dlfcn.c revision 110804 
1/*-
2 * Copyright (c) 1998 John D. Polstra
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/lib/libc/gen/dlfcn.c 110804 2003-02-13 17:47:44Z kan $");
29
30/*
31 * Linkage to services provided by the dynamic linker.
32 */
33#include <dlfcn.h>
34#include <stddef.h>
35
36static const char sorry[] = "Service unavailable";
37
38/*
39 * For ELF, the dynamic linker directly resolves references to its
40 * services to functions inside the dynamic linker itself.  These
41 * weak-symbol stubs are necessary so that "ld" won't complain about
42 * undefined symbols.  The stubs are executed only when the program is
43 * linked statically, or when a given service isn't implemented in the
44 * dynamic linker.  They must return an error if called, and they must
45 * be weak symbols so that the dynamic linker can override them.
46 */
47
48#pragma weak _rtld_error
49void
50_rtld_error(const char *fmt, ...)
51{
52}
53
54#pragma weak dladdr
55int
56dladdr(const void *addr, Dl_info *dlip)
57{
58	_rtld_error(sorry);
59	return 0;
60}
61
62#pragma weak dlclose
63int
64dlclose(void *handle)
65{
66	_rtld_error(sorry);
67	return -1;
68}
69
70#pragma weak dlerror
71const char *
72dlerror(void)
73{
74	return sorry;
75}
76
77#pragma weak dllockinit
78void
79dllockinit(void *context,
80	   void *(*lock_create)(void *context),
81	   void (*rlock_acquire)(void *lock),
82	   void (*wlock_acquire)(void *lock),
83	   void (*lock_release)(void *lock),
84	   void (*lock_destroy)(void *lock),
85	   void (*context_destroy)(void *context))
86{
87	if (context_destroy != NULL)
88		context_destroy(context);
89}
90
91#pragma weak dlopen
92void *
93dlopen(const char *name, int mode)
94{
95	_rtld_error(sorry);
96	return NULL;
97}
98
99#pragma weak dlsym
100void *
101dlsym(void * __restrict handle, const char * __restrict name)
102{
103	_rtld_error(sorry);
104	return NULL;
105}
106
107#pragma weak dlinfo
108int
109dlinfo(void * __restrict handle, int request, void * __restrict p)
110{
111	_rtld_error(sorry);
112	return NULL;
113}
114