Re: [PATCH v2] blk-iocost: fix shift-out-of-bounds in iocg_hick_delay()

[Tejun Heo <tj@xxxxxxxxxx>]

On Mon, Nov 28, 2022 at 11:04:13AM +0800, Li Jinlin wrote:
>  	/* calculate the current delay in effect - 1/2 every second */
>  	tdelta = now->now - iocg->delay_at;
>  	if (iocg->delay)
> -		delay = iocg->delay >> div64_u64(tdelta, USEC_PER_SEC);
> +		delay = iocg->delay >>
> +			min_t(u64, div64_u64(tdelta, USEC_PER_SEC), 63);

I replied earlier but the right thing to do here is setting delay to 0 if
the shift is >= 64.

Thanks.

-- 
tejun