[gentoo-dev] [PATCH 1/4] kernel-{build,install}.eclass: make kernel install paths match release

[Andrew Nowa Ammerlaan <andrewammerlaan@gentoo.org>]

Part of https://github.com/gentoo/gentoo/pull/37327

 From d57b75ed204432c11ae643ea3526b46dab40c746 Mon Sep 17 00:00:00 2001
From: James Calligeros <jcalligeros99@gmail.com>
Date: Thu, 27 Jun 2024 05:56:44 +0000
Subject: [PATCH] kernel-{build,install}.eclass: make kernel install paths
  match release

dist-kernel releases are required to match the package's version, with
'_' substituted for '-' as per kernel release format rules. Curiously,
we made no such substitution on the kernel install directory names.

The consequence of this is that Catalyst has technically only been
working with dist-kernels by pure coincidence - it had never been tested
with kernels containing '_' in ${PV}. When attempting to build install
media for the Gentoo Asahi project, which necessitates using kernels
versioned with '_p*', Catalyst's call to Dracut's --kver argument
passes in the name of the source directory while Dracut expects
the kernel release (module directory).

Make sure that all directories installed by the kernel match the
kernel's own idea of its version exactly. This fixes Catalyst,
makes directories like /usr/src/linux-* consistent with /lib/modules

For compatibility with existing bin kernels, KV_FULL will be
set to ${PV}${KV_LOCALVERSION} in kernel-install.eclass if it
has not been explicitly set elsewhere.

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
  eclass/kernel-build.eclass   | 46 +++++++++++++++-------------
  eclass/kernel-install.eclass | 59 +++++++++++++++++++++---------------
  2 files changed, 60 insertions(+), 45 deletions(-)

diff --git a/eclass/kernel-build.eclass b/eclass/kernel-build.eclass
index 86c7cd4a172d5..7d4b98ac027d9 100644
--- a/eclass/kernel-build.eclass
+++ b/eclass/kernel-build.eclass
@@ -20,6 +20,14 @@
  # the kernel and installing it along with its modules and subset
  # of sources needed to build external modules.

+# @ECLASS_VARIABLE: KV_FULL
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# A string containing the full kernel release version, e.g.
+# '6.9.6-gentoo-dist'. This is used to ensure consistency between the
+# kernel's release version and Gentoo's tooling. This is set by
+# kernel-build_src_configure() once we have a kernel.release file.
+
  case ${EAPI} in
  	8) ;;
  	*) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;;
@@ -225,6 +233,12 @@ kernel-build_src_configure() {
  	emake O="${WORKDIR}"/modprep "${MAKEARGS[@]}" olddefconfig
  	emake O="${WORKDIR}"/modprep "${MAKEARGS[@]}" modules_prepare
  	cp -pR "${WORKDIR}"/modprep "${WORKDIR}"/build || die
+
+	# Now that we have a release file, set KV_FULL
+	if [[ -z ${KV_FULL} ]]; then
+		local relfile=${WORKDIR}/build/include/config/kernel.release
+		KV_FULL=$(<"${relfile}") || die
+	fi
  }

  # @FUNCTION: kernel-build_src_compile
@@ -254,20 +268,15 @@ kernel-build_src_test() {
  		INSTALL_MOD_PATH="${T}" INSTALL_MOD_STRIP="${strip_args}" \
  		modules_install

-	local dir_ver=${PV}${KV_LOCALVERSION}
-	local relfile=${WORKDIR}/build/include/config/kernel.release
-	local module_ver
-	module_ver=$(<"${relfile}") || die
-
-	kernel-install_test "${module_ver}" \
+	kernel-install_test "${KV_FULL}" \
  		"${WORKDIR}/build/$(dist-kernel_get_image_path)" \
-		"${T}/lib/modules/${module_ver}"
+		"${T}/lib/modules/${KV_FULL}"
  }

  # @FUNCTION: kernel-build_src_install
  # @DESCRIPTION:
  # Install the built kernel along with subset of sources
-# into /usr/src/linux-${PV}.  Install the modules.  Save the config.
+# into /usr/src/linux-${KV_FULL}.  Install the modules.  Save the config.
  kernel-build_src_install() {
  	debug-print-function ${FUNCNAME} "${@}"

@@ -304,8 +313,7 @@ kernel-build_src_install() {
  	# note: we're using mv rather than doins to save space and time
  	# install main and arch-specific headers first, and scripts
  	local kern_arch=$(tc-arch-kernel)
-	local dir_ver=${PV}${KV_LOCALVERSION}
-	local kernel_dir=/usr/src/linux-${dir_ver}
+	local kernel_dir=/usr/src/linux-${KV_FULL}

  	if use sparc ; then
  		# We don't want tc-arch-kernel's sparc64, even though we do
@@ -378,10 +386,6 @@ kernel-build_src_install() {
  	# strip empty directories
  	find "${D}" -type d -empty -exec rmