From nobody Tue Jun 23 02:04:16 2026 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 135EAC433EF for ; Mon, 14 Mar 2022 01:54:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235749AbiCNBzV (ORCPT ); Sun, 13 Mar 2022 21:55:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52650 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235756AbiCNBzS (ORCPT ); Sun, 13 Mar 2022 21:55:18 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF5FA1EEE5; Sun, 13 Mar 2022 18:54:09 -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 258F860F0A; Mon, 14 Mar 2022 01:54:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B24D8C340E8; Mon, 14 Mar 2022 01:54:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1647222848; bh=JzzzQoL0GbYCQzlYz/yEZ+EV3sEjDtQ9rE0YeOlbuRI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UiT/qfTkpJ/SOem5Hpbqf/5AhqLnmO+NAlKIs0E+xLVW2frrhi5UgaAXhG2s8ZsRi tM42odHvXAmxnfq8G62+XQGC/65LCKbi6vUm3B5gjxPU9vv49JqUQTMQRfxy6O8iaO AWH9WRluirf5LFCjCTsPXHit2tTE8By95FK+ArLDIhSRYZnSNDhlmN8gpkYWvoiBQl Sci/UFsfToPmJ3c8eXUx84fncb4yIPWLn/OUWjkjzra0OmDDpQtJR8tPMqFXYBrEtW SRsLKmiwEd5uJIvMtNLynAkMUqkm36VhycuHkF4CVAql/mOurY6z8sxQ6T2uvM7s+i MQ3QsrHkCu6nw== From: Masami Hiramatsu To: Steven Rostedt Cc: Masami Hiramatsu , Padmanabha Srinivasaiah , LKML , Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap Subject: [PATCH v2 1/3] bootconfig: Check the checksum before removing the bootconfig from initrd Date: Mon, 14 Mar 2022 10:54:04 +0900 Message-Id: <164722284387.689258.6569515754244465668.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <164722283333.689258.144495814460576707.stgit@devnote2> References: <164722283333.689258.144495814460576707.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Check the bootconfig's checksum before removing the bootcinfig data from initrd to avoid modifying initrd by mistake. This will also simplifies the get_boot_config_from_initrd() interface. Signed-off-by: Masami Hiramatsu --- init/main.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/init/main.c b/init/main.c index 65fa2e41a9c0..421050be5039 100644 --- a/init/main.c +++ b/init/main.c @@ -265,7 +265,7 @@ static int __init loglevel(char *str) early_param("loglevel", loglevel); =20 #ifdef CONFIG_BLK_DEV_INITRD -static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum) +static void * __init get_boot_config_from_initrd(u32 *_size) { u32 size, csum; char *data; @@ -299,17 +299,20 @@ static void * __init get_boot_config_from_initrd(u32 = *_size, u32 *_csum) return NULL; } =20 + if (xbc_calc_checksum(data, size) !=3D csum) { + pr_err("bootconfig checksum failed\n"); + return NULL; + } + /* Remove bootconfig from initramfs/initrd */ initrd_end =3D (unsigned long)data; if (_size) *_size =3D size; - if (_csum) - *_csum =3D csum; =20 return data; } #else -static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum) +static void * __init get_boot_config_from_initrd(u32 *_size) { return NULL; } @@ -408,12 +411,12 @@ static void __init setup_boot_config(void) static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; const char *msg; int pos; - u32 size, csum; + u32 size; char *data, *err; int ret; =20 /* Cut out the bootconfig data even if we have no bootconfig option */ - data =3D get_boot_config_from_initrd(&size, &csum); + data =3D get_boot_config_from_initrd(&size); =20 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); err =3D parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, @@ -437,11 +440,6 @@ static void __init setup_boot_config(void) return; } =20 - if (xbc_calc_checksum(data, size) !