dlfcn/dlmopen.c

   1 /* Load a shared object at run time.
   2    Copyright (C) 1995-2022 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 #include <shlib-compat.h>
  26
  27 struct dlmopen_args
  28 {
  29   /* Namespace ID.  */
  30   Lmid_t nsid;
  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 static void
  41 dlmopen_doit (void *a)
  42 {
  43   struct dlmopen_args *args = (struct dlmopen_args *) a;
  44
  45   /* Non-shared code has no support for multiple namespaces.  */
  46   if (args->nsid != LM_ID_BASE)
  47     {
  48 # ifdef SHARED
  49       /* If trying to open the link map for the main executable the namespace
  50          must be the main one.  */
  51       if (args->file == NULL)
  52 # endif
  53         _dl_signal_error (EINVAL, NULL, NULL, N_("invalid namespace"));
  54
  55       /* It makes no sense to use RTLD_GLOBAL when loading a DSO into
  56          a namespace other than the base namespace.  */
  57       if (__glibc_unlikely (args->mode & RTLD_GLOBAL))
  58         _dl_signal_error (EINVAL, NULL, NULL, N_("invalid mode"));
  59     }
  60
  61   args->new = GLRO(dl_open) (args->file ?: "", args->mode | __RTLD_DLOPEN,
  62                              args->caller,
  63                              args->nsid, __libc_argc, __libc_argv, __environ);
  64 }
  65
  66 static void *
  67 dlmopen_implementation (Lmid_t nsid, const char *file, int mode,
  68                         void *dl_caller)
  69 {
  70   struct dlmopen_args args;
  71   args.nsid = nsid;
  72   args.file = file;
  73   args.mode = mode;
  74   args.caller = dl_caller;
  75
  76   return _dlerror_run (dlmopen_doit, &args) ? NULL : args.new;
  77 }
  78
  79 #ifdef SHARED
  80 void *
  81 ___dlmopen (Lmid_t nsid, const char *file, int mode)
  82 {
  83   if (!rtld_active ())
  84     return GLRO (dl_dlfcn_hook)->dlmopen (nsid, file, mode, RETURN_ADDRESS (0));
  85   else
  86     return dlmopen_implementation (nsid, file, mode, RETURN_ADDRESS (0));
  87 }
  88 versioned_symbol (libc, ___dlmopen, dlmopen, GLIBC_2_34);
  89
  90 # if OTHER_SHLIB_COMPAT (libdl, GLIBC_2_3_4, GLIBC_2_34)
  91 compat_symbol (libdl, ___dlmopen, dlmopen, GLIBC_2_3_4);
  92 # endif
  93 #else /* !SHARED */
  94 /* Also used with _dlfcn_hook.  */
  95 void *
  96 __dlmopen (Lmid_t nsid, const char *file, int mode, void *dl_caller)
  97 {
  98   return dlmopen_implementation (nsid, file, mode, RETURN_ADDRESS (0));
  99 }
 100
 101 void *
 102 ___dlmopen (Lmid_t nsid, const char *file, int mode)
 103 {
 104   return __dlmopen (nsid, file, mode, RETURN_ADDRESS (0));
 105 }
 106 weak_alias (___dlmopen, dlmopen)
 107 static_link_warning (dlmopen)
 108 #endif /* !SHARED */