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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 03FACC43462 for ; Tue, 11 May 2021 19:56:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D0CF3611C1 for ; Tue, 11 May 2021 19:56:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229973AbhEKT5v (ORCPT ); Tue, 11 May 2021 15:57:51 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:58282 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229716AbhEKT5u (ORCPT ); Tue, 11 May 2021 15:57:50 -0400 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 14BJX9WQ187435; Tue, 11 May 2021 15:56:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=6Ji2N+g5BEfEKgFOPSitgWqnRCwc0MS0b5j0S+cgxRA=; b=nKZDvavjx0xkDejKD85V0i7DLKZWzCaqxPQOF0RG3/okgPSMzJjRIXV9XE1uMR13u8rs E5+TX4BJX5epoij2VSKgKnyUw5dPK2CwqYwUt24aV1c4dd4fnB393BNDxSoQBV2Uk3Ds sz+j2rRXukEPqqdMq4vM4BO/pz4toulSfloBc3lot/UIuIX07167bGbHUkXGzQDTj5r6 x4XmTlO6WuqJ2pIaxzWsPMkOjSntNPDV2AqlaWq3vgwr77RHx7D5WWgRaPzSxdZUU3w4 dbYfgryHf4T8IfpwCki8OxbnplDylJWnbDnQhf70dZNvnqp0IGhPq7np6JdtyQEIYFJk dw== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 38fyke9ewm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 11 May 2021 15:56:43 -0400 Received: from m0098409.ppops.net (m0098409.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 14BJmcGq065396; Tue, 11 May 2021 15:56:43 -0400 Received: from ppma06ams.nl.ibm.com (66.31.33a9.ip4.static.sl-reverse.com [169.51.49.102]) by mx0a-001b2d01.pphosted.com with ESMTP id 38fyke9evh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 11 May 2021 15:56:42 -0400 Received: from pps.filterd (ppma06ams.nl.ibm.com [127.0.0.1]) by ppma06ams.nl.ibm.com (8.16.0.43/8.16.0.43) with SMTP id 14BJmXMt011228; Tue, 11 May 2021 19:56:40 GMT Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by ppma06ams.nl.ibm.com with ESMTP id 38dhwh9ubg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 11 May 2021 19:56:40 +0000 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 14BJub6926476904 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 11 May 2021 19:56:37 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B470AA4064; Tue, 11 May 2021 19:56:37 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A19D5A405F; Tue, 11 May 2021 19:56:37 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Tue, 11 May 2021 19:56:37 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 4958) id 5CC1DE0369; Tue, 11 May 2021 21:56:32 +0200 (CEST) From: Eric Farman To: Cornelia Huck , Matthew Rosato , Halil Pasic Cc: Jared Rossi , linux-s390@vger.kernel.org, kvm@vger.kernel.org, Eric Farman Subject: [PATCH v6 1/3] vfio-ccw: Check initialized flag in cp_init() Date: Tue, 11 May 2021 21:56:29 +0200 Message-Id: <20210511195631.3995081-2-farman@linux.ibm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210511195631.3995081-1-farman@linux.ibm.com> References: <20210511195631.3995081-1-farman@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: C8_8_6tvji8GkULHofeINhOCWr6zPq6q X-Proofpoint-GUID: Qpivyg11w_ssSyxti82dlSJanEYrTAY8 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.761 definitions=2021-05-11_04:2021-05-11,2021-05-11 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 suspectscore=0 lowpriorityscore=0 phishscore=0 malwarescore=0 adultscore=0 impostorscore=0 mlxscore=0 spamscore=0 bulkscore=0 mlxlogscore=999 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2105110130 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org We have a really nice flag in the channel_program struct that indicates if it had been initialized by cp_init(), and use it as a guard in the other cp accessor routines, but not for a duplicate call into cp_init(). The possibility of this occurring is low, because that flow is protected by the private->io_mutex and FSM CP_PROCESSING state. But then why bother checking it in (for example) cp_prefetch() then? Let's just be consistent and check for that in cp_init() too. Fixes: 71189f263f8a3 ("vfio-ccw: make it safe to access channel programs") Signed-off-by: Eric Farman Reviewed-by: Cornelia Huck --- drivers/s390/cio/vfio_ccw_cp.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index b9febc581b1f..8d1b2771c1aa 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -638,6 +638,10 @@ int cp_init(struct channel_program *cp, struct device *mdev, union orb *orb) static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 1); int ret; + /* this is an error in the caller */ + if (cp->initialized) + return -EBUSY; + /* * We only support prefetching the channel program. We assume all channel * programs executed by supported guests likewise support prefetching. -- 2.25.1