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;
37 static char sorry[] = "Service unavailable";
40 * For ELF, the dynamic linker directly resolves references to its
41 * services to functions inside the dynamic linker itself. These
42 * weak-symbol stubs are necessary so that "ld" won't complain about
43 * undefined symbols. The stubs are executed only when the program is
44 * linked statically, or when a given service isn't implemented in the
45 * dynamic linker. They must return an error if called, and they must
46 * be weak symbols so that the dynamic linker can override them.
49 #pragma weak _rtld_error
51 _rtld_error(const char *fmt __unused, ...)
57 dladdr(const void *addr __unused, Dl_info *dlip __unused)
65 dlclose(void *handle __unused)
80 dlopen(const char *name __unused, int mode __unused)
88 dlsym(void *handle __unused, const char *name __unused)
96 dlfunc(void * handle __unused, const char * name __unused)
104 dlvsym(void *handle __unused,const char *name __unused,
105 const char *version __unused)
111 #pragma weak _rtld_thread_init
113 _rtld_thread_init(void * li)
120 dlinfo(void *handle __unused, int request __unused, void *p __unused)
126 __dso_hidden struct dl_phdr_info
127 build_phdr_info(void)
129 struct dl_phdr_info phdr_info;
131 Elf_Auxinfo *aux, *auxp;
134 sp = (Elf_Addr *) environ;
137 aux = (Elf_Auxinfo *) sp;
138 memset (&phdr_info, 0, sizeof(phdr_info));
139 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
140 switch (auxp->a_type) {
142 phdr_info.dlpi_addr = (Elf_Addr) auxp->a_un.a_ptr;
145 phdr_info.dlpi_name = (const char *) auxp->a_un.a_ptr;
148 phdr_info.dlpi_phdr = (const Elf_Phdr *) auxp->a_un.a_ptr;
151 phdr_info.dlpi_phnum = (Elf_Half) auxp->a_un.a_val;
156 for (i = 0; i < phdr_info.dlpi_phnum; i++)
157 if (phdr_info.dlpi_phdr[i].p_type == PT_TLS) {
158 phdr_info.dlpi_tls_modid = 1;
159 phdr_info.dlpi_tls_data =
160 (void*)phdr_info.dlpi_phdr[i].p_vaddr;
166 #pragma weak dl_iterate_phdr
168 dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *),
172 static struct dl_phdr_info phdr_info;
175 phdr_info = build_phdr_info();
178 return callback(&phdr_info, sizeof(phdr_info), data);
183 fdlopen(int fd __unused, int mode __unused)
189 #pragma weak _rtld_addr_phdr
191 _rtld_addr_phdr(const void *addr __unused,
192 struct dl_phdr_info *phdr_info __unused)
198 #pragma weak _rtld_get_stack_prot
200 _rtld_get_stack_prot(void)
202 return (PROT_EXEC | PROT_READ | PROT_WRITE);