From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752477AbdIFTua (ORCPT ); Wed, 6 Sep 2017 15:50:30 -0400 Received: from mx2.suse.de ([195.135.220.15]:38154 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751969AbdIFTu2 (ORCPT ); Wed, 6 Sep 2017 15:50:28 -0400 Date: Wed, 6 Sep 2017 21:50:27 +0200 From: "Luis R. Rodriguez" To: Ethan Zhao Cc: Peter Zijlstra , mingo@redhat.com, mcgrof@kernel.org, keescook@chromium.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, james.puthukattukaran@oracle.com, ethan.kernel@gmail.com Subject: Re: [PATCH v2] sched: check user input value of sysctl_sched_time_avg Message-ID: <20170906195027.GK29261@wotan.suse.de> References: <1504335452-31806-1-git-send-email-ethan.zhao@oracle.com> <20170904074931.oyhe4gz5jnhfmnw6@hirez.programming.kicks-ass.net> <759b1eb2-2d3d-89df-9ea0-38622f285284@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <759b1eb2-2d3d-89df-9ea0-38622f285284@oracle.com> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 04, 2017 at 03:54:23PM +0800, Ethan Zhao wrote: > Peter, > > > On 2017/9/4 15:49, Peter Zijlstra wrote: > > On Sat, Sep 02, 2017 at 02:57:32PM +0800, Ethan Zhao wrote: > > > diff --git a/kernel/sysctl.c b/kernel/sysctl.c > > > index 6648fbb..609bed2 100644 > > > --- a/kernel/sysctl.c > > > +++ b/kernel/sysctl.c > > > @@ -367,7 +367,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write, > > > .data = &sysctl_sched_time_avg, > > > .maxlen = sizeof(unsigned int), > > > .mode = 0644, > > > - .proc_handler = proc_dointvec, > > > + .proc_handler = sched_time_avg_handler, > > *sigh*, what's wrong with the below? Too easy? >  :),  seems I walked zigzag several cycles to get the right point. It sounds like negative values are not possible too, right? If so then you can use proc_douintvec_minmax(). Luis