Re: [PATCH 1/2] HPET: disallow zero interrupt frequency

[Bob Picco]

Clemens Ladisch wrote:	[Thu Sep 22 2005, 11:08:32AM EDT]
> Trying to set an interrupt frequency of zero would result in a
> division by zero, so disallow this.
> 
> Enabling the interrupt when the frequency hasn't yet been set would
> use an interrupt period of minimum length, so disallow this, too.
> 
> Signed-off-by: Clemens Ladisch <clemens@xxxxxxxxxx>
> 
> --- linux-2.6.13.orig/drivers/char/hpet.c	2005-09-22 10:56:23.000000000 +0200
> +++ linux-2.6.13/drivers/char/hpet.c	2005-09-22 10:56:26.000000000 +0200
> @@ -365,6 +365,9 @@ static int hpet_ioctl_ieon(struct hpet_d
>  	hpet = devp->hd_hpet;
>  	hpetp = devp->hd_hpets;
>  
> +	if (!devp->hd_ireqfreq)
> +		return -EIO;
> +
>  	v = readq(&timer->hpet_config);
>  	spin_lock_irq(&hpet_lock);
>  
> @@ -517,7 +520,7 @@ hpet_ioctl_common(struct hpet_dev *devp,
>  			break;
>  		}
>  
> -		if (arg & (arg - 1)) {
> +		if (arg < 1 || (arg & (arg - 1))) {
Well it seems like what you want is:
		if (!arg || (arg & (arg - 1))) {
>  			err = -EINVAL;
>  			break;
>  		}
> -

BTW, it will be a day or two before I can review your other patch.

thanks,

bob
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