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 <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
dlopen_doit(void * a)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 *
__dlopen_nocheck(const char * file,int mode)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
80