From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josh Triplett Subject: Re: How to fix CHECK warning: testing a 'safe expression' Date: Fri, 2 Jan 2015 14:20:03 -0800 Message-ID: <20150102222003.GB2645@thin> References: <54907884.2040502@ti.com> <54A6B06D.50102@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <54A6B06D.50102@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Murali Karicheri Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-sparse@vger.kernel.org List-Id: linux-sparse@vger.kernel.org +linux-sparse On Fri, Jan 02, 2015 at 09:51:25AM -0500, Murali Karicheri wrote: > On 12/16/2014 01:23 PM, Murali Karicheri wrote: > >netdev maintainers, > > > >I got a comment to address CHECK warning and wondering how to address > >'warning: testing a 'safe expression' which appears when using > >IS_ERR_OR_NULL(foo) > > > >where foo is defined as > > > >struct foo_type *foo; > > > >The foo get assigned only NULL or ERR_PTR(error code). So I believe the > >usage is correct. But then how do I make the CHECK happy of its usage? > > > >I have tried doing a grep on the current usage of IS_ERR_OR_NULL() and > >found 276 of them causes this warning in the v3.18 version of the kernel > >that I am using > > > >$ grep -r "warning: testing a 'safe expression" * | wc -l > >276 > > > >1) Can someone explain what this warning means? > > > >2) Is it acceptable to post patches to netdev list with this warning? > > > >3) if not, how this is expected to be fixed? Any example usage to fix > >this warning will be helpful. > > > >Thanks in advance for > > > -- > Murali Karicheri > Linux Kernel, Texas Instruments