Re: [PATCH rdma-next 07/16] RDMA/hfi1: Delete unreachable code

[Ira Weiny <ira.weiny@intel.com>]

On Tue, Oct 29, 2019 at 08:27:36AM +0200, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@mellanox.com>
> 
> All callers allocate MAD structures with proper sizes,
> there is no need to recheck it.
> 
> Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
> ---
>  drivers/infiniband/hw/hfi1/mad.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/hfi1/mad.c b/drivers/infiniband/hw/hfi1/mad.c
> index d8ff063a5419..a54746f4a0ae 100644
> --- a/drivers/infiniband/hw/hfi1/mad.c
> +++ b/drivers/infiniband/hw/hfi1/mad.c
> @@ -4921,10 +4921,6 @@ int hfi1_process_mad(struct ib_device *ibdev, int mad_flags, u8 port,
>  {
>  	switch (in_mad->base_version) {
>  	case OPA_MGMT_BASE_VERSION:
> -		if (unlikely(in_mad_size != sizeof(struct opa_mad))) {
> -			dev_err(ibdev->dev.parent, "invalid in_mad_size\n");
> -			return IB_MAD_RESULT_FAILURE;
> -		}

It's been a while but I'm not 100% sure we can safely remove this check.  A
user can send an IB sized MAD to an OPA device and AFAIR there is nothing
checking that the base version is set correctly for the size of mad received by
the mad stack.

Are you 100% sure that the in_mad_size is based off the management base
version?

Also, regarding the patches to remove the checks on the IB devices I would want
to see that check in the core MAD stack to verify we are not sending an OPA mad
to an IB device.  I may have put a check in there already so removing the code
in those drivers may be ok.  I'm not sure off the top of my head...

Ira

>  		return hfi1_process_opa_mad(ibdev, mad_flags, port,
>  					    in_wc, in_grh,
>  					    (struct opa_mad *)in_mad,
> -- 
> 2.20.1
>