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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Greylist: Sender IP whitelisted, Sender e-mail whitelisted, not delayed by milter-greylist-4.4.3 (isis.lip6.fr [132.227.60.2]); Sat, 06 Jun 2020 22:36:34 +0200 (CEST) X-Greylist: Sender DNS name whitelisted, not delayed by milter-greylist-4.4.3 (isis.lip6.fr [132.227.60.2]); Sat, 06 Jun 2020 22:36:31 +0200 (CEST) X-Scanned-By: MIMEDefang 2.78 on 132.227.60.2 X-Scanned-By: MIMEDefang 2.78 on 132.227.60.2 Cc: Joe Perches , cocci@systeme.lip6.fr, linux-kernel@vger.kernel.org Subject: Re: [Cocci] [PATCH 1/2] Coccinelle: extend memdup_user transformation with GFP_USER X-BeenThere: cocci@systeme.lip6.fr X-Mailman-Version: 2.1.13 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: cocci-bounces@systeme.lip6.fr Errors-To: cocci-bounces@systeme.lip6.fr On 6/6/20 11:24 AM, Julia Lawall wrote: > > > On Sat, 30 May 2020, Denis Efremov wrote: > >> Match GFP_USER allocations with memdup_user.cocci rule. >> Commit 6c2c97a24f09 ("memdup_user(): switch to GFP_USER") switched >> memdup_user() from GFP_KERNEL to GFP_USER. In most cases it is still >> a good idea to use memdup_user() for GFP_KERNEL allocations. The >> motivation behind altering memdup_user() to GFP_USER is here: >> https://lkml.org/lkml/2018/1/6/333 > > Should the rule somehow document the cases in which memdup_user should now > not be used? As for now, I can't provide a counterexample. GPF_USER is more permissive than GFP_KERNEL. It's completely ok to use GPF_USER with copy_from_user. Given that memdup_user() was "silently" switched to GPF_USER from GPF_KERNEL with no callside fixes, I think it's ok to recommend to use memdup_user for GPF_KERNEL matches with no additional restrictions. Thanks, Denis _______________________________________________ Cocci mailing list Cocci@systeme.lip6.fr https://systeme.lip6.fr/mailman/listinfo/cocci 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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 2B53BC433E0 for ; Sat, 6 Jun 2020 20:40:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A2D020663 for ; Sat, 6 Jun 2020 20:40:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728884AbgFFUgf (ORCPT ); Sat, 6 Jun 2020 16:36:35 -0400 Received: from mail-lj1-f196.google.com ([209.85.208.196]:41594 "EHLO mail-lj1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727957AbgFFUgd (ORCPT ); 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Sat, 06 Jun 2020 13:36:31 -0700 (PDT) Received: from [192.168.1.8] ([213.87.137.116]) by smtp.gmail.com with ESMTPSA id y130sm2553195lfc.22.2020.06.06.13.36.27 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 06 Jun 2020 13:36:30 -0700 (PDT) To: Julia Lawall Cc: Joe Perches , cocci@systeme.lip6.fr, linux-kernel@vger.kernel.org References: <20200530205348.5812-1-efremov@linux.com> <20200530205348.5812-2-efremov@linux.com> From: Denis Efremov Autocrypt: addr=efremov@linux.com; keydata= mQINBFsJUXwBEADDnzbOGE/X5ZdHqpK/kNmR7AY39b/rR+2Wm/VbQHV+jpGk8ZL07iOWnVe1 ZInSp3Ze+scB4ZK+y48z0YDvKUU3L85Nb31UASB2bgWIV+8tmW4kV8a2PosqIc4wp4/Qa2A/ Ip6q+bWurxOOjyJkfzt51p6Th4FTUsuoxINKRMjHrs/0y5oEc7Wt/1qk2ljmnSocg3fMxo8+ y6IxmXt5tYvt+FfBqx/1XwXuOSd0WOku+/jscYmBPwyrLdk/pMSnnld6a2Fp1zxWIKz+4VJm QEIlCTe5SO3h5sozpXeWS916VwwCuf8oov6706yC4MlmAqsQpBdoihQEA7zgh+pk10sCvviX FYM4gIcoMkKRex/NSqmeh3VmvQunEv6P+hNMKnIlZ2eJGQpz/ezwqNtV/przO95FSMOQxvQY 11TbyNxudW4FBx6K3fzKjw5dY2PrAUGfHbpI3wtVUNxSjcE6iaJHWUA+8R6FLnTXyEObRzTS fAjfiqcta+iLPdGGkYtmW1muy/v0juldH9uLfD9OfYODsWia2Ve79RB9cHSgRv4nZcGhQmP2 wFpLqskh+qlibhAAqT3RQLRsGabiTjzUkdzO1gaNlwufwqMXjZNkLYu1KpTNUegx3MNEi2p9 CmmDxWMBSMFofgrcy8PJ0jUnn9vWmtn3gz10FgTgqC7B3UvARQARAQABtCFEZW5pcyBFZnJl bW92IDxlZnJlbW92QGxpbnV4LmNvbT6JAlcEEwEIAEECGwMFCwkIBwIGFQoJCAsCBBYCAwEC HgECF4ACGQEWIQR2VAM2ApQN8ZIP5AO1IpWwM1AwHwUCXsQtuwUJB31DPwAKCRC1IpWwM1Aw H3dQD/9E/hFd2yPwWA5cJ5jmBeQt4lBi5wUXd2+9Y0mBIn40F17Xrjebo+D8E5y6S/wqfImW nSDYaMfIIljdjmUUanR9R7Cxd/Z548Qaa4F1AtB4XN3W1L49q21h942iu0yxSLZtq9ayeja6 flCB7a+gKjHMWFDB4nRi4gEJvZN897wdJp2tAtUfErXvvxR2/ymKsIf5L0FZBnIaGpqRbfgG Slu2RSpCkvxqlLaYGeYwGODs0QR7X2i70QGeEzznN1w1MGKLOFYw6lLeO8WPi05fHzpm5pK6 mTKkpZ53YsRfWL/HY3kLZPWm1cfAxa/rKvlhom+2V8cO4UoLYOzZLNW9HCFnNxo7zHoJ1shR gYcCq8XgiJBF6jfM2RZYkOAJd6E3mVUxctosNq6av3NOdsp1Au0CYdQ6Whi13azZ81pDlJQu Hdb0ZpDzysJKhORsf0Hr0PSlYKOdHuhl8fXKYOGQxpYrWpOnjrlEORl7NHILknXDfd8mccnf 4boKIZP7FbqSLw1RSaeoCnqH4/b+ntsIGvY3oJjzbQVq7iEpIhIoQLxeklFl1xvJAOuSQwII I9S0MsOm1uoT/mwq+wCYux4wQhALxSote/EcoUxK7DIW9ra4fCCo0bzaX7XJ+dJXBWb0Ixxm yLl39M+7gnhvZyU+wkTYERp1qBe9ngjd0QTZNVi7MbkCDQRbCVF8ARAA3ITFo8OvvzQJT2cY nPR718Npm+UL6uckm0Jr0IAFdstRZ3ZLW/R9e24nfF3A8Qga3VxJdhdEOzZKBbl1nadZ9kKU nq87te0eBJu+EbcuMv6+njT4CBdwCzJnBZ7ApFpvM8CxIUyFAvaz4EZZxkfEpxaPAivR1Sa2 2x7OMWH/78laB6KsPgwxV7fir45VjQEyJZ5ac5ydG9xndFmb76upD7HhV7fnygwf/uIPOzNZ YVElGVnqTBqisFRWg9w3Bqvqb/W6prJsoh7F0/THzCzp6PwbAnXDedN388RIuHtXJ+wTsPA0 oL0H4jQ+4XuAWvghD/+RXJI5wcsAHx7QkDcbTddrhhGdGcd06qbXe2hNVgdCtaoAgpCEetW8 /a8H+lEBBD4/iD2La39sfE+dt100cKgUP9MukDvOF2fT6GimdQ8TeEd1+RjYyG9SEJpVIxj6 H3CyGjFwtIwodfediU/ygmYfKXJIDmVpVQi598apSoWYT/ltv+NXTALjyNIVvh5cLRz8YxoF sFI2VpZ5PMrr1qo+DB1AbH00b0l2W7HGetSH8gcgpc7q3kCObmDSa3aTGTkawNHzbceEJrL6 mRD6GbjU4GPD06/dTRIhQatKgE4ekv5wnxBK6v9CVKViqpn7vIxiTI9/VtTKndzdnKE6C72+ jTwSYVa1vMxJABtOSg8AEQEAAYkCPAQYAQgAJgIbDBYhBHZUAzYClA3xkg/kA7UilbAzUDAf BQJexC4MBQkHfUOQAAoJELUilbAzUDAfPYoQAJdBGd9WZIid10FCoI30QXA82SHmxWe0Xy7h r4bbZobDPc7GbTHeDIYmUF24jI15NZ/Xy9ADAL0TpEg3fNVad2eslhCwiQViWfKOGOLLMe7v zod9dwxYdGXnNRlW+YOCdFNVPMvPDr08zgzXaZ2+QJjp44HSyzxgONmHAroFcqCFUlfAqUDO T30gV5bQ8BHqvfWyEhJT+CS3JJyP8BmmSgPa0Adlp6Do+pRsOO1YNNO78SYABhMi3fEa7X37 WxL31TrNCPnIauTgZtf/KCFQJpKaakC3ffEkPhyTjEl7oOE9xccNjccZraadi+2uHV0ULA1m ycHhb817A03n1I00QwLf2wOkckdqTqRbFFI/ik69hF9hemK/BmAHpShI+z1JsYT9cSs8D7wb aF/jQVy4URensgAPkgXsRiboqOj/rTz9F5mpd/gPU/IOUPFEMoo4TInt/+dEVECHioU3RRrW EahrGMfRngbdp/mKs9aBR56ECMfFFUPyI3VJsNbgpcIJjV/0N+JdJKQpJ/4uQ2zNm0wH/RU8 CRJvEwtKemX6fp/zLI36Gvz8zJIjSBIEqCb7vdgvWarksrhmi6/Jay5zRZ03+k6YwiqgX8t7 ANwvYa1h1dQ36OiTqm1cIxRCGl4wrypOVGx3OjCar7sBLD+NkwO4RaqFvdv0xuuy4x01VnOF Subject: Re: [Cocci] [PATCH 1/2] Coccinelle: extend memdup_user transformation with GFP_USER Message-ID: Date: Sat, 6 Jun 2020 23:36:21 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/6/20 11:24 AM, Julia Lawall wrote: > > > On Sat, 30 May 2020, Denis Efremov wrote: > >> Match GFP_USER allocations with memdup_user.cocci rule. >> Commit 6c2c97a24f09 ("memdup_user(): switch to GFP_USER") switched >> memdup_user() from GFP_KERNEL to GFP_USER. In most cases it is still >> a good idea to use memdup_user() for GFP_KERNEL allocations. The >> motivation behind altering memdup_user() to GFP_USER is here: >> https://lkml.org/lkml/2018/1/6/333 > > Should the rule somehow document the cases in which memdup_user should now > not be used? As for now, I can't provide a counterexample. GPF_USER is more permissive than GFP_KERNEL. It's completely ok to use GPF_USER with copy_from_user. Given that memdup_user() was "silently" switched to GPF_USER from GPF_KERNEL with no callside fixes, I think it's ok to recommend to use memdup_user for GPF_KERNEL matches with no additional restrictions. Thanks, Denis