From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: Re: [PATCH] virtio_net: memset scatterlist before using Date: Sun, 26 Apr 2009 22:28:08 +0930 Message-ID: <200904262228.09451.rusty@rustcorp.com.au> References: <20090423163847.200f227e.sfr@canb.auug.org.au> <1240583823.16438.14.camel@lappy> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Return-path: Received: from ozlabs.org ([203.10.76.45]:47720 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750871AbZDZM6N (ORCPT ); Sun, 26 Apr 2009 08:58:13 -0400 In-Reply-To: <1240583823.16438.14.camel@lappy> Content-Disposition: inline Sender: linux-next-owner@vger.kernel.org List-ID: To: Alex Williamson Cc: Stephen Rothwell , "David S. Miller" , linux-next@vger.kernel.org, LKML.netdev@vger.kernel.org On Sat, 25 Apr 2009 12:07:03 am Alex Williamson wrote: > A powerpc gcc-4.4 build generates the following warnings: > > drivers/net/virtio_net.c: In function 'virnet_vlan_rx_add_vid': > include/linux/scatterlist.h:57: warning: 'sg' is used uninitialized in this function > drivers/net/virtio_net.c:746: note: 'sg' was declared here > drivers/net/virtio_net.c: In function 'virnet_vlan_rx_kill_vid': > include/linux/scatterlist.h:57: warning: 'sg' is used uninitialized in this function > drivers/net/virtio_net.c:758: note: 'sg' was declared here > > We need to clear the scatterlist before using it. This sg entry will > get copied into another scatterlist before it's used, so memset it > rather than using sg_init_table or sg_init_one to avoid a bogus end > marker. This will break CONFIG_DEBUG_SG=y. Why not sg_init_one? This is what it's for... Thanks, Rusty