freebsd-dev/lib/libc/gen/dlfcn.c
Konstantin Belousov 5d8aec9c02 Implement fdlopen(3), an rtld interface to load shared object by file
descriptor.

Requested and tested by:	des (previous version)
Reviewed by:  des, kan (previous version)
MFC after:    2 weeks
2012-01-07 10:33:01 +00:00

187 lines
4.0 KiB
C

/*-
* Copyright (c) 1998 John D. Polstra
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Linkage to services provided by the dynamic linker.
*/
#include <sys/mman.h>
#include <dlfcn.h>
#include <link.h>
#include <stddef.h>
static char sorry[] = "Service unavailable";
/*
* For ELF, the dynamic linker directly resolves references to its
* services to functions inside the dynamic linker itself. These
* weak-symbol stubs are necessary so that "ld" won't complain about
* undefined symbols. The stubs are executed only when the program is
* linked statically, or when a given service isn't implemented in the
* dynamic linker. They must return an error if called, and they must
* be weak symbols so that the dynamic linker can override them.
*/
#pragma weak _rtld_error
void
_rtld_error(const char *fmt, ...)
{
}
#pragma weak dladdr
int
dladdr(const void *addr, Dl_info *dlip)
{
_rtld_error(sorry);
return 0;
}
#pragma weak dlclose
int
dlclose(void *handle)
{
_rtld_error(sorry);
return -1;
}
#pragma weak dlerror
char *
dlerror(void)
{
return sorry;
}
#pragma weak dllockinit
void
dllockinit(void *context,
void *(*lock_create)(void *context),
void (*rlock_acquire)(void *lock),
void (*wlock_acquire)(void *lock),
void (*lock_release)(void *lock),
void (*lock_destroy)(void *lock),
void (*context_destroy)(void *context))
{
if (context_destroy != NULL)
context_destroy(context);
}
#pragma weak dlopen
void *
dlopen(const char *name, int mode)
{
_rtld_error(sorry);
return NULL;
}
#pragma weak dlsym
void *
dlsym(void * __restrict handle, const char * __restrict name)
{
_rtld_error(sorry);
return NULL;
}
#pragma weak dlfunc
dlfunc_t
dlfunc(void * __restrict handle, const char * __restrict name)
{
_rtld_error(sorry);
return NULL;
}
#pragma weak dlvsym
void *
dlvsym(void * __restrict handle, const char * __restrict name,
const char * __restrict version)
{
_rtld_error(sorry);
return NULL;
}
#pragma weak dlinfo
int
dlinfo(void * __restrict handle, int request, void * __restrict p)
{
_rtld_error(sorry);
return 0;
}
#pragma weak _rtld_thread_init
void
_rtld_thread_init(void * li)
{
_rtld_error(sorry);
}
#pragma weak dl_iterate_phdr
int
dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *),
void *data)
{
_rtld_error(sorry);
return 0;
}
#pragma weak fdlopen
void *
fdlopen(int fd, int mode)
{
_rtld_error(sorry);
return NULL;
}
#pragma weak _rtld_atfork_pre
void
_rtld_atfork_pre(int *locks)
{
}
#pragma weak _rtld_atfork_post
void
_rtld_atfork_post(int *locks)
{
}
#pragma weak _rtld_addr_phdr
int
_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info)
{
return (0);
}
#pragma weak _rtld_get_stack_prot
int
_rtld_get_stack_prot(void)
{
return (PROT_EXEC | PROT_READ | PROT_WRITE);
}