From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751747AbaHRQ3p (ORCPT ); Mon, 18 Aug 2014 12:29:45 -0400 Received: from smtprelay0101.hostedemail.com ([216.40.44.101]:55624 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750977AbaHRQ3n (ORCPT ); Mon, 18 Aug 2014 12:29:43 -0400 X-Session-Marker: 6A6F6540706572636865732E636F6D X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,joe@perches.com,:::::::::,RULES_HIT:41:355:379:541:599:973:982:988:989:1260:1261:1277:1311:1313:1314:1345:1359:1373:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2194:2199:2393:2559:2562:2691:2828:3138:3139:3140:3141:3142:3353:3622:3653:3865:3866:3867:3870:3871:3872:3874:4043:4250:4321:5007:6119:7652:7903:8603:10004:10400:10848:11232:11658:11914:12296:12517:12519:12663:12740:13069:13161:13229:13255:13311:13357:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: jump10_3776f88d46c01 X-Filterd-Recvd-Size: 2228 Message-ID: <1408379379.2741.9.camel@joe-AO725> Subject: Re: [PATCH] drivers: net: ethernet: intel: e1000: e1000_ethtool.c coding style fixes From: Joe Perches To: Alexander Duyck Cc: Krzysztof Majzerowicz-Jaszcz , jeffrey.t.kirsher@intel.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 18 Aug 2014 09:29:39 -0700 In-Reply-To: <53F21FB1.7060607@intel.com> References: <1408180328-4827-1-git-send-email-cristos@vipserv.org> <1408214489.2683.87.camel@joe-AO725> <53F21BEC.2070204@intel.com> <1408375914.2741.1.camel@joe-AO725> <53F21FB1.7060607@intel.com> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.10.4-0ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2014-08-18 at 08:45 -0700, Alexander Duyck wrote: > On 08/18/2014 08:31 AM, Joe Perches wrote: > > On Mon, 2014-08-18 at 08:29 -0700, Alexander Duyck wrote: > >> Doing any kind of pointer math on a void pointer is generally unsafe as > >> it is an incomplete type. The only reason why it works in GCC is > >> because GCC has a nonstandard extension that makes it report as having a > >> size of 1. > > > > I know. It's used in quite a few places in kernel code > > so I believe it's now a base assumption for the kernel. > > Well that is something that should probably be fixed then. I don't > believe it is safe to be doing any kind of pointer math on a void pointer. > > We really shouldn't be using any GCC specific bits unless we absolutely > have to. Good luck with that. Here's a little coccinelle script to find them: $ cat void_arithmetic.spatch @@ void *p; expression e; @@ * p + e $ There are at least 23 uses just in lib/ $ spatch -sp_file void_arithmetic.spatch lib | \ grep "^\-[^\-]" | wc -l 23 I'm fairly confident there are more than that, but using spatch with --recursive-includes is pretty slow on my machine.