.\" $NetBSD: sigreturn.2,v 1.12 2001/09/16 01:39:03 wiz Exp $ .\" .\" Copyright (c) 1985, 1991, 1993 .\" The Regents of the University of California. 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. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. .\" .\" @(#)sigreturn.2 8.1 (Berkeley) 6/4/93 .\" .Dd June 4, 1993 .Dt SIGRETURN 2 .Os .Sh NAME .Nm sigreturn .Nd return from signal .Sh LIBRARY .Lb libc .Sh SYNOPSIS .Fd #include .Bd -literal struct sigcontext { int sc_onstack; int sc_mask; int sc_sp; int sc_fp; int sc_ap; int sc_pc; int sc_ps; }; .Ed .Ft int .Fn sigreturn "struct sigcontext *scp" .Sh DESCRIPTION .Fn sigreturn allows users to atomically unmask, switch stacks, and return from a signal context. The processes signal mask and stack status are restored from the context. The system call does not return; the users stack pointer, frame pointer, argument pointer, and processor status longword are restored from the context. Execution resumes at the specified pc. This system call is used by the trampoline code and .Xr longjmp 3 when returning from a signal to the previously executing program. .Sh NOTES This system call is not available in .Bx 4.2 hence it should not be used if backward compatibility is needed. .Sh RETURN VALUES If successful, the system call does not return. Otherwise, a value of -1 is returned and .Va errno is set to indicate the error. .Sh ERRORS .Fn sigreturn will fail and the process context will remain unchanged if one of the following occurs. .Bl -tag -width Er .It Bq Er EFAULT .Fa scp points to memory that is not a valid part of the process address space. .It Bq Er EINVAL The process status longword is invalid or would improperly raise the privilege level of the process. .El .Sh SEE ALSO .Xr sigaction 2 , .Xr setjmp 3 , .Xr signal 7 .Sh HISTORY The .Fn sigreturn function call appeared in .Bx 4.3 . .wiz 2014-09-26add VIS_META/VIS_SHELL support to encode all shell metacharacters.christos XXX: /etc/rc.d/wizd fix $ 2013-10-29Small typo. From Michael W. Bombardieri.njoly 2013-03-14Add missing .El macro.njoly 2013-02-27update dates, versionchristos 2013-02-14do the encoding character by character instead of failing on encoding mismatchchristos 2013-02-14Mark up LC_CTYPE with Ev (didn't I just do this? :) ).wiz 2013-02-13Multi-byte docs and fixes for > 2 mblen charsets from J.R. Oldroydchristos 2009-02-10Add RFC 2045 MIME Quoted-Printable support.christos 2004-04-22fix silly cut & paste error in -h descriptionlukem 2004-04-22Add -h to enable VIS_HTTPSTYLE.lukem Reorder getopt & usage strings to be alphabetical to match man page. 2003-08-07Move UCB-licensed code from 4-clause to 3-clause licence.agc Patches provided by Joel Baker in PR 22365, verified by myself. 2002-12-23Implement '-e extra', as per svis(3)'s "extra" argument.lukem Document which vis(3) flag particular options enable (for easier cross referencing between vis(1) and vis(3)) 2002-09-30New sentence, new line.grant 2000-10-05Move out-of-order line to where it belongs.wennmach