On Mon, Mar 14, 2016 at 10:46 AM, Sowmini Varadhan <sowmini.varad...@oracle.com> wrote: > > For LLC based protocols like lldp, stp etc., the ethernet header > is an 802.3 header with a h_proto that is not 0x800, 0x86dd, or > even 0x806. In this world, the skb_network_header() points at > the DSAP/SSAP/.. and is not likely to be NET_IP_ALIGNed in > ixgbe_atr(). > > With LLC, drivers are not likely to correctly find IPVERSION, > or "6", at hdr.ipv4->version, but will instead just needlessly > trigger an unaligned access. (IPv4/IPv6 over LLC is almost never > implemented). > > The unaligned access is thus avoidable: bail out quickly after > examining first->protocol. > > Signed-off-by: Sowmini Varadhan <sowmini.varad...@oracle.com> > --- > v2: Alexander Duyck comments. > > drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 5 +++++ > 1 files changed, 5 insertions(+), 0 deletions(-) > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > index 4d6223d..b25e603 100644 > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > @@ -7574,6 +7574,11 @@ static void ixgbe_atr(struct ixgbe_ring *ring, > if (!ring->atr_sample_rate) > return; > > + if (first->protocol != htons(ETH_P_IP) && > + first->protocol != htons(ETH_P_IPV6) && > + first->protocol != htons(ETH_P_ARP)) > + return; > +
One other thing I forgot to mention is that we don't support ARP so that check could be dropped. The ATR code only supports IPv4 or IPv6 with TCP. - Alex