From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Dichtel Subject: Re: [PATCH] netlink: downgrade warning about leftover bytes to debug level Date: Wed, 28 May 2014 14:47:33 +0200 Message-ID: <5385DAE5.2020009@6wind.com> References: <1401196563-6999-1-git-send-email-mschmidt@redhat.com> <53859359.70304@6wind.com> <5385A9D1.4000102@redhat.com> Reply-To: nicolas.dichtel@6wind.com Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev@vger.kernel.org To: Michal Schmidt , David Miller Return-path: Received: from mail-wi0-f171.google.com ([209.85.212.171]:61146 "EHLO mail-wi0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753325AbaE1Mrg (ORCPT ); Wed, 28 May 2014 08:47:36 -0400 Received: by mail-wi0-f171.google.com with SMTP id cc10so3541848wib.16 for ; Wed, 28 May 2014 05:47:35 -0700 (PDT) In-Reply-To: <5385A9D1.4000102@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: Le 28/05/2014 11:18, Michal Schmidt a =C3=A9crit : > On 05/28/2014 09:42 AM, Nicolas Dichtel wrote: >> Le 27/05/2014 15:16, Michal Schmidt a =C3=A9crit : >>> Any process is able to send netlink messages with leftover bytes, s= o >>> downgrade the warning message to pr_debug in order to avoid possibl= e >>> kernel log spam. >> Yes, but that's not a normal case. I think that the level warning is= good, >> there is something wrong with this kind of messages. > > As an alternative we could at least guard it with net_ratelimit(). I would prefer this solution. > > But still, the message indicates a userspace bug. It can be useful > for a developer of a netlink library, but not for many more. Or to let you know why a userspace tool does not work ;-) > I think it's odd to let unprivileged userspace spam the dmesg, > even if rate-limited. The kernel does not emit warning messages when > userspace is buggy in other ways, like calling syscalls with invalid > arguments. If it's really a problem (this message is here since 2.6.15 and nobody complains), maybe a level between warning and debug may be acceptable. Regards, Nicolas