From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755535Ab2KVSon (ORCPT ); Thu, 22 Nov 2012 13:44:43 -0500 Received: from mail-ea0-f174.google.com ([209.85.215.174]:48086 "EHLO mail-ea0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755463Ab2KVSoZ (ORCPT ); Thu, 22 Nov 2012 13:44:25 -0500 Message-ID: <50AD60EC.3090302@suse.cz> Date: Thu, 22 Nov 2012 00:17:00 +0100 From: Jiri Slaby User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Greg KH CC: Sachin Kamat , linux-kernel@vger.kernel.org, patches@linaro.org Subject: Re: [PATCH 1/1] tty: vt: Remove redundant null check before kfree. References: <1353475147-28308-1-git-send-email-sachin.kamat@linaro.org> <20121121144624.GA21766@kroah.com> <50AD5916.3030604@suse.cz> <20121121230057.GA29095@kroah.com> In-Reply-To: <20121121230057.GA29095@kroah.com> X-Enigmail-Version: 1.5a1pre Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/22/2012 12:00 AM, Greg KH wrote: > On Wed, Nov 21, 2012 at 11:43:34PM +0100, Jiri Slaby wrote: >> On 11/21/2012 03:46 PM, Greg KH wrote: >>> On Wed, Nov 21, 2012 at 10:49:07AM +0530, Sachin Kamat wrote: >>>> --- a/drivers/tty/vt/consolemap.c >>>> +++ b/drivers/tty/vt/consolemap.c >>>> @@ -410,10 +410,8 @@ static void con_release_unimap(struct uni_pagedir *p) >>>> kfree(p->inverse_translations[i]); >>>> p->inverse_translations[i] = NULL; >>>> } >>>> - if (p->inverse_trans_unicode) { >>>> - kfree(p->inverse_trans_unicode); >>>> - p->inverse_trans_unicode = NULL; >>>> - } >>>> + kfree(p->inverse_trans_unicode); >>>> + p->inverse_trans_unicode = NULL; >>> >>> kfree with NULL is a no-op, but the line after that just caused a kernel >>> crash if it was NULL, so I can't accept this type of thing. >> >> Greg, I'm not sure -- what do you mean here? The change actually looks >> fine to me... We do not dereference p->inverse_trans_unicode there. > > If we never dereference it, why is it being set to NULL? I'm not disputing the assignment. Let it there. But I do not see any issues with the patch. What problem do you see exactly? -- js suse labs