| Message ID | 164921227943.1090670.14035119557571329218.stgit@devnote2 (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | bootconfig: Support embedding a bootconfig in kernel for non initrd boot | expand |
Hello Masami Hiramatsu, On Wed, Apr 06, 2022 at 11:31:19AM +0900, Masami Hiramatsu wrote: > 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 <mhiramat@kernel.org> > --- > Changes in v8: > - Fix a build error in CONFIG_BLK_DEV_INITRD=n case. > 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 | 22 ++++++++++++---------- > lib/.gitignore | 1 + > lib/Makefile | 8 ++++++++ > lib/bootconfig-data.S | 10 ++++++++++ > lib/bootconfig.c | 13 +++++++++++++ > 8 files changed, 75 insertions(+), 11 deletions(-) > create mode 100644 lib/bootconfig-data.S > > diff --git a/MAINTAINERS b/MAINTAINERS > index c10fbd13080a..88c9d62acd90 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -7318,6 +7318,7 @@ 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 beb5b866c318..e7c75fb7d244 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -1347,7 +1347,7 @@ 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. > @@ -1357,6 +1357,25 @@ 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 4f3ba3b84e34..d00c6f77d0e0 100644 > --- a/init/main.c > +++ b/init/main.c > @@ -265,7 +265,7 @@ 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; > @@ -312,7 +312,7 @@ static void * __init get_boot_config_from_initrd(u32 *_size) > return data; > } > #else > -static void * __init get_boot_config_from_initrd(u32 *_size) > +static void * __init get_boot_config_from_initrd(size_t *_size) > { > return NULL; > } > @@ -409,14 +409,16 @@ 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, > @@ -435,8 +437,8 @@ 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; > } > > @@ -449,7 +451,7 @@ 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 4fc48543dc8f..62a103aaabd4 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -277,6 +277,14 @@ $(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 <linux/kernel.h> > #include <linux/memblock.h> > #include <linux/string.h> > + > +#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 > Tested using llvm 15.0.0 [p1] with FULL and THIN LTO as suggested here [p2], with full and incremental builds results are as expected and no issues observed. [p1] https://download.01.org/0day-ci/cross-package/clang-latest/clang-latest/clang.tar.xz [p2] https://lore.kernel.org/lkml/20220327115526.cc4b0ff55fc53c97683c3e4d@kernel.org/ Thanks and Regards, Padmanabha.S
diff --git a/MAINTAINERS b/MAINTAINERS index c10fbd13080a..88c9d62acd90 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -7318,6 +7318,7 @@ 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 beb5b866c318..e7c75fb7d244 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1347,7 +1347,7 @@ 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. @@ -1357,6 +1357,25 @@ 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 4f3ba3b84e34..d00c6f77d0e0 100644 --- a/init/main.c +++ b/init/main.c @@ -265,7 +265,7 @@ 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; @@ -312,7 +312,7 @@ static void * __init get_boot_config_from_initrd(u32 *_size) return data; } #else -static void * __init get_boot_config_from_initrd(u32 *_size) +static void * __init get_boot_config_from_initrd(size_t *_size) { return NULL; } @@ -409,14 +409,16 @@ 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, @@ -435,8 +437,8 @@ 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; } @@ -449,7 +451,7 @@ 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 4fc48543dc8f..62a103aaabd4 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -277,6 +277,14 @@ $(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 <linux/kernel.h> #include <linux/memblock.h> #include <linux/string.h> + +#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
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 <mhiramat@kernel.org> --- Changes in v8: - Fix a build error in CONFIG_BLK_DEV_INITRD=n case. 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 | 22 ++++++++++++---------- lib/.gitignore | 1 + lib/Makefile | 8 ++++++++ lib/bootconfig-data.S | 10 ++++++++++ lib/bootconfig.c | 13 +++++++++++++ 8 files changed, 75 insertions(+), 11 deletions(-) create mode 100644 lib/bootconfig-data.S