From 85c46b78da58398be1c5166f55063c0512decd39 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 20 Feb 2020 21:18:42 +0900 Subject: bootconfig: Add bootconfig magic word for indicating bootconfig explicitly Add bootconfig magic word to the end of bootconfig on initrd image for indicating explicitly the bootconfig is there. Also tools/bootconfig treats wrong size or wrong checksum or parse error as an error, because if there is a bootconfig magic word, there must be a bootconfig. The bootconfig magic word is "#BOOTCONFIG\n", 12 bytes word. Thus the block image of the initrd file with bootconfig is as follows. [Initrd][bootconfig][size][csum][#BOOTCONFIG\n] Link: http://lkml.kernel.org/r/158220112263.26565.3944814205960612841.stgit@devnote2 Suggested-by: Steven Rostedt Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- init/Kconfig | 2 +- init/main.c | 6 +++++- 2 files changed, 6 insertions(+), 2 deletions(-) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index f586878410d2..a84e7aa89a29 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1222,7 +1222,7 @@ config BOOT_CONFIG Extra boot config allows system admin to pass a config file as complemental extension of kernel cmdline when booting. The boot config file must be attached at the end of initramfs - with checksum and size. + with checksum, size and magic word. See for details. If unsure, say Y. diff --git a/init/main.c b/init/main.c index d96cc5f65022..2fe8dec93e68 100644 --- a/init/main.c +++ b/init/main.c @@ -374,7 +374,11 @@ static void __init setup_boot_config(const char *cmdline) if (!initrd_end) goto not_found; - hdr = (u32 *)(initrd_end - 8); + data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN; + if (memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN)) + goto not_found; + + hdr = (u32 *)(data - 8); size = hdr[0]; csum = hdr[1]; -- cgit v1.2.3