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References: <20240414174139.3001175-1-masahiroy@kernel.org>
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From: Masahiro Yamada <masahiroy@kernel.org>
Date: Tue, 16 Apr 2024 11:07:48 +0900
Message-ID: <CAK7LNATqLwewFaMNEy6yDguv5mNoGZJus9p4kbyMOGV9T+yopQ@mail.gmail.com>
Subject: Re: [PATCH] kbuild: buildtar: add comments about inconsistent package generation
To: linux-kbuild@vger.kernel.org
Cc: Albert Ou <aou@eecs.berkeley.edu>, Nathan Chancellor <nathan@kernel.org>, 
	Nicolas Schier <nicolas@fjasle.eu>, Palmer Dabbelt <palmer@dabbelt.com>, 
	Paul Walmsley <paul.walmsley@sifive.com>, linux-kernel@vger.kernel.org, 
	linux-riscv@lists.infradead.org
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On Mon, Apr 15, 2024 at 2:42=E2=80=AFAM Masahiro Yamada <masahiroy@kernel.o=
rg> wrote:
>
> 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.
>
> When CONFIG_EFI_ZBOOT is enabled in the pristine source tree,
> 'make ARCH=3Darm64 tar-pkg' will build and copy vmlinuz.efi. This is the
> expected behavior.
>
> If you build the kernel with CONFIG_EFI_ZBOOT, Image.gz will be created,


The correct sentence is

If you build the kernel with CONFIG_EFI_ZBOOT disabled, ...


> which will remain in the build directory unless you clean it. Even if
> CONFIG_EFI_ZBOOT is turned on later, 'make ARCH=3Darm64 tar-pkg' will cop=
y
> 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.
>
> The other package scripts are deterministic; scripts/package/mkdebian,
> for example, chooses a copied kernel image based on 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.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> ---
>
>  scripts/package/buildtar | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/scripts/package/buildtar b/scripts/package/buildtar
> index 72c91a1b832f..ed8d9b496305 100755
> --- a/scripts/package/buildtar
> +++ b/scripts/package/buildtar
> @@ -53,18 +53,24 @@ cp -v -- "${objtree}/vmlinux" "${tmpdir}/boot/vmlinux=
-${KERNELRELEASE}"
>  #
>  # Install arch-specific kernel image(s)
>  #
> +# Note:
> +#   mips, arm64, and riscv copy the first image found. This may not prod=
uce
> +#   the desired outcome because it may pick up a stale file remaining in=
 the
> +#   build tree.
> +#
>  case "${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}/bo=
ot/vmlinuz-${KERNELRELEASE}"
>                 ;;
>         alpha)
> -               [ -f "${objtree}/arch/alpha/boot/vmlinux.gz" ] && cp -v -=
- "${objtree}/arch/alpha/boot/vmlinux.gz" "${tmpdir}/boot/vmlinuz-${KERNELR=
ELEASE}"
> +               cp -v -- "${objtree}/arch/alpha/boot/vmlinux.gz" "${tmpdi=
r}/boot/vmlinuz-${KERNELRELEASE}"
>                 ;;
>         parisc*)
> -               [ -f "${KBUILD_IMAGE}" ] && cp -v -- "${KBUILD_IMAGE}" "$=
{tmpdir}/boot/vmlinux-${KERNELRELEASE}"
> +               cp -v -- "${KBUILD_IMAGE}" "${tmpdir}/boot/vmlinux-${KERN=
ELRELEASE}"
>                 [ -f "${objtree}/lifimage" ] && cp -v -- "${objtree}/lifi=
mage" "${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 -- "${objtree}/arch/mips/boot/compressed/vm=
linux.bin" "${tmpdir}/boot/vmlinuz-${KERNELRELEASE}"
>                 elif [ -f "${objtree}/arch/mips/boot/compressed/vmlinux.e=
coff" ]; then
> @@ -86,6 +92,7 @@ case "${ARCH}" in
>                 fi
>                 ;;
>         arm64)
> +               # Please note the following code may copy a stale file.
>                 for i in Image.bz2 Image.gz Image.lz4 Image.lzma Image.lz=
o vmlinuz.efi ; do
>                         if [ -f "${objtree}/arch/arm64/boot/${i}" ] ; the=
n
>                                 cp -v -- "${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}" ] ; the=
n
>                                 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
> --
> 2.40.1
>


--
Best Regards
Masahiro Yamada