From patchwork Fri Mar 26 13:44:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 12166669 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,URIBL_BLOCKED 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 E4700C433F8 for ; Fri, 26 Mar 2021 13:46:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C571461A1E for ; Fri, 26 Mar 2021 13:46:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230289AbhCZNqA (ORCPT ); Fri, 26 Mar 2021 09:46:00 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:42407 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230179AbhCZNoz (ORCPT ); Fri, 26 Mar 2021 09:44:55 -0400 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4F6NWM2kR9z9tyyX; Fri, 26 Mar 2021 14:44:47 +0100 (CET) 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 WniDc8Yabw7u; Fri, 26 Mar 2021 14:44:47 +0100 (CET) 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 4F6NWM1m9wz9tyyV; Fri, 26 Mar 2021 14:44:47 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 18F9E8B8C9; Fri, 26 Mar 2021 14:44:48 +0100 (CET) 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 BZpKcB1zy9W0; Fri, 26 Mar 2021 14:44:48 +0100 (CET) Received: from po16121vm.idsi0.si.c-s.fr (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id C3A018B8C7; Fri, 26 Mar 2021 14:44:47 +0100 (CET) Received: by po16121vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 4859067611; Fri, 26 Mar 2021 13:44:48 +0000 (UTC) Message-Id: <878228ad88df38f8914c7aa25dede3ed05c50f48.1616765869.git.christophe.leroy@csgroup.eu> In-Reply-To: References: From: Christophe Leroy Subject: [PATCH v3 01/17] cmdline: Add generic function to build command line. To: will@kernel.org, danielwa@cisco.com, robh@kernel.org, daniel@gimpelevich.san-francisco.ca.us 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 Date: Fri, 26 Mar 2021 13:44:48 +0000 (UTC) Precedence: bulk List-ID: X-Mailing-List: linux-mips@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 --- include/linux/cmdline.h | 57 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 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..dea87edd41be --- /dev/null +++ b/include/linux/cmdline.h @@ -0,0 +1,57 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_CMDLINE_H +#define _LINUX_CMDLINE_H + +#include + +/* Allow architectures to override strlcat, powerpc can't use strings so early */ +#ifndef cmdline_strlcat +#define cmdline_strlcat strlcat +#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 appended/prepended string. + * @src: The starting string or NULL if there isn't one. + * @len: the length of dest buffer. + */ +static __always_inline void __cmdline_build(char *dst, const char *src, size_t len) +{ + if (!len || src == dst) + return; + + if (IS_ENABLED(CONFIG_CMDLINE_FORCE) || !src) { + dst[0] = 0; + cmdline_strlcat(dst, CONFIG_CMDLINE, len); + return; + } + + if (dst != src) + dst[0] = 0; + + if (IS_ENABLED(CONFIG_CMDLINE_PREPEND)) + cmdline_strlcat(dst, CONFIG_CMDLINE " ", len); + + cmdline_strlcat(dst, src, len); + + if (IS_ENABLED(CONFIG_CMDLINE_EXTEND)) + cmdline_strlcat(dst, " " CONFIG_CMDLINE, len); +} + +#define cmdline_build(dst, src, len) do { \ + char *__c_dst = (dst); \ + const char *__c_src = (src); \ + \ + if (__c_src == __c_dst) { \ + static char __c_tmp[COMMAND_LINE_SIZE] __initdata = ""; \ + \ + cmdline_strlcat(__c_tmp, __c_src, COMMAND_LINE_SIZE); \ + __cmdline_build(__c_dst, __c_tmp, (len)); \ + } else { \ + __cmdline_build(__c_dst, __c_src, (len)); \ + } \ +} while (0) + +#endif /* _LINUX_CMDLINE_H */