Return-path: Received: from charlotte.tuxdriver.com ([70.61.120.58]:38957 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752024AbZFETAe (ORCPT ); Fri, 5 Jun 2009 15:00:34 -0400 Date: Fri, 5 Jun 2009 14:50:48 -0400 From: "John W. Linville" To: Michael Buesch Cc: linux-wireless@vger.kernel.org, bcm43xx-dev@lists.berlios.de, Matthieu CASTET Subject: Re: [PATCH] b43: Fix possible unaligned u32 access Message-ID: <20090605185047.GA7361@tuxdriver.com> References: <200906042318.33895.mb@bu3sch.de> <20090605122503.GA2791@tuxdriver.com> <200906051929.07714.mb@bu3sch.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <200906051929.07714.mb@bu3sch.de> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Fri, Jun 05, 2009 at 07:29:07PM +0200, Michael Buesch wrote: > On Friday 05 June 2009 14:25:03 John W. Linville wrote: > > On Thu, Jun 04, 2009 at 11:18:33PM +0200, Michael Buesch wrote: > > > From: Matthieu CASTET > > > > > > Fix possible unaligned u32 access in b43_generate_plcp_hdr(). > > > Unaligned data is read/write with a u32 pointer instead of using the > > > packed structure. Some versions of gcc ignore the "packed" attribute, if the > > > structure element is accessed through a local pointer. > > > > > > Signed-off-by: Matthieu CASTET > > > Signed-off-by: Michael Buesch > > > > That seems pretty brain-dead...can you cite a source for this > > information? The patch seems like a no-op... > > > > John > > struct foo { > int data; > } __attribute__((packed)); > > struct foo foo; > int *d = &foo->data; > foo->data = x; /* Works for unaligned */ > *d = y; /* Does not work for unaligned */ Why not? -- John W. Linville Someday the world will need a hero, and you linville@tuxdriver.com might be all we have. Be ready.