Messages in this thread | | | Date | Wed, 01 Sep 2010 18:23:18 -0700 (PDT) | Subject | Re: [Bug #16626] Machine hangs with EIP at skb_copy_and_csum_dev | From | David Miller <> |
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From: Eric Dumazet <eric.dumazet@gmail.com> Date: Wed, 01 Sep 2010 12:50:51 +0200
> [PATCH] gro: fix different skb headrooms > > packets entering GRO might have different headrooms, even for a given > flow (because of implementation details in drivers, like copybreak). > We cant force drivers to deliver packets with a fixed headroom. > > 1) fix skb_segment() > > skb_segment() makes the false assumption headrooms of fragments are same > than the head. When CHECKSUM_PARTIAL is used, this can give csum_start > errors, and crash later in skb_copy_and_csum_dev() > > 2) allocate a minimal skb for head of frag_list > > skb_gro_receive() uses netdev_alloc_skb(headroom + skb_gro_offset(p)) to > allocate a fresh skb. This adds NET_SKB_PAD to a padding already > provided by netdevice, depending on various things, like copybreak. > > Use alloc_skb() to allocate an exact padding, to reduce cache line > needs: > NET_SKB_PAD + NET_IP_ALIGN > > bugzilla : https://bugzilla.kernel.org/show_bug.cgi?id=16626 > > Many thanks to Plamen Petrov, testing many debugging patches ! > With help of Jarek Poplawski. > > Reported-by: Plamen Petrov <pvp-lsts@fs.uni-ruse.bg> > Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> > CC: Jarek Poplawski <jarkao2@gmail.com>
Good spotting, applied, thanks!
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