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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9227C63797 for ; Mon, 30 Jan 2023 21:46:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231550AbjA3Vqu (ORCPT ); Mon, 30 Jan 2023 16:46:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231513AbjA3Vqr (ORCPT ); Mon, 30 Jan 2023 16:46:47 -0500 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E38DA4996D; Mon, 30 Jan 2023 13:46:44 -0800 (PST) Received: from pps.filterd (m0279870.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 30UKxEiv005232; Mon, 30 Jan 2023 21:46:33 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=qcppdkim1; bh=s/98MwVcL38UIsZzsytvTp8dsTQvjFf4DXmZcFk5S+U=; b=PmX3xWP98oz/HCRjxw+iBKIzjsXsKHyuxf+dOjonidaMDRaqEY6a2Yf7wscHb2cdXpCc dU6Lu4Bxac9vCBepnbO+YkfRPV9HOMAbmV6e2ia9iJtMZdpnmJV4jI2dvBpjxF/k/Zev /aZjwQZFm59oCBJryguzzAwp1D12gbs7AHRAYDQdl9YVL71ROBeIhtr7YvD+y8rAkn1j YPQaTzuyZ1Uae55A71kC/fRvjfxmfbcs4cIvNvM0Yrw2/aJQ7jNuckiIrkS2B4QGKtjY z3dyBu/Fb+XXDMlyLy97ZzIeZmU5XIzkbxfCl/mU9WGHQH86MU7OtwuPoi/lfG5sy9Ol ng== Received: from nasanppmta01.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3ncut2n2fq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 30 Jan 2023 21:46:33 +0000 Received: from nasanex01b.na.qualcomm.com (nasanex01b.na.qualcomm.com [10.46.141.250]) by NASANPPMTA01.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 30ULkV8W017131 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 30 Jan 2023 21:46:31 GMT Received: from [10.134.67.48] (10.80.80.8) by nasanex01b.na.qualcomm.com (10.46.141.250) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.36; Mon, 30 Jan 2023 13:46:31 -0800 Message-ID: Date: Mon, 30 Jan 2023 13:46:30 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Subject: Re: [PATCH v9 13/27] gunyah: vm_mgr: Add/remove user memory regions Content-Language: en-US To: Srivatsa Vaddagiri CC: Bjorn Andersson , Alex Elder , Murali Nalajala , Trilok Soni , Carl van Schaik , Prakruthi Deepak Heragu , Dmitry Baryshkov , Arnd Bergmann , "Greg Kroah-Hartman" , Rob Herring , Krzysztof Kozlowski , Jonathan Corbet , Bagas Sanjaya , Catalin Marinas , Will Deacon , Marc Zyngier , Jassi Brar , Sudeep Holla , , , , , References: <20230120224627.4053418-1-quic_eberman@quicinc.com> <20230120224627.4053418-14-quic_eberman@quicinc.com> <20230125133424.GA332@quicinc.com> From: Elliot Berman In-Reply-To: <20230125133424.GA332@quicinc.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nasanex01b.na.qualcomm.com (10.46.141.250) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: fqnEkPeUjsUKnmNLhO8oAmGwD9z7K8UP X-Proofpoint-ORIG-GUID: fqnEkPeUjsUKnmNLhO8oAmGwD9z7K8UP X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.930,Hydra:6.0.562,FMLib:17.11.122.1 definitions=2023-01-30_17,2023-01-30_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 bulkscore=0 phishscore=0 lowpriorityscore=0 adultscore=0 malwarescore=0 spamscore=0 suspectscore=0 mlxlogscore=722 impostorscore=0 priorityscore=1501 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2301300201 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/25/2023 5:34 AM, Srivatsa Vaddagiri wrote: > * Elliot Berman [2023-01-20 14:46:12]: > >> + /* Check for overlap */ >> + list_for_each_entry(tmp_mapping, &ghvm->memory_mappings, list) { >> + if (!((mapping->guest_phys_addr + (mapping->npages << PAGE_SHIFT) <= >> + tmp_mapping->guest_phys_addr) || >> + (mapping->guest_phys_addr >= >> + tmp_mapping->guest_phys_addr + (tmp_mapping->npages << PAGE_SHIFT)))) { >> + ret = -EEXIST; >> + goto unlock; >> + } >> + } >> + >> + list_add(&mapping->list, &ghvm->memory_mappings); > > I think the potential race condition described last time is still possible. Pls > check. > >> +unlock: >> + mutex_unlock(&ghvm->mm_lock); >> + if (ret) >> + goto free_mapping; >> + >> + mapping->pages = kcalloc(mapping->npages, sizeof(*mapping->pages), GFP_KERNEL); >> + if (!mapping->pages) { >> + ret = -ENOMEM; >> + goto reclaim; > > Same comment as last time. Can you check this error path? We seem to call > unpin_user_page() in this path, which is not correct. > >> + } >> + >> + pinned = pin_user_pages_fast(region->userspace_addr, mapping->npages, >> + FOLL_WRITE | FOLL_LONGTERM, mapping->pages); >> + if (pinned < 0) { >> + ret = pinned; >> + goto reclaim; > > Same comment as above. > Caught the race condition you are describing between adding and removing the memory parcels. Should be fixed for v10. - Elliot