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Diffstat (limited to 'lib/libc/sys/sigreturn.2')
| -rw-r--r-- | lib/libc/sys/sigreturn.2 | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/lib/libc/sys/sigreturn.2 b/lib/libc/sys/sigreturn.2 new file mode 100644 index 0000000..f995d11 --- /dev/null +++ b/lib/libc/sys/sigreturn.2 @@ -0,0 +1,97 @@ +.\" 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 BSD 4.3 +.Sh NAME +.Nm sigreturn +.Nd return from signal +.Sh SYNOPSIS +.Fd #include <signal.h> +.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 4.2 +.Tn BSD +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 [EINVAL] +.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 sigvec 2 , +.Xr setjmp 3 +.Sh HISTORY +The +.Nm +function call appeared in +.Bx 4.3 . |
