From patchwork Sat Jan 22 06:12:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12720506 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0A369C433FE for ; Sat, 22 Jan 2022 06:12:54 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 94AD06B00B3; Sat, 22 Jan 2022 01:12:53 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8F9A96B00B4; Sat, 22 Jan 2022 01:12:53 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7E89B6B00B6; Sat, 22 Jan 2022 01:12:53 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0021.hostedemail.com [216.40.44.21]) by kanga.kvack.org (Postfix) with ESMTP id 6D15B6B00B4 for ; Sat, 22 Jan 2022 01:12:53 -0500 (EST) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 2D3A096F1E for ; Sat, 22 Jan 2022 06:12:53 +0000 (UTC) X-FDA: 79056904584.07.33CF5F3 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf01.hostedemail.com (Postfix) with ESMTP id 42FB840011; Sat, 22 Jan 2022 06:12:52 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 4F1AFB81FCB; Sat, 22 Jan 2022 06:12:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8BF53C004E1; Sat, 22 Jan 2022 06:12:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1642831970; bh=hCIh7qsjInigdWBIhJJ/omUzzqBVH3uWgnygAj28vwk=; h=Date:From:To:Subject:In-Reply-To:From; b=P1LwCePdshhDKPdcKy6HWqWuZW8Gdux1JRtcUqhBbo4gbQAdP8+PgCJ0Oak7n5PZT y9q98LUF99CX/eAgz8CySDxVb6xOT5iji5GaCBOOV9sPHy4HKFzuOGeeLnccr77fCl dJK4ZJIbzWZ72uqRFy9z37zHfQE+jjGdaHXvX/Po= Date: Fri, 21 Jan 2022 22:12:48 -0800 From: Andrew Morton To: airlied@linux.ie, akpm@linux-foundation.org, amir73il@gmail.com, andriy.shevchenko@linux.intel.com, arnd@arndb.de, bcrl@kvack.org, benh@kernel.crashing.org, clemens@ladisch.de, crope@iki.fi, dgilbert@interlog.com, ebiederm@xmission.com, gregkh@linuxfoundation.org, jack@suse.cz, jani.nikula@intel.com, jani.nikula@linux.intel.com, jejb@linux.ibm.com, jlbec@evilplan.org, john.ogness@linutronix.de, joonas.lahtinen@linux.intel.com, joseph.qi@linux.alibaba.com, julia.lawall@inria.fr, keescook@chromium.org, kernel@tuxforce.de, linux-mm@kvack.org, mark@fasheh.com, martin.petersen@oracle.com, mcgrof@kernel.org, mm-commits@vger.kernel.org, nixiaoming@huawei.com, penguin-kernel@I-love.SAKURA.ne.jp, peterz@infradead.org, phil@philpotter.co.uk, pjt@google.com, pmladek@suse.com, rafael@kernel.org, rodrigo.vivi@intel.com, rostedt@goodmis.org, senozhatsky@chromium.org, sre@kernel.org, steve@sk2.org, surenb@google.com, torvalds@linux-foundation.org, tytso@mit.edu, viro@zeniv.linux.org.uk, wangqing@vivo.com, yzaikin@google.com Subject: [patch 26/69] sysctl: share unsigned long const values Message-ID: <20220122061248.6shD-rqjy%akpm@linux-foundation.org> In-Reply-To: <20220121221021.60533b009c357d660791476e@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 42FB840011 X-Stat-Signature: go91y8hu8e9qic3eewyrxxtcwbhm5ej5 Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=P1LwCePd; spf=pass (imf01.hostedemail.com: domain of akpm@linux-foundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Rspam-User: nil X-HE-Tag: 1642831972-507983 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Luis