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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 76D2DC76186 for ; Tue, 23 Jul 2019 17:09:47 +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 4B72A2184E for ; Tue, 23 Jul 2019 17:09:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4B72A2184E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.vnet.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:46044 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hpyIL-00016d-WA for qemu-devel@archiver.kernel.org; Tue, 23 Jul 2019 13:09:46 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43221) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hpyBE-0007Tb-Aj for qemu-devel@nongnu.org; Tue, 23 Jul 2019 13:02:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hpyBC-00063B-8r for qemu-devel@nongnu.org; Tue, 23 Jul 2019 13:02:24 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:63086 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 1hpyBA-0005lJ-7P for qemu-devel@nongnu.org; Tue, 23 Jul 2019 13:02:22 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x6NH24Ef077587 for ; Tue, 23 Jul 2019 13:02:07 -0400 Received: from e32.co.us.ibm.com (e32.co.us.ibm.com [32.97.110.150]) by mx0b-001b2d01.pphosted.com with ESMTP id 2tx60r8n1p-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 23 Jul 2019 13:02:02 -0400 Received: from localhost by e32.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 23 Jul 2019 18:01:29 +0100 Received: from b03ledav005.gho.boulder.ibm.com (b03ledav005.gho.boulder.ibm.com [9.17.130.236]) by b03cxnp07029.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x6NH1SNH26149202 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 23 Jul 2019 17:01:28 GMT Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BDC48BE051; Tue, 23 Jul 2019 17:01:28 +0000 (GMT) Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B1ACEBE05B; Tue, 23 Jul 2019 17:01:28 +0000 (GMT) Received: from localhost (unknown [9.53.179.212]) by b03ledav005.gho.boulder.ibm.com (Postfix) with ESMTP; Tue, 23 Jul 2019 17:01:28 +0000 (GMT) From: Michael Roth To: qemu-devel@nongnu.org Date: Tue, 23 Jul 2019 12:00:35 -0500 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190723170104.4327-1-mdroth@linux.vnet.ibm.com> References: <20190723170104.4327-1-mdroth@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-TM-AS-GCONF: 00 x-cbid: 19072317-0004-0000-0000-0000152DB9B4 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00011482; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000287; SDB=6.01236375; UDB=6.00651638; IPR=6.01017731; MB=3.00027856; MTD=3.00000008; XFM=3.00000015; UTC=2019-07-23 17:01:31 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19072317-0005-0000-0000-00008C9463D1 Message-Id: <20190723170104.4327-8-mdroth@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-07-23_07:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1907230170 Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by mx0b-001b2d01.pphosted.com id x6NH24Ef077587 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] X-Received-From: 148.163.158.5 Subject: [Qemu-devel] [PATCH 07/36] linux-user: make pwrite64/pread64(fd, NULL, 0, offset) return 0 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: Peter Maydell , qemu-stable@nongnu.org, Laurent Vivier Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Peter Maydell Linux returns success if pwrite64() or pread64() are called with a zero length NULL buffer, but QEMU was returning -TARGET_EFAULT. This is the same bug that we fixed in commit 58cfa6c2e6eb51b23cc9 for the write syscall, and long before that in 38d840e6790c29f59 for the read syscall. Fixes: https://bugs.launchpad.net/qemu/+bug/1810433 Signed-off-by: Peter Maydell Reviewed-by: Laurent Vivier Reviewed-by: Philippe Mathieu-Daud=C3=A9 Message-Id: <20190108184900.9654-1-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier (cherry picked from commit 2bd3f8998e1e7dcd9afc29fab252fb9936f9e956) Signed-off-by: Michael Roth --- linux-user/syscall.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 280137da8c..b13a170e52 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -9677,8 +9677,15 @@ static abi_long do_syscall1(void *cpu_env, int num= , abi_long arg1, arg4 =3D arg5; arg5 =3D arg6; } - if (!(p =3D lock_user(VERIFY_WRITE, arg2, arg3, 0))) - return -TARGET_EFAULT; + if (arg2 =3D=3D 0 && arg3 =3D=3D 0) { + /* Special-case NULL buffer and zero length, which should su= cceed */ + p =3D 0; + } else { + p =3D lock_user(VERIFY_WRITE, arg2, arg3, 0); + if (!p) { + return -TARGET_EFAULT; + } + } ret =3D get_errno(pread64(arg1, p, arg3, target_offset64(arg4, a= rg5))); unlock_user(p, arg2, ret); return ret; @@ -9687,8 +9694,15 @@ static abi_long do_syscall1(void *cpu_env, int num= , abi_long arg1, arg4 =3D arg5; arg5 =3D arg6; } - if (!(p =3D lock_user(VERIFY_READ, arg2, arg3, 1))) - return -TARGET_EFAULT; + if (arg2 =3D=3D 0 && arg3 =3D=3D 0) { + /* Special-case NULL buffer and zero length, which should su= cceed */ + p =3D 0; + } else { + p =3D lock_user(VERIFY_READ, arg2, arg3, 1); + if (!p) { + return -TARGET_EFAULT; + } + } ret =3D get_errno(pwrite64(arg1, p, arg3, target_offset64(arg4, = arg5))); unlock_user(p, arg2, 0); return ret; --=20 2.17.1