freebsd-nq/lib/libc/i386/sys/i386_set_watch.c
Pedro F. Giffuni d915a14ef0 libc: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-25 17:12:48 +00:00

87 lines
2.5 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright 2000 Brian S. Dean <bsd@bsdhome.com>
* 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 BRIAN S. DEAN ``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 BRIAN S. DEAN 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <machine/reg.h>
#include <machine/sysarch.h>
int
i386_set_watch(int watchnum, unsigned int watchaddr, int size,
int access, struct dbreg * d)
{
int i;
unsigned int mask;
if (watchnum == -1) {
for (i = 0, mask = 0x3; i < 4; i++, mask <<= 2)
if ((DBREG_DRX(d,7) & mask) == 0)
break;
if (i < 4)
watchnum = i;
else
return -1;
}
switch (access) {
case DBREG_DR7_EXEC:
size = 1; /* size must be 1 for an execution breakpoint */
/* fall through */
case DBREG_DR7_WRONLY:
case DBREG_DR7_RDWR:
break;
default : return -1; break;
}
/*
* we can watch a 1, 2, or 4 byte sized location
*/
switch (size) {
case 1 : mask = 0x00; break;
case 2 : mask = 0x01 << 2; break;
case 4 : mask = 0x03 << 2; break;
default : return -1; break;
}
mask |= access;
/* clear the bits we are about to affect */
DBREG_DRX(d,7) &= ~((0x3 << (watchnum*2)) | (0x0f << (watchnum*4+16)));
/* set drN register to the address, N=watchnum */
DBREG_DRX(d,watchnum) = watchaddr;
/* enable the watchpoint */
DBREG_DRX(d,7) |= (0x2 << (watchnum*2)) | (mask << (watchnum*4+16));
return watchnum;
}