From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id 3D85C7F37 for ; Sun, 11 Oct 2015 17:26:45 -0500 (CDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay3.corp.sgi.com (Postfix) with ESMTP id DE76CAC001 for ; Sun, 11 Oct 2015 15:26:41 -0700 (PDT) Received: from ipmail04.adl6.internode.on.net (ipmail04.adl6.internode.on.net [150.101.137.141]) by cuda.sgi.com with ESMTP id Cb6SMHs7V4EWHF4h for ; Sun, 11 Oct 2015 15:26:39 -0700 (PDT) Date: Mon, 12 Oct 2015 09:26:18 +1100 From: Dave Chinner Subject: Re: [PATCH 2/4] xfs_repair: fix unaligned accesses Message-ID: <20151011222618.GX27164@dastard> References: <56170906.5090301@redhat.com> <56170974.5020604@sandeen.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <56170974.5020604@sandeen.net> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Eric Sandeen Cc: xfs@oss.sgi.com On Thu, Oct 08, 2015 at 07:25:24PM -0500, Eric Sandeen wrote: > This fixes some unaligned accesses spotted by libubsan in repair. > > Signed-off-by: Eric Sandeen > --- > repair/dinode.c | 19 +++++++++---------- > repair/prefetch.c | 4 ++-- > 2 files changed, 11 insertions(+), 12 deletions(-) > > diff --git a/repair/dinode.c b/repair/dinode.c > index f78f907..44bbb8f 100644 > --- a/repair/dinode.c > +++ b/repair/dinode.c > @@ -960,13 +960,13 @@ _("bad numrecs 0 in inode %" PRIu64 " bmap btree root block\n"), > * btree, we'd do it right here. For now, if there's a > * problem, we'll bail out and presumably clear the inode. > */ > - if (!verify_dfsbno(mp, be64_to_cpu(pp[i]))) { > + if (!verify_dfsbno(mp, get_unaligned_be64(&pp[i]))) { I don't understand - when are pointers in the BMBT not 64 bit aligned? The buffers are allocated by memalign to be 64 bit aligned, and all the internal BMBT structures are 64 bit aligned, too. i.e the BMBT block header is 24/72 bytes in length (depending on CRCs), the pointers are 64 bit, and the records are 128 bit. So where's the unaligned access coming from? Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs