From patchwork Thu Mar 31 08:24:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12796848 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D30B4C433FE for ; Thu, 31 Mar 2022 08:25:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232754AbiCaI04 (ORCPT ); Thu, 31 Mar 2022 04:26:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56020 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232760AbiCaI0q (ORCPT ); Thu, 31 Mar 2022 04:26:46 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2EBE0C6EFE; Thu, 31 Mar 2022 01:24:59 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BEC2A616D3; Thu, 31 Mar 2022 08:24:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3E1A4C340ED; Thu, 31 Mar 2022 08:24:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648715098; bh=Tw4EwvZXZvAbB7rmJ6FatvNo4a/BuwctLIn7ma+Ckb0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LmjtF1FW0X+GP/mNLMYJ2eXQTe8lj4CB9CYCVuzhufiMMW1iNLxBfdJEEGbXBZvWh IVMp+x9oTZzbB2ztXnC9EvEjPnVndNiLWXR58rEXgQ4FlpCeLZ6gvSWGClKAQNpb1j Ncb1NVRlqh/B6dnvlNmWMRn27FCwPUgwnf0Eikes1aS1g941UyR/hHbhIwW6mtizDe RJVL7fYJhi0m96waLtHQqrWnsGYRGDNoVg08DtdXSXYaW4ouhD+0FGYNvCdaaYbCDE 6hZ7GSZ7PT8tJfHueXbX7Z1ViPWUPuHiZuPFLS5cPCDvE1Zx1jLNXzfywxI1AGwvg1 yQgfcsybWCYTA== From: Masami Hiramatsu To: Steven Rostedt Cc: Masami Hiramatsu , Padmanabha Srinivasaiah , LKML , Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap , Nick Desaulniers , Sami Tolvanen , Nathan Chancellor , llvm@lists.linux.dev, Masahiro Yamada , Linux Kbuild mailing list Subject: [PATCH v7 3/4] bootconfig: Support embedding a bootconfig file in kernel Date: Thu, 31 Mar 2022 17:24:51 +0900 Message-Id: <164871509158.178991.12705786877340857725.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <164871505771.178991.7870442736805590948.stgit@devnote2> References: <164871505771.178991.7870442736805590948.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org This allows kernel developer to embed a default bootconfig file in the kernel instead of embedding it in the initrd. This will be good for who are using the kernel without initrd, or who needs a default bootconfigs. This needs to set two kconfigs: CONFIG_BOOT_CONFIG_EMBED=y and set the file path to CONFIG_BOOT_CONFIG_EMBED_FILE. Note that you still need 'bootconfig' command line option to load the embedded bootconfig. Also if you boot using an initrd with a different bootconfig, the kernel will use the bootconfig in the initrd, instead of the default bootconfig. Signed-off-by: Masami Hiramatsu --- Changes in v7: - Change kconfig option name to share the common prefix so that we can search it easier. - Make embedded_bootconfig_data readonly. - Select CONFIG_BLK_DEV_INITRD only if CONFIG_BOOT_CONFIG_EMBED=n - Remove redundant default settings for new Kconfig options. Changes in v6: - Split out the .incbin asm part as bootconfig-data.S according to Masahiro's comment. Changes in v5: - Fix .gitignore to be sorted alphabetically. - Make default.bconf is cleaned up correctly. - Allow user to specify relative path to CONFIG_EMBED_BOOT_CONFIG_FILE. (Thanks Masahiro!) Changes in v4: - Avoid updating the default.bconf if the file is not changed. --- MAINTAINERS | 1 + include/linux/bootconfig.h | 10 ++++++++++ init/Kconfig | 21 ++++++++++++++++++++- init/main.c | 20 +++++++++++--------- lib/.gitignore | 1 + lib/Makefile | 8 ++++++++ lib/bootconfig-data.S | 10 ++++++++++ lib/bootconfig.c | 13 +++++++++++++ 8 files changed, 74 insertions(+), 10 deletions(-) create mode 100644 lib/bootconfig-data.S diff --git a/MAINTAINERS b/MAINTAINERS index b555a5e8704f..9b4910685412 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -7350,6 +7350,7 @@ S: Maintained F: Documentation/admin-guide/bootconfig.rst F: fs/proc/bootconfig.c F: include/linux/bootconfig.h +F: lib/bootconfig-data.S F: lib/bootconfig.c F: tools/bootconfig/* F: tools/bootconfig/scripts/* diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h index a4665c7ab07c..1611f9db878e 100644 --- a/include/linux/bootconfig.h +++ b/include/linux/bootconfig.h @@ -289,4 +289,14 @@ int __init xbc_get_info(int *node_size, size_t *data_size); /* XBC cleanup data structures */ void __init xbc_exit(void); +/* XBC embedded bootconfig data in kernel */ +#ifdef CONFIG_BOOT_CONFIG_EMBED +const char * __init xbc_get_embedded_bootconfig(size_t *size); +#else +static inline const char *xbc_get_embedded_bootconfig(size_t *size) +{ + return NULL; +} +#endif + #endif diff --git a/init/Kconfig b/init/Kconfig index 97463a33baa7..756872d17fe1 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1351,7 +1351,7 @@ endif config BOOT_CONFIG bool "Boot config support" - select BLK_DEV_INITRD + select BLK_DEV_INITRD