xref: /freebsd/lib/libc/sys/swapcontext.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1 /*
2  * Copyright (c) 2001 Daniel M. Eischen <deischen@freebsd.org>
3  * Copyright (c) 2014 The FreeBSD Foundation.
4  * All rights reserved.
5  *
6  * Portions of this software were developed by Konstantin Belousov
7  * under sponsorship from the FreeBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Neither the name of the author nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/param.h>
32 #include <sys/signal.h>
33 #include <sys/ucontext.h>
34 #include <errno.h>
35 #include <stddef.h>
36 #include "libc_private.h"
37 
38 __weak_reference(__sys_swapcontext, __swapcontext);
39 __sym_compat(swapcontext, __impl_swapcontext, FBSD_1.0);
40 __weak_reference(swapcontext, __impl_swapcontext);
41 __sym_default(swapcontext, swapcontext, FBSD_1.2);
42 
43 #pragma weak swapcontext
44 int
45 swapcontext(ucontext_t *oucp, const ucontext_t *ucp)
46 {
47 	return (((int (*)(ucontext_t *, const ucontext_t *))
48 	    *(__libc_interposing_slot(INTERPOS_swapcontext)))(oucp, ucp));
49 }
50