kbuild: Use CRC32 and a 1MiB dictionary for XZ compressed modules

Kmod is now (since kmod commit 09c9f8c5df04 ("libkmod: Use kernel
decompression when available")) using the kernel decompressor, when
loading compressed modules.

However, the kernel XZ decompressor is XZ Embedded, which doesn't
handle CRC64 and dictionaries larger than 1MiB.

Use CRC32 and 1MiB dictionary when XZ compressing and installing
kernel modules.

Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1050582
Signed-off-by: Martin Nybo Andersen <tweek@tweek.dk>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

diff --git a/scripts/Makefile.modinst b/scripts/Makefile.modinst
index 346f5ec..0afd754 100644 (file)
--- a/scripts/Makefile.modinst
+++ b/scripts/Makefile.modinst
@@ -144,7 +144,7 @@ endif
 quiet_cmd_gzip = GZIP    $@
       cmd_gzip = $(KGZIP) -n -f $<
 quiet_cmd_xz = XZ      $@
-      cmd_xz = $(XZ) --lzma2=dict=2MiB -f $<
+      cmd_xz = $(XZ) --check=crc32 --lzma2=dict=1MiB -f $<
 quiet_cmd_zstd = ZSTD    $@
       cmd_zstd = $(ZSTD) -T0 --rm -f -q $<