On 25/06/2020 09:54, Thomas Martitz wrote:
> The eth_addr member is passed to ether_addr functions that require
> 2-byte alignment, therefore the member must be properly aligned
> to avoid unaligned accesses.
>
> The problem is in place since the initial merge of multicast to unicast:
> commit 6db6f0eae6052b70885562e1733896647ec1d807 bridge: multicast to unicast
>
> Fixes: 6db6f0eae605 ("bridge: multicast to unicast")
> Cc: Roopa Prabhu <ro...@cumulusnetworks.com>
> Cc: Nikolay Aleksandrov <niko...@cumulusnetworks.com>
> Cc: David S. Miller <da...@davemloft.net>
> Cc: Jakub Kicinski <k...@kernel.org>
> Cc: Felix Fietkau <n...@nbd.name>
> Cc: sta...@vger.kernel.org
> Signed-off-by: Thomas Martitz <t.mart...@avm.de>
> ---
> net/bridge/br_private.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
> index 7501be4eeba0..22cb2f1993ef 100644
> --- a/net/bridge/br_private.h
> +++ b/net/bridge/br_private.h
> @@ -217,8 +217,8 @@ struct net_bridge_port_group {
> struct rcu_head rcu;
> struct timer_list timer;
> struct br_ip addr;
> + unsigned char eth_addr[ETH_ALEN]; /* 2-byte aligned */
> unsigned char flags;
> - unsigned char eth_addr[ETH_ALEN];
> };
>
> struct net_bridge_mdb_entry {
>
Hi Thomas,
To document it and guarantee that future struct changes won't break it I think
it'd be a good idea to add __aligned(2) for that member instead of the comment.
Other than that the patch looks good.
Thanks,
Nik
