From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net] net: avoid skb_warn_bad_offload false positives on UFO Date: Tue, 08 Aug 2017 21:39:49 -0700 (PDT) Message-ID: <20170808.213949.1689446847623847043.davem@davemloft.net> References: <20170808182255.88431-1-willemdebruijn.kernel@gmail.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, xiangxia.m.yue@gmail.com, willemb@google.com To: willemdebruijn.kernel@gmail.com Return-path: Received: from shards.monkeyblade.net ([184.105.139.130]:60600 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750792AbdHIEju (ORCPT ); Wed, 9 Aug 2017 00:39:50 -0400 In-Reply-To: <20170808182255.88431-1-willemdebruijn.kernel@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Willem de Bruijn Date: Tue, 8 Aug 2017 14:22:55 -0400 > From: Willem de Bruijn > > skb_warn_bad_offload triggers a warning when an skb enters the GSO > stack at __skb_gso_segment that does not have CHECKSUM_PARTIAL > checksum offload set. > > Commit b2504a5dbef3 ("net: reduce skb_warn_bad_offload() noise") > observed that SKB_GSO_DODGY producers can trigger the check and > that passing those packets through the GSO handlers will fix it > up. But, the software UFO handler will set ip_summed to > CHECKSUM_NONE. > > When __skb_gso_segment is called from the receive path, this > triggers the warning again. > > Make UFO set CHECKSUM_UNNECESSARY instead of CHECKSUM_NONE. On > Tx these two are equivalent. On Rx, this better matches the > skb state (checksum computed), as CHECKSUM_NONE here means no > checksum computed. > > See also this thread for context: > http://patchwork.ozlabs.org/patch/799015/ > > Fixes: b2504a5dbef3 ("net: reduce skb_warn_bad_offload() noise") > Signed-off-by: Willem de Bruijn Applied and queued up for -stable, thank you.