1.\" Copyright (c) 2000 Brian S. Dean 2.\" All rights reserved. 3.\" 4.\" This man-page is based on a similar man-page by Jonathan Lemon 5.\" which is copyrighted under the following conditions: 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.Dd August 24, 2000 29.Dt I386_SET_WATCH 3 30.Os 31.Sh NAME 32.Nm i386_clr_watch , 33.Nm i386_set_watch 34.Nd manage i386 debug register values 35.Sh LIBRARY 36.Lb libc 37.Sh SYNOPSIS 38.In machine/reg.h 39.In machine/sysarch.h 40.Ft int 41.Fn i386_clr_watch "int watchnum" "struct dbreg *d" 42.Ft int 43.Fn i386_set_watch "int watchnum" "unsigned int watchaddr" "int size" "int access" "struct dbreg *d" 44.Sh DESCRIPTION 45The 46.Fn i386_clr_watch 47function 48will disable the indicated watch point within the specified debug 49register set. 50.Pp 51The 52.Fn i386_set_watch 53function 54will set up the specified debug registers as indicated by the 55arguments. 56The 57.Fa watchnum 58argument specifies which watch register is used, 0, 1, 2, 3, or \-1. 59If 60.Fa watchnum 61is \-1, a free watch register is found and used. 62If there are no free 63watch registers, an error code of \-1 is returned. 64The 65.Fa watchaddr 66argument 67specifies the watch address, 68.Fa size 69specifies the size in bytes of the area to be watched (1, 2, or 4 bytes), 70and 71.Fa access 72specifies the type of watch point: 73.Pp 74.Bd -literal -offset indent -compact 75DBREG_DR7_EXEC An execution breakpoint. 76DBREG_DR7_WRONLY Break only when the watch area is written to. 77DBREG_DR7_RDWR Break when the watch area is read from or written 78 to. 79.Ed 80.Pp 81Note that these functions do not actually set or clear breakpoints; 82they manipulate the indicated debug register set. 83You must use 84.Xr ptrace 2 85to retrieve and install the debug register values for a process. 86.Sh RETURN VALUES 87On success, the 88.Fn i386_clr_watch 89function returns 0. 90On error, \-1 returned which indicates that 91.Fa watchnum 92is invalid (not in the range of 0-3). 93If the specified watchnum was already disabled, no error is returned. 94.Pp 95On success, the 96.Fn i386_set_watch 97function returns the 98.Fa watchnum 99argument, or the watchnum actually used in the case where the specified 100.Fa watchnum 101was \-1. 102On error, the 103.Fn i386_set_watch 104function returns \-1 indicating that the watchpoint could not established 105because either no more watchpoints are available, or 106.Fa watchnum , 107.Fa size , 108or 109.Fa access 110is invalid. 111.Sh SEE ALSO 112.Xr ptrace 2 , 113.Xr procfs 4 114.Sh AUTHORS 115This man page was written by 116.An Brian S. Dean . 117