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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 07180C43600 for ; Fri, 2 Apr 2021 15:18:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5A3E61103 for ; Fri, 2 Apr 2021 15:18:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235189AbhDBPSI (ORCPT ); Fri, 2 Apr 2021 11:18:08 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:40685 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229553AbhDBPSH (ORCPT ); Fri, 2 Apr 2021 11:18:07 -0400 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4FBkFj2vNPz9v2lt; Fri, 2 Apr 2021 17:18:01 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id NJ34BehnDmHj; Fri, 2 Apr 2021 17:18:01 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4FBkFj1ndyz9v2ls; Fri, 2 Apr 2021 17:18:01 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 2774B8BB7C; Fri, 2 Apr 2021 17:18:03 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id wc8EW3tptikR; Fri, 2 Apr 2021 17:18:03 +0200 (CEST) Received: from po16121vm.idsi0.si.c-s.fr (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 99C3C8BB7B; Fri, 2 Apr 2021 17:18:02 +0200 (CEST) Received: by po16121vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 701DA67989; Fri, 2 Apr 2021 15:18:02 +0000 (UTC) Message-Id: <68db4e57bb88c523f76dcae12feafbb0cae1a85d.1617375802.git.christophe.leroy@csgroup.eu> In-Reply-To: References: From: Christophe Leroy Subject: [PATCH v4 01/20] cmdline: Add generic function to build command line. To: will@kernel.org, danielwa@cisco.com, robh@kernel.org, daniel@gimpelevich.san-francisco.ca.us, arnd@kernel.org, akpm@linux-foundation.org Cc: linux-arch@vger.kernel.org, devicetree@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, microblaze , linux-mips@vger.kernel.org, nios2 , openrisc@lists.librecores.org, linux-hexagon@vger.kernel.org, linux-riscv@lists.infradead.org, x86@kernel.org, linux-xtensa@linux-xtensa.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org Date: Fri, 2 Apr 2021 15:18:02 +0000 (UTC) Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org This code provides architectures with a way to build command line based on what is built in the kernel and what is handed over by the bootloader, based on selected compile-time options. Signed-off-by: Christophe Leroy --- v3: - Addressed comments from Will - Added capability to have src == dst v4: - Add cmdline_strlcpy() - Removed cmdline_build() macro, __cmdline_build() becomes cmdline_build() - Fixed the destination length to COMMAND_LINE_SIZE - Truncate at a space not in a quote when too long - Added a message when forcing the command line --- include/linux/cmdline.h | 79 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 include/linux/cmdline.h diff --git a/include/linux/cmdline.h b/include/linux/cmdline.h new file mode 100644 index 000000000000..a0773dc365c7 --- /dev/null +++ b/include/linux/cmdline.h @@ -0,0 +1,79 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_CMDLINE_H +#define _LINUX_CMDLINE_H + +#include +#include +#include + +/* Allow users to override strlcat/strlcpy, powerpc can't use strings so early*/ +#ifndef cmdline_strlcat +#define cmdline_strlcat strlcat +#define cmdline_strlcpy strlcpy +#endif + +/* + * This function will append or prepend a builtin command line to the command + * line provided by the bootloader. Kconfig options can be used to alter + * the behavior of this builtin command line. + * @dst: The destination of the final command line (Min. size COMMAND_LINE_SIZE) + * @src: The starting string or NULL if there isn't one. Must not equal dst. + * Returns: false if the string was truncated, true otherwise + */ +static __always_inline bool __cmdline_build(char *dst, const char *src) +{ + int len; + char *ptr, *last_space; + bool in_quote = false; + + if (IS_ENABLED(CONFIG_CMDLINE_FORCE)) + src = NULL; + + dst[0] = 0; + + if (IS_ENABLED(CONFIG_CMDLINE_PREPEND)) + len = cmdline_strlcat(dst, CONFIG_CMDLINE " ", COMMAND_LINE_SIZE); + + len = cmdline_strlcat(dst, src, COMMAND_LINE_SIZE); + + if (IS_ENABLED(CONFIG_CMDLINE_EXTEND)) + len = cmdline_strlcat(dst, " " CONFIG_CMDLINE, COMMAND_LINE_SIZE); + + if (len < COMMAND_LINE_SIZE - 1) + return true; + + for (ptr = dst; *ptr; ptr++) { + if (*ptr == '"') + in_quote = !in_quote; + if (*ptr == ' ' && !in_quote) + last_space = ptr; + } + if (last_space) + *last_space = 0; + + return false; +} + +/* + * This function will append or prepend a builtin command line to the command + * line provided by the bootloader. Kconfig options can be used to alter + * the behavior of this builtin command line. + * @dst: The destination of the final command line (Min. size COMMAND_LINE_SIZE) + * @src: The starting string or NULL if there isn't one. + */ +static __always_inline void cmdline_build(char *dst, const char *src) +{ + static char tmp[COMMAND_LINE_SIZE] __initdata; + + if (src == dst) { + cmdline_strlcpy(tmp, src, COMMAND_LINE_SIZE); + src = tmp; + } + if (!__cmdline_build(dst, src)) + pr_warn("Command line is too long, it has been truncated\n"); + + if (IS_ENABLED(CONFIG_CMDLINE_FORCE)) + pr_info("Forcing kernel command line to: %s\n", dst); +} + +#endif /* _LINUX_CMDLINE_H */ -- 2.25.0