kbuild: buildtar: add comments about inconsistent package generation

scripts/package/buildtar checks some kernel packages, and copies the
first image found. This may potentially produce an inconsistent (and
possibly wrong) package.

For instance, the for-loop for arm64 checks Image.{bz2,gz,lz4,lzma,lzo},
and vmlinuz.efi, then copies the first image found, which might be a
stale image created in a previous build.

When CONFIG_EFI_ZBOOT is enabled in the pristine source tree,
'make ARCH=arm64 tar-pkg' will build and copy vmlinuz.efi. This is the
expected behavior.

If you build the kernel with CONFIG_EFI_ZBOOT disabled, Image.gz will
be created, which will remain in the tree until you run 'make clean'.
Even if CONFIG_EFI_ZBOOT is turned on later, 'make ARCH=arm64 tar-pkg'
will copy stale Image.gz instead of the latest vmlinuz.efi, as Image.gz
takes precedence over vmlinuz.efi.

In summary, the code "[ -f ... ] && cp" does not consistently produce
the desired outcome.

Other packaging targets are deterministic; deb-pkg and rpm-pkg copies
${KBUILD_IMAGE}, which is determined by CONFIG options.

I removed [ -f ... ] checks from x86, alpha, parisc, and the default
because they have a single kernel image to copy. If it is missing, it
should be an error.

I did not modify the code for mips, arm64, riscv. Instead, I left some
comments. Eventually, someone may fix the code, or at the very least,
it may discourage the copy-pasting of incorrect code to another
architecture.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
This commit is contained in:
Masahiro Yamada 2024-04-15 02:41:39 +09:00
parent 604a57ba97
commit c3f7bed8fa

View file

@ -53,18 +53,24 @@ cp -v -- "${objtree}/vmlinux" "${tmpdir}/boot/vmlinux-${KERNELRELEASE}"
#
# Install arch-specific kernel image(s)
#
# Note:
# mips, arm64, and riscv copy the first image found. This may not produce
# the desired outcome because it may pick up a stale file remaining in the
# build tree.
#
case "${ARCH}" in
x86|i386|x86_64)
[ -f "${objtree}/arch/x86/boot/bzImage" ] && cp -v -- "${objtree}/arch/x86/boot/bzImage" "${tmpdir}/boot/vmlinuz-${KERNELRELEASE}"
cp -v -- "${objtree}/arch/x86/boot/bzImage" "${tmpdir}/boot/vmlinuz-${KERNELRELEASE}"
;;
alpha)
[ -f "${objtree}/arch/alpha/boot/vmlinux.gz" ] && cp -v -- "${objtree}/arch/alpha/boot/vmlinux.gz" "${tmpdir}/boot/vmlinuz-${KERNELRELEASE}"
cp -v -- "${objtree}/arch/alpha/boot/vmlinux.gz" "${tmpdir}/boot/vmlinuz-${KERNELRELEASE}"
;;
parisc*)
[ -f "${KBUILD_IMAGE}" ] && cp -v -- "${KBUILD_IMAGE}" "${tmpdir}/boot/vmlinux-${KERNELRELEASE}"
cp -v -- "${KBUILD_IMAGE}" "${tmpdir}/boot/vmlinux-${KERNELRELEASE}"
[ -f "${objtree}/lifimage" ] && cp -v -- "${objtree}/lifimage" "${tmpdir}/boot/lifimage-${KERNELRELEASE}"
;;
mips)
# Please note the following code may copy a stale file.
if [ -f "${objtree}/arch/mips/boot/compressed/vmlinux.bin" ]; then
cp -v -- "${objtree}/arch/mips/boot/compressed/vmlinux.bin" "${tmpdir}/boot/vmlinuz-${KERNELRELEASE}"
elif [ -f "${objtree}/arch/mips/boot/compressed/vmlinux.ecoff" ]; then
@ -86,6 +92,7 @@ case "${ARCH}" in
fi
;;
arm64)
# Please note the following code may copy a stale file.
for i in Image.bz2 Image.gz Image.lz4 Image.lzma Image.lzo vmlinuz.efi ; do
if [ -f "${objtree}/arch/arm64/boot/${i}" ] ; then
cp -v -- "${objtree}/arch/arm64/boot/${i}" "${tmpdir}/boot/vmlinuz-${KERNELRELEASE}"
@ -94,6 +101,7 @@ case "${ARCH}" in
done
;;
riscv)
# Please note the following code may copy a stale file.
for i in Image.bz2 Image.gz Image; do
if [ -f "${objtree}/arch/riscv/boot/${i}" ] ; then
cp -v -- "${objtree}/arch/riscv/boot/${i}" "${tmpdir}/boot/vmlinux-${KERNELRELEASE}"
@ -102,7 +110,7 @@ case "${ARCH}" in
done
;;
*)
[ -f "${KBUILD_IMAGE}" ] && cp -v -- "${KBUILD_IMAGE}" "${tmpdir}/boot/vmlinux-kbuild-${KERNELRELEASE}"
cp -v -- "${KBUILD_IMAGE}" "${tmpdir}/boot/vmlinux-kbuild-${KERNELRELEASE}"
echo "" >&2
echo '** ** ** WARNING ** ** **' >&2
echo "" >&2