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SubjectRe: AT91SAM9/CAP9 watchdog driver

> +static long at91_wdt_ioctl(struct file *file, unsigned int cmd,
> + unsigned long arg)
> +{
> + void __user *argp = (void __user *)arg;
> + int __user *p = argp;

No locking.. so you could get two set timeout calls in parallel. Probably
you need a simple mutex in at91_wdt_settimeout();


> + res = misc_register(&at91wdt_miscdev);
> + if (res)
> + return res;
> +
> + /* Set watchdog */
> + if (at91_wdt_settimeout(wdt_timeout) == -EINVAL) {
> + pr_info("at91sam9_wdt: timeout must be between 1 and %d.\n",
> + WDT_MAX_TIME);
> + return 0;

At the moment those two are safe. When the open lock_kernel
goes away it will be possible to get

misc_register
open
ioctl
wdt_settimout()

So you may want to swap those two around (and disable the timer if the
register fails ?), or lock the open against the register routine.

Otherwise looks good.

Alan


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