212 строки
5.2 KiB
C
212 строки
5.2 KiB
C
/*
|
|
* SoftDog: A Software Watchdog Device
|
|
*
|
|
* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
|
|
* All Rights Reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*
|
|
* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
|
|
* warranty for any of this software. This material is provided
|
|
* "AS-IS" and at no charge.
|
|
*
|
|
* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
|
|
*
|
|
* Software only watchdog driver. Unlike its big brother the WDT501P
|
|
* driver this won't always recover a failed machine.
|
|
*
|
|
* 03/96: Angelo Haritsis <ah@doc.ic.ac.uk> :
|
|
* Modularised.
|
|
* Added soft_margin; use upon insmod to change the timer delay.
|
|
* NB: uses same minor as wdt (WATCHDOG_MINOR); we could use separate
|
|
* minors.
|
|
*
|
|
* 19980911 Alan Cox
|
|
* Made SMP safe for 2.3.x
|
|
*
|
|
* 20011127 Joel Becker (jlbec@evilplan.org>
|
|
* Added soft_noboot; Allows testing the softdog trigger without
|
|
* requiring a recompile.
|
|
* Added WDIOC_GETTIMEOUT and WDIOC_SETTIMOUT.
|
|
*
|
|
* 20020530 Joel Becker <joel.becker@oracle.com>
|
|
* Added Matt Domsch's nowayout module option.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/types.h>
|
|
#include <linux/timer.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/init.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/kernel.h>
|
|
|
|
#define TIMER_MARGIN 60 /* Default is 60 seconds */
|
|
static unsigned int soft_margin = TIMER_MARGIN; /* in seconds */
|
|
module_param(soft_margin, uint, 0);
|
|
MODULE_PARM_DESC(soft_margin,
|
|
"Watchdog soft_margin in seconds. (0 < soft_margin < 65536, default="
|
|
__MODULE_STRING(TIMER_MARGIN) ")");
|
|
|
|
static bool nowayout = WATCHDOG_NOWAYOUT;
|
|
module_param(nowayout, bool, 0);
|
|
MODULE_PARM_DESC(nowayout,
|
|
"Watchdog cannot be stopped once started (default="
|
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|
|
|
|
static int soft_noboot = 0;
|
|
module_param(soft_noboot, int, 0);
|
|
MODULE_PARM_DESC(soft_noboot,
|
|
"Softdog action, set to 1 to ignore reboots, 0 to reboot (default=0)");
|
|
|
|
static int soft_panic;
|
|
module_param(soft_panic, int, 0);
|
|
MODULE_PARM_DESC(soft_panic,
|
|
"Softdog action, set to 1 to panic, 0 to reboot (default=0)");
|
|
|
|
/*
|
|
* Our timer
|
|
*/
|
|
|
|
static void watchdog_fire(unsigned long);
|
|
|
|
static struct timer_list watchdog_ticktock =
|
|
TIMER_INITIALIZER(watchdog_fire, 0, 0);
|
|
|
|
/*
|
|
* If the timer expires..
|
|
*/
|
|
|
|
static void watchdog_fire(unsigned long data)
|
|
{
|
|
if (soft_noboot)
|
|
pr_crit("Triggered - Reboot ignored\n");
|
|
else if (soft_panic) {
|
|
pr_crit("Initiating panic\n");
|
|
panic("Software Watchdog Timer expired");
|
|
} else {
|
|
pr_crit("Initiating system reboot\n");
|
|
emergency_restart();
|
|
pr_crit("Reboot didn't ?????\n");
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Softdog operations
|
|
*/
|
|
|
|
static int softdog_ping(struct watchdog_device *w)
|
|
{
|
|
mod_timer(&watchdog_ticktock, jiffies+(w->timeout*HZ));
|
|
return 0;
|
|
}
|
|
|
|
static int softdog_stop(struct watchdog_device *w)
|
|
{
|
|
del_timer(&watchdog_ticktock);
|
|
return 0;
|
|
}
|
|
|
|
static int softdog_set_timeout(struct watchdog_device *w, unsigned int t)
|
|
{
|
|
w->timeout = t;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Notifier for system down
|
|
*/
|
|
|
|
static int softdog_notify_sys(struct notifier_block *this, unsigned long code,
|
|
void *unused)
|
|
{
|
|
if (code == SYS_DOWN || code == SYS_HALT)
|
|
/* Turn the WDT off */
|
|
softdog_stop(NULL);
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
/*
|
|
* Kernel Interfaces
|
|
*/
|
|
|
|
static struct notifier_block softdog_notifier = {
|
|
.notifier_call = softdog_notify_sys,
|
|
};
|
|
|
|
static struct watchdog_info softdog_info = {
|
|
.identity = "Software Watchdog",
|
|
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
|
|
};
|
|
|
|
static struct watchdog_ops softdog_ops = {
|
|
.owner = THIS_MODULE,
|
|
.start = softdog_ping,
|
|
.stop = softdog_stop,
|
|
.ping = softdog_ping,
|
|
.set_timeout = softdog_set_timeout,
|
|
};
|
|
|
|
static struct watchdog_device softdog_dev = {
|
|
.info = &softdog_info,
|
|
.ops = &softdog_ops,
|
|
.min_timeout = 1,
|
|
.max_timeout = 0xFFFF
|
|
};
|
|
|
|
static int __init watchdog_init(void)
|
|
{
|
|
int ret;
|
|
|
|
/* Check that the soft_margin value is within it's range;
|
|
if not reset to the default */
|
|
if (soft_margin < 1 || soft_margin > 65535) {
|
|
pr_info("soft_margin must be 0 < soft_margin < 65536, using %d\n",
|
|
TIMER_MARGIN);
|
|
return -EINVAL;
|
|
}
|
|
softdog_dev.timeout = soft_margin;
|
|
|
|
watchdog_set_nowayout(&softdog_dev, nowayout);
|
|
|
|
ret = register_reboot_notifier(&softdog_notifier);
|
|
if (ret) {
|
|
pr_err("cannot register reboot notifier (err=%d)\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
ret = watchdog_register_device(&softdog_dev);
|
|
if (ret) {
|
|
unregister_reboot_notifier(&softdog_notifier);
|
|
return ret;
|
|
}
|
|
|
|
pr_info("Software Watchdog Timer: 0.08 initialized. soft_noboot=%d soft_margin=%d sec soft_panic=%d (nowayout=%d)\n",
|
|
soft_noboot, soft_margin, soft_panic, nowayout);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit watchdog_exit(void)
|
|
{
|
|
watchdog_unregister_device(&softdog_dev);
|
|
unregister_reboot_notifier(&softdog_notifier);
|
|
}
|
|
|
|
module_init(watchdog_init);
|
|
module_exit(watchdog_exit);
|
|
|
|
MODULE_AUTHOR("Alan Cox");
|
|
MODULE_DESCRIPTION("Software Watchdog Device Driver");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|