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 #if !defined(IN_LIBDL) || defined(PIC) 31 32 /* 33 * Linkage to services provided by the dynamic linker. 34 */ 35 #include <sys/mman.h> 36 #include <dlfcn.h> 37 #include <link.h> 38 #include <stddef.h> 39 #include "namespace.h" 40 #include <pthread.h> 41 #include "un-namespace.h" 42 #include "libc_private.h" 43 44 static char sorry[] = "Service unavailable"; 45 46 void _rtld_thread_init(void *); 47 void _rtld_atfork_pre(int *); 48 void _rtld_atfork_post(int *); 49 50 /* 51 * For ELF, the dynamic linker directly resolves references to its 52 * services to functions inside the dynamic linker itself. These 53 * weak-symbol stubs are necessary so that "ld" won't complain about 54 * undefined symbols. The stubs are executed only when the program is 55 * linked statically, or when a given service isn't implemented in the 56 * dynamic linker. They must return an error if called, and they must 57 * be weak symbols so that the dynamic linker can override them. 58 */ 59 60 #pragma weak _rtld_error 61 void 62 _rtld_error(const char *fmt __unused, ...) 63 { 64 } 65 66 #pragma weak dladdr 67 int 68 dladdr(const void *addr __unused, Dl_info *dlip __unused) 69 { 70 71 _rtld_error(sorry); 72 return (0); 73 } 74 75 #pragma weak dlclose 76 int 77 dlclose(void *handle __unused) 78 { 79 80 _rtld_error(sorry); 81 return (-1); 82 } 83 84 #pragma weak dlerror 85 char * 86 dlerror(void) 87 { 88 89 return (sorry); 90 } 91 92 #pragma weak dllockinit 93 void 94 dllockinit(void *context, 95 void *(*lock_create)(void *context) __unused, 96 void (*rlock_acquire)(void *lock) __unused, 97 void (*wlock_acquire)(void *lock) __unused, 98 void (*lock_release)(void *lock) __unused, 99 void (*lock_destroy)(void *lock) __unused, 100 void (*context_destroy)(void *context) __unused) 101 { 102 103 if (context_destroy != NULL) 104 context_destroy(context); 105 } 106 107 #pragma weak dlopen 108 void * 109 dlopen(const char *name __unused, int mode __unused) 110 { 111 112 _rtld_error(sorry); 113 return (NULL); 114 } 115 116 #pragma weak dlsym 117 void * 118 dlsym(void * __restrict handle __unused, const char * __restrict name __unused) 119 { 120 121 _rtld_error(sorry); 122 return (NULL); 123 } 124 125 #pragma weak dlfunc 126 dlfunc_t 127 dlfunc(void * __restrict handle __unused, const char * __restrict name __unused) 128 { 129 130 _rtld_error(sorry); 131 return (NULL); 132 } 133 134 #pragma weak dlvsym 135 void * 136 dlvsym(void * __restrict handle __unused, const char * __restrict name __unused, 137 const char * __restrict version __unused) 138 { 139 140 _rtld_error(sorry); 141 return (NULL); 142 } 143 144 #pragma weak dlinfo 145 int 146 dlinfo(void * __restrict handle __unused, int request __unused, 147 void * __restrict p __unused) 148 { 149 150 _rtld_error(sorry); 151 return (0); 152 } 153 154 #pragma weak _rtld_thread_init 155 void 156 _rtld_thread_init(void *li __unused) 157 { 158 159 _rtld_error(sorry); 160 } 161 162 #ifndef IN_LIBDL 163 static pthread_once_t dl_phdr_info_once = PTHREAD_ONCE_INIT; 164 static struct dl_phdr_info phdr_info; 165 166 static void 167 dl_init_phdr_info(void) 168 { 169 Elf_Auxinfo *auxp; 170 unsigned int i; 171 172 for (auxp = __elf_aux_vector; auxp->a_type != AT_NULL; auxp++) { 173 switch (auxp->a_type) { 174 case AT_BASE: 175 phdr_info.dlpi_addr = (Elf_Addr)auxp->a_un.a_ptr; 176 break; 177 case AT_EXECPATH: 178 phdr_info.dlpi_name = (const char *)auxp->a_un.a_ptr; 179 break; 180 case AT_PHDR: 181 phdr_info.dlpi_phdr = 182 (const Elf_Phdr *)auxp->a_un.a_ptr; 183 break; 184 case AT_PHNUM: 185 phdr_info.dlpi_phnum = (Elf_Half)auxp->a_un.a_val; 186 break; 187 } 188 } 189 for (i = 0; i < phdr_info.dlpi_phnum; i++) { 190 if (phdr_info.dlpi_phdr[i].p_type == PT_TLS) { 191 phdr_info.dlpi_tls_modid = 1; 192 phdr_info.dlpi_tls_data = 193 (void*)phdr_info.dlpi_phdr[i].p_vaddr; 194 } 195 } 196 phdr_info.dlpi_adds = 1; 197 } 198 #endif 199 200 #pragma weak dl_iterate_phdr 201 int 202 dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *) __unused, 203 void *data __unused) 204 { 205 206 #ifndef IN_LIBDL 207 __init_elf_aux_vector(); 208 if (__elf_aux_vector == NULL) 209 return (1); 210 _once(&dl_phdr_info_once, dl_init_phdr_info); 211 return (callback(&phdr_info, sizeof(phdr_info), data)); 212 #else 213 return (0); 214 #endif 215 } 216 217 #pragma weak fdlopen 218 void * 219 fdlopen(int fd __unused, int mode __unused) 220 { 221 222 _rtld_error(sorry); 223 return (NULL); 224 } 225 226 #pragma weak _rtld_atfork_pre 227 void 228 _rtld_atfork_pre(int *locks __unused) 229 { 230 } 231 232 #pragma weak _rtld_atfork_post 233 void 234 _rtld_atfork_post(int *locks __unused) 235 { 236 } 237 238 #pragma weak _rtld_addr_phdr 239 int 240 _rtld_addr_phdr(const void *addr __unused, 241 struct dl_phdr_info *phdr_info_a __unused) 242 { 243 244 return (0); 245 } 246 247 #pragma weak _rtld_get_stack_prot 248 int 249 _rtld_get_stack_prot(void) 250 { 251 252 return (PROT_EXEC | PROT_READ | PROT_WRITE); 253 } 254 255 #pragma weak _rtld_is_dlopened 256 int 257 _rtld_is_dlopened(void *arg __unused) 258 { 259 260 return (0); 261 } 262 263 #endif /* !defined(IN_LIBDL) || defined(PIC) */ 264