xref: /netbsd-src/lib/libc/dlfcn/dlfcn_elf.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: dlfcn_elf.c,v 1.6 2009/09/24 21:21:33 pooka Exp $	*/
2 
3 /*
4  * Copyright (c) 2000 Takuya SHIOZAKI
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 #if defined(LIBC_SCCS) && !defined(lint)
30 __RCSID("$NetBSD: dlfcn_elf.c,v 1.6 2009/09/24 21:21:33 pooka Exp $");
31 #endif /* LIBC_SCCS and not lint */
32 
33 #include "namespace.h"
34 
35 #undef dlopen
36 #undef dlclose
37 #undef dlsym
38 #undef dlerror
39 #undef dladdr
40 #undef dfinfo
41 
42 #define	dlopen		___dlopen
43 #define	dlclose		___dlclose
44 #define	dlsym		___dlsym
45 #define	dlerror		___dlerror
46 #define	dladdr		___dladdr
47 #define	dlinfo		___dlinfo
48 
49 #define ELFSIZE ARCH_ELFSIZE
50 #include "rtld.h"
51 
52 #ifdef __weak_alias
53 __weak_alias(dlopen,___dlopen)
54 __weak_alias(dlclose,___dlclose)
55 __weak_alias(dlsym,___dlsym)
56 __weak_alias(dlerror,___dlerror)
57 __weak_alias(dladdr,___dladdr)
58 __weak_alias(dlinfo,___dlinfo)
59 
60 __weak_alias(__dlopen,___dlopen)
61 __weak_alias(__dlclose,___dlclose)
62 __weak_alias(__dlsym,___dlsym)
63 __weak_alias(__dlerror,___dlerror)
64 __weak_alias(__dladdr,___dladdr)
65 __weak_alias(__dlinfo,___dlinfo)
66 #endif
67 
68 /*
69  * For ELF, the dynamic linker directly resolves references to its
70  * services to functions inside the dynamic linker itself.  These
71  * weak-symbol stubs are necessary so that "ld" won't complain about
72  * undefined symbols.  The stubs are executed only when the program is
73  * linked statically, or when a given service isn't implemented in the
74  * dynamic linker.  They must return an error if called, and they must
75  * be weak symbols so that the dynamic linker can override them.
76  */
77 
78 static char dlfcn_error[] = "Service unavailable";
79 
80 /*ARGSUSED*/
81 void *
82 dlopen(const char *name, int mode)
83 {
84 
85 	return NULL;
86 }
87 
88 /*ARGSUSED*/
89 int
90 dlclose(void *fd)
91 {
92 
93 	return -1;
94 }
95 
96 /*ARGSUSED*/
97 void *
98 dlsym(void *handle, const char *name)
99 {
100 
101 	return NULL;
102 }
103 
104 /*ARGSUSED*/
105 __aconst char *
106 dlerror()
107 {
108 
109 	return dlfcn_error;
110 }
111 
112 /*ARGSUSED*/
113 int
114 dladdr(const void *addr, Dl_info *dli)
115 {
116 
117 	return 0;
118 }
119 
120 /*ARGSUSED*/
121 int
122 dlinfo(void *handle, int req, void *v)
123 {
124 
125 	return -1;
126 }
127