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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 1089AC10F13 for ; Mon, 8 Apr 2019 22:09:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DAB2A20880 for ; Mon, 8 Apr 2019 22:09:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727222AbfDHWJl (ORCPT ); Mon, 8 Apr 2019 18:09:41 -0400 Received: from mail-wm1-f65.google.com ([209.85.128.65]:37086 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726538AbfDHWJk (ORCPT ); Mon, 8 Apr 2019 18:09:40 -0400 Received: by mail-wm1-f65.google.com with SMTP id v14so958231wmf.2 for ; Mon, 08 Apr 2019 15:09:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=H/H+BPiceixq2PxCNPJzqXmyv8QW6SP78HvIow6e2qA=; b=SvHT2akd1A78CbJJUGo79JOPrSsPF9yTZufmdNJzkS6joeZ87iWm84WNEa1f2jhKli vYAxTn8xvI2PyFunDpeLrWhfsPxbOcgZ/I6/93vsVI81nUm+rDwLvsrnTfjTJVznKK+F rMGF/Rpl+IbUCYOEcfDPPQxlDk1bobe8WYKXUNwzjOxA4GK6phbbXDcC+0xWIr2YLWrB VeptIPDAq99bbf4jQhg3svlizoLROV04dD02Z75YbtRzPU7gE6uvcBNBVHcY8LUjQqvL TIQ9u7kwwk0mGWdWb4YoDyF5HGSM/WhHPr6qPvXB9MCAzE+lDyGTPTBsfzvtBQrcBeIY 56gw== X-Gm-Message-State: APjAAAUzLGdxdIdILQr7q4jOHW22A1cJRLIunVKMQ5I4NIMevQ22qOLk BPC+nsMohuh8DWwJYx5N8+LSIg== X-Google-Smtp-Source: APXvYqwJ98n6gwITz41dx7J6xIQQgi9/KFVIMJx8KHbSI7QtyPd10+wYv6bDtjqd/CnNHRlKWz+Hvg== X-Received: by 2002:a1c:44d7:: with SMTP id r206mr20080229wma.129.1554761379278; Mon, 08 Apr 2019 15:09:39 -0700 (PDT) Received: from raver.teknoraver.net (net-93-70-69-135.cust.vodafonedsl.it. [93.70.69.135]) by smtp.gmail.com with ESMTPSA id h2sm49894204wro.11.2019.04.08.15.09.38 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 08 Apr 2019 15:09:38 -0700 (PDT) From: Matteo Croce To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: Luis Chamberlain , Kees Cook , Alexey Dobriyan Subject: [PATCH 1/2] proc/sysctl: add shared variables for range check Date: Tue, 9 Apr 2019 00:09:24 +0200 Message-Id: <20190408220925.13077-2-mcroce@redhat.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190408220925.13077-1-mcroce@redhat.com> References: <20190408220925.13077-1-mcroce@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org In the sysctl code the proc_dointvec_minmax() function is often used to validate the user supplied value between an allowed range. This function uses the extra1 and extra2 members from struct ctl_table as minimum and maximum allowed value. On sysctl handler declaration, in every source file there are some readonly variables containing just an integer which address is assigned to the extra1 and extra2 members, so the sysctl range is enforced. The special values 0, 1 and INT_MAX are very often used as range boundary, leading duplication of variables like zero=0, one=1, int_max=INT_MAX in different source files: $ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l 261 This patch adds three variables for the most commonly used values, so they can be referenced instead of creating a local one for every object file. Signed-off-by: Matteo Croce --- fs/proc/proc_sysctl.c | 5 +++++ include/linux/sysctl.h | 4 ++++ 2 files changed, 9 insertions(+) diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index d65390727541..e7a96169fced 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -21,6 +21,11 @@ static const struct inode_operations proc_sys_inode_operations; static const struct file_operations proc_sys_dir_file_operations; static const struct inode_operations proc_sys_dir_operations; +/* shared constants to be used in various sysctls */ +const int sysctl_zero = 0; +const int sysctl_one = 1; +const int sysctl_int_max = INT_MAX; + /* Support for permanently empty directories */ struct ctl_table sysctl_mount_point[] = { diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index b769ecfcc3bd..f3b191799747 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -37,6 +37,10 @@ struct ctl_table_root; struct ctl_table_header; struct ctl_dir; +extern const int sysctl_zero; +extern const int sysctl_one; +extern const int sysctl_int_max; + typedef int proc_handler (struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos); -- 2.21.0