On Tue, Dec 17, 2024 at 2:46 AM Enrico Jörns <e...@pengutronix.de> wrote:
> The git commit hashes for the kernel checkout are not reproducible under
> certain conditions:
>
> - If the git repository is initialized on an archive (rather than a
> git), the initial git commit not only has the current user name set,
> it also uses the current system time as committer and author date.
> This will affect the initial git hash and thus all subsequent ones.
>
> - The patches applied by the kern-tools have a valid author and date.
> However, their committer again depends on the user building the BSP.
>
> This is an issue, for example, if one compiles a kernel with
> CONFIG_LOCALVERSION_AUTO enabled where the commit hash lands into the
> kernel and thus the package version. This not only makes the package
> version non-reproducible, but also leads to version mismatches between
> kernel modules built against a fresh kernel checkout and the kernel
> retrieved from the sstate cache.
>
> The class uses 'check_git_config', but this only sets the git user and
> only if none existed before. Thus it doesn't really help here.
>
> Since in Git the committer information can be set only from the
> environment variables GIT_COMMITTER_NAME, GIT_COMMITTER_EMAIL, and
> GIT_COMMITTER_DATE, we introduce the helper function
> 'reproducible_git_committer' here to set those.
> As values simply use PATCH_GIT_USER_NAME, PATCH_GIT_USER_EMAIL (from
> patch.bbclass) and SOURCE_DATE_EPOCH.
>
> Using this helper makes the committer date/name/email for the initial
> reproducible, as well as the committer name/email for the patches
> applied with kern-tools.
>
> What's still missing is the initial commit's date/name/email which we
> just set explicitly via command line arguments.
>
> Suggested-by: Felix Klöckner <f.kloeck...@weinmann-emt.de>
> Signed-off-by: Enrico Jörns <e...@pengutronix.de>
> ---
> meta/classes-recipe/kernel-yocto.bbclass | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/meta/classes-recipe/kernel-yocto.bbclass
> b/meta/classes-recipe/kernel-yocto.bbclass
> index a5d89dc2c8..1ba2f91e62 100644
> --- a/meta/classes-recipe/kernel-yocto.bbclass
> +++ b/meta/classes-recipe/kernel-yocto.bbclass
> @@ -9,6 +9,12 @@ SRCTREECOVEREDTASKS += "do_validate_branches
> do_kernel_configcheck do_kernel_che
> PATCH_GIT_USER_EMAIL ?= "kernel-yocto@oe"
> PATCH_GIT_USER_NAME ?= "OpenEmbedded"
>
> +reproducible_git_committer() {
> + export GIT_COMMITTER_NAME="${PATCH_GIT_USER_NAME}"
> + export GIT_COMMITTER_EMAIL="${PATCH_GIT_USER_EMAIL}"
> + export GIT_COMMITTER_DATE="$(date -d @${SOURCE_DATE_EPOCH})"
> +}
>
These would be better set in the same class and I'd argue
that they should just be set in same function as our other
settings check_git_config()
While the check_git_config name might not convey it, the
original intent of that routine was to make sure that if what we
needed wasn't set, that we'd configure/set it for the upcoming
git commands.
Is there any reason this wouldn't work when exported from
classes-global/utils.bbclass ?
We also have already have get_kernel_source_date_epoch(),
that should be used instead of going directly at
SOURCE_DATE_EPOCH (unless the routine is causing a
problem, and then I'd be interested in hearing what it is).
There are some builds that for debugging purposes
we want to inhibit all reproducibility and forced setting of
timestamps, so setting these options should be
conditional on KERNEL_DEBUG_TIMESTAMPS not being
set. I realize that this is a slightly different use of setting
the timestamp as when we build the kernel, but it would
still be useful to disable the forced timestamp in some
scenarios.
+
> # The distro or local.conf should set this, but if nobody cares...
> LINUX_KERNEL_TYPE ??= "standard"
>
> @@ -349,6 +355,7 @@ do_patch() {
> cd ${S}
>
> check_git_config
> + reproducible_git_committer
> meta_dir=$(kgit --meta)
> (cd ${meta_dir}; ln -sf patch.queue series)
> if [ -f "${meta_dir}/series" ]; then
> @@ -431,8 +438,9 @@ do_kernel_checkout() {
> rm -f .gitignore
> git init
> check_git_config
> + reproducible_git_committer
> git add .
> - git commit -q -n -m "baseline commit: creating repo for
> ${PN}-${PV}"
> + git commit --author="${PATCH_GIT_USER_NAME}
> <${PATCH_GIT_USER_EMAIL}>" --date=${SOURCE_DATE_EPOCH} -q -n -m "baseline
> commit: creating repo for ${PN}-${PV}"
>
The author, author date and author email can also come from the environment
in my experiments.
Can we just set them the same way as the other variables for consistency ?
Bruce
> git clean -d -f
> fi
>
> --
> 2.39.5
>
>
--
- Thou shalt not follow the NULL pointer, for chaos and madness await thee
at its end
- "Use the force Harry" - Gandalf, Star Trek II
-=-=-=-=-=-=-=-=-=-=-=-
Links: You receive all messages sent to this group.
View/Reply Online (#208981):
https://lists.openembedded.org/g/openembedded-core/message/208981
Mute This Topic: https://lists.openembedded.org/mt/110159643/21656
Group Owner: openembedded-core+ow...@lists.openembedded.org
Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub
[arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-
