1 /* $NetBSD: hijackdlsym.c,v 1.5 2013/09/10 16:53:06 pooka Exp $ */
2
3 /*-
4 * Copyright (c) 2011 Antti Kantee. All Rights Reserved.
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 ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * 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 #include <rump/rumpuser_port.h>
29
30 #if !defined(lint)
31 __RCSID("$NetBSD: hijackdlsym.c,v 1.5 2013/09/10 16:53:06 pooka Exp $");
32 #endif
33
34 #include <dlfcn.h>
35
36 #include "hijack.h"
37
38 /*
39 * This is called from librumpclient in case of LD_PRELOAD.
40 * It ensures correct RTLD_NEXT.
41 *
42 * (note, this module is compiled with -O0 to make sure this
43 * function is not treated as a tailcall or other optimizations
44 * applied)
45 */
46
47 /* why is this indirection required for powerpc ???? */
48 static void * __noinline
bouncer(void * handle,const char * symbol)49 bouncer(void *handle, const char *symbol)
50 {
51
52 return dlsym(handle, symbol);
53 }
54
55 void *
rumphijack_dlsym(void * handle,const char * symbol)56 rumphijack_dlsym(void *handle, const char *symbol)
57 {
58
59 return bouncer(handle, symbol);
60 }
61