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("$FreeBSD$"); 29 30 /* 31 * Linkage to services provided by the dynamic linker. 32 */ 33 #include <sys/mman.h> 34 #include <dlfcn.h> 35 #include <link.h> 36 #include <stddef.h> 37 38 static char sorry[] = "Service unavailable"; 39 40 /* 41 * For ELF, the dynamic linker directly resolves references to its 42 * services to functions inside the dynamic linker itself. These 43 * weak-symbol stubs are necessary so that "ld" won't complain about 44 * undefined symbols. The stubs are executed only when the program is 45 * linked statically, or when a given service isn't implemented in the 46 * dynamic linker. They must return an error if called, and they must 47 * be weak symbols so that the dynamic linker can override them. 48 */ 49 50 #pragma weak _rtld_error 51 void 52 _rtld_error(const char *fmt, ...) 53 { 54 } 55 56 #pragma weak dladdr 57 int 58 dladdr(const void *addr, Dl_info *dlip) 59 { 60 _rtld_error(sorry); 61 return 0; 62 } 63 64 #pragma weak dlclose 65 int 66 dlclose(void *handle) 67 { 68 _rtld_error(sorry); 69 return -1; 70 } 71 72 #pragma weak dlerror 73 char * 74 dlerror(void) 75 { 76 return sorry; 77 } 78 79 #pragma weak dllockinit 80 void 81 dllockinit(void *context, 82 void *(*lock_create)(void *context), 83 void (*rlock_acquire)(void *lock), 84 void (*wlock_acquire)(void *lock), 85 void (*lock_release)(void *lock), 86 void (*lock_destroy)(void *lock), 87 void (*context_destroy)(void *context)) 88 { 89 if (context_destroy != NULL) 90 context_destroy(context); 91 } 92 93 #pragma weak dlopen 94 void * 95 dlopen(const char *name, int mode) 96 { 97 _rtld_error(sorry); 98 return NULL; 99 } 100 101 #pragma weak dlsym 102 void * 103 dlsym(void * __restrict handle, const char * __restrict name) 104 { 105 _rtld_error(sorry); 106 return NULL; 107 } 108 109 #pragma weak dlfunc 110 dlfunc_t 111 dlfunc(void * __restrict handle, const char * __restrict name) 112 { 113 _rtld_error(sorry); 114 return NULL; 115 } 116 117 #pragma weak dlvsym 118 void * 119 dlvsym(void * __restrict handle, const char * __restrict name, 120 const char * __restrict version) 121 { 122 _rtld_error(sorry); 123 return NULL; 124 } 125 126 #pragma weak dlinfo 127 int 128 dlinfo(void * __restrict handle, int request, void * __restrict p) 129 { 130 _rtld_error(sorry); 131 return 0; 132 } 133 134 #pragma weak _rtld_thread_init 135 void 136 _rtld_thread_init(void * li) 137 { 138 _rtld_error(sorry); 139 } 140 141 #pragma weak dl_iterate_phdr 142 int 143 dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *), 144 void *data) 145 { 146 _rtld_error(sorry); 147 return 0; 148 } 149 150 #pragma weak fdlopen 151 void * 152 fdlopen(int fd, int mode) 153 { 154 155 _rtld_error(sorry); 156 return NULL; 157 } 158 159 #pragma weak _rtld_atfork_pre 160 void 161 _rtld_atfork_pre(int *locks) 162 { 163 } 164 165 #pragma weak _rtld_atfork_post 166 void 167 _rtld_atfork_post(int *locks) 168 { 169 } 170 171 #pragma weak _rtld_addr_phdr 172 int 173 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 174 { 175 176 return (0); 177 } 178 179 #pragma weak _rtld_get_stack_prot 180 int 181 _rtld_get_stack_prot(void) 182 { 183 184 return (PROT_EXEC | PROT_READ | PROT_WRITE); 185 } 186 187