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From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
To: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Cc: Network Development <netdev@vger.kernel.org>,
	David Miller <davem@davemloft.net>,
	"Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [PATCH net] net/packet: tpacket_rcv: do not increment ring index on drop
Date: Mon, 9 Mar 2020 11:50:23 -0400	[thread overview]
Message-ID: <CA+FuTSc9gdNO1O1HxOz+j-KVhL_+24LyQjb_gB0tF6uH++ykGg@mail.gmail.com> (raw)
In-Reply-To: <CA+FuTSfTac=Ut43nFJdB_z605Y-NO7En8AqKT3X8q8=SjFHe6Q@mail.gmail.com>

On Mon, Mar 9, 2020 at 11:42 AM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> On Mon, Mar 9, 2020 at 11:34 AM Willem de Bruijn
> <willemdebruijn.kernel@gmail.com> wrote:
> >
> > From: Willem de Bruijn <willemb@google.com>
> >
> > In one error case, tpacket_rcv drops packets after incrementing the
> > ring producer index.
> >
> > If this happens, it does not update tp_status to TP_STATUS_USER and
> > thus the reader is stalled for an iteration of the ring, causing out
> > of order arrival.
> >
> > The only such error path is when virtio_net_hdr_from_skb fails due
> > to encountering an unknown GSO type.
> >
> > Signed-off-by: Willem de Bruijn <willemb@google.com>
>
>
> Fixes: bfd5f4a3d605 ("packet: Add GSO/csum offload support.")
>
> I forgot to add the Fixes tag, sorry. This goes back to the
> introduction of GSO support for virtio_net.

The problem of blinding receivers to certain packet types goes back to
that commit.

But the specific issue of ring out of order arrival is added later,
when vnet_hdr support is extended to tpacket_rcv:

Fixes: 58d19b19cd99 ("packet: vnet_hdr support for tpacket_rcv")

  reply	other threads:[~2020-03-09 15:51 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-09 15:34 [PATCH net] net/packet: tpacket_rcv: do not increment ring index on drop Willem de Bruijn
2020-03-09 15:42 ` Willem de Bruijn
2020-03-09 15:50   ` Willem de Bruijn [this message]
2020-03-10  6:46     ` Michael S. Tsirkin
2020-03-10  6:43 ` Michael S. Tsirkin
2020-03-10 12:49   ` Willem de Bruijn
2020-03-10 12:59     ` Michael S. Tsirkin
2020-03-10 14:16       ` Willem de Bruijn
2020-03-10 14:43         ` Michael S. Tsirkin
2020-03-10 15:38           ` Willem de Bruijn
2020-03-10 16:14             ` Willem de Bruijn
2020-03-10 21:29             ` Michael S. Tsirkin
2020-03-10 21:35               ` Willem de Bruijn
2020-03-10 21:57                 ` Michael S. Tsirkin
2020-03-10 23:13                   ` Willem de Bruijn
2020-03-11  7:56                     ` Michael S. Tsirkin
2020-03-11 14:31                       ` Willem de Bruijn
2020-03-11 21:25                         ` Michael S. Tsirkin
2020-03-11 21:49                           ` Willem de Bruijn
2020-03-12  6:13 ` David Miller
2020-03-12  6:27   ` Michael S. Tsirkin

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