From mboxrd@z Thu Jan 1 00:00:00 1970 From: Antoine Tenart Subject: Re: [PATCH 2/2] net: spider_net: avoid using signed char for bitops Date: Fri, 3 Oct 2014 17:17:24 +0200 Message-ID: <20141003151724.GB20398@kwain> References: <1412348517-20352-1-git-send-email-antoine.tenart@free-electrons.com> <1412348517-20352-4-git-send-email-antoine.tenart@free-electrons.com> <9201792.OAu7xPjvdN@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-arm-kernel@lists.infradead.org, Antoine Tenart , dan.carpenter@oracle.com, kou.ishizaki@toshiba.co.jp, jens@de.ibm.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Arnd Bergmann Return-path: Received: from top.free-electrons.com ([176.31.233.9]:46903 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751773AbaJCPR2 (ORCPT ); Fri, 3 Oct 2014 11:17:28 -0400 Content-Disposition: inline In-Reply-To: <9201792.OAu7xPjvdN@wuerfel> Sender: netdev-owner@vger.kernel.org List-ID: Hi Arnd, On Fri, Oct 03, 2014 at 05:15:05PM +0200, Arnd Bergmann wrote: > On Friday 03 October 2014 17:01:56 Antoine Tenart wrote: > > Signedness bugs may occur when using signed char for bitops, > > depending on if the highest bit is ever used. > >=20 > > Signed-off-by: Antoine Tenart > >=20 >=20 > It's probably worth mentioning here that this cannot happen in this > driver because it's only used in one powerpc-specific chip, and 'char= ' > is always 'unsigned' on powerpc. Oh, that's good to know :) Antoine --=20 Antoine T=E9nart, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com