xref: /netbsd-src/lib/libc/dlfcn/dlfcn_elf.c (revision c2f76ff004a2cb67efe5b12d97bd3ef7fe89e18d)
1 /*	$NetBSD: dlfcn_elf.c,v 1.7 2010/10/16 10:27:07 skrll 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 1.7 2010/10/16 10:27:07 skrll 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 #define	dl_iterate_phdr		___dl_iterate_phdr
49 
50 #define ELFSIZE ARCH_ELFSIZE
51 #include "rtld.h"
52 
53 #ifdef __weak_alias
54 __weak_alias(dlopen,___dlopen)
55 __weak_alias(dlclose,___dlclose)
56 __weak_alias(dlsym,___dlsym)
57 __weak_alias(dlerror,___dlerror)
58 __weak_alias(dladdr,___dladdr)
59 __weak_alias(dlinfo,___dlinfo)
60 __weak_alias(dl_iterate_phdr,___dl_iterate_phdr)
61 
62 __weak_alias(__dlopen,___dlopen)
63 __weak_alias(__dlclose,___dlclose)
64 __weak_alias(__dlsym,___dlsym)
65 __weak_alias(__dlerror,___dlerror)
66 __weak_alias(__dladdr,___dladdr)
67 __weak_alias(__dlinfo,___dlinfo)
68 __weak_alias(__dl_iterate_phdr,___dl_iterate_phdr)
69 #endif
70 
71 /*
72  * For ELF, the dynamic linker directly resolves references to its
73  * services to functions inside the dynamic linker itself.  These
74  * weak-symbol stubs are necessary so that "ld" won't complain about
75  * undefined symbols.  The stubs are executed only when the program is
76  * linked statically, or when a given service isn't implemented in the
77  * dynamic linker.  They must return an error if called, and they must
78  * be weak symbols so that the dynamic linker can override them.
79  */
80 
81 static char dlfcn_error[] = "Service unavailable";
82 
83 /*ARGSUSED*/
84 void *
85 dlopen(const char *name, int mode)
86 {
87 
88 	return NULL;
89 }
90 
91 /*ARGSUSED*/
92 int
93 dlclose(void *fd)
94 {
95 
96 	return -1;
97 }
98 
99 /*ARGSUSED*/
100 void *
101 dlsym(void *handle, const char *name)
102 {
103 
104 	return NULL;
105 }
106 
107 /*ARGSUSED*/
108 __aconst char *
109 dlerror()
110 {
111 
112 	return dlfcn_error;
113 }
114 
115 /*ARGSUSED*/
116 int
117 dladdr(const void *addr, Dl_info *dli)
118 {
119 
120 	return 0;
121 }
122 
123 /*ARGSUSED*/
124 int
125 dlinfo(void *handle, int req, void *v)
126 {
127 
128 	return -1;
129 }
130 
131 /*ARGSUSED*/
132 int
133 dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *),
134     void *data)
135 {
136 
137 	return 0;
138 }
139