Re: [PATCH][next] io-wq: fix unintentional integer overflow on left shift

From: Jens Axboe
Date: Fri Oct 25 2019 - 09:59:45 EST

On 10/25/19 7:59 AM, Colin Ian King wrote:
> On 25/10/2019 14:56, Jens Axboe wrote:
>> On 10/25/19 6:54 AM, Jens Axboe wrote:
>>> On 10/25/19 6:43 AM, Colin King wrote:
>>>> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>>>> Shifting the integer value 1U is evaluated with type unsigned int
>>>> using 32-bit arithmetic and then used in an expression that expects
>>>> a 64-bit value, so there is potentially an integer overflow. Fix this
>>>> by using the BIT_ULL macro to perform the shift and avoid the overflow.
>>> Good catch, that should indeed have been 1ULL. I'll fold in your
>>> fix, thanks!
>> BTW, this missed the same issue on the clear side of it, in
>> io_worker_handle_work(). I've fixed that one up the same way.
> Ah, good, somehow the scanner missed that.

Something to take a look at! :-)

Jens Axboe