From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexei Starovoitov Subject: Re: [PATCH net-next] bpf, skb_do_redirect: clear sender_cpu before xmit Date: Fri, 9 Oct 2015 21:55:58 -0700 Message-ID: <56189A5E.7010405@plumgrid.com> References: <56153E6C.9050202@plumgrid.com> <561727D5.2070001@plumgrid.com> <5617FA5A.9090406@iogearbox.net> <561883CB.4030808@plumgrid.com> <1444451914.27760.116.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Daniel Borkmann , "Devon H. O'Dell" , davem@davemloft.net, edumazet@google.com, netdev@vger.kernel.org To: Eric Dumazet Return-path: Received: from mail-pa0-f42.google.com ([209.85.220.42]:35603 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750732AbbJJE4B (ORCPT ); Sat, 10 Oct 2015 00:56:01 -0400 Received: by pabve7 with SMTP id ve7so46087104pab.2 for ; Fri, 09 Oct 2015 21:56:00 -0700 (PDT) In-Reply-To: <1444451914.27760.116.camel@edumazet-glaptop2.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: On 10/9/15 9:38 PM, Eric Dumazet wrote: > On Fri, 2015-10-09 at 20:19 -0700, Alexei Starovoitov wrote: > >> since this bug wasn't fixed at once in all places, it means >> that it is hard to review _all_ needed call-sites. >> There are 7 places that call skb_sender_cpu_clear() in net-next. >> Plus 2 more in net. >> How many such paths from rx to tx left? >> On the first glance ovs is missing one and who knows what else. > > Alexei, what's happening ? > > The original patch is 6 months old. If this issue was so urgent, how > comes it took so long to catch the remaining bugs ? no urgency at all. bpf side is clean, so I'm not worried :) > Just add skb_sender_cpu_clear() where needed, thanks. > > Using union is hard, but there is a price to performance. > > skb size is absolutely critical and deserves some headaches. yep. as I said it shouldn't be increased and proposed in-band sign bit. Anyway, since you and Daniel are ok with adding skb_sender_cpu_clear() in other places, I rest my case.