if !BOOT_CONFIG_EMBED help Extra boot config allows system admin to pass a config file as complemental extension of kernel cmdline when booting. @@ -1361,6 +1361,25 @@ config BOOT_CONFIG If unsure, say Y. +config BOOT_CONFIG_EMBED + bool "Embed bootconfig file in the kernel" + depends on BOOT_CONFIG + help + Embed a bootconfig file given by BOOT_CONFIG_EMBED_FILE in the + kernel. Usually, the bootconfig file is loaded with the initrd + image. But if the system doesn't support initrd, this option will + help you by embedding a bootconfig file while building the kernel. + + If unsure, say N. + +config BOOT_CONFIG_EMBED_FILE + string "Embedded bootconfig file path" + depends on BOOT_CONFIG_EMBED + help + Specify a bootconfig file which will be embedded to the kernel. + This bootconfig will be used if there is no initrd or no other + bootconfig in the initrd. + choice prompt "Compiler optimization level" default CC_OPTIMIZE_FOR_PERFORMANCE diff --git a/init/main.c b/init/main.c index 266d61bc67b0..62dddc4206b4 100644 --- a/init/main.c +++ b/init/main.c @@ -266,7 +266,7 @@ static int __init loglevel(char *str) early_param("loglevel", loglevel); #ifdef CONFIG_BLK_DEV_INITRD -static void * __init get_boot_config_from_initrd(u32 *_size) +static void * __init get_boot_config_from_initrd(size_t *_size) { u32 size, csum; char *data; @@ -410,14 +410,16 @@ static int __init warn_bootconfig(char *str) static void __init setup_boot_config(void) { static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; - const char *msg; - int pos; - u32 size; - char *data, *err; - int ret; + const char *msg, *data; + int pos, ret; + size_t size; + char *err; /* Cut out the bootconfig data even if we have no bootconfig option */ data = get_boot_config_from_initrd(&size); + /* If there is no bootconfig in initrd, try embedded one. */ + if (!data) + data = xbc_get_embedded_bootconfig(&size); strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, @@ -436,8 +438,8 @@ static void __init setup_boot_config(void) } if (size >= XBC_DATA_MAX) { - pr_err("bootconfig size %d greater than max size %d\n", - size, XBC_DATA_MAX); + pr_err("bootconfig size %ld greater than max size %d\n", + (long)size, XBC_DATA_MAX); return; } @@ -450,7 +452,7 @@ static void __init setup_boot_config(void) msg, pos); } else { xbc_get_info(&ret, NULL); - pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret); + pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret); /* keys starting with "kernel." are passed via cmdline */ extra_command_line = xbc_make_cmdline("kernel"); /* Also, "init." keys are init arguments */ diff --git a/lib/.gitignore b/lib/.gitignore index e5e217b8307b..54596b634ecb 100644 --- a/lib/.gitignore +++ b/lib/.gitignore @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-only /crc32table.h /crc64table.h +/default.bconf /gen_crc32table /gen_crc64table /oid_registry_data.c diff --git a/lib/Makefile b/lib/Makefile index 08053df16c7c..95268d6c75b7 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -280,6 +280,14 @@ $(foreach file, $(libfdt_files), \ lib-$(CONFIG_LIBFDT) += $(libfdt_files) obj-$(CONFIG_BOOT_CONFIG) += bootconfig.o +obj-$(CONFIG_BOOT_CONFIG_EMBED) += bootconfig-data.o + +$(obj)/bootconfig-data.o: $(obj)/default.bconf + +targets += default.bconf +filechk_defbconf = cat $(or $(real-prereqs), /dev/null) +$(obj)/default.bconf: $(CONFIG_BOOT_CONFIG_EMBED_FILE) FORCE + $(call filechk,defbconf) obj-$(CONFIG_RBTREE_TEST) += rbtree_test.o obj-$(CONFIG_INTERVAL_TREE_TEST) += interval_tree_test.o diff --git a/lib/bootconfig-data.S b/lib/bootconfig-data.S new file mode 100644 index 000000000000..ef85ba1a82f4 --- /dev/null +++ b/lib/bootconfig-data.S @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Embed default bootconfig in the kernel. + */ + .section .init.rodata, "aw" + .global embedded_bootconfig_data +embedded_bootconfig_data: + .incbin "lib/default.bconf" + .global embedded_bootconfig_data_end +embedded_bootconfig_data_end: diff --git a/lib/bootconfig.c b/lib/bootconfig.c index 74f3201ab8e5..c59d26068a64 100644 --- a/lib/bootconfig.c +++ b/lib/bootconfig.c @@ -12,6 +12,19 @@ #include #include #include + +#ifdef CONFIG_BOOT_CONFIG_EMBED +/* embedded_bootconfig_data is defined in bootconfig-data.S */ +extern __visible const char embedded_bootconfig_data[]; +extern __visible const char embedded_bootconfig_data_end[]; + +const char * __init xbc_get_embedded_bootconfig(size_t *size) +{ + *size = embedded_bootconfig_data_end - embedded_bootconfig_data; + return (*size) ? embedded_bootconfig_data : NULL; +} +#endif + #else /* !__KERNEL__ */ /* * NOTE: This is only for tools/bootconfig, because tools/bootconfig will