Commit c3f7bed8 authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

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: default avatarMasahiro Yamada <masahiroy@kernel.org>
Reviewed-by: default avatarEmil Renner Berthing <emil.renner.berthing@canonical.com>
Reviewed-by: default avatarNicolas Schier <nicolas@fjasle.eu>
parent 604a57ba

scripts/package/buildtar

+12 −4
Original line number Diff line number Diff line
@@ -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