From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753852AbaJCPHN (ORCPT ); Fri, 3 Oct 2014 11:07:13 -0400 Received: from top.free-electrons.com ([176.31.233.9]:46773 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753330AbaJCPHH (ORCPT ); Fri, 3 Oct 2014 11:07:07 -0400 Date: Fri, 3 Oct 2014 17:07:03 +0200 From: Antoine Tenart To: dan.carpenter@oracle.com Cc: Antoine Tenart , sebastian.hesselbarth@gmail.com, alexandre.belloni@free-electrons.com, thomas.petazzoni@free-electrons.com, zmxu@marvell.com, jszhang@marvell.com, netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] net: pxa168_eth: avoid using signed char for bitops Message-ID: <20141003150703.GA20398@kwain> References: <1412348517-20352-1-git-send-email-antoine.tenart@free-electrons.com> <1412348517-20352-2-git-send-email-antoine.tenart@free-electrons.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1412348517-20352-2-git-send-email-antoine.tenart@free-electrons.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 03, 2014 at 05:01:54PM +0200, Antoine Tenart wrote: > Signedness bugs may occur when using signed char for bitops, > depending on if the highest bit is ever used. > > Signed-off-by: Antoine Tenart > Reported-by: Dan Carpenter > --- > > Dan reported a static checker warning: > http://marc.info/?l=kernel-janitors&m=141218246222535&w=2 > > This patch fixes it. Instead of using sa->sa_data we now use > dev->dev_addr (of type unsigned char *) to avoid possible > signedness issues. Well, this patch shouldn't be in this thread. I'm resending it. Sorry for the noise. Antoine > > drivers/net/ethernet/marvell/pxa168_eth.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/net/ethernet/marvell/pxa168_eth.c b/drivers/net/ethernet/marvell/pxa168_eth.c > index 24de41231593..c3b209cd0660 100644 > --- a/drivers/net/ethernet/marvell/pxa168_eth.c > +++ b/drivers/net/ethernet/marvell/pxa168_eth.c > @@ -634,12 +634,12 @@ static int pxa168_eth_set_mac_address(struct net_device *dev, void *addr) > memcpy(oldMac, dev->dev_addr, ETH_ALEN); > memcpy(dev->dev_addr, sa->sa_data, ETH_ALEN); > > - mac_h = sa->sa_data[0] << 24; > - mac_h |= sa->sa_data[1] << 16; > - mac_h |= sa->sa_data[2] << 8; > - mac_h |= sa->sa_data[3]; > - mac_l = sa->sa_data[4] << 8; > - mac_l |= sa->sa_data[5]; > + mac_h = dev->dev_addr[0] << 24; > + mac_h |= dev->dev_addr[1] << 16; > + mac_h |= dev->dev_addr[2] << 8; > + mac_h |= dev->dev_addr[3]; > + mac_l = dev->dev_addr[4] << 8; > + mac_l |= dev->dev_addr[5]; > wrl(pep, MAC_ADDR_HIGH, mac_h); > wrl(pep, MAC_ADDR_LOW, mac_l); > > -- > 1.9.1 > -- Antoine Ténart, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com