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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 85BE2C54FD0 for ; Mon, 27 Apr 2020 18:04:53 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 53D3821835 for ; Mon, 27 Apr 2020 18:04:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 53D3821835 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id F30AF8E0008; Mon, 27 Apr 2020 14:04:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E98488E0001; Mon, 27 Apr 2020 14:04:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B39038E0008; Mon, 27 Apr 2020 14:04:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0181.hostedemail.com [216.40.44.181]) by kanga.kvack.org (Postfix) with ESMTP id 958188E0005 for ; Mon, 27 Apr 2020 14:04:51 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 43BB9824805A for ; Mon, 27 Apr 2020 18:04:51 +0000 (UTC) X-FDA: 76754410782.21.elbow73_648676035da52 X-HE-Tag: elbow73_648676035da52 X-Filterd-Recvd-Size: 5001 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf21.hostedemail.com (Postfix) with ESMTP for ; Mon, 27 Apr 2020 18:04:50 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id E7407AB5C; Mon, 27 Apr 2020 18:04:47 +0000 (UTC) From: Vlastimil Babka To: Andrew Morton , Luis Chamberlain , Kees Cook , Iurii Zaikin Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-mm@kvack.org, Ivan Teterevkov , Michal Hocko , David Rientjes , Matthew Wilcox , "Eric W . Biederman" , "Guilherme G . Piccoli" , Alexey Dobriyan , Thomas Gleixner , Greg Kroah-Hartman , Christian Brauner , Masami Hiramatsu , Vlastimil Babka , Michal Hocko Subject: [PATCH v3 2/5] kernel/sysctl: support handling command line aliases Date: Mon, 27 Apr 2020 20:04:30 +0200 Message-Id: <20200427180433.7029-3-vbabka@suse.cz> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200427180433.7029-1-vbabka@suse.cz> References: <20200427180433.7029-1-vbabka@suse.cz> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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: We can now handle sysctl parameters on kernel command line, but historica= lly some parameters introduced their own command line equivalent, which we do= n't want to remove for compatibility reasons. We can however convert them to = the generic infrastructure with a table translating the legacy command line parameters to their sysctl names, and removing the one-off param handlers= . This patch adds the support and makes the first conversion to demonstrate= it, on the (deprecated) numa_zonelist_order parameter. Signed-off-by: Vlastimil Babka Reviewed-by: Luis Chamberlain Acked-by: Kees Cook Acked-by: Michal Hocko --- fs/proc/proc_sysctl.c | 48 ++++++++++++++++++++++++++++++++++++------- mm/page_alloc.c | 9 -------- 2 files changed, 41 insertions(+), 16 deletions(-) diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 7804da5f5be0..209ad03e1b82 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -1694,6 +1694,37 @@ int __init proc_sys_init(void) return sysctl_init(); } =20 +struct sysctl_alias { + const char *kernel_param; + const char *sysctl_param; +}; + +/* + * Historically some settings had both sysctl and a command line paramet= er. + * With the generic sysctl. parameter support, we can handle them at a s= ingle + * place and only keep the historical name for compatibility. This is no= t meant + * to add brand new aliases. When adding existing aliases, consider whet= her + * the possibly different moment of changing the value (e.g. from early_= param + * to the moment do_sysctl_args() is called) is an issue for the specifi= c + * parameter. + */ +static const struct sysctl_alias sysctl_aliases[] =3D { + {"numa_zonelist_order", "vm.numa_zonelist_order" }, + { } +}; + +static const char *sysctl_find_alias(char *param) +{ + const struct sysctl_alias *alias; + + for (alias =3D &sysctl_aliases[0]; alias->kernel_param !=3D NULL; alias= ++) { + if (strcmp(alias->kernel_param, param) =3D=3D 0) + return alias->sysctl_param; + } + + return NULL; +} + /* Set sysctl value passed on kernel command line. */ static int process_sysctl_arg(char *param, char *val, const char *unused, void *arg) @@ -1707,15 +1738,18 @@ static int process_sysctl_arg(char *param, char *= val, loff_t pos =3D 0; ssize_t wret; =20 - if (strncmp(param, "sysctl", sizeof("sysctl") - 1)) - return 0; - - param +=3D sizeof("sysctl") - 1; + if (strncmp(param, "sysctl", sizeof("sysctl") - 1) =3D=3D 0) { + param +=3D sizeof("sysctl") - 1; =20 - if (param[0] !=3D '/' && param[0] !=3D '.') - return 0; + if (param[0] !=3D '/' && param[0] !=3D '.') + return 0; =20 - param++; + param++; + } else { + param =3D (char *) sysctl_find_alias(param); + if (!param) + return 0; + } =20 /* * To set sysctl options, we use a temporary mount of proc, look up the diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 69827d4fa052..80b2788711c9 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5531,15 +5531,6 @@ static int __parse_numa_zonelist_order(char *s) return 0; } =20 -static __init int setup_numa_zonelist_order(char *s) -{ - if (!s) - return 0; - - return __parse_numa_zonelist_order(s); -} -early_param("numa_zonelist_order", setup_numa_zonelist_order); - char numa_zonelist_order[] =3D "Node"; =20 /* --=20 2.26.0