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 A4427C77B6C for ; Thu, 13 Apr 2023 07:53:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230260AbjDMHxM (ORCPT ); Thu, 13 Apr 2023 03:53:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37306 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230019AbjDMHxH (ORCPT ); Thu, 13 Apr 2023 03:53:07 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7AA226A5 for ; Thu, 13 Apr 2023 00:53:06 -0700 (PDT) Received: from dggpemm500013.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4PxsGh65mVzrbJW; Thu, 13 Apr 2023 15:51:40 +0800 (CST) Received: from [10.67.108.67] (10.67.108.67) by dggpemm500013.china.huawei.com (7.185.36.172) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Thu, 13 Apr 2023 15:53:04 +0800 Message-ID: Date: Thu, 13 Apr 2023 15:53:04 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.0 Subject: Re: [PATCH 1/2] x86: profiling: remove lock functions hack for !FRAME_POINTER Content-Language: en-US To: David Laight , Dave Hansen , "x86@kernel.org" , "linux-kernel@vger.kernel.org" CC: "tglx@linutronix.de" , "mingo@redhat.com" , "bp@alien8.de" , "dave.hansen@linux.intel.com" , "hpa@zytor.com" , "akpm@linux-foudation.org" , "ben-linux@fluff.org" , "wuchi.zero@gmail.com" References: <20230410022226.181812-1-chenzhongjin@huawei.com> <20230410022226.181812-2-chenzhongjin@huawei.com> <1ceb1769-f01b-c417-e912-4ee1149dd0cb@huawei.com> <4c601a93e55341fc8cff766af43cb5e6@AcuMS.aculab.com> From: Chen Zhongjin In-Reply-To: <4c601a93e55341fc8cff766af43cb5e6@AcuMS.aculab.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.108.67] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm500013.china.huawei.com (7.185.36.172) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/4/12 18:01, David Laight wrote: > From: Chen Zhongjin >> Sent: 12 April 2023 08:02 > ... >>> 4. !CONFIG_FRAME_POINTER is probably even more rare today than it was in >>> 2006 >> No. !CONFIG_FRAME_POINTER is more common today because of UNWINDER_ORC. >> And that is why the bug is triggered more frequently. > CONFIG_FRAME_POINTER is pretty much required (on x86-64) > for the user copy checks that are enabled in distro kernels. Thanks for reminding.. I know little about distro kernels. I though at least !CONFIG_FRAME_POINTER is more common than it was in 2006. Not investigated but just because UNWINDER_ORC is defconfig and it disables CONFIG_FRAME_POINTER. Anyway, I kept the CONFIG_FRAME_POINTER not removed so it won't be affected. Best, Chen > David > > - > Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK > Registration No: 1397386 (Wales)