classes/kernel: Generate reproducible kernel module tarball

If reproducible binaries are requested, generate the kernel modules
tarball in a reproducible way. Namely, sort the tarball contents, clamp
the mtime to the source date epoch, compress the archive with a
consistent compression level (9), and don't include the name and
timestamp in the compressed file.

[YOCTO #12719]

(From OE-Core rev: 5c6a472c82a9b3c122fc54d3ee7171508c643a8b)

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/meta/classes/kernel.bbclass b/meta/classes/kernel.bbclass
index a724645466..6846d6040d 100644
--- a/meta/classes/kernel.bbclass
+++ b/meta/classes/kernel.bbclass
@@ -691,7 +691,13 @@ kernel_do_deploy() {
 
         if [ ${MODULE_TARBALL_DEPLOY} = "1" ] && (grep -q -i -e '^CONFIG_MODULES=y$' .config); then
                 mkdir -p ${D}${root_prefix}/lib
-                tar -cvzf $deployDir/modules-${MODULE_TARBALL_NAME}.tgz -C ${D}${root_prefix} lib
+                if [ -n "${SOURCE_DATE_EPOCH}" ]; then
+                        TAR_ARGS="--sort=name --clamp-mtime --mtime=@${SOURCE_DATE_EPOCH}"
+                else
+                        TAR_ARGS=""
+                fi
+                tar $TAR_ARGS -cv -C ${D}${root_prefix} lib | gzip -9n > $deployDir/modules-${MODULE_TARBALL_NAME}.tgz
+
                 ln -sf modules-${MODULE_TARBALL_NAME}.tgz $deployDir/modules-${MODULE_TARBALL_LINK_NAME}.tgz
         fi