Re: [PATCH 2/3] kbuild: deb-pkg: add pkg.linux-upstream.nokernelheaders build profile

Ron Economos
2024-10-23T13:06:12Z

On 10/22/24 11:16 AM, Masahiro Yamada wrote:
> Since commit f1d87664b82a ("kbuild: cross-compile linux-headers package
> when possible"), 'make bindeb-pkg' may attempt to cross-compile the
> linux-headers package, but it fails under certain circumstances.
>
> For example, when CONFIG_MODULE_SIG_FORMAT is enabled on Debian, the
> following command fails:
>
> $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- bindeb-pkg
> [ snip ]
> Rebuilding host programs with aarch64-linux-gnu-gcc...
> HOSTCC debian/linux-headers-6.12.0-rc4/usr/src/linux-headers-6.12.0-rc4/scripts/kallsyms
> HOSTCC debian/linux-headers-6.12.0-rc4/usr/src/linux-headers-6.12.0-rc4/scripts/sorttable
> HOSTCC debian/linux-headers-6.12.0-rc4/usr/src/linux-headers-6.12.0-rc4/scripts/asn1_compiler
> HOSTCC debian/linux-headers-6.12.0-rc4/usr/src/linux-headers-6.12.0-rc4/scripts/sign-file
> In file included from /usr/include/openssl/opensslv.h:109,
> from debian/linux-headers-6.12.0-rc4/usr/src/linux-headers-6.12.0-rc4/scripts/sign-file.c:25:
> /usr/include/openssl/macros.h:14:10: fatal error: openssl/opensslconf.h: No such file or directory
> 14 | #include <openssl/opensslconf.h>
> | ^~~~~~~~~~~~~~~~~~~~~~~
> compilation terminated.
>
> This commit adds a new profile, pkg.linux-upstream.nokernelheaders, to
> guard the linux-headers package.
>
> There are two options to fix the above issue.
>
> [option 1] Set the pkg.linux-upstream.nokernelheaders build profile
>
> $ DEB_BUILD_PROFILES=pkg.linux-upstream.nokernelheaders \
> make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- bindeb-pkg
>
> This skips the building of the linux-headers package.
>
> [option 2] Install the necessary build dependencies
>
> If you want to cross-compile the linux-headers package, you need to
> install additional packages. This is a one-time installation step.
>
> For example, on Debian, the packages necessary for cross-compiling it
> to arm64 can be installed with the following commands:
>
> # dpkg --add-architecture arm64
> # apt update
> # apt install gcc-aarch64-linux-gnu libssl-dev:arm64
>
> Fixes: f1d87664b82a ("kbuild: cross-compile linux-headers package when possible")
> Reported-by: Ron Economos <re@w6rz.net>
> Closes: https://lore.kernel.org/all/b3d4f49e-7ddb-29ba-0967-689232329b53@w6rz.net/
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> ---
>
> scripts/package/builddeb | 2 +-
> scripts/package/install-extmod-build | 6 ++----
> scripts/package/mkdebian | 9 ++++++++-
> 3 files changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/scripts/package/builddeb b/scripts/package/builddeb
> index 404587fc71fe..441b0bb66e0d 100755
> --- a/scripts/package/builddeb
> +++ b/scripts/package/builddeb
> @@ -123,7 +123,7 @@ install_kernel_headers () {
> pdir=debian/$1
> version=${1#linux-headers-}
>
> - "${srctree}/scripts/package/install-extmod-build" "${pdir}/usr/src/linux-headers-${version}"
> + CC="${DEB_HOST_GNU_TYPE}-gcc" "${srctree}/scripts/package/install-extmod-build" "${pdir}/usr/src/linux-headers-${version}"
>
> mkdir -p $pdir/lib/modules/$version/
> ln -s /usr/src/linux-headers-$version $pdir/lib/modules/$version/build
> diff --git a/scripts/package/install-extmod-build b/scripts/package/install-extmod-build
> index d2c9cacecc0c..7ec1f061a519 100755
> --- a/scripts/package/install-extmod-build
> +++ b/scripts/package/install-extmod-build
> @@ -44,13 +44,11 @@ mkdir -p "${destdir}"
> fi
> } | tar -c -f - -T - | tar -xf - -C "${destdir}"
>
> -# When ${CC} and ${HOSTCC} differ, we are likely cross-compiling. Rebuild host
> -# programs using ${CC}. This assumes CC=${CROSS_COMPILE}gcc, which is usually
> -# the case for package building. It does not cross-compile when CC=clang.
> +# When ${CC} and ${HOSTCC} differ, rebuild host programs using ${CC}.
> #
> # This caters to host programs that participate in Kbuild. objtool and
> # resolve_btfids are out of scope.
> -if [ "${CC}" != "${HOSTCC}" ] && is_enabled CONFIG_CC_CAN_LINK; then
> +if [ "${CC}" != "${HOSTCC}" ]; then
> echo "Rebuilding host programs with ${CC}..."
>
> cat <<-'EOF' > "${destdir}/Kbuild"
> diff --git a/scripts/package/mkdebian b/scripts/package/mkdebian
> index 10637d403777..93eb50356ddb 100755
> --- a/scripts/package/mkdebian
> +++ b/scripts/package/mkdebian
> @@ -179,6 +179,8 @@ fi
>
> echo $debarch > debian/arch
>
> +host_gnu=$(dpkg-architecture -a "${debarch}" -q DEB_HOST_GNU_TYPE | sed 's/_/-/g')
> +
> # Generate a simple changelog template
> cat <<EOF > debian/changelog
> $sourcename ($packageversion) $distribution; urgency=low
> @@ -196,7 +198,11 @@ Priority: optional
> Maintainer: $maintainer
> Rules-Requires-Root: no
> Build-Depends: debhelper-compat (= 12)
> -Build-Depends-Arch: bc, bison, cpio, flex, kmod, libelf-dev:native, libssl-dev:native, rsync
> +Build-Depends-Arch: bc, bison, cpio, flex,
> + gcc-${host_gnu} <!pkg.${sourcename}.nokernelheaders>,
> + kmod, libelf-dev:native,
> + libssl-dev:native, libssl-dev <!pkg.${sourcename}.nokernelheaders>,
> + rsync
> Homepage: https://www.kernel.org/
>
> Package: $packagename-$version
> @@ -224,6 +230,7 @@ cat <<EOF >> debian/control
>
> Package: linux-headers-$version
> Architecture: $debarch
> +Build-Profiles: <!pkg.${sourcename}.nokernelheaders>
> Description: Linux kernel headers for $version on $debarch
> This package provides kernel header files for $version on $debarch
> .

Tested with option 2 for RISC-V. On Ubuntu 24.04, the following must be
added to the file /etc/apt/sources.list.d/ubuntu.sources for apt update
to fetch the correct repositories:

Types: deb
URIs: http://ports.ubuntu.com/ubuntu-ports
Suites: noble noble-updates noble-backports
Components: main universe restricted multiverse
Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
Architectures: riscv64

Then:

sudo dpkg --add-architecture riscv64
sudo apt-get update
sudo apt-get install libssl-dev:riscv64

The tool chain at https://github.com/riscv-collab/riscv-gnu-toolchain
can also be made to work. See:

https://github.com/riscv-collab/riscv-gnu-toolchain/issues/1590

Tested-by: Ron Economos <re@w6rz.net>