From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 569CFC43381 for ; Tue, 12 Mar 2019 14:22:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 235652075C for ; Tue, 12 Mar 2019 14:22:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726914AbfCLOWI (ORCPT ); Tue, 12 Mar 2019 10:22:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34522 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726657AbfCLOWG (ORCPT ); Tue, 12 Mar 2019 10:22:06 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F16DF307E044; Tue, 12 Mar 2019 14:22:05 +0000 (UTC) Received: from redhat.com (ovpn-122-134.rdu2.redhat.com [10.10.122.134]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0CFB510018F9; Tue, 12 Mar 2019 14:22:04 +0000 (UTC) Date: Tue, 12 Mar 2019 09:22:02 -0500 From: Bill O'Donnell To: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org, Nathan Chancellor , linux-kernel@vger.kernel.org, Nick Desaulniers , clang-built-linux@googlegroups.com Subject: Re: [PATCH 1/2] xfs: zero initialize highstale and lowstale in xfs_dir2_leaf_addname Message-ID: <20190312142202.GA28037@redhat.com> References: <20190311161948.GC4359@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190311161948.GC4359@magnolia> User-Agent: Mutt/1.11.3 (2019-02-01) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Tue, 12 Mar 2019 14:22:06 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 11, 2019 at 09:19:48AM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong > > Smatch complains about the following: > > fs/xfs/libxfs/xfs_dir2_leaf.c:848 xfs_dir2_leaf_addname() error: > uninitialized symbol 'lowstale'. > > fs/xfs/libxfs/xfs_dir2_leaf.c:849 xfs_dir2_leaf_addname() error: > uninitialized symbol 'highstale'. > > I don't think there's any incorrect behavior associated with the > uninitialized variable, but as the author of the previous zero-init > patch points out, it's best not to be passing around pointers to > uninitialized stack areas. > > Signed-off-by: Darrick J. Wong Reviewed-by: Bill O'Donnell > --- > fs/xfs/libxfs/xfs_dir2_leaf.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_dir2_leaf.c b/fs/xfs/libxfs/xfs_dir2_leaf.c > index 9a3767818c50..2abf945e5844 100644 > --- a/fs/xfs/libxfs/xfs_dir2_leaf.c > +++ b/fs/xfs/libxfs/xfs_dir2_leaf.c > @@ -574,7 +574,7 @@ xfs_dir2_leaf_addname( > xfs_dir2_data_unused_t *dup; /* data unused entry */ > int error; /* error return value */ > int grown; /* allocated new data block */ > - int highstale; /* index of next stale leaf */ > + int highstale = 0; /* index of next stale leaf */ > int i; /* temporary, index */ > int index; /* leaf table position */ > struct xfs_buf *lbp; /* leaf's buffer */ > @@ -583,7 +583,7 @@ xfs_dir2_leaf_addname( > xfs_dir2_leaf_entry_t *lep; /* leaf entry table pointer */ > int lfloglow; /* low leaf logging index */ > int lfloghigh; /* high leaf logging index */ > - int lowstale; /* index of prev stale leaf */ > + int lowstale = 0; /* index of prev stale leaf */ > xfs_dir2_leaf_tail_t *ltp; /* leaf tail pointer */ > int needbytes; /* leaf block bytes needed */ > int needlog; /* need to log data header */