diff --git a/Documentation/kbuild/reproducible-builds.rst b/Documentation/kbuild/reproducible-builds.rst index 503393854e2e..ab92e98c89c8 100644 --- a/Documentation/kbuild/reproducible-builds.rst +++ b/Documentation/kbuild/reproducible-builds.rst @@ -16,21 +16,16 @@ the kernel may be unreproducible, and how to avoid them. Timestamps ---------- -The kernel embeds timestamps in three places: +The kernel embeds a timestamp in two places: * The version string exposed by ``uname()`` and included in ``/proc/version`` * File timestamps in the embedded initramfs -* If enabled via ``CONFIG_IKHEADERS``, file timestamps of kernel - headers embedded in the kernel or respective module, - exposed via ``/sys/kernel/kheaders.tar.xz`` - -By default the timestamp is the current time and in the case of -``kheaders`` the various files' modification times. This must -be overridden using the `KBUILD_BUILD_TIMESTAMP`_ variable. -If you are building from a git commit, you could use its commit date. +By default the timestamp is the current time. This must be overridden +using the `KBUILD_BUILD_TIMESTAMP`_ variable. If you are building +from a git commit, you could use its commit date. The kernel does *not* use the ``__DATE__`` and ``__TIME__`` macros, and enables warnings if they are used. If you incorporate external diff --git a/kernel/gen_kheaders.sh b/kernel/gen_kheaders.sh index aff79e461fc9..9ff449888d9c 100755 --- a/kernel/gen_kheaders.sh +++ b/kernel/gen_kheaders.sh @@ -71,10 +71,7 @@ done | cpio --quiet -pd $cpio_dir >/dev/null 2>&1 find $cpio_dir -type f -print0 | xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;' -# Create archive and try to normalize metadata for reproducibility -tar "${KBUILD_BUILD_TIMESTAMP:+--mtime=$KBUILD_BUILD_TIMESTAMP}" \ - --owner=0 --group=0 --sort=name --numeric-owner \ - -Jcf $tarfile -C $cpio_dir/ . > /dev/null +tar -Jcf $tarfile -C $cpio_dir/ . > /dev/null echo "$src_files_md5" > kernel/kheaders.md5 echo "$obj_files_md5" >> kernel/kheaders.md5