linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Fengguang Wu <lkp@intel.com>
To: Daniel Borkmann <daniel@iogearbox.net>
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
Date: Wed, 13 Jul 2016 08:01:55 +0800	[thread overview]
Message-ID: <20160713000155.GA20432@wfg-t540p.sh.intel.com> (raw)
In-Reply-To: <5785812B.4080505@iogearbox.net>

Hi Daniel,

On Wed, Jul 13, 2016 at 01:45:47AM +0200, Daniel Borkmann wrote:
>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.

Yes it does look so. All such warnings happen only in s390:

% g -h -o '[^ ]*config' *dynamic-stack* | sort | uniq -c | sort -nr
    118 s390-allyesconfig
     80 s390-allmodconfig

Let's ignore all of them on s390.

Thanks,
Fengguang

>   [1] http://lkml.iu.edu/hypermail/linux/kernel/1601.2/04074.html
>   [2] https://lkml.org/lkml/2013/6/25/42

      reply	other threads:[~2016-07-13  0:02 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-12 22:36 [PATCH net-next 0/3] BPF event output helper improvements Daniel Borkmann
2016-07-12 22:36 ` [PATCH net-next 1/3] perf, events: add non-linear data support for raw records Daniel Borkmann
2016-07-13  7:52   ` Peter Zijlstra
2016-07-13  9:24     ` Daniel Borkmann
2016-07-13 12:10       ` Peter Zijlstra
2016-07-13 13:16         ` Daniel Borkmann
2016-07-13 13:42   ` Peter Zijlstra
2016-07-13 14:08     ` Daniel Borkmann
2016-07-13 16:40       ` Peter Zijlstra
2016-07-13 16:53         ` Daniel Borkmann
2016-07-12 22:36 ` [PATCH net-next 2/3] bpf, perf: split bpf_perf_event_output Daniel Borkmann
2016-07-12 22:36 ` [PATCH net-next 3/3] bpf: avoid stack copy and use skb ctx for event output Daniel Borkmann
2016-07-12 23:25   ` kbuild test robot
2016-07-12 23:45     ` Daniel Borkmann
2016-07-13  0:01       ` Fengguang Wu [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20160713000155.GA20432@wfg-t540p.sh.intel.com \
    --to=lkp@intel.com \
    --cc=alexei.starovoitov@gmail.com \
    --cc=daniel@iogearbox.net \
    --cc=davem@davemloft.net \
    --cc=kbuild-all@01.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=peterz@infradead.org \
    --cc=tgraf@suug.ch \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).