Re: [PATCH] flow-dissector: Fix alignment issue in __skb_flow_get_ports

From: Alexander Duyck <redacted>
Date: Fri, 10 Oct 2014 11:02:04 -0700

On 10/10/2014 10:58 AM, David Miller wrote:

quoted

From: Alexander Duyck <redacted>
Date: Fri, 10 Oct 2014 09:50:17 -0700

quoted

If I just use get_unaligned that is pretty easy in terms of cleanup
for the ports and IPv4 addresses, the IPv6 will still be a significant
hurdle to overcome though.

Actually, it's not that simple.

When the compiler sees things like "th->doff" it will load the 32-bit
word that 4-bit field contains and extract the value using shifts and
masking.

So we might need to sprinkle a "attribute((packed))" here and there
to make it work.

I'll do some digging.  I know I had this working in igb/ixgbe before so
I probably just need to add a few small tweaks to resolve the remaining
issues for v4 of the patch.

Ok, I think v3 + resolving the th->doff thing will get rid of everything.