linux/arch/um/drivers/harddog_kern.c
Al Viro cb787f4ac0 [tree-wide] finally take no_llseek out
no_llseek had been defined to NULL two years ago, in commit 868941b144
("fs: remove no_llseek")

To quote that commit,

  At -rc1 we'll need do a mechanical removal of no_llseek -

  git grep -l -w no_llseek | grep -v porting.rst | while read i; do
	sed -i '/\<no_llseek\>/d' $i
  done

  would do it.

Unfortunately, that hadn't been done.  Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
	.llseek = no_llseek,
so it's obviously safe.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-09-27 08:18:43 -07:00

175 lines
4.0 KiB
C

/* 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/mutex.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include "mconsole.h"
#include "harddog.h"
MODULE_DESCRIPTION("UML hardware watchdog");
MODULE_LICENSE("GPL");
static DEFINE_MUTEX(harddog_mutex);
static DEFINE_SPINLOCK(lock);
static int timer_alive;
static int harddog_in_fd = -1;
static int harddog_out_fd = -1;
/*
* Allow only one person to hold it open
*/
static int harddog_open(struct inode *inode, struct file *file)
{
int err = -EBUSY;
char *sock = NULL;
mutex_lock(&harddog_mutex);
spin_lock(&lock);
if(timer_alive)
goto err;
#ifdef CONFIG_WATCHDOG_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)
goto err;
timer_alive = 1;
spin_unlock(&lock);
mutex_unlock(&harddog_mutex);
return stream_open(inode, file);
err:
spin_unlock(&lock);
mutex_unlock(&harddog_mutex);
return err;
}
static int harddog_release(struct inode *inode, struct file *file)
{
/*
* Shut off the timer.
*/
spin_lock(&lock);
stop_watchdog(harddog_in_fd, harddog_out_fd);
harddog_in_fd = -1;
harddog_out_fd = -1;
timer_alive=0;
spin_unlock(&lock);
return 0;
}
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_unlocked(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 long harddog_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
long ret;
mutex_lock(&harddog_mutex);
ret = harddog_ioctl_unlocked(file, cmd, arg);
mutex_unlock(&harddog_mutex);
return ret;
}
static const struct file_operations harddog_fops = {
.owner = THIS_MODULE,
.write = harddog_write,
.unlocked_ioctl = harddog_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.open = harddog_open,
.release = harddog_release,
};
static struct miscdevice harddog_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &harddog_fops,
};
module_misc_device(harddog_miscdev);