From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752161AbcGLXq0 (ORCPT ); Tue, 12 Jul 2016 19:46:26 -0400 Received: from www62.your-server.de ([213.133.104.62]:49194 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750784AbcGLXqS (ORCPT ); Tue, 12 Jul 2016 19:46:18 -0400 Message-ID: <5785812B.4080505@iogearbox.net> Date: Wed, 13 Jul 2016 01:45:47 +0200 From: Daniel Borkmann User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: kbuild test robot CC: kbuild-all@01.org, davem@davemloft.net, alexei.starovoitov@gmail.com, peterz@infradead.org, tgraf@suug.ch, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next 3/3] bpf: avoid stack copy and use skb ctx for event output References: <201607130750.HlB4VMOA%fengguang.wu@intel.com> In-Reply-To: <201607130750.HlB4VMOA%fengguang.wu@intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated-Sender: daniel@iogearbox.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/13/2016 01:25 AM, kbuild test robot wrote: > Hi, > > [auto build test WARNING on net-next/master] > > url: https://github.com/0day-ci/linux/commits/Daniel-Borkmann/BPF-event-output-helper-improvements/20160713-065944 > config: s390-allyesconfig (attached as .config) > compiler: s390x-linux-gnu-gcc (Debian 5.3.1-8) 5.3.1 20160205 > reproduce: > wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # save the attached .config to linux build tree > make.cross ARCH=s390 > > All warnings (new ones prefixed by >>): > > kernel/trace/bpf_trace.c: In function 'bpf_perf_event_output': > kernel/trace/bpf_trace.c:284:1: warning: 'bpf_perf_event_output' uses dynamic stack allocation > } > ^ > kernel/trace/bpf_trace.c: In function 'bpf_event_output': >>> kernel/trace/bpf_trace.c:319:1: warning: 'bpf_event_output' uses dynamic stack allocation > } > ^ Hmm, searching a bit on lkml, it seems these warnings on s390 are actually mostly harmless I believe [1][2] ... looks like they are there to find structs sitting on stack, for example, at least that's also what the currently existing one in the above line (bpf_trace.c +284) appears to be about. Thanks, Daniel [1] http://lkml.iu.edu/hypermail/linux/kernel/1601.2/04074.html [2] https://lkml.org/lkml/2013/6/25/42