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=-3.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 00F24C35E04 for ; Tue, 25 Feb 2020 18:07:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C0C4C206E6 for ; Tue, 25 Feb 2020 18:07:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="kjY4KEu9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731167AbgBYSH1 (ORCPT ); Tue, 25 Feb 2020 13:07:27 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:44184 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728367AbgBYSH1 (ORCPT ); Tue, 25 Feb 2020 13:07:27 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=aCaDXtbBQPVEc9XwUeRXZXycGtd4URd8os8NhYVB/ZI=; b=kjY4KEu9G68waT7PVGTNrC5OTD alIjGbCn1cTJsnpr7OKaq8fT6XfrJox2JDRDqiEwD0GbL+GW8RZHNIrTyijbZv2RTE6IFbZw0GycS px2U5yzIkx4yBHBZNEsQZUIR8AhuJULSbGSX8aD+vTlOllUVyTuBdlnVNybDzC3rjDYLJ+T4/h/NX ughbMwxKWUz3R2frUfteJaPIOkvA/s8M8gUKk0Tf0V2gn//LWFcCOpj0kuikDHj2jwVJnm2DqU/5K qYcrvlBIicxkjoSW0dGlrrSpvqZ6WpURqmoG7qyqr6CeCM5tR4vENw6dl0ArDHKogeKPwm6/xuZrL 6G18/UDg==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1j6ec9-0007zW-2t; Tue, 25 Feb 2020 18:07:25 +0000 Date: Tue, 25 Feb 2020 10:07:25 -0800 From: Christoph Hellwig To: Qian Cai Cc: darrick.wong@oracle.com, linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] xfs: fix an undefined behaviour in _da3_path_shift Message-ID: <20200225180725.GA29862@infradead.org> References: <1582641477-4011-1-git-send-email-cai@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1582641477-4011-1-git-send-email-cai@lca.pw> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I think we code do this a tad more cleaner, something like: diff --git a/fs/xfs/libxfs/xfs_da_btree.c b/fs/xfs/libxfs/xfs_da_btree.c index 875e04f82541..542a4edfcf54 100644 --- a/fs/xfs/libxfs/xfs_da_btree.c +++ b/fs/xfs/libxfs/xfs_da_btree.c @@ -1986,7 +1986,8 @@ xfs_da3_path_shift( ASSERT(path != NULL); ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH)); level = (path->active-1) - 1; /* skip bottom layer in path */ - for (blk = &path->blk[level]; level >= 0; blk--, level--) { + for ( ; level >= 0; level--) { + blk = &path->blk[level]; xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, blk->bp->b_addr);