From patchwork Mon Jan 16 21:12:00 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Farman X-Patchwork-Id: 9519503 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 3F35E60209 for ; Mon, 16 Jan 2017 21:18:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 30BBA28210 for ; Mon, 16 Jan 2017 21:18:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 25165281F9; Mon, 16 Jan 2017 21:18:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 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.wl.linuxfoundation.org (Postfix) with ESMTPS id C3A1C281F9 for ; Mon, 16 Jan 2017 21:18:57 +0000 (UTC) Received: from localhost ([::1]:59642 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cTEg4-0001Xn-SL for patchwork-qemu-devel@patchwork.kernel.org; Mon, 16 Jan 2017 16:18:56 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50591) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cTEZa-0004Fd-EC for qemu-devel@nongnu.org; Mon, 16 Jan 2017 16:12:15 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cTEZX-0001AI-GY for qemu-devel@nongnu.org; Mon, 16 Jan 2017 16:12:14 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:36616 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cTEZX-0001A5-A1 for qemu-devel@nongnu.org; Mon, 16 Jan 2017 16:12:11 -0500 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v0GL8xWC126587 for ; Mon, 16 Jan 2017 16:12:10 -0500 Received: from e06smtp14.uk.ibm.com (e06smtp14.uk.ibm.com [195.75.94.110]) by mx0b-001b2d01.pphosted.com with ESMTP id 281551hhk2-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 16 Jan 2017 16:12:10 -0500 Received: from localhost by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 16 Jan 2017 21:12:05 -0000 Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by d06dlp02.portsmouth.uk.ibm.com (Postfix) with ESMTP id 98AD4219004D; Mon, 16 Jan 2017 21:11:11 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v0GLC48l917774; Mon, 16 Jan 2017 21:12:04 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B7C2EAE055; Mon, 16 Jan 2017 20:10:06 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A6AFDAE045; Mon, 16 Jan 2017 20:10:06 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Mon, 16 Jan 2017 20:10:06 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 4958) id 68F6420F5CE; Mon, 16 Jan 2017 22:12:04 +0100 (CET) From: Eric Farman To: qemu-devel@nongnu.org, qemu-block@nongnu.org Date: Mon, 16 Jan 2017 22:12:00 +0100 X-Mailer: git-send-email 2.8.4 In-Reply-To: <20170116211201.46601-1-farman@linux.vnet.ibm.com> References: <20170116211201.46601-1-farman@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 17011621-0016-0000-0000-00000428B45A X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17011621-0017-0000-0000-0000261A8422 Message-Id: <20170116211201.46601-3-farman@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-01-16_17:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1701160297 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 148.163.158.5 Subject: [Qemu-devel] [PATCH 2/3] block: Fix target variable of BLKSECTGET ioctl X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, pbonzini@redhat.com, Eric Farman , mreitz@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Commit 6f607174 introduced a routine to call the kernel BLKSECTGET ioctl, which stores the result back to user space. However, the size of the data returned depends on the routine handling the ioctl. The (compat_)blkdev_ioctl returns a short, while sg_ioctl returns an int. Thus, on big-endian systems, we can find ourselves accidentally shifting the result to a much larger value. (On s390x, a short is 16 bits while an int is 32 bits.) Signed-off-by: Eric Farman --- block/file-posix.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index 28b47d9..2115155 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -651,12 +651,15 @@ static void raw_reopen_abort(BDRVReopenState *state) state->opaque = NULL; } -static int hdev_get_max_transfer_length(int fd) +static int hdev_get_max_transfer_length(BlockDriverState *bs, int fd) { #ifdef BLKSECTGET int max_sectors = 0; - if (ioctl(fd, BLKSECTGET, &max_sectors) == 0) { + short max_sectors_short = 0; + if (bs->sg && ioctl(fd, BLKSECTGET, &max_sectors) == 0) { return max_sectors; + } else if (!bs->sg && ioctl(fd, BLKSECTGET, &max_sectors_short) == 0) { + return max_sectors_short; } else { return -errno; } @@ -672,7 +675,7 @@ static void raw_refresh_limits(BlockDriverState *bs, Error **errp) if (!fstat(s->fd, &st)) { if (S_ISBLK(st.st_mode)) { - int ret = hdev_get_max_transfer_length(s->fd); + int ret = hdev_get_max_transfer_length(bs, s->fd); if (ret > 0 && ret <= BDRV_REQUEST_MAX_SECTORS) { bs->bl.max_transfer = pow2floor(ret << BDRV_SECTOR_BITS); }