From patchwork Fri Feb 5 18:12:33 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Snow X-Patchwork-Id: 8237941 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 52129BEEE5 for ; Fri, 5 Feb 2016 18:13:27 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B6DD020392 for ; Fri, 5 Feb 2016 18:13:26 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0615420389 for ; Fri, 5 Feb 2016 18:13:26 +0000 (UTC) Received: from localhost ([::1]:49827 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aRksn-0000hh-D1 for patchwork-qemu-devel@patchwork.kernel.org; Fri, 05 Feb 2016 13:13:25 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39466) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aRks6-0008K3-J9 for qemu-devel@nongnu.org; Fri, 05 Feb 2016 13:12:43 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aRks5-00019f-Ee for qemu-devel@nongnu.org; Fri, 05 Feb 2016 13:12:42 -0500 Received: from mx1.redhat.com ([209.132.183.28]:54672) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aRks0-00018c-7s; Fri, 05 Feb 2016 13:12:36 -0500 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id 7D55380500; Fri, 5 Feb 2016 18:12:35 +0000 (UTC) Received: from scv.usersys.redhat.com (vpn-57-160.rdu2.redhat.com [10.10.57.160]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u15ICYnf001295; Fri, 5 Feb 2016 13:12:34 -0500 From: John Snow To: qemu-block@nongnu.org Date: Fri, 5 Feb 2016 13:12:33 -0500 Message-Id: <1454695953-14710-1-git-send-email-jsnow@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: kwolf@redhat.com, John Snow , famz@redhat.com, qemu-devel@nongnu.org Subject: [Qemu-devel] [PATCH v2] qemu-img: initialize MapEntry object X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Commit 16b0d555 introduced an issue where we are not initializing has_filename for the 'next' MapEntry object, which leads to interesting errors in Valgrind and Clang -fsanitize=undefined both. Zero the stack object at allocation AND make sure the utility to populate the fields properly marks has_filename as false if applicable. Signed-off-by: John Snow Reviewed-by: Eric Blake --- v2: Initialize with a compound literal as a future-proofing measure. qemu-img.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/qemu-img.c b/qemu-img.c index f121980..4617d3b 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -2195,6 +2195,7 @@ static int get_block_status(BlockDriverState *bs, int64_t sector_num, int64_t ret; int depth; BlockDriverState *file; + bool has_offset; /* As an optimization, we could cache the current range of unallocated * clusters in each file of the chain, and avoid querying the same @@ -2221,17 +2222,20 @@ static int get_block_status(BlockDriverState *bs, int64_t sector_num, depth++; } - e->start = sector_num * BDRV_SECTOR_SIZE; - e->length = nb_sectors * BDRV_SECTOR_SIZE; - e->data = !!(ret & BDRV_BLOCK_DATA); - e->zero = !!(ret & BDRV_BLOCK_ZERO); - e->offset = ret & BDRV_BLOCK_OFFSET_MASK; - e->has_offset = !!(ret & BDRV_BLOCK_OFFSET_VALID); - e->depth = depth; - if (file && e->has_offset) { - e->has_filename = true; - e->filename = file->filename; - } + has_offset = !!(ret & BDRV_BLOCK_OFFSET_VALID); + + *e = (MapEntry) { + .start = sector_num * BDRV_SECTOR_SIZE, + .length = nb_sectors * BDRV_SECTOR_SIZE, + .data = !!(ret & BDRV_BLOCK_DATA), + .zero = !!(ret & BDRV_BLOCK_ZERO), + .offset = ret & BDRV_BLOCK_OFFSET_MASK, + .has_offset = has_offset, + .depth = depth, + .has_filename = file && has_offset, + .filename = file && has_offset ? file->filename : NULL, + }; + return 0; }