From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 08/54] kernel/sysctl: support handling command line aliases Date: Sun, 07 Jun 2020 21:40:27 -0700 Message-ID: <20200608044027.4zeyRQNU3%akpm@linux-foundation.org> References: <20200607212615.b050e41fac139a1e16fe00bd@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:35744 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726929AbgFHEka (ORCPT ); Mon, 8 Jun 2020 00:40:30 -0400 In-Reply-To: <20200607212615.b050e41fac139a1e16fe00bd@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: adobriyan@gmail.com, akpm@linux-foundation.org, christian.brauner@ubuntu.com, ebiederm@xmission.com, gpiccoli@canonical.com, gregkh@linuxfoundation.org, ivan.teterevkov@nutanix.com, keescook@chromium.org, linux-mm@kvack.org, mcgrof@kernel.org, mhiramat@kernel.org, mhocko@kernel.org, mhocko@suse.com, mm-commits@vger.kernel.org, rientjes@google.com, tglx@linutronix.de, torvalds@linux-foundation.org, vbabka@suse.cz, willy@infradead.org, yzaikin@google.com From: Vlastimil Babka Subject: kernel/sysctl: support handling command line aliases 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. Link: http://lkml.kernel.org/r/20200427180433.7029-3-vbabka@suse.cz Signed-off-by: Vlastimil Babka Reviewed-by: Luis Chamberlain Acked-by: Kees Cook Acked-by: Michal Hocko Cc: Alexey Dobriyan Cc: Christian Brauner Cc: David Rientjes Cc: "Eric W . Biederman" Cc: Greg Kroah-Hartman Cc: "Guilherme G . Piccoli" Cc: Iurii Zaikin Cc: Ivan Teterevkov Cc: Masami Hiramatsu Cc: Matthew Wilcox Cc: Michal Hocko Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- fs/proc/proc_sysctl.c | 48 ++++++++++++++++++++++++++++++++++------ mm/page_alloc.c | 9 ------- 2 files changed, 41 insertions(+), 16 deletions(-) --- a/fs/proc/proc_sysctl.c~kernel-sysctl-support-handling-command-line-aliases +++ a/fs/proc/proc_sysctl.c @@ -1705,6 +1705,37 @@ 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) @@ -1718,15 +1749,18 @@ static int process_sysctl_arg(char *para 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 --- a/mm/page_alloc.c~kernel-sysctl-support-handling-command-line-aliases +++ a/mm/page_alloc.c @@ -5575,15 +5575,6 @@ static int __parse_numa_zonelist_order(c 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); 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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no 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 64C0AC433E1 for ; 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d=kernel.org; s=default; t=1591591228; bh=z0b4OftCJbRRmQ8T3H21PlNJWjeg4CjvdkvZ+txkCr8=; h=Date:From:To:Subject:In-Reply-To:From; b=sCkyJNxIJzradF5kX0KvEW1qwLUCr9xzZE/2g81p/Mly0H/Ff3hLT8nu7vZ6ByOIZ V442HFyyuF1Z3qRek33FL6m2J/Y1mBLmEdOh7e7QujiFuccyIGX/jvBQDnMEi/48Es CH7cGYshWp0IviQDnPzCYMc0dpmu7PKCLeNhYNnA= Date: Sun, 07 Jun 2020 21:40:27 -0700 From: Andrew Morton To: adobriyan@gmail.com, akpm@linux-foundation.org, christian.brauner@ubuntu.com, ebiederm@xmission.com, gpiccoli@canonical.com, gregkh@linuxfoundation.org, ivan.teterevkov@nutanix.com, keescook@chromium.org, linux-mm@kvack.org, mcgrof@kernel.org, mhiramat@kernel.org, mhocko@kernel.org, mhocko@suse.com, mm-commits@vger.kernel.org, rientjes@google.com, tglx@linutronix.de, torvalds@linux-foundation.org, vbabka@suse.cz, willy@infradead.org, yzaikin@google.com Subject: [patch 08/54] kernel/sysctl: support handling command line aliases Message-ID: <20200608044027.4zeyRQNU3%akpm@linux-foundation.org> In-Reply-To: <20200607212615.b050e41fac139a1e16fe00bd@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Queue-Id: 24A1F1800CFED X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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: Vlastimil Babka Subject: kernel/sysctl: support handling command line aliases 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. Link: http://lkml.kernel.org/r/20200427180433.7029-3-vbabka@suse.cz Signed-off-by: Vlastimil Babka Reviewed-by: Luis Chamberlain Acked-by: Kees Cook Acked-by: Michal Hocko Cc: Alexey Dobriyan Cc: Christian Brauner Cc: David Rientjes Cc: "Eric W . Biederman" Cc: Greg Kroah-Hartman Cc: "Guilherme G . Piccoli" Cc: Iurii Zaikin Cc: Ivan Teterevkov Cc: Masami Hiramatsu Cc: Matthew Wilcox Cc: Michal Hocko Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- fs/proc/proc_sysctl.c | 48 ++++++++++++++++++++++++++++++++++------ mm/page_alloc.c | 9 ------- 2 files changed, 41 insertions(+), 16 deletions(-) --- a/fs/proc/proc_sysctl.c~kernel-sysctl-support-handling-command-line-aliases +++ a/fs/proc/proc_sysctl.c @@ -1705,6 +1705,37 @@ 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) @@ -1718,15 +1749,18 @@ static int process_sysctl_arg(char *para 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 --- a/mm/page_alloc.c~kernel-sysctl-support-handling-command-line-aliases +++ a/mm/page_alloc.c @@ -5575,15 +5575,6 @@ static int __parse_numa_zonelist_order(c 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"; /* _