From patchwork Thu Nov 5 15:51:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 322495 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=-9.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 C03C2C4741F for ; Thu, 5 Nov 2020 15:52:58 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2AA5420782 for ; Thu, 5 Nov 2020 15:52:58 +0000 (UTC) Authentication-Results: mail.kernel.org; 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Thu, 5 Nov 2020 15:51:27 +0000 (UTC) Received: from blue.redhat.com (ovpn-114-103.phx2.redhat.com [10.3.114.103]) by smtp.corp.redhat.com (Postfix) with ESMTP id CAE811002382; Thu, 5 Nov 2020 15:51:26 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Subject: [PATCH v4] block: Fix integer promotion error in bdrv_getlength() Date: Thu, 5 Nov 2020 09:51:22 -0600 Message-Id: <20201105155122.60943-1-eblake@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/11/05 01:14:53 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, chengchiwen@h3c.com, berto@igalia.com, tu.guoyi@h3c.com, "open list:Block layer core" , armbru@redhat.com, mreitz@redhat.com, wang.yongD@h3c.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Back in 2015, we attempted to fix error reporting for images that claimed to have more than INT64_MAX/512 sectors, but due to the type promotions caused by BDRV_SECTOR_SIZE being unsigned, this inadvertently forces all negative ret values to be slammed into -EFBIG rather than the original error. While we're at it, we can avoid the confusing ?: by spelling the logic more directly. Fixes: 4a9c9ea0d3 Reported-by: Guoyi Tu Signed-off-by: Eric Blake --- block.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/block.c b/block.c index 56bacc9e9f13..2fd932154e12 100644 --- a/block.c +++ b/block.c @@ -5091,8 +5091,13 @@ int64_t bdrv_getlength(BlockDriverState *bs) { int64_t ret = bdrv_nb_sectors(bs); - ret = ret > INT64_MAX / BDRV_SECTOR_SIZE ? -EFBIG : ret; - return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE; + if (ret < 0) { + return ret; + } + if (ret > INT64_MAX / BDRV_SECTOR_SIZE) { + return -EFBIG; + } + return ret * BDRV_SECTOR_SIZE; } /* return 0 as number of sectors if no device present or error */