1 /* $OpenBSD: dlfcn_stubs.c,v 1.18 2020/10/09 16:31:03 otto 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 <stdio.h>
32 #include <link.h>
33 #include <dlfcn.h>
34 #include <tib.h>
35
36 #include "init.h"
37
38 static int dlerror_ret;
39
40 void *
dlopen(const char * libname,int how)41 dlopen(const char *libname, int how)
42 {
43 if (_dl_cb != NULL && _dl_cb->dlopen != NULL)
44 return _dl_cb->dlopen(libname, how);
45 return NULL;
46 }
47
48 int
dlclose(void * handle)49 dlclose(void *handle)
50 {
51 if (_dl_cb != NULL && _dl_cb->dlclose != NULL)
52 return _dl_cb->dlclose(handle);
53 dlerror_ret = 1;
54 return -1;
55 }
56
57 void *
dlsym(void * handle,const char * name)58 dlsym(void *handle, const char *name)
59 {
60 if (_dl_cb != NULL && _dl_cb->dlsym != NULL)
61 return _dl_cb->dlsym(handle, name);
62 dlerror_ret = 1;
63 return NULL;
64 }
65
66 int
dlctl(void * handle,int command,void * data)67 dlctl(void *handle, int command, void *data)
68 {
69 if (_dl_cb != NULL && _dl_cb->dlctl != NULL)
70 return _dl_cb->dlctl(handle, command, data);
71 dlerror_ret = 1;
72 return -1;
73 }
74 DEF_WEAK(dlctl);
75
76 char *
dlerror(void)77 dlerror(void)
78 {
79 if (_dl_cb != NULL && _dl_cb->dlerror != NULL)
80 return _dl_cb->dlerror();
81 if (dlerror_ret) {
82 dlerror_ret = 0;
83 return _dl_cb == NULL ? "No dynamic linker" :
84 "Incompatible dynamic linker";
85 }
86 return NULL;
87 }
88
89 int
dl_iterate_phdr(int (* callback)(struct dl_phdr_info *,size_t,void *),void * data)90 dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *),
91 void *data)
92 {
93 if (_dl_cb != NULL && _dl_cb->dl_iterate_phdr != NULL)
94 return _dl_cb->dl_iterate_phdr(callback, data);
95 #ifndef PIC
96 if (_static_phdr_info.dlpi_phdr != NULL)
97 return callback(&_static_phdr_info, sizeof(_static_phdr_info),
98 data);
99 #endif /* !PIC */
100 return -1;
101 }
102 DEF_WEAK(dl_iterate_phdr);
103
104 int
dladdr(const void * addr,struct dl_info * info)105 dladdr(const void *addr, struct dl_info *info)
106 {
107 if (_dl_cb != NULL && _dl_cb->dladdr != NULL)
108 return _dl_cb->dladdr(addr, info);
109 dlerror_ret = 1;
110 return 0;
111 }
112 DEF_WEAK(dladdr);
113
114 #if 0
115 /* Thread Local Storage argument structure */
116 typedef struct {
117 unsigned long int ti_module;
118 unsigned long int ti_offset;
119 } tls_index;
120
121 void *__tls_get_addr(tls_index *) __attribute__((weak));
122 #ifdef __i386
123 void *___tls_get_addr(tls_index *) __attribute__((weak, __regparm__(1)));
124 #endif
125
126 #if defined(__amd64) || defined(__i386) || defined(__sparc64)
127 void *
128 __tls_get_addr(tls_index *ti)
129 {
130 return NULL;
131 }
132
133 #ifdef __i386
134 __attribute__((__regparm__(1))) void *
135 ___tls_get_addr(tls_index *ti)
136 {
137 return NULL;
138 }
139 #endif /* __i386 */
140 #endif /* arch with TLS support enabled */
141 #endif
142