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| author | Masahiro Yamada <masahiroy@kernel.org> | 2022-01-10 03:15:27 +0900 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2022-01-14 02:54:05 +0900 |
| commit | 7ce7e984ab2b218d6e92d5165629022fe2daf9ee (patch) | |
| tree | 9d81ea6b592cd4f52170799460e58347f6b26bb2 /usr | |
| parent | 64d8aaa4ef388b22372de4dc9ce3b9b3e5f45b6c (diff) | |
| download | lwn-7ce7e984ab2b218d6e92d5165629022fe2daf9ee.tar.gz lwn-7ce7e984ab2b218d6e92d5165629022fe2daf9ee.zip | |
kbuild: rename cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22}
GZIP-compressed files end with 4 byte data that represents the size
of the original input. The decompressors (the self-extracting kernel)
exploit it to know the vmlinux size beforehand. To mimic the GZIP's
trailer, Kbuild provides cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22}.
Unfortunately these macros are used everywhere despite the appended
size data is only useful for the decompressors.
There is no guarantee that such hand-crafted trailers are safely ignored.
In fact, the kernel refuses compressed initramdfs with the garbage data.
That is why usr/Makefile overrides size_append to make it no-op.
To limit the use of such broken compressed files, this commit renames
the existing macros as follows:
cmd_bzip2 --> cmd_bzip2_with_size
cmd_lzma --> cmd_lzma_with_size
cmd_lzo --> cmd_lzo_with_size
cmd_lz4 --> cmd_lz4_with_size
cmd_xzkern --> cmd_xzkern_with_size
cmd_zstd22 --> cmd_zstd22_with_size
To keep the decompressors working, I updated the following Makefiles
accordingly:
arch/arm/boot/compressed/Makefile
arch/h8300/boot/compressed/Makefile
arch/mips/boot/compressed/Makefile
arch/parisc/boot/compressed/Makefile
arch/s390/boot/compressed/Makefile
arch/sh/boot/compressed/Makefile
arch/x86/boot/compressed/Makefile
I reused the current macro names for the normal usecases; they produce
the compressed data in the proper format.
I did not touch the following:
arch/arc/boot/Makefile
arch/arm64/boot/Makefile
arch/csky/boot/Makefile
arch/mips/boot/Makefile
arch/riscv/boot/Makefile
arch/sh/boot/Makefile
kernel/Makefile
This means those Makefiles will stop appending the size data.
I dropped the 'override size_append' hack from usr/Makefile.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Diffstat (limited to 'usr')
| -rw-r--r-- | usr/Makefile | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/usr/Makefile b/usr/Makefile index 7374873a539f..cc0d2824e100 100644 --- a/usr/Makefile +++ b/usr/Makefile @@ -3,11 +3,6 @@ # kbuild file for usr/ - including initramfs image # -# cmd_bzip2, cmd_lzma, cmd_lzo, cmd_lz4 from scripts/Makefile.lib appends the -# size at the end of the compressed file, which unfortunately does not work -# with unpack_to_rootfs(). Make size_append no-op. -override size_append := : - compress-y := shipped compress-$(CONFIG_INITRAMFS_COMPRESSION_GZIP) := gzip compress-$(CONFIG_INITRAMFS_COMPRESSION_BZIP2) := bzip2 |