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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 6FB8AC433DF for ; Fri, 15 May 2020 09:06:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 57AD7205CB for ; Fri, 15 May 2020 09:06:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727836AbgEOJGj (ORCPT ); Fri, 15 May 2020 05:06:39 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:4787 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726922AbgEOJGj (ORCPT ); Fri, 15 May 2020 05:06:39 -0400 Received: from DGGEMS409-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 95C3FEB4EA6DAC2EFC8B; Fri, 15 May 2020 17:06:36 +0800 (CST) Received: from [127.0.0.1] (10.67.102.197) by DGGEMS409-HUB.china.huawei.com (10.3.19.209) with Microsoft SMTP Server id 14.3.487.0; Fri, 15 May 2020 17:06:29 +0800 Subject: Re: [PATCH 2/4] proc/sysctl: add shared variables -1 To: Kees Cook CC: , , , , , , , , , , , , , , , , , , , References: <1589517224-123928-1-git-send-email-nixiaoming@huawei.com> <1589517224-123928-3-git-send-email-nixiaoming@huawei.com> <202005150105.33CAEEA6C5@keescook> From: Xiaoming Ni Message-ID: <88f3078b-9419-b9c6-e789-7d6e50ca2cef@huawei.com> Date: Fri, 15 May 2020 17:06:28 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <202005150105.33CAEEA6C5@keescook> Content-Type: text/plain; charset="gbk"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.102.197] X-CFilter-Loop: Reflected Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 2020/5/15 16:06, Kees Cook wrote: > On Fri, May 15, 2020 at 12:33:42PM +0800, Xiaoming Ni wrote: >> Add the shared variable SYSCTL_NEG_ONE to replace the variable neg_one >> used in both sysctl_writes_strict and hung_task_warnings. >> >> Signed-off-by: Xiaoming Ni >> --- >> fs/proc/proc_sysctl.c | 2 +- >> include/linux/sysctl.h | 1 + >> kernel/hung_task_sysctl.c | 3 +-- >> kernel/sysctl.c | 3 +-- > > How about doing this refactoring in advance of the extraction patch? Before advance of the extraction patch, neg_one is only used in one file, does it seem to have no value for refactoring? > >> 4 files changed, 4 insertions(+), 5 deletions(-) >> >> diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c >> index b6f5d45..acae1fa 100644 >> --- a/fs/proc/proc_sysctl.c >> +++ b/fs/proc/proc_sysctl.c >> @@ -23,7 +23,7 @@ >> static const struct inode_operations proc_sys_dir_operations; >> >> /* shared constants to be used in various sysctls */ >> -const int sysctl_vals[] = { 0, 1, INT_MAX }; >> +const int sysctl_vals[] = { 0, 1, INT_MAX, -1 }; >> EXPORT_SYMBOL(sysctl_vals); >> >> /* Support for permanently empty directories */ >> diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h >> index 02fa844..6d741d6 100644 >> --- a/include/linux/sysctl.h >> +++ b/include/linux/sysctl.h >> @@ -41,6 +41,7 @@ >> #define SYSCTL_ZERO ((void *)&sysctl_vals[0]) >> #define SYSCTL_ONE ((void *)&sysctl_vals[1]) >> #define SYSCTL_INT_MAX ((void *)&sysctl_vals[2]) >> +#define SYSCTL_NEG_ONE ((void *)&sysctl_vals[3]) > > Nit: let's keep these value-ordered? i.e. -1, 0, 1, INT_MAX. Thanks for guidance, your method is better Thanks. Xiaoming Ni