Call xbc_prepend_embedded_cmdline() in setup_arch() right after the CONFIG_CMDLINE merge and before strscpy(command_line, ...) so the build-time-rendered embedded bootconfig "kernel" subtree is part of boot_command_line by the time parse_early_param() runs. early_param() handlers (mem=, earlycon=, loglevel=, ...) now see values supplied via CONFIG_BOOT_CONFIG_EMBED_FILE without parsing bootconfig at runtime.
Gate the prepend on the same opt-in the runtime parser uses: prepend when "bootconfig" is present on the command line, or when CONFIG_BOOT_CONFIG_FORCE is set. setup_boot_config()'s parse_args() loop treats any presence of the "bootconfig" key as opt-in regardless of value, so check both cmdline_find_option_bool() (matches the bare key) and cmdline_find_option() (matches "bootconfig=<anything>"). Without the latter check, "bootconfig=0" would skip the early prepend yet still trigger the late runtime apply, leaving the embedded keys invisible to early_param() but applied to saved_command_line. Signed-off-by: Breno Leitao <[email protected]> --- arch/x86/Kconfig | 1 + arch/x86/kernel/setup.c | 27 +++++++++++++++++++++++++++ init/main.c | 25 ++++++++++++++++++++++--- 3 files changed, 50 insertions(+), 3 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0de23e647197..8ab11199c16d 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -127,6 +127,7 @@ config X86 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 select ARCH_SUPPORTS_CFI if X86_64 + select ARCH_SUPPORTS_CMDLINE_FROM_BOOTCONFIG select ARCH_USES_CFI_TRAPS if X86_64 && CFI select ARCH_SUPPORTS_LTO_CLANG select ARCH_SUPPORTS_LTO_CLANG_THIN diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 46882ce79c3a..d69ba84c203f 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -6,6 +6,7 @@ * parts of early kernel initialization. */ #include <linux/acpi.h> +#include <linux/bootconfig.h> #include <linux/console.h> #include <linux/cpu.h> #include <linux/crash_dump.h> @@ -36,6 +37,7 @@ #include <asm/bios_ebda.h> #include <asm/bugs.h> #include <asm/cacheinfo.h> +#include <asm/cmdline.h> #include <asm/coco.h> #include <asm/cpu.h> #include <asm/efi.h> @@ -924,6 +926,31 @@ void __init setup_arch(char **cmdline_p) builtin_cmdline_added = true; #endif + /* + * Match the runtime bootconfig parser's opt-in: only fold the + * embedded kernel.* keys into the cmdline when "bootconfig" is + * present on the command line, or CONFIG_BOOT_CONFIG_FORCE is set. + * setup_boot_config()'s parse_args() loop treats any presence of + * the "bootconfig" key as opt-in (bare, =0, =1, ...), so check both + * forms here: cmdline_find_option_bool() matches the bare key, + * cmdline_find_option() matches "bootconfig=<anything>". Without + * the second check, "bootconfig=0" would skip the early prepend + * but still trigger the late runtime apply -- a split-brain state. + * CONFIG_BOOT_CONFIG_FORCE defaults to y when BOOT_CONFIG_EMBED is + * set, so on the default config the embedded keys are applied + * unconditionally. + */ + { + char buf[8]; + + if (IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE) || + cmdline_find_option_bool(boot_command_line, "bootconfig") || + cmdline_find_option(boot_command_line, "bootconfig", + buf, sizeof(buf)) >= 0) + xbc_prepend_embedded_cmdline(boot_command_line, + COMMAND_LINE_SIZE); + } + strscpy(command_line, boot_command_line, COMMAND_LINE_SIZE); *cmdline_p = command_line; diff --git a/init/main.c b/init/main.c index e363232b428b..2ecb6aa536dd 100644 --- a/init/main.c +++ b/init/main.c @@ -378,12 +378,15 @@ static void __init setup_boot_config(void) int pos, ret; size_t size; char *err; + bool from_embedded = false; /* 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) + if (!data) { data = xbc_get_embedded_bootconfig(&size); + from_embedded = true; + } strscpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, @@ -421,8 +424,24 @@ static void __init setup_boot_config(void) } else { xbc_get_info(&ret, NULL); 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"); + /* + * keys starting with "kernel." are passed via cmdline. When + * this bootconfig came from the embedded source and + * setup_arch() already prepended the rendered "kernel" subtree + * to boot_command_line, rendering again here would duplicate + * the keys in saved_command_line and make accumulating handlers + * (console=, earlycon=, ...) re-register the same value. Skip + * only when the prepend really happened. + * + * On arches that do not select ARCH_SUPPORTS_CMDLINE_FROM_BOOTCONFIG, + * CONFIG_BOOT_CONFIG_EMBED_CMDLINE is unselectable and + * xbc_embedded_cmdline_applied() collapses to a stub returning + * false, so this path still runs and the embedded "kernel" + * keys reach the cmdline via the runtime parser exactly as + * before this series. + */ + if (!from_embedded || !xbc_embedded_cmdline_applied()) + extra_command_line = xbc_make_cmdline("kernel"); /* Also, "init." keys are init arguments */ extra_init_args = xbc_make_cmdline("init"); } -- 2.53.0-Meta
