Re: [RFC] Kernel unaligned access at __skb_flow_dissect

[Eric Dumazet]

On Fri, 2016-01-29 at 10:33 -0800, Eric Dumazet wrote:

> 
> Why ipv6 stack itself does not trigger the issue ?
> 
> Maybe the driver itself does not properly align IP headers on sparc ?
> 
> Make sure NET_IP_ALIGN is 2 on your build.
> 
> Note that x86 does not care, but a driver should always align Ethernet
> header to NET_IP_ALIGN, so that IP headers are aligned to 4 bytes
> boundaries.
> 

I would try following ixgbe fix (sorry, totally untested, but you get
the idea...)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c 
b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index c4003a88bbf6..7ba64ed463a6 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -1525,7 +1525,7 @@ static bool ixgbe_alloc_mapped_page(struct ixgbe_ring 
*rx_ring,
 
        bi->dma = dma;
        bi->page = page;
-       bi->page_offset = 0;
+       bi->page_offset = NET_IP_ALIGN;
 
        return true;
 }