2 * Copyright (c) 1998 John D. Polstra
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
26 * $FreeBSD: src/lib/libc/gen/dlfcn.c 217154 2011-01-08 17:13:43Z kib $
35 extern char **environ;
36 void _rtld_error(const char *, ...);
38 static char sorry[] = "Service unavailable";
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.
50 #pragma weak _rtld_error
52 _rtld_error(const char *fmt __unused, ...)
58 dladdr(const void *addr __unused, Dl_info *dlip __unused)
66 dlclose(void *handle __unused)
81 dlopen(const char *name __unused, int mode __unused)
89 dlsym(void *handle __unused, const char *name __unused)
97 dlfunc(void * handle __unused, const char * name __unused)
105 dlvsym(void *handle __unused,const char *name __unused,
106 const char *version __unused)
114 dlinfo(void *handle __unused, int request __unused, void *p __unused)
120 __dso_hidden struct dl_phdr_info
121 build_phdr_info(void)
123 struct dl_phdr_info phdr_info;
125 Elf_Auxinfo *aux, *auxp;
128 sp = (Elf_Addr *) environ;
131 aux = (Elf_Auxinfo *) sp;
132 memset (&phdr_info, 0, sizeof(phdr_info));
133 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
134 switch (auxp->a_type) {
136 phdr_info.dlpi_addr = (Elf_Addr) auxp->a_un.a_ptr;
140 phdr_info.dlpi_name = (const char *) auxp->a_un.a_ptr;
144 phdr_info.dlpi_phdr = (const Elf_Phdr *) auxp->a_un.a_ptr;
148 phdr_info.dlpi_phnum = (Elf_Half) auxp->a_un.a_val;
153 for (i = 0; i < phdr_info.dlpi_phnum; i++)
154 if (phdr_info.dlpi_phdr[i].p_type == PT_TLS) {
155 phdr_info.dlpi_tls_modid = 1;
156 phdr_info.dlpi_tls_data =
157 (void*) phdr_info.dlpi_phdr[i].p_vaddr;
163 #pragma weak dl_iterate_phdr
165 dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *),
169 static struct dl_phdr_info phdr_info;
172 phdr_info = build_phdr_info();
175 return callback(&phdr_info, sizeof(phdr_info), data);
180 fdlopen(int fd __unused, int mode __unused)
186 #pragma weak _rtld_addr_phdr
188 _rtld_addr_phdr(const void *addr __unused,
189 struct dl_phdr_info *phdr_info __unused)
195 #pragma weak _rtld_get_stack_prot
197 _rtld_get_stack_prot(void)
199 return (PROT_EXEC | PROT_READ | PROT_WRITE);