64
  65       /* It makes no sense to use RTLD_GLOBAL when loading a DSO into
  66          a namespace other than the base namespace.  */
  67       if (__glibc_unlikely (args->mode & RTLD_GLOBAL))
  68         _dl_signal_error (EINVAL, NULL, NULL, N_("invalid mode"));
  69     }
  70
  71   args->new = GLRO(dl_open) (args->file ?: "", args->mode | __RTLD_DLOPEN,
  72                              args->caller,
  73                              args->nsid, __dlfcn_argc, __dlfcn_argv,
  74                              __environ);
  75 }
  76
  77
  78 void *
  79 __dlmopen (Lmid_t nsid, const char *file, int mode DL_CALLER_DECL)
  80 {
  81 # ifdef SHARED
  82   if (!rtld_active ())
  83     return _dlfcn_hook->dlmopen (nsid, file, mode, RETURN_ADDRESS (0));
  84 # endif
  85
  86   struct dlmopen_args args;
  87   args.nsid = nsid;
  88   args.file = file;
  89   args.mode = mode;
  90   args.caller = DL_CALLER;
  91
  92 # ifdef SHARED
  93   return _dlerror_run (dlmopen_doit, &args) ? NULL : args.new;
  94 # else
  95   if (_dlerror_run (dlmopen_doit, &args))
  96     return NULL;
  97
  98   __libc_register_dl_open_hook ((struct link_map *) args.new);
  99   __libc_register_dlfcn_hook ((struct link_map *) args.new);
 100
 101   return args.new;
 102 # endif
 103 }
 104 # ifdef SHARED
 105 strong_alias (__dlmopen, dlmopen)
 106 # endif
 107 #endif