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 <libintl.h>
21 #include <stddef.h>
22 #include <unistd.h>
23 #include <ldsodefs.h>
24 #include <shlib-compat.h>
25
26 struct dlopen_args
27 {
28 /* The arguments for dlopen_doit. */
29 const char *file;
30 int mode;
31 /* The return value of dlopen_doit. */
32 void *new;
33 /* Address of the caller. */
34 const void *caller;
35 };
36
37
38 /* Non-shared code has no support for multiple namespaces. */
39 #ifdef SHARED
40 # define NS __LM_ID_CALLER
41 #else
42 # define NS LM_ID_BASE
43 #endif
44
45
46 static void
dlopen_doit(void * a)47 dlopen_doit (void *a)
48 {
49 struct dlopen_args *args = (struct dlopen_args *) a;
50
51 if (args->mode & ~(RTLD_BINDING_MASK | RTLD_NOLOAD | RTLD_DEEPBIND
52 | RTLD_GLOBAL | RTLD_LOCAL | RTLD_NODELETE
53 | __RTLD_SPROF))
54 _dl_signal_error (0, NULL, NULL, _("invalid mode parameter"));
55
56 args->new = GLRO(dl_open) (args->file ?: "", args->mode | __RTLD_DLOPEN,
57 args->caller,
58 args->file == NULL ? LM_ID_BASE : NS,
59 __libc_argc, __libc_argv, __environ);
60 }
61
62
63 static void *
dlopen_implementation(const char * file,int mode,void * dl_caller)64 dlopen_implementation (const char *file, int mode, void *dl_caller)
65 {
66 struct dlopen_args args;
67 args.file = file;
68 args.mode = mode;
69 args.caller = dl_caller;
70
71 return _dlerror_run (dlopen_doit, &args) ? NULL : args.new;
72 }
73
74 #ifdef SHARED
75 void *
___dlopen(const char * file,int mode)76 ___dlopen (const char *file, int mode)
77 {
78 if (GLRO (dl_dlfcn_hook) != NULL)
79 return GLRO (dl_dlfcn_hook)->dlopen (file, mode, RETURN_ADDRESS (0));
80 else
81 return dlopen_implementation (file, mode, RETURN_ADDRESS (0));
82 }
83 versioned_symbol (libc, ___dlopen, dlopen, GLIBC_2_34);
84
85 # if OTHER_SHLIB_COMPAT (libdl, GLIBC_2_1, GLIBC_2_34)
86 compat_symbol (libdl, ___dlopen, dlopen, GLIBC_2_1);
87 # endif
88 #else /* !SHARED */
89 /* Also used with _dlfcn_hook. */
90 void *
__dlopen(const char * file,int mode,void * dl_caller)91 __dlopen (const char *file, int mode, void *dl_caller)
92 {
93 return dlopen_implementation (file, mode, RETURN_ADDRESS (0));
94 }
95
96 void *
___dlopen(const char * file,int mode)97 ___dlopen (const char *file, int mode)
98 {
99 return __dlopen (file, mode, RETURN_ADDRESS (0));
100 }
101 weak_alias (___dlopen, dlopen)
102 static_link_warning (dlopen)
103 #endif /* !SHARED */
104