freebsd-dev/sys/ddb/db_sysctl.c
archie cb33e8102b Add a new sysctl "debug.enter_debugger" (when the kernel is compiled
with 'options DDB').  Setting this to `ddb' or `gdb' breaks into the
kernel debugger in the corresponding mode.  This mechanism has proven
very useful at Whistle for setting breakpoints, etc., while doing
remote serial line kernel debugging.

Obtained from:	Whistle source tree
2000-01-27 22:27:34 +00:00

78 lines
2.9 KiB
C

/*
* db_sysctl.c
*
* Copyright (c) 2000 Whistle Communications, Inc.
* All rights reserved.
*
* Subject to the following obligations and disclaimer of warranty, use and
* redistribution of this software, in source or object code forms, with or
* without modifications are expressly permitted by Whistle Communications;
* provided, however, that:
* 1. Any and all reproductions of the source or object code must include the
* copyright notice above and the following disclaimer of warranties; and
* 2. No rights are granted, in any manner or form, to use Whistle
* Communications, Inc. trademarks, including the mark "WHISTLE
* COMMUNICATIONS" on advertising, endorsements, or otherwise except as
* such appears in the above copyright notice or in the software.
*
* THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
* TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
* REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
* INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
* WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
* REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
* SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
* IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
* RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
* WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
* PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER 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 WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* Author: Archie Cobbs <archie@whistle.com>
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/reboot.h>
#define DESCRIPTION "Set to `ddb' or `gdb' to enter the kernel debugger"
#define READ_MODE ""
#define MODE_DDB "ddb"
#define MODE_GDB "gdb"
static int
sysctl_debug_enter_debugger SYSCTL_HANDLER_ARGS
{
char dmode[64];
int error;
strncpy(dmode, READ_MODE, sizeof(dmode) - 1);
dmode[sizeof(dmode) - 1] = '\0';
error = sysctl_handle_string(oidp, &dmode[0], sizeof(dmode), req);
if (error == 0 && req->newptr != NULL) {
if (strcmp(dmode, MODE_DDB) == 0)
boothowto &= ~RB_GDB;
else if (strcmp(dmode, MODE_GDB) == 0)
boothowto |= RB_GDB;
else
return EINVAL;
Debugger("debug.enter_debugger");
}
return error;
}
SYSCTL_PROC(_debug, OID_AUTO, enter_debugger, CTLTYPE_STRING | CTLFLAG_RW,
0, 0, sysctl_debug_enter_debugger, "A", DESCRIPTION);