=3D csum) { - pr_err("bootconfig checksum failed\n"); - return; - } - ret =3D xbc_init(data, size, &msg, &pos); if (ret < 0) { if (pos < 0) @@ -470,7 +468,7 @@ static void __init exit_boot_config(void) static void __init setup_boot_config(void) { /* Remove bootconfig data from initrd */ - get_boot_config_from_initrd(NULL, NULL); + get_boot_config_from_initrd(NULL); } =20 static int __init warn_bootconfig(char *str) From nobody Tue Jun 23 02:04:16 2026 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 17939C433F5 for ; Mon, 14 Mar 2022 01:54:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235767AbiCNBzb (ORCPT ); Sun, 13 Mar 2022 21:55:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229771AbiCNBz3 (ORCPT ); Sun, 13 Mar 2022 21:55:29 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 031BFDE0; Sun, 13 Mar 2022 18:54:21 -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 ams.source.kernel.org (Postfix) with ESMTPS id 8EC2AB80CAA; Mon, 14 Mar 2022 01:54:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 894C1C340E8; Mon, 14 Mar 2022 01:54:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1647222858; bh=HkY4AKvDFSS79zzzIvswIAn4ip/2HgVf/Bi/e3C+ezM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u9PoaLMXY3amWAlswBgR2nT0g98Q/W4xTzRMiRwgCUxwxWaWzc+24AhGbvDKXx0nU hzt8ayBI6Z7qObCDAyLuwTOVZ/0XwFSW9nJ7Ay7JCCqIR3+DgaYV9460Tlb3C41EXx 6FR8dxVtXCf6ASx4KPNn3yakzwX9xnUU/x+4p1jIhv1EV0HRZ7QUdJVcSEm2W6RuZz NqYF/qBBn0AIlk1YstirSXMHqDauKyZ/WupSL6UHvE8zofuQQMmw95bwAhukcQ18If cL+XXRHIF2NkxTkX8khDnZk7rZnuTuR2dUkWtEOxAIsaYzisXiyomQ0ryAxmR1gZur XvfBChzZc2Zpg== From: Masami Hiramatsu To: Steven Rostedt Cc: Masami Hiramatsu , Padmanabha Srinivasaiah , LKML , Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap Subject: [PATCH v2 2/3] bootconfig: Support embedding a bootconfig file in kernel Date: Mon, 14 Mar 2022 10:54:14 +0900 Message-Id: <164722285390.689258.8067973965378285190.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <164722283333.689258.144495814460576707.stgit@devnote2> References: <164722283333.689258.144495814460576707.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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_EMBED_BOOT_CONFIG=3Dy and set the file path to CONFIG_EMBED_BOOT_CONFIG_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 --- include/linux/bootconfig.h | 10 ++++++++++ init/Kconfig | 21 +++++++++++++++++++++ init/main.c | 13 ++++++++----- lib/.gitignore | 1 + lib/Makefile | 12 ++++++++++++ lib/bootconfig.c | 23 +++++++++++++++++++++++ 6 files changed, 75 insertions(+), 5 deletions(-) diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h index a4665c7ab07c..5dbda5e3e9bb 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_s= ize); /* XBC cleanup data structures */ void __init xbc_exit(void); =20 +/* XBC embedded bootconfig data in kernel */ +#ifdef CONFIG_EMBED_BOOT_CONFIG +char * __init xbc_get_embedded_bootconfig(size_t *size); +#else +static inline char *xbc_get_embedded_bootconfig(size_t *size) +{ + return NULL; +} +#endif + #endif diff --git a/init/Kconfig b/init/Kconfig index e9119bf54b1f..70440804874d 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1357,6 +1357,27 @@ config BOOT_CONFIG =20 If unsure, say Y. =20 +config EMBED_BOOT_CONFIG + bool "Embed bootconfig file in the kernel" + depends on BOOT_CONFIG + default n + help + Embed a bootconfig file given by EMBED_BOOT_CONFIG_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 EMBED_BOOT_CONFIG_FILE + string "Embedded bootconfig file path" + default "" + depends on EMBED_BOOT_CONFIG + 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 421050be5039..3803bf2e22ea 100644 --- a/init/main.c +++ b/init/main.c @@ -265,7 +265,7 @@ static int __init loglevel(char *str) early_param("loglevel", loglevel); =20 #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; @@ -411,12 +411,15 @@ static void __init setup_boot_config(void) static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; const char *msg; int pos; - u32 size; + size_t size; char *data, *err; int ret; =20 /* Cut out the bootconfig data even if we have no bootconfig option */ data =3D get_boot_config_from_initrd(&size); + /* If there is no bootconfig in initrd, try embedded one. */ + if (!data) + data =3D xbc_get_embedded_bootconfig(&size); =20 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); err =3D parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, @@ -435,8 +438,8 @@ static void __init setup_boot_config(void) } =20 if (size >=3D 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; } =20 @@ -449,7 +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 =3D xbc_make_cmdline("kernel"); /* Also, "init." keys are init arguments */ diff --git a/lib/.gitignore b/lib/.gitignore index e5e217b8307b..30a2a5db7033 100644 --- a/lib/.gitignore +++ b/lib/.gitignore @@ -6,3 +6,4 @@ /oid_registry_data.c /test_fortify.log /test_fortify/*.log +/default.bconf diff --git a/lib/Makefile b/lib/Makefile index 300f569c626b..8183785ee99d 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -279,6 +279,18 @@ $(foreach file, $(libfdt_files), \ $(eval CFLAGS_$(file) =3D -I $(srctree)/scripts/dtc/libfdt)) lib-$(CONFIG_LIBFDT) +=3D $(libfdt_files) =20 +ifeq ($(CONFIG_EMBED_BOOT_CONFIG),y) +# Since the specified bootconfig file can be switched, we forcibly update = the +# default.bconf file always. +$(obj)/default.bconf: FORCE + $(call cmd,defbconf) + +quiet_cmd_defbconf =3D GEN $@ + cmd_defbconf =3D cat < /dev/null $(CONFIG_EMBED_BOOT_CONFIG_FILE) > = $@ +clean-files +=3D default.bconf +$(obj)/bootconfig.o: $(obj)/default.bconf +endif + lib-$(CONFIG_BOOT_CONFIG) +=3D bootconfig.o =20 obj-$(CONFIG_RBTREE_TEST) +=3D rbtree_test.o diff --git a/lib/bootconfig.c b/lib/bootconfig.c index 74f3201ab8e5..3a3bf3a208e3 100644 --- a/lib/bootconfig.c +++ b/lib/bootconfig.c @@ -12,6 +12,29 @@ #include #include #include + +#ifdef CONFIG_EMBED_BOOT_CONFIG +asm ( +" .pushsection .init.data, \"aw\" \n" +" .global embedded_bootconfig_data \n" +"embedded_bootconfig_data: \n" +" .incbin \"lib/default.bconf\" \n" +" .global embedded_bootconfig_data_end \n" +"embedded_bootconfig_data_end: \n" +" .popsection \n" +); + +extern __visible char embedded_bootconfig_data[]; +extern __visible char embedded_bootconfig_data_end[]; + +char * __init xbc_get_embedded_bootconfig(size_t *size) +{ + *size =3D 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 From nobody Tue Jun 23 02:04:16 2026 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 7CDCCC433F5 for ; Mon, 14 Mar 2022 01:54:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235793AbiCNBzr (ORCPT ); Sun, 13 Mar 2022 21:55:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235781AbiCNBzl (ORCPT ); Sun, 13 Mar 2022 21:55:41 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7838B1FA7D; Sun, 13 Mar 2022 18:54:30 -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 ams.source.kernel.org (Postfix) with ESMTPS id 2BF86B80CA5; Mon, 14 Mar 2022 01:54:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 475E3C340F3; Mon, 14 Mar 2022 