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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 F37A2C169C4 for ; Tue, 29 Jan 2019 10:10:18 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 3A4CE20881 for ; Tue, 29 Jan 2019 10:10:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3A4CE20881 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=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 43pj135gYQzDqNr for ; Tue, 29 Jan 2019 21:10:15 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=none (mailfrom) smtp.mailfrom=linux.vnet.ibm.com (client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=clombard@linux.vnet.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.vnet.ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 43phzH48hjzDqHr for ; Tue, 29 Jan 2019 21:08:43 +1100 (AEDT) Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x0TA3ijn140218 for ; Tue, 29 Jan 2019 05:08:40 -0500 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0a-001b2d01.pphosted.com with ESMTP id 2qamfa1d6g-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 29 Jan 2019 05:08:40 -0500 Received: from localhost by e06smtp01.uk.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, 29 Jan 2019 10:08:35 -0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x0TA8Ydw36765826 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 29 Jan 2019 10:08:34 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3918011C04A; Tue, 29 Jan 2019 10:08:34 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E3F7F11C052; Tue, 29 Jan 2019 10:08:33 +0000 (GMT) Received: from [9.134.167.118] (unknown [9.134.167.118]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 29 Jan 2019 10:08:33 +0000 (GMT) Subject: Re: [PATCH v3] cxl: Wrap iterations over afu slices inside 'afu_list_lock' To: Vaibhav Jain , linuxppc-dev@lists.ozlabs.org, Frederic Barrat References: <20190129061558.2122-1-vaibhav@linux.ibm.com> From: christophe lombard Date: Tue, 29 Jan 2019 11:08:33 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20190129061558.2122-1-vaibhav@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-MW Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19012910-4275-0000-0000-000003073D3F X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19012910-4276-0000-0000-000038153ECC Message-Id: <81f361bd-3f51-7e63-f967-1f8625c0812d@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-01-29_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=8.0.1-1810050000 definitions=main-1901290077 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Philippe Bergheaud , Alastair D'Silva , Christophe Lombard , Andrew Donnellan Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 29/01/2019 07:15, Vaibhav Jain wrote: > Within cxl module, iteration over array 'adapter->slices' may be racy > at few points as it might be simultaneously read during an EEH and its > contents being set to NULL while driver is being unloaded or unbound > from the adapter. This might result in a NULL pointer to 'struct afu' > being de-referenced during an EEH thereby causing a kernel oops. > > This patch fixes this by making sure that all access to the array > 'adapter->slices' is wrapped within the context of spin-lock > 'adapter->afu_list_lock'. > > Signed-off-by: Vaibhav Jain > --- > Changelog: > > v3: > * Updated a slice loop in cxl_pci_error_detectected() to ignore NULL > slices [Fred] > * Added a NULL AFU check in cxl_pci_slot_reset() [Fred] > > v2: > * Fixed a wrong comparison of non-null pointer [Fred] > * Moved a call to cxl_vphb_error_detected() within a branch that > checks for not null AFU pointer in 'adapter->slices' [Fred] > * Removed a misleading comment in code. > --- Thanks Acked-by: Christophe Lombard