> -----Original Message-----
> From: Xiao Yang <yangx.jy@xxxxxxxxxxx>
> Sent: Tuesday, January 11, 2022 7:54 AM
> To: rpearsonhpe@xxxxxxxxx; leon@xxxxxxxxxx
> Cc: linux-rdma@xxxxxxxxxxxxxxx; Xiao Yang <yangx.jy@xxxxxxxxxxx>
> Subject: [PATCH rdma-core RESEND] providers/rxe: Replace '%' with '&' in
> check_qp_queue_full()
>
> The expression "cons == ((qp->cur_index + 1) % q->index_mask)" mistakenly
> assumes the queue is full when the number of entires is equal to "maximum
> - 1"
> (maximum is correct).
>
> For example:
> If cons and qp->cur_index are 0 and q->index_mask is 1,
> check_qp_queue_full() reports ENOSPC.
>
> Fixes: 1a894ca10105 ("Providers/rxe: Implement ibv_create_qp_ex verb")
> Signed-off-by: Xiao Yang <yangx.jy@xxxxxxxxxxx>
> ---
> providers/rxe/rxe_queue.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/providers/rxe/rxe_queue.h b/providers/rxe/rxe_queue.h index
> 6de8140c..708e76ac 100644
> --- a/providers/rxe/rxe_queue.h
> +++ b/providers/rxe/rxe_queue.h
> @@ -205,7 +205,7 @@ static inline int check_qp_queue_full(struct rxe_qp
> *qp)
> if (qp->err)
> goto err;
>
> - if (cons == ((qp->cur_index + 1) % q->index_mask))
> + if (cons == ((qp->cur_index + 1) & q->index_mask))
Are you sure that index_mask would always be aligned with 2^X?
> qp->err = ENOSPC;
> err:
> return qp->err;
> --
> 2.25.1
>
>