01:54:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1647222868; bh=RifitOjP23r/n90fOwga9VQHt9fkjAf4eMxj3baN9Y0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bF+eGwI4xtJGHh4ld2A/T1LFP4O5uH7X0Y00OD4/iHYsNkmEPZsznCpJuq8XqKSe5 Xd+GDiefpzt72fEd+dqVC+FekUBvQViExgZAbIq2orjOoolhDT7si7oTjVVrxfd/Sm kZ8FU4l8RFvyC60ngNUbYCtjxzjeEBmePyz0Q8bJYXmNkrC8Z3k17ul5qE5bOAJb7+ NJOYP578acSznTx2NGeUn2V+U2yviKZFbuQKiof+rQ7b9mo+/UDWBDxnM5yUKJ5m5H RMosLkKz80zB4gfGx50s8LzqTDIzCKjFRsFQmn9JC+e1FaBLVBtpIZixD/nS/UHWaM SCkergFEFQbZA== From: Masami Hiramatsu To: Steven Rostedt Cc: Masami Hiramatsu , Padmanabha Srinivasaiah , LKML , Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap Subject: [PATCH v2 3/3] docs: bootconfig: Add how to embed the bootconfig into kernel Date: Mon, 14 Mar 2022 10:54:23 +0900 Message-Id: <164722286373.689258.9817790360544187508.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <164722283333.689258.144495814460576707.stgit@devnote2> References: <164722283333.689258.144495814460576707.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a description how to embed the bootconfig file into kernel. Signed-off-by: Masami Hiramatsu --- Changes in v2: - Corrected the text accoding to Randy's suggestion. - Do not reccomend to use relative path for CONFIG_EMBED_BOOT_CONFIG_FILE. --- Documentation/admin-guide/bootconfig.rst | 30 ++++++++++++++++++++++++++= +--- 1 file changed, 27 insertions(+), 3 deletions(-) diff --git a/Documentation/admin-guide/bootconfig.rst b/Documentation/admin= -guide/bootconfig.rst index a1860fc0ca88..1af1a172fdd4 100644 --- a/Documentation/admin-guide/bootconfig.rst +++ b/Documentation/admin-guide/bootconfig.rst @@ -158,9 +158,15 @@ Each key-value pair is shown in each line with followi= ng style:: Boot Kernel With a Boot Config =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D =20 -Since the boot configuration file is loaded with initrd, it will be added -to the end of the initrd (initramfs) image file with padding, size, -checksum and 12-byte magic word as below. +There are two options to boot the kernel with bootconfig: attaching the +bootconfig to the initrd image or embedding it in the kernel itself. + +Attaching a Boot Config to Initrd +--------------------------------- + +Since the boot configuration file is loaded with initrd by default, +it will be added to the end of the initrd (initramfs) image file with +padding, size, checksum and 12-byte magic word as below. =20 [initrd][bootconfig][padding][size(le32)][checksum(le32)][#BOOTCONFIG\n] =20 @@ -196,6 +202,24 @@ To remove the config from the image, you can use -d op= tion as below:: Then add "bootconfig" on the normal kernel command line to tell the kernel to look for the bootconfig at the end of the initrd file. =20 +Embedding a Boot Config into Kernel +----------------------------------- + +If you can not use initrd, you can also embed the bootconfig file in the +kernel by Kconfig options. In this case, you need to recompile the kernel +with the following configs:: + + COFNIG_EMBED_BOOT_CONFIG=3Dy + CONFIG_EMBED_BOOT_CONFIG_FILE=3D"/PATH/TO/BOOTCONFIG/FILE" + +``CONFIG_EMBED_BOOT_CONFIG_FILE`` requires a correct absolute path to +the bootconfig file. The kernel will embed it as the default bootconfig. + +Just as when attaching the bootconfig to the initrd, you need ``bootconfig= `` +option to the kernel command line to enable the embedded bootconfig. + +Note that even if you set this option, you can override the embedded +bootconfig by another bootconfig which attached to the initrd. =20 Kernel parameters via Boot Config =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D