From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from proxima.lasnet.de ([78.47.171.185]:44929 "EHLO proxima.lasnet.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726865AbeHFLc6 (ORCPT ); Mon, 6 Aug 2018 07:32:58 -0400 Subject: Re: [PATCHv2 wpan] net: 6lowpan: fix reserved space for single frames References: <20180714165210.20517-1-aring@mojatatu.com> From: Stefan Schmidt Message-ID: <2c6cad37-beea-e9ca-569a-5f976bdd2927@datenfreihafen.org> Date: Mon, 6 Aug 2018 11:24:44 +0200 MIME-Version: 1.0 In-Reply-To: <20180714165210.20517-1-aring@mojatatu.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-wpan-owner@vger.kernel.org List-ID: To: Alexander Aring , stefan@osg.samsung.com Cc: linux-wpan@vger.kernel.org, netdev@vger.kernel.org, david.palma@ntnu.no, rabinarayans0828@gmail.com Hello. On 07/14/2018 06:52 PM, Alexander Aring wrote: > This patch fixes patch add handling to take care tail and headroom for > single 6lowpan frames. We need to be sure we have a skb with the right > head and tailroom for single frames. This patch do it by using > skb_copy_expand() if head and tailroom is not enough allocated by upper > layer. > > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=195059 > Reported-by: David Palma > Reported-by: Rabi Narayan Sahoo > Signed-off-by: Alexander Aring > --- > changes since v2: > skb to nskb, pointed out by stefan > > net/ieee802154/6lowpan/tx.c | 21 ++++++++++++++++++--- > 1 file changed, 18 insertions(+), 3 deletions(-) > > diff --git a/net/ieee802154/6lowpan/tx.c b/net/ieee802154/6lowpan/tx.c > index e6ff5128e61a..ca53efa17be1 100644 > --- a/net/ieee802154/6lowpan/tx.c > +++ b/net/ieee802154/6lowpan/tx.c > @@ -265,9 +265,24 @@ netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *ldev) > /* We must take a copy of the skb before we modify/replace the ipv6 > * header as the header could be used elsewhere > */ > - skb = skb_unshare(skb, GFP_ATOMIC); > - if (!skb) > - return NET_XMIT_DROP; > + if (unlikely(skb_headroom(skb) < ldev->needed_headroom || > + skb_tailroom(skb) < ldev->needed_tailroom)) { > + struct sk_buff *nskb; > + > + nskb = skb_copy_expand(skb, ldev->needed_headroom, > + ldev->needed_tailroom, GFP_ATOMIC); > + if (likely(nskb)) { > + consume_skb(skb); > + skb = nskb; > + } else { > + kfree_skb(skb); > + return NET_XMIT_DROP; > + } > + } else { > + skb = skb_unshare(skb, GFP_ATOMIC); > + if (!skb) > + return NET_XMIT_DROP; > + } > > ret = lowpan_header(skb, ldev, &dgram_size, &dgram_offset); > if (ret < 0) { > This patch has been applied to the wpan-next tree and will be part of the next pull request to net-next. Thanks! I know you submitted this for wpan instead of wpan-next, but with rc8 being out I will not submit another pull request for 4.18. Instead I added cc stable to the patch to make sure it gets picked into the stable tree once 4.18 is out. regards Stefan Schmidt