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, URIBL_BLOCKED,USER_AGENT_GIT 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 269A4C2BB86 for ; Tue, 14 Apr 2020 11:32:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 087AB2075E for ; Tue, 14 Apr 2020 11:32:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439293AbgDNLcn (ORCPT ); Tue, 14 Apr 2020 07:32:43 -0400 Received: from mx2.suse.de ([195.135.220.15]:46608 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2439264AbgDNLcb (ORCPT ); Tue, 14 Apr 2020 07:32:31 -0400 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 36D2DAE9A; Tue, 14 Apr 2020 11:32:27 +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 Subject: [PATCH v2 2/3] kernel/sysctl: support handling command line aliases Date: Tue, 14 Apr 2020 13:32:21 +0200 Message-Id: <20200414113222.16959-3-vbabka@suse.cz> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200414113222.16959-1-vbabka@suse.cz> References: <20200414113222.16959-1-vbabka@suse.cz> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We can now handle sysctl parameters on kernel command line, but historically some parameters introduced their own command line equivalent, which we don'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 Acked-by: Kees Cook Reviewed-by: Luis Chamberlain --- 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(); } +struct sysctl_alias { + const char *kernel_param; + const char *sysctl_param; +}; + +/* + * Historically some settings had both sysctl and a command line parameter. + * With the generic sysctl. parameter support, we can handle them at a single + * place and only keep the historical name for compatibility. This is not meant + * to add brand new aliases. When adding existing aliases, consider whether + * 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 specific + * parameter. + */ +static const struct sysctl_alias sysctl_aliases[] = { + {"numa_zonelist_order", "vm.numa_zonelist_order" }, + { } +}; + +static const char *sysctl_find_alias(char *param) +{ + const struct sysctl_alias *alias; + + for (alias = &sysctl_aliases[0]; alias->kernel_param != NULL; alias++) { + if (strcmp(alias->kernel_param, param) == 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 = 0; ssize_t wret; - if (strncmp(param, "sysctl", sizeof("sysctl") - 1)) - return 0; - - param += sizeof("sysctl") - 1; + if (strncmp(param, "sysctl", sizeof("sysctl") - 1) == 0) { + param += sizeof("sysctl") - 1; - if (param[0] != '/' && param[0] != '.') - return 0; + if (param[0] != '/' && param[0] != '.') + return 0; - param++; + param++; + } else { + param = (char *) sysctl_find_alias(param); + if (!param) + return 0; + } /* * 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; } -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[] = "Node"; /* -- 2.26.0