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 * $FreeBSD: src/lib/libc/gen/dlfcn.c,v 1.6.2.1 2003/02/20 20:42:45 kan Exp $ 27 * $DragonFly: src/lib/libc/gen/dlfcn.c,v 1.3 2004/03/20 16:27:39 drhodus Exp $ 28 */ 29 30 #include <dlfcn.h> 31 #include <stddef.h> 32 33 static const char sorry[] = "Service unavailable"; 34 35 /* 36 * For ELF, the dynamic linker directly resolves references to its 37 * services to functions inside the dynamic linker itself. These 38 * weak-symbol stubs are necessary so that "ld" won't complain about 39 * undefined symbols. The stubs are executed only when the program is 40 * linked statically, or when a given service isn't implemented in the 41 * dynamic linker. They must return an error if called, and they must 42 * be weak symbols so that the dynamic linker can override them. 43 */ 44 45 #pragma weak _rtld_error 46 void 47 _rtld_error(const char *fmt, ...) 48 { 49 } 50 51 #pragma weak dladdr 52 int 53 dladdr(const void *addr, Dl_info *dlip) 54 { 55 _rtld_error(sorry); 56 return 0; 57 } 58 59 #pragma weak dlclose 60 int 61 dlclose(void *handle) 62 { 63 _rtld_error(sorry); 64 return -1; 65 } 66 67 #pragma weak dlerror 68 const char * 69 dlerror(void) 70 { 71 return sorry; 72 } 73 74 #pragma weak dllockinit 75 void 76 dllockinit(void *context, 77 void *(*lock_create)(void *context), 78 void (*rlock_acquire)(void *lock), 79 void (*wlock_acquire)(void *lock), 80 void (*lock_release)(void *lock), 81 void (*lock_destroy)(void *lock), 82 void (*context_destroy)(void *context)) 83 { 84 if (context_destroy != NULL) 85 context_destroy(context); 86 } 87 88 #pragma weak dlopen 89 void * 90 dlopen(const char *name, int mode) 91 { 92 _rtld_error(sorry); 93 return NULL; 94 } 95 96 #pragma weak dlsym 97 void * 98 dlsym(void *handle, const char *name) 99 { 100 _rtld_error(sorry); 101 return NULL; 102 } 103 104 #pragma weak dlinfo 105 int 106 dlinfo(void *handle, int request, void *p) 107 { 108 _rtld_error(sorry); 109 return NULL; 110 } 111