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 503ACECAAD2 for ; Sat, 27 Aug 2022 10:43:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233786AbiH0KnN (ORCPT ); Sat, 27 Aug 2022 06:43:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229737AbiH0KnL (ORCPT ); Sat, 27 Aug 2022 06:43:11 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0087572EE0 for ; Sat, 27 Aug 2022 03:43:09 -0700 (PDT) Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4MFCrP2pptzlVhw; Sat, 27 Aug 2022 18:39:49 +0800 (CST) Received: from kwepemm600017.china.huawei.com (7.193.23.234) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Sat, 27 Aug 2022 18:43:08 +0800 Received: from [10.174.179.234] (10.174.179.234) by kwepemm600017.china.huawei.com (7.193.23.234) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Sat, 27 Aug 2022 18:43:06 +0800 Message-ID: Date: Sat, 27 Aug 2022 18:43:06 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH -next v2 1/2] riscv: uaccess: rename __get/put_user_nocheck to __get/put_mem_nocheck To: Arnd Bergmann CC: Paul Walmsley , Palmer Dabbelt , Palmer Dabbelt , Albert Ou , , , , , Guohanjun References: <20220815032025.2685516-1-tongtiangen@huawei.com> <20220815032025.2685516-2-tongtiangen@huawei.com> From: Tong Tiangen In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.179.234] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To kwepemm600017.china.huawei.com (7.193.23.234) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2022/8/26 17:30, Arnd Bergmann 写道: > On Mon, Aug 15, 2022 at 5:20 AM Tong Tiangen wrote: >> >> Current, The helpers __get/put_user_nocheck() is used by get/put_user() and >> __get/put_kernel_nofault(), which is not always uaccess, so the name with >> *user* is not appropriate. >> >> Also rename xxx_user_xxx to xxx_mem_xx on the call path of >> __get/put_user_nocheck() >> >> Only refactor code without any functional changes. >> >> Signed-off-by: Tong Tiangen > > I would prefer this not being done, it just makes riscv diverge from the > code on other architectures. While the new name does make more sense, > it ends up making it harder to refactor this across architectures in the end. > > There are two important cleanups that I would like to see done in > asm/uaccess.h across architectures: > > - generalize the __get_user()/__put_user()/__get_kernel_nofault()/ > __put_kernel_nofault() wrappers to the point that architectures do not > need to worry about the variable type stuff but instead just provide > trivial fixed-length helpers of some sort > > - change the calling conventions in a way that allows the use of the > asm-goto-with-output method for better object code on modern > compilers. > > The x86 version already has most of this, with their > __get_user_size() macro supporting both the asm-goto label > and the error code assignment, so the generalized code should > probably be based on that approach. I am very interested in the implementation of X86. I need to investigate and consider a cross architecture implementation. However, I understand that the modification of the current patch has little to do with the two points mentioned above. We can optimize the code step by step. Thanks, Tong. > > Arnd > > .