From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id A892A7F91 for ; Fri, 9 Oct 2015 15:08:29 -0500 (CDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay2.corp.sgi.com (Postfix) with ESMTP id 9BF5F304039 for ; Fri, 9 Oct 2015 13:08:26 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id OmxOdotEbdCg2FuW (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Fri, 09 Oct 2015 13:08:25 -0700 (PDT) Date: Fri, 9 Oct 2015 16:08:22 -0400 From: Brian Foster Subject: Re: [PATCH 2/5] xfs_repair: fix unaligned accesses Message-ID: <20151009200822.GG27982@bfoster.bfoster> References: <56181A17.9080503@sandeen.net> <56181AAD.9080505@sandeen.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <56181AAD.9080505@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 Fri, Oct 09, 2015 at 02:51:09PM -0500, Eric Sandeen wrote: > This fixes some unaligned accesses spotted by libubsan in repair. > > See Documentation/unaligned-memory-access.txt in the kernel > tree for why these can be a problem. > > Signed-off-by: Eric Sandeen > --- Reviewed-by: Brian Foster > > V2: > Add note about why ... > Add another in libxfs_bmbt_disk_get_all > Fix mistaken double-swap in dinode.c in original patch > > include/libxfs.h | 4 ++-- > repair/dinode.c | 47 ++++++++++++++++++++++++----------------------- > repair/prefetch.c | 4 ++-- > 3 files changed, 28 insertions(+), 27 deletions(-) > > diff --git a/include/libxfs.h b/include/libxfs.h > index b1604e2..52fb483 100644 > --- a/include/libxfs.h > +++ b/include/libxfs.h > @@ -206,8 +206,8 @@ libxfs_bmbt_disk_get_all( > { > struct xfs_bmbt_rec_host hrec; > > - hrec.l0 = be64_to_cpu(rp->l0); > - hrec.l1 = be64_to_cpu(rp->l1); > + hrec.l0 = get_unaligned_be64(&rp->l0); > + hrec.l1 = get_unaligned_be64(&rp->l1); > libxfs_bmbt_get_all(&hrec, irec); > } > > diff --git a/repair/dinode.c b/repair/dinode.c > index f78f907..f99cba3 100644 > --- a/repair/dinode.c > +++ b/repair/dinode.c > @@ -960,15 +960,17 @@ _("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]))) { > - do_warn(_("bad bmap btree ptr 0x%llx in ino %" PRIu64 "\n"), > - (unsigned long long) be64_to_cpu(pp[i]), lino); > + if (!verify_dfsbno(mp, get_unaligned_be64(&pp[i]))) { > + do_warn( > +("bad bmap btree ptr 0x%" PRIx64 " in ino %" PRIu64 "\n"), > + get_unaligned_be64(&pp[i]), lino); > return(1); > } > > - if (scan_lbtree(be64_to_cpu(pp[i]), level, scan_bmapbt, type, > - whichfork, lino, tot, nex, blkmapp, &cursor, > - 1, check_dups, magic, &xfs_bmbt_buf_ops)) > + if (scan_lbtree(get_unaligned_be64(&pp[i]), level, scan_bmapbt, > + type, whichfork, lino, tot, nex, blkmapp, > + &cursor, 1, check_dups, magic, > + &xfs_bmbt_buf_ops)) > return(1); > /* > * fix key (offset) mismatches between the keys in root > @@ -977,28 +979,27 @@ _("bad numrecs 0 in inode %" PRIu64 " bmap btree root block\n"), > * blocks but the parent hasn't been updated > */ > if (!check_dups && cursor.level[level-1].first_key != > - be64_to_cpu(pkey[i].br_startoff)) { > + get_unaligned_be64(&pkey[i].br_startoff)) { > if (!no_modify) { > do_warn( > - _("correcting key in bmbt root (was %llu, now %" PRIu64") in inode " > - "%" PRIu64" %s fork\n"), > - (unsigned long long) > - be64_to_cpu(pkey[i].br_startoff), > - cursor.level[level-1].first_key, > - XFS_AGINO_TO_INO(mp, agno, ino), > - forkname); > +_("correcting key in bmbt root (was %" PRIu64 ", now %" PRIu64") in inode " > + "%" PRIu64" %s fork\n"), > + get_unaligned_be64(&pkey[i].br_startoff), > + cursor.level[level-1].first_key, > + XFS_AGINO_TO_INO(mp, agno, ino), > + forkname); > *dirty = 1; > - pkey[i].br_startoff = cpu_to_be64( > - cursor.level[level-1].first_key); > + put_unaligned_be64( > + cursor.level[level-1].first_key, > + &pkey[i].br_startoff); > } else { > do_warn( > - _("bad key in bmbt root (is %llu, would reset to %" PRIu64 ") in inode " > - "%" PRIu64 " %s fork\n"), > - (unsigned long long) > - be64_to_cpu(pkey[i].br_startoff), > - cursor.level[level-1].first_key, > - XFS_AGINO_TO_INO(mp, agno, ino), > - forkname); > +_("bad key in bmbt root (is %" PRIu64 ", would reset to %" PRIu64 ") in inode " > + "%" PRIu64 " %s fork\n"), > + get_unaligned_be64(&pkey[i].br_startoff), > + cursor.level[level-1].first_key, > + XFS_AGINO_TO_INO(mp, agno, ino), > + forkname); > } > } > /* > diff --git a/repair/prefetch.c b/repair/prefetch.c > index 32ec55e..52238ca 100644 > --- a/repair/prefetch.c > +++ b/repair/prefetch.c > @@ -330,7 +330,7 @@ pf_scanfunc_bmap( > pp = XFS_BMBT_PTR_ADDR(mp, block, 1, mp->m_bmap_dmxr[1]); > > for (i = 0; i < numrecs; i++) { > - dbno = be64_to_cpu(pp[i]); > + dbno = get_unaligned_be64(&pp[i]); > if (!verify_dfsbno(mp, dbno)) > return 0; > if (!pf_scan_lbtree(dbno, level, isadir, args, pf_scanfunc_bmap)) > @@ -372,7 +372,7 @@ pf_read_btinode( > pp = XFS_BMDR_PTR_ADDR(dib, 1, xfs_bmdr_maxrecs(dsize, 0)); > > for (i = 0; i < numrecs; i++) { > - dbno = be64_to_cpu(pp[i]); > + dbno = get_unaligned_be64(&pp[i]); > if (!verify_dfsbno(mp, dbno)) > break; > if (!pf_scan_lbtree(dbno, level, isadir, args, pf_scanfunc_bmap)) > -- > 2.6.1 > > > _______________________________________________ > xfs mailing list > xfs@oss.sgi.com > http://oss.sgi.com/mailman/listinfo/xfs _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs