2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 1998 John D. Polstra
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #if !defined(IN_LIBDL) || defined(PIC)
35 * Linkage to services provided by the dynamic linker.
37 #include <sys/types.h>
39 #include <machine/atomic.h>
43 #include "namespace.h"
45 #include "un-namespace.h"
47 #include "libc_private.h"
48 #include "reentrant.h"
50 static const char sorry[] = "Service unavailable";
52 void _rtld_thread_init(void *);
53 void _rtld_atfork_pre(int *);
54 void _rtld_atfork_post(int *);
57 * For ELF, the dynamic linker directly resolves references to its
58 * services to functions inside the dynamic linker itself. These
59 * weak-symbol stubs are necessary so that "ld" won't complain about
60 * undefined symbols. The stubs are executed only when the program is
61 * linked statically, or when a given service isn't implemented in the
62 * dynamic linker. They must return an error if called, and they must
63 * be weak symbols so that the dynamic linker can override them.
66 #pragma weak _rtld_error
68 _rtld_error(const char *fmt __unused, ...)
74 dladdr(const void *addr __unused, Dl_info *dlip __unused)
83 dlclose(void *handle __unused)
95 return (__DECONST(char *, sorry));
98 #pragma weak dllockinit
100 dllockinit(void *context,
101 void *(*lock_create)(void *context) __unused,
102 void (*rlock_acquire)(void *lock) __unused,
103 void (*wlock_acquire)(void *lock) __unused,
104 void (*lock_release)(void *lock) __unused,
105 void (*lock_destroy)(void *lock) __unused,
106 void (*context_destroy)(void *context) __unused)
109 if (context_destroy != NULL)
110 context_destroy(context);
115 dlopen(const char *name __unused, int mode __unused)
124 dlsym(void * __restrict handle __unused, const char * __restrict name __unused)
133 dlfunc(void * __restrict handle __unused, const char * __restrict name __unused)
142 dlvsym(void * __restrict handle __unused, const char * __restrict name __unused,
143 const char * __restrict version __unused)
152 dlinfo(void * __restrict handle __unused, int request __unused,
153 void * __restrict p __unused)
160 #pragma weak _rtld_thread_init
162 _rtld_thread_init(void *li __unused)
169 static pthread_once_t dl_phdr_info_once = PTHREAD_ONCE_INIT;
170 static struct dl_phdr_info phdr_info;
171 static mutex_t dl_phdr_info_lock = MUTEX_INITIALIZER;
174 dl_init_phdr_info(void)
179 for (auxp = __elf_aux_vector; auxp->a_type != AT_NULL; auxp++) {
180 switch (auxp->a_type) {
182 phdr_info.dlpi_addr = (Elf_Addr)auxp->a_un.a_ptr;
185 phdr_info.dlpi_name = (const char *)auxp->a_un.a_ptr;
188 phdr_info.dlpi_phdr =
189 (const Elf_Phdr *)auxp->a_un.a_ptr;
192 phdr_info.dlpi_phnum = (Elf_Half)auxp->a_un.a_val;
196 for (i = 0; i < phdr_info.dlpi_phnum; i++) {
197 if (phdr_info.dlpi_phdr[i].p_type == PT_TLS) {
198 phdr_info.dlpi_tls_modid = 1;
201 phdr_info.dlpi_adds = 1;
205 #pragma weak dl_iterate_phdr
207 dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *) __unused,
214 __init_elf_aux_vector();
215 if (__elf_aux_vector == NULL)
217 _once(&dl_phdr_info_once, dl_init_phdr_info);
220 mutex_lock(&dl_phdr_info_lock);
221 phdr_info.dlpi_tls_data = __tls_get_addr(&ti);
222 ret = callback(&phdr_info, sizeof(phdr_info), data);
223 mutex_unlock(&dl_phdr_info_lock);
232 fdlopen(int fd __unused, int mode __unused)
239 #pragma weak _rtld_atfork_pre
241 _rtld_atfork_pre(int *locks __unused)
245 #pragma weak _rtld_atfork_post
247 _rtld_atfork_post(int *locks __unused)
251 #pragma weak _rtld_addr_phdr
253 _rtld_addr_phdr(const void *addr __unused,
254 struct dl_phdr_info *phdr_info_a __unused)
260 #pragma weak _rtld_get_stack_prot
262 _rtld_get_stack_prot(void)
269 r = atomic_load_int(&ret);
273 _once(&dl_phdr_info_once, dl_init_phdr_info);
274 r = PROT_EXEC | PROT_READ | PROT_WRITE;
275 for (i = 0; i < phdr_info.dlpi_phnum; i++) {
276 if (phdr_info.dlpi_phdr[i].p_type != PT_GNU_STACK)
278 r = PROT_READ | PROT_WRITE;
279 if ((phdr_info.dlpi_phdr[i].p_flags & PF_X) != 0)
283 atomic_store_int(&ret, r);
290 #pragma weak _rtld_is_dlopened
292 _rtld_is_dlopened(void *arg __unused)
298 #endif /* !defined(IN_LIBDL) || defined(PIC) */