mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-16 10:20:30 +00:00
107 lines
3.3 KiB
Groff
107 lines
3.3 KiB
Groff
.\" Copyright (c) 2000 David E. O'Brien
|
|
.\" 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.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd January 18, 2000
|
|
.Dt UAC 1
|
|
.Os
|
|
.Sh NAME
|
|
.Nm uac
|
|
.Nd Unaligned Access Message Control
|
|
.Sh SYNOPSIS
|
|
.Nm uac
|
|
.Op Fl fprs
|
|
.Sh DESCRIPTION
|
|
.Nm
|
|
sets the per-process handling of "Unaligned Access" events. Unlike many
|
|
other CPU's the DEC Alpha processor cannot access unaligned data. To work
|
|
around this, the Alpha has the ability to fix the UA fault rather than send
|
|
the faulting process a
|
|
.Dv SIGBUS
|
|
signal.
|
|
However, doing so does slow down the
|
|
execution of the faulting process.
|
|
At boot up, the DEC Alpha CPU defaults to printing
|
|
.Bl -tag -width indent
|
|
.It pid Ar nnn Pq Ar <progname> Ns Xo
|
|
.No : unaligned access: Xo
|
|
.Va va Ns = Ns Ar 0xADDR Xo
|
|
.Va pc Ns = Ns Ar 0xADDR Xo
|
|
.Va ra Ns = Ns Ar 0xADDR Xo
|
|
.Xc Va op Ns = Ns Ar ldl
|
|
.Xc
|
|
.Xc
|
|
.Xc
|
|
.Xc
|
|
.El
|
|
when a UA happens along with fixing it so
|
|
the faulting instruction can continue.
|
|
UA handling settings are inherited by child process.
|
|
Issued with out any options,
|
|
.Nm
|
|
displays the current UA handling for the parent process.
|
|
.Pp
|
|
The options are as follows:
|
|
.Bl -tag -width Fl
|
|
.It Fl f
|
|
Unaligned access errors are not fixed for the parent and its future descendants.
|
|
.It Fl p
|
|
Unaligned access errors are not printed for the parent and its future
|
|
descendants.
|
|
.It Fl r
|
|
Resets the unaligned access error settings back to their bootup defaults.
|
|
.It Fl s
|
|
Unaligned access errors result in a
|
|
.Dv SIGBUS
|
|
being delivered to the parent and
|
|
its future descendants. This aid in pin pointing the faulting access so it
|
|
debugged.
|
|
.El
|
|
.Sh DIAGNOSTICS
|
|
Exit status is 0 on success, and 1 if the command
|
|
fails for any reason.
|
|
.Sh COMPATIBILITY
|
|
The
|
|
.Nm
|
|
command syntax is incompatible with the DEC OSF/1 syntax.
|
|
.Sh SEE ALSO
|
|
.Xr signal 3
|
|
.Sh HISTORY
|
|
.Nm
|
|
first appeared in DEC OSF/1.
|
|
.Pp
|
|
.Sh AUTHORS
|
|
The
|
|
.Fx
|
|
version of
|
|
.Nm
|
|
was originally written by
|
|
.An Andrew Gallatin Aq gallatin@cs.duke.edu
|
|
and modified by
|
|
.An David E. O'Brien Aq obrien@FreeBSD.org .
|
|
This
|
|
manual page was written by
|
|
.An David E. O'Brien Aq obrien@FreeBSD.org .
|