1 /* $OpenBSD: dlfcn_stubs.c,v 1.14 2016/09/06 18:49:34 guenther Exp $ */ 2 3 /* 4 * Copyright (c) 1998 Per Fogelstrom, Opsycon AB 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 */ 28 29 #include <sys/types.h> 30 #include <stddef.h> 31 #include <link.h> 32 33 #include "init.h" 34 35 /* 36 * All functions here are just stubs that will be overridden 37 * by the real functions in ld.so when dynamic loading is 38 * performed at exec. The symbols here are provided as a link 39 * helper so we can link a program using the dl functions 40 * without getting any unresolved references. 41 */ 42 43 void *dlopen(const char *libname, int how) __attribute__((weak)); 44 int dlclose(void *handle) __attribute__((weak)); 45 void *dlsym(void *handle, const char *name) __attribute__((weak)); 46 int dlctl(void *handle, int command, void *data) __attribute__((weak)); 47 char *dlerror(void) __attribute__((weak)); 48 49 struct dl_info; 50 int dladdr(const void *addr, struct dl_info *info) __attribute__((weak)); 51 52 int dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *), void *date) __attribute__((weak)); 53 54 #include <stdio.h> 55 56 void * 57 dlopen(const char *libname, int how) 58 { 59 printf("Wrong dl symbols!\n"); 60 return NULL; 61 } 62 63 int 64 dlclose(void *handle) 65 { 66 printf("Wrong dl symbols!\n"); 67 return 0; 68 } 69 70 void * 71 dlsym(void *handle, const char *name) 72 { 73 printf("Wrong dl symbols!\n"); 74 return NULL; 75 } 76 77 int 78 dlctl(void *handle, int command, void *data) 79 { 80 return -1; 81 } 82 83 char * 84 dlerror(void) 85 { 86 return "Wrong dl symbols!\n"; 87 } 88 89 int 90 dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *), 91 void *data) 92 { 93 #ifndef PIC 94 if (_static_phdr_info.dlpi_phdr != NULL) 95 return callback(&_static_phdr_info, sizeof(_static_phdr_info), 96 data); 97 #endif /* !PIC */ 98 return -1; 99 } 100 101 int 102 dladdr(const void *addr, struct dl_info *info) 103 { 104 printf("Wrong dl symbols!\n"); 105 return -1; 106 } 107 108 /* Thread Local Storage argument structure */ 109 typedef struct { 110 unsigned long int ti_module; 111 unsigned long int ti_offset; 112 } tls_index; 113 114 void *__tls_get_addr(tls_index *) __attribute__((weak)); 115 #ifdef __i386 116 void *___tls_get_addr(tls_index *) __attribute__((weak, __regparm__(1))); 117 #endif 118 119 #if defined(__amd64) || defined(__i386) || defined(__sparc64) 120 void * 121 __tls_get_addr(tls_index *ti) 122 { 123 return NULL; 124 } 125 126 #ifdef __i386 127 __attribute__((__regparm__(1))) void * 128 ___tls_get_addr(tls_index *ti) 129 { 130 return NULL; 131 } 132 #endif /* __i386 */ 133 #endif /* arch with TLS support enabled */ 134