Re: [oss-drivers] [PATCH][next] nfp: flower: use struct_size() helper

From: Jakub Kicinski
Date: Wed Jun 05 2019 - 17:22:49 EST


On Wed, 5 Jun 2019 15:38:27 -0500, Gustavo A. R. Silva wrote:
> One of the more common cases of allocation size calculations is finding
> the size of a structure that has a zero-sized array at the end, along
> with memory for some number of elements for that array. For example:
>
> struct nfp_tun_active_tuns {
> ...
> struct route_ip_info {
> __be32 ipv4;
> __be32 egress_port;
> __be32 extra[2];
> } tun_info[];
> };
>
> Make use of the struct_size() helper instead of an open-coded version
> in order to avoid any potential type mistakes.
>
> So, replace the following form:
>
> sizeof(struct nfp_tun_active_tuns) + sizeof(struct route_ip_info) * count
>
> with:
>
> struct_size(payload, tun_info, count)
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>

Acked-by: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>

Thanks!