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=-7.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 72A38C4338F for ; Wed, 25 Aug 2021 14:15:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4D9A9601FD for ; Wed, 25 Aug 2021 14:15:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240768AbhHYOQa (ORCPT ); Wed, 25 Aug 2021 10:16:30 -0400 Received: from szxga03-in.huawei.com ([45.249.212.189]:14320 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229760AbhHYOQ3 (ORCPT ); Wed, 25 Aug 2021 10:16:29 -0400 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.53]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4Gvp0Y4cY3z7tFX; Wed, 25 Aug 2021 22:15:25 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) 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 15.1.2176.2; Wed, 25 Aug 2021 22:15:40 +0800 Received: from [10.174.177.243] (10.174.177.243) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 25 Aug 2021 22:15:40 +0800 Subject: Re: [PATCH 0/4] ARM: Support KFENCE feature To: Marco Elver CC: Russell King , Alexander Potapenko , Dmitry Vyukov , , , , Andrew Morton References: <20210825092116.149975-1-wangkefeng.wang@huawei.com> From: Kefeng Wang Message-ID: Date: Wed, 25 Aug 2021 22:15:39 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/8/25 18:57, Marco Elver wrote: > On Wed, Aug 25, 2021 at 12:14PM +0200, Marco Elver wrote: >> On Wed, 25 Aug 2021 at 11:17, Kefeng Wang wrote: >>> The patch 1~3 is to support KFENCE feature on ARM. >>> >>> NOTE: >>> The context of patch2/3 changes in arch/arm/mm/fault.c is based on link[1], >>> which make some refactor and cleanup about page fault. >>> >>> kfence_test is not useful when kfence is not enabled, skip kfence test >>> when kfence not enabled in patch4. >>> >>> I tested the kfence_test on ARM QEMU with or without ARM_LPAE and all passed. >> Thank you for enabling KFENCE on ARM -- I'll leave arch-code review to >> an ARM maintainer. >> >> However, as said on the patch, please drop the change to the >> kfence_test and associated changes. This is working as intended; while >> you claim that it takes a long time to run when disabled, when running >> manually you just should not run it when disabled. There are CI >> systems that rely on the KUnit test output and the fact that the >> various test cases say "not ok" etc. Changing that would mean such CI >> systems would no longer fail if KFENCE was accidentally disabled (once >> KFENCE is enabled on various CI, which we'd like to do at some point). >> There are ways to fail the test faster, but they all complicate the >> test for no good reason. (And the addition of a new exported function >> that is essentially useless.) > I spoke too soon -- we export __kfence_pool, and that's good enough to > fail the test fast if KFENCE was disabled at boot: > > https://lkml.kernel.org/r/20210825105533.1247922-1-elver@google.com > > will do the trick. So please drop your patch 4/4 here. Sure , please ignore it. > > Thanks, > -- Marco > . >