Chamberlain Subject: sysctl: share unsigned long const values Provide a way to share unsigned long values. This will allow others to not have to re-invent these values. Link: https://lkml.kernel.org/r/20211124231435.1445213-9-mcgrof@kernel.org Signed-off-by: Luis Chamberlain Cc: Al Viro Cc: Amir Goldstein Cc: Andy Shevchenko Cc: Antti Palosaari Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: Benjamin LaHaise Cc: Clemens Ladisch Cc: David Airlie Cc: Douglas Gilbert Cc: Eric Biederman Cc: Greg Kroah-Hartman Cc: Iurii Zaikin Cc: James E.J. Bottomley Cc: Jani Nikula Cc: Jani Nikula Cc: Jan Kara Cc: Joel Becker Cc: John Ogness Cc: Joonas Lahtinen Cc: Joseph Qi Cc: Julia Lawall Cc: Kees Cook Cc: Lukas Middendorf Cc: Mark Fasheh Cc: Martin K. Petersen Cc: Paul Turner Cc: Peter Zijlstra Cc: Petr Mladek Cc: Phillip Potter Cc: Qing Wang Cc: "Rafael J. Wysocki" Cc: Rodrigo Vivi Cc: Sebastian Reichel Cc: Sergey Senozhatsky Cc: Stephen Kitt Cc: Steven Rostedt (VMware) Cc: Suren Baghdasaryan Cc: Tetsuo Handa Cc: "Theodore Ts'o" Cc: Xiaoming Ni Signed-off-by: Andrew Morton --- fs/proc/proc_sysctl.c | 3 +++ include/linux/sysctl.h | 6 ++++++ kernel/sysctl.c | 9 +++------ 3 files changed, 12 insertions(+), 6 deletions(-) --- a/fs/proc/proc_sysctl.c~sysctl-share-unsigned-long-const-values +++ a/fs/proc/proc_sysctl.c @@ -29,6 +29,9 @@ static const struct inode_operations pro const int sysctl_vals[] = { -1, 0, 1, 2, 4, 100, 200, 1000, 3000, INT_MAX }; EXPORT_SYMBOL(sysctl_vals); +const unsigned long sysctl_long_vals[] = { 0, 1, LONG_MAX }; +EXPORT_SYMBOL_GPL(sysctl_long_vals); + /* Support for permanently empty directories */ struct ctl_table sysctl_mount_point[] = { --- a/include/linux/sysctl.h~sysctl-share-unsigned-long-const-values +++ a/include/linux/sysctl.h @@ -51,6 +51,12 @@ struct ctl_dir; extern const int sysctl_vals[]; +#define SYSCTL_LONG_ZERO ((void *)&sysctl_long_vals[0]) +#define SYSCTL_LONG_ONE ((void *)&sysctl_long_vals[1]) +#define SYSCTL_LONG_MAX ((void *)&sysctl_long_vals[2]) + +extern const unsigned long sysctl_long_vals[]; + typedef int proc_handler(struct ctl_table *ctl, int write, void *buffer, size_t *lenp, loff_t *ppos); --- a/kernel/sysctl.c~sysctl-share-unsigned-long-const-values +++ a/kernel/sysctl.c @@ -100,9 +100,6 @@ /* Constants used for minimum and maximum */ -static const unsigned long zero_ul; -static const unsigned long one_ul = 1; -static const unsigned long long_max = LONG_MAX; #ifdef CONFIG_PRINTK static const int ten_thousand = 10000; #endif @@ -2513,7 +2510,7 @@ static struct ctl_table vm_table[] = { .maxlen = sizeof(dirty_background_bytes), .mode = 0644, .proc_handler = dirty_background_bytes_handler, - .extra1 = (void *)&one_ul, + .extra1 = SYSCTL_LONG_ONE, }, { .procname = "dirty_ratio", @@ -2931,8 +2928,8 @@ static struct ctl_table fs_table[] = { .maxlen = sizeof(files_stat.max_files), .mode = 0644, .proc_handler = proc_doulongvec_minmax, - .extra1 = (void *)&zero_ul, - .extra2 = (void *)&long_max, + .extra1 = SYSCTL_LONG_ZERO, + .extra2 = SYSCTL_LONG_MAX, }, { .procname = "nr_open",