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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2020-02-20 21:18:42 +0900 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-02-20 17:52:34 -0500 |
| commit | 85c46b78da58398be1c5166f55063c0512decd39 (patch) | |
| tree | 61c46743c7f5dd9eaec9afa135020da8b5e66d04 /init | |
| parent | d8a953ddde5ec30a36810d0a892c3949b50849e9 (diff) | |
| download | lwn-85c46b78da58398be1c5166f55063c0512decd39.tar.gz lwn-85c46b78da58398be1c5166f55063c0512decd39.zip | |
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 <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'init')
| -rw-r--r-- | init/Kconfig | 2 | ||||
| -rw-r--r-- | init/main.c | 6 |
2 files changed, 6 insertions, 2 deletions
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 <file:Documentation/admin-guide/bootconfig.rst> 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]; |