Re: [PATCH for-next v4] Subject: RDMA/rxe: Handle zero length rdma

[Jason Gunthorpe <jgg@nvidia.com>]

On Wed, Feb 01, 2023 at 10:42:41PM -0600, Bob Pearson wrote:
> Currently the rxe driver does not handle all cases of zero length
> rdma operations correctly. The client does not have to provide an
> rkey for zero length RDMA read or write operations so the rkey
> provided may be invalid and should not be used to lookup an mr.
> 
> This patch corrects the driver to ignore the provided rkey if the
> reth length is zero for read or write operations and make sure to
> set the mr to NULL. In read_reply() if length is zero rxe_recheck_mr()
> is not called. Warnings are added in the routines in rxe_mr.c to
> catch NULL MRs when the length is non-zero.
> 
> Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
> Reviewed-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>
> ---
> v4:
>   Fixed a regression in flush operations because the rkey must be
>   valid in that case even if the length is zero which maybe the
>   case for selectivity level of the entire memory region.
> 
> Reported-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>

Applied to for-next, I added a fixes line for day 0

Jason