1 .\" Copyright (c) 1985, 1991, 1993
2 .\" The Regents of the University of California. All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
7 .\" 1. Redistributions of source code must retain the above copyright
8 .\" notice, this list of conditions and the following disclaimer.
9 .\" 2. Redistributions in binary form must reproduce the above copyright
10 .\" notice, this list of conditions and the following disclaimer in the
11 .\" documentation and/or other materials provided with the distribution.
12 .\" 3. All advertising materials mentioning features or use of this software
13 .\" must display the following acknowledgement:
14 .\" This product includes software developed by the University of
15 .\" California, Berkeley and its contributors.
16 .\" 4. Neither the name of the University nor the names of its contributors
17 .\" may be used to endorse or promote products derived from this software
18 .\" without specific prior written permission.
20 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 .\" @(#)sigreturn.2 8.1 (Berkeley) 6/4/93
33 .\" $FreeBSD: src/lib/libc/sys/sigreturn.2,v 1.6.2.6 2002/09/15 00:33:23 archie Exp $
34 .\" $DragonFly: src/lib/libc/sys/sigreturn.2,v 1.2 2003/06/17 04:26:47 dillon Exp $
41 .Nd return from signal
47 .Fn sigreturn "ucontext_t *scp"
50 allows users to atomically unmask, switch stacks,
51 and return from a signal context.
52 The processes signal mask and stack status are
53 restored from the context structure pointed to by
55 The system call does not return;
56 the users stack pointer, frame pointer, argument pointer,
57 and processor status longword are restored from the context.
58 Execution resumes at the specified pc.
59 This system call is used by the trampoline code and
61 when returning from a signal to the previously executing program.
63 This system call is not available in
65 hence it should not be used if backward compatibility is needed.
67 If successful, the system call does not return.
68 Otherwise, a value of -1 is returned and
70 is set to indicate the error.
73 will fail and the process context will remain unchanged
74 if one of the following occurs.
78 points to memory that is not a valid part of the process
81 The process status longword is invalid or would improperly
82 raise the privilege level of the process.
91 function call appeared in