Subject: Re: [RFC net-next 2/2] ice: make use of DECLARE_FLEX() in ice_switch.c

From: Kees Cook <[email-masked]>
Date: Tue, 1 Aug 2023 15:35:21 -0700

On Tue, Aug 01, 2023 at 01:19:23PM +0200, Przemek Kitszel wrote:
> Use DECLARE_FLEX() macro for 1-elem flex array members of ice_switch.c
> 
> Signed-off-by: Przemek Kitszel <[email-masked]>
> ---
>  drivers/net/ethernet/intel/ice/ice_switch.c | 53 +++++----------------
>  1 file changed, 12 insertions(+), 41 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_switch.c b/drivers/net/ethernet/intel/ice/ice_switch.c
> index a7afb612fe32..41679cb6b548 100644
> --- a/drivers/net/ethernet/intel/ice/ice_switch.c
> +++ b/drivers/net/ethernet/intel/ice/ice_switch.c
> @@ -1812,15 +1812,11 @@ ice_aq_alloc_free_vsi_list(struct ice_hw *hw, u16 *vsi_list_id,
>  			   enum ice_sw_lkup_type lkup_type,
>  			   enum ice_adminq_opc opc)
>  {
> -	struct ice_aqc_alloc_free_res_elem *sw_buf;
> +	DECLARE_FLEX(struct ice_aqc_alloc_free_res_elem *, sw_buf, elem, 1);
> +	u16 buf_len = struct_size(sw_buf, elem, 1);

With the macro I suggested, I think this line can become:

	u16 buf_len = __builtin_object_size(sw_buf, 1);

but either is fine. (N.B. the "1" here is a bitfield, not the "1" size
above).

-Kees

-- 
Kees Cook