On Mon, Mar 20, 2023 at 1:09 PM Benjamin Gray <bgray@xxxxxxxxxxxxx> wrote:
>
> gen_initramfs.sh has an internal dependency on KBUILD_BUILD_TIMESTAMP
> for generating file mtimes that is not exposed to make, so changing
> KBUILD_BUILD_TIMESTAMP will not trigger a rebuild of the archive.
>
> Declare the mtime date as a new parameter to gen_initramfs.sh to encode
> KBUILD_BUILD_TIMESTAMP in the shell command, thereby making make aware
> of the dependency.
>
> It will rebuild if KBUILD_BUILD_TIMESTAMP changes or is newly set/unset.
> It will _not_ rebuild if KBUILD_BUILD_TIMESTAMP is unset before and
> after. This should be fine for anyone who doesn't care about setting
> specific build times in the first place.
>
> Signed-off-by: Benjamin Gray <bgray@xxxxxxxxxxxxx>
>
> ---
>
> Ran into this while debugging the issue in the first patch. Made for a
> very perplexing debug session before we worked out the state wasn't
> being rebuilt.
> ---
> usr/Makefile | 2 ++
> usr/gen_initramfs.sh | 16 +++++++++-------
> 2 files changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/usr/Makefile b/usr/Makefile
> index 59d9e8b07a01..2aa386cf48d6 100644
> --- a/usr/Makefile
> +++ b/usr/Makefile
> @@ -64,6 +64,7 @@ quiet_cmd_initfs = GEN $@
> $(CONFIG_SHELL) $< -o $@ -l $(obj)/.initramfs_data.cpio.d \
> $(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \
> $(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID)) \
> + $(if $(KBUILD_BUILD_TIMESTAMP), -d $(KBUILD_BUILD_TIMESTAMP)) \
> $(ramfs-input)
If I apply this patch, I see a build error.
$ make -j16 KBUILD_BUILD_TIMESTAMP="$(date)"
[snip]
GEN usr/initramfs_data.cpio
usr/gen_initramfs.sh: Cannot open 'Apr'
make[2]: *** [usr/Makefile:76: usr/initramfs_data.cpio] Error 1
make[1]: *** [scripts/Makefile.build:494: usr] Error 2
make[1]: *** Waiting for unfinished jobs....
Because KBUILD_BUILD_TIMESTAMP may contain spaces
depending on the format, init/Makefile and
kernel/gen_kheaders.sh surround the date with
double-quotes.
Double-quoting it in the same way fixes the issue.
$(if $(KBUILD_BUILD_TIMESTAMP), -d "$(KBUILD_BUILD_TIMESTAMP)") \
> # We rebuild initramfs_data.cpio if:
> @@ -71,6 +72,7 @@ quiet_cmd_initfs = GEN $@
> # 2) There are changes in which files are included (added or deleted)
> # 3) If gen_init_cpio are newer than initramfs_data.cpio
> # 4) Arguments to gen_initramfs.sh changes
> +# 5) KBUILD_BUILD_TIMESTAMP is changed
This is unneeded because the change of KBUILD_BUILD_TIMESTAMP
is contained in
4) Arguments to gen_initramfs.sh changes
> $(obj)/initramfs_data.cpio: $(src)/gen_initramfs.sh $(obj)/gen_init_cpio $(deps_initramfs) FORCE
> $(call if_changed,initfs)
>
> diff --git a/usr/gen_initramfs.sh b/usr/gen_initramfs.sh
> index 63476bb70b41..14b5782f961a 100755
> --- a/usr/gen_initramfs.sh
> +++ b/usr/gen_initramfs.sh
> @@ -23,6 +23,7 @@ $0 [-o <file>] [-l <dep_list>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...
> -g <gid> Group ID to map to group ID 0 (root).
> <gid> is only meaningful if <cpio_source> is a
> directory. "squash" forces all files to gid 0.
> + -d <date> Use date for all file mtime values
> <cpio_source> File list or directory for cpio archive.
> If <cpio_source> is a .cpio file it will be used
> as direct input to initramfs.
> @@ -190,6 +191,7 @@ prog=$0
> root_uid=0
> root_gid=0
> dep_list=
> +timestamp=
> cpio_list=$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)
> output="/dev/stdout"
>
> @@ -218,6 +220,13 @@ while [ $# -gt 0 ]; do
> [ "$root_gid" = "-1" ] && root_gid=$(id -g || echo 0)
> shift
> ;;
> + "-d") # date for file mtimes
> + timestamp="$(date -d"$1" +%s || :)"
> + if test -n "$timestamp"; then
> + timestamp="-t $timestamp"
> + fi
> + shift
> + ;;
> "-h")
> usage
> exit 0
> @@ -237,11 +246,4 @@ done
>
> # If output_file is set we will generate cpio archive
> # we are careful to delete tmp files
> -timestamp=
> -if test -n "$KBUILD_BUILD_TIMESTAMP"; then
> - timestamp="$(date -d"$KBUILD_BUILD_TIMESTAMP" +%s || :)"
> - if test -n "$timestamp"; then
> - timestamp="-t $timestamp"
> - fi
> -fi
> usr/gen_init_cpio $timestamp $cpio_list > $output
> --
> 2.39.2
>
--
Best Regards
Masahiro Yamada
