1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
/* UML hardware watchdog, shamelessly stolen from:
*
* SoftDog 0.05: A Software Watchdog Device
*
* (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
* http://www.redhat.com
*
* 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.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/reboot.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <asm/uaccess.h>
#include "mconsole.h"
MODULE_LICENSE("GPL");
/* Locked by the BKL in harddog_open and harddog_release */
static int timer_alive;
static int harddog_in_fd = -1;
static int harddog_out_fd = -1;
/*
* Allow only one person to hold it open
*/
extern int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock);
static int harddog_open(struct inode *inode, struct file *file)
{
int err;
char *sock = NULL;
lock_kernel();
if(timer_alive)
return -EBUSY;
#ifdef CONFIG_HARDDOG_NOWAYOUT
__module_get(THIS_MODULE);
#endif
#ifdef CONFIG_MCONSOLE
sock = mconsole_notify_socket();
#endif
err = start_watchdog(&harddog_in_fd, &harddog_out_fd, sock);
if(err) return(err);
timer_alive = 1;
unlock_kernel();
return nonseekable_open(inode, file);
}
extern void stop_watchdog(int in_fd, int out_fd);
static int harddog_release(struct inode *inode, struct file *file)
{
/*
* Shut off the timer.
*/
lock_kernel();
stop_watchdog(harddog_in_fd, harddog_out_fd);
harddog_in_fd = -1;
harddog_out_fd = -1;
timer_alive=0;
unlock_kernel();
return 0;
}
extern int ping_watchdog(int fd);
static ssize_t harddog_write(struct file *file, const char __user *data, size_t len,
loff_t *ppos)
{
/*
* Refresh the timer.
*/
if(len)
return(ping_watchdog(harddog_out_fd));
return 0;
}
static int harddog_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
void __user *argp= (void __user *)arg;
static struct watchdog_info ident = {
WDIOC_SETTIMEOUT,
0,
"UML Hardware Watchdog"
};
switch (cmd) {
default:
return -ENOTTY;
case WDIOC_GETSUPPORT:
if(copy_to_user(argp, &ident, sizeof(ident)))
return -EFAULT;
return 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0,(int __user *)argp);
case WDIOC_KEEPALIVE:
return(ping_watchdog(harddog_out_fd));
}
}
static struct file_operations harddog_fops = {
.owner = THIS_MODULE,
.write = harddog_write,
.ioctl = harddog_ioctl,
.open = harddog_open,
.release = harddog_release,
};
static struct miscdevice harddog_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &harddog_fops,
};
static char banner[] __initdata = KERN_INFO "UML Watchdog Timer\n";
static int __init harddog_init(void)
{
int ret;
ret = misc_register(&harddog_miscdev);
if (ret)
return ret;
printk(banner);
return(0);
}
static void __exit harddog_exit(void)
{
misc_deregister(&harddog_miscdev);
}
module_init(harddog_init);
module_exit(harddog_exit);
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/
|
