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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 C7C8DC35DF9 for ; Tue, 25 Feb 2020 08:34:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 985A421744 for ; Tue, 25 Feb 2020 08:34:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="QszlcDQT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726867AbgBYIeM (ORCPT ); Tue, 25 Feb 2020 03:34:12 -0500 Received: from mail-pl1-f196.google.com ([209.85.214.196]:44219 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725783AbgBYIeL (ORCPT ); Tue, 25 Feb 2020 03:34:11 -0500 Received: by mail-pl1-f196.google.com with SMTP id d9so5181046plo.11 for ; Tue, 25 Feb 2020 00:34:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=EIG5peTBvtZ2crp8lRotOHODI8wwfFW0u8sMOW/L1sk=; b=QszlcDQTF2Q2LkffTbIRI3lryFDMXd0PvmTxvgXjQgWVs4b+u9xfRQUq/q2qapPqNX 6fOPzA5/MBsQgoclTc8R1RazJoG0IS7T8sos5KrxMx5nBAW3g4033Z3oFaDO0Eyvi8m3 zKy6Qi4OpF8r2sA/VDjAV9GgFmLoehFxHt654aIZejm36g9ICrWPyQKq0Lu15SjcQ4RO NPGZbO9dCZs/ib/WPLdzP7z8+gzQOA9Pv/qeO4Gi8PGifICutSTCGxHk0vCYhwwtfgIw hrVeyJ9wDt3tGfUHHyS4FZgjozzQzt4g4KuNlUS6KvgJqNGeWsBMVWSXZ+QrBZT3VSJk s1Ug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=EIG5peTBvtZ2crp8lRotOHODI8wwfFW0u8sMOW/L1sk=; b=anrvFW9sss5c3r6OVaxYDkXoQOSED/UezVIg3/XLXqyv6BlH3agPTC1LbAShm61pHh Nvr9nNclLgmEPXajH8vNkczb1A96HuduKDp0iKYeyu9uEaDt1CQMnHp9cXLsjdjAy5Vx Nv1aUtiiIKPqAi8/qWcKruJxxRGy19q30aa4C/j+2hea+5j/B6ty/ZIhkTH9az5HD0Uv 3El82EgiHYwO80jPEVPEl0F8dlne7trYdbGTXgnFRDlZCA5uQPzH+16D0ua/7FOZalUH Y2Wf4/rM6ZCCvP+p5b+Y6bh0TPBEZaaRcebABhNSrSleWd0+/r8WDdQffrosvKlYGx6L G40w== X-Gm-Message-State: APjAAAWT0pM9vAMFN1WJbHb7fLoTYhNqbPOfGPq+CuFyTfPQiCzs68hD qmAQ4ngTruDdgM3MkL5Pfyd5NA== X-Google-Smtp-Source: APXvYqzAbMNZB07THyLuieZ3+XL0SoHji7KzYKVpxSVKAYezqzD3vcQYoYbTfpEkMi2a8G49muU0DA== X-Received: by 2002:a17:90a:c084:: with SMTP id o4mr3747200pjs.35.1582619651238; Tue, 25 Feb 2020 00:34:11 -0800 (PST) Received: from ?IPv6:240e:362:421:7f00:524:e1bd:8061:a346? ([240e:362:421:7f00:524:e1bd:8061:a346]) by smtp.gmail.com with ESMTPSA id f1sm2106681pjq.31.2020.02.25.00.33.48 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 25 Feb 2020 00:34:10 -0800 (PST) Subject: Re: [PATCH] uacce: unmap remaining mmapping from user space To: Xu Zaibo , Greg Kroah-Hartman , Arnd Bergmann , Herbert Xu , jonathan.cameron@huawei.com, dave.jiang@intel.com, grant.likely@arm.com, jean-philippe , Jerome Glisse , ilias.apalodimas@linaro.org, francois.ozog@linaro.org, kenneth-lee-2012@foxmail.com, Wangzhou , "haojian . zhuang" , guodong.xu@linaro.org Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-accelerators@lists.ozlabs.org, linux-crypto@vger.kernel.org References: <1582528016-2873-1-git-send-email-zhangfei.gao@linaro.org> From: zhangfei Message-ID: Date: Tue, 25 Feb 2020 16:33:37 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Zaibo On 2020/2/24 下午3:17, Xu Zaibo wrote: >>   @@ -585,6 +595,13 @@ void uacce_remove(struct uacce_device *uacce) >>           cdev_device_del(uacce->cdev, &uacce->dev); >>       xa_erase(&uacce_xa, uacce->dev_id); >>       put_device(&uacce->dev); >> + >> +    /* >> +     * unmap remainning mapping from user space, preventing user still >> +     * access the mmaped area while parent device is already removed >> +     */ >> +    if (uacce->inode) >> +        unmap_mapping_range(uacce->inode->i_mapping, 0, 0, 1); > Should we unmap them at the first of 'uacce_remove',  and before > 'uacce_put_queue'? > We can do this, Though it does not matter, since user space can not interrupt kernel function uacce_remove. Thanks