initramfs: Use KBUILD_BUILD_TIMESTAMP for generated entries

gen_init_cpio gets the current time and uses it for each symlink,
special file, and directory.  Grab the current time once and make it
possible to override it with the KBUILD_BUILD_TIMESTAMP variable for
reproducible builds.

Signed-off-by: Michal Marek <mmarek@suse.cz>

1 files changed, 8 insertions, 1 deletions

diff --git a/scripts/gen_initramfs_list.sh b/scripts/gen_initramfs_list.sh
index 4a43fe12d179..d44cf675bc22 100644
--- a/scripts/gen_initramfs_list.sh
+++ b/scripts/gen_initramfs_list.sh
@@ -287,8 +287,15 @@ done
 # we are carefull to delete tmp files
 if [ ! -z ${output_file} ]; then
         if [ -z ${cpio_file} ]; then
+                timestamp=
+                if test -n "$KBUILD_BUILD_TIMESTAMP"; then
+                        timestamp="$(date -d"$KBUILD_BUILD_TIMESTAMP" +%s || :)"
+                        if test -n "$timestamp"; then
+                                timestamp="-t $timestamp"
+                        fi
+                fi
                 cpio_tfile="$(mktemp ${TMPDIR:-/tmp}/cpiofile.XXXXXX)"
-                usr/gen_init_cpio ${cpio_list} > ${cpio_tfile}
+                usr/gen_init_cpio $timestamp ${cpio_list} > ${cpio_tfile}
         else
                 cpio_tfile=${cpio_file}
         fi