Re: [PATCH] distributor: fix potential overflow bug

[David Hunt <david.hunt@intel.com>]

Hi Bruce,

On 17/2/2022 3:02 PM, Bruce Richardson wrote:
> Coverity flags the fact that the tag values used in distributor are
> 32-bit, which means that when we use bit-manipulation to convert a tag
> match/no-match to a bit in an array, we need to typecast to a 64-bit
> type before shifting past 32 bits.
>
> Coverity issue: 375808
> Fixes: 08ccf3faa6a9 ("distributor: new packet distributor library")
> Cc: stable@dpdk.org
>
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> ---
>   lib/distributor/rte_distributor_single.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/lib/distributor/rte_distributor_single.c b/lib/distributor/rte_distributor_single.c
> index b653620688..60ca86152f 100644
> --- a/lib/distributor/rte_distributor_single.c
> +++ b/lib/distributor/rte_distributor_single.c
> @@ -247,8 +247,7 @@ rte_distributor_process_single(struct rte_distributor_single *d,
>   			 * worker given by the bit-position
>   			 */
>   			for (i = 0; i < d->num_workers; i++)
> -				match |= (!(d->in_flight_tags[i] ^ new_tag)
> -					<< i);
> +				match |= ((uint64_t)!(d->in_flight_tags[i] ^ new_tag) << i);
>   
>   			/* Only turned-on bits are considered as match */
>   			match &= d->in_flight_bitmask;


LGTM

Acked-by: David Hunt <david.hunt@intel.com>