From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753891AbbERLuo (ORCPT ); Mon, 18 May 2015 07:50:44 -0400 Received: from mail-wg0-f53.google.com ([74.125.82.53]:34359 "EHLO mail-wg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753481AbbERLuh (ORCPT ); Mon, 18 May 2015 07:50:37 -0400 From: Iulia Manda To: tim.bird@sonymobile.com Cc: linux-kernel@vger.kernel.org, josh@joshtriplett.org Subject: [PATCH 1/3] kernel: Add a new config option to remove command line parsing Date: Mon, 18 May 2015 14:50:30 +0300 Message-Id: <1431949832-13606-1-git-send-email-iulia.manda21@gmail.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch introduces CONFIG_CMDLINE_PARSE option which conditionally compiles the support for parsing kernel command line arguments. The corresponding functions that actually do the parsing will be compiled out. This is used when no parameters will be specified neither at compile time nor at boot time. Bloat-o-meter output (compared to the version in which builtin cmdline is set to 'Y'): add/remove: 0/8 grow/shrink: 0/6 up/down: 0/-3669 (-3669) function old new delta load_module 5571 5563 -8 parse_early_param 54 44 -10 parse_early_options 33 5 -28 initcall_level_names 32 - -32 kernel_init_freeable 413 360 -53 unknown_module_param_cb 60 - -60 setup_arch 3041 2972 -69 set_init_arg 73 - -73 repair_env_string 81 - -81 start_kernel 857 759 -98 do_early_param 117 - -117 unknown_bootoption 366 - -366 parse_args 626 - -626 builtin_cmdline 2048 - -2048 Signed-off-by: Iulia Manda Reviewed-by: Josh Triplett Reviewed-by: Tim Bird --- arch/x86/Kconfig | 15 +++++++++++++++ include/linux/moduleparam.h | 14 ++++++++++++++ kernel/params.c | 2 ++ 3 files changed, 31 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 6049d58..daabbc3 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2002,8 +2002,23 @@ config COMPAT_VDSO If unsure, say N: if you are compiling your own kernel, you are unlikely to be using a buggy version of glibc. +config CMDLINE_PARSE + bool "Enable support for command line parsing" + default y + ---help--- + With this option set to 'Y', kernel parameters, both the ones + passed at boot time and at compile time are parsed. + + If you say no here, all the kernel parameters' values will be set + to their defaults at compile time, in order to make constant + folding possible. + + Systems with no space constraints should leave this option set to + 'Y'. + config CMDLINE_BOOL bool "Built-in kernel command line" + depends on CMDLINE_PARSE ---help--- Allow for specifying boot arguments to the kernel at build time. On some systems (e.g. embedded ones), it is diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index 1c9effa..570f70e 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -350,6 +350,7 @@ extern bool parameq(const char *name1, const char *name2); */ extern bool parameqn(const char *name1, const char *name2, size_t n); +#ifdef CONFIG_CMDLINE_PARSE /* Called on module insert or kernel boot */ extern char *parse_args(const char *name, char *args, @@ -359,6 +360,19 @@ extern char *parse_args(const char *name, s16 level_max, int (*unknown)(char *param, char *val, const char *doing)); +#else +static inline char *parse_args(const char *name, + char *args, + const struct kernel_param *params, + unsigned num, + s16 level_min, + s16 level_max, + int (*unknown)(char *param, char *val, + const char *doing)) +{ + return NULL; +} +#endif /* Called by module remove. */ #ifdef CONFIG_SYSFS diff --git a/kernel/params.c b/kernel/params.c index 728e05b..d3bfe47 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -93,6 +93,7 @@ static void param_check_unsafe(const struct kernel_param *kp) } } +#ifdef CONFIG_CMDLINE_PARSE static int parse_one(char *param, char *val, const char *doing, @@ -239,6 +240,7 @@ char *parse_args(const char *doing, /* All parsed OK. */ return NULL; } +#endif /* Lazy bastard, eh? */ #define STANDARD_PARAM_DEF(name, type, format, strtolfn) \ -- 1.8.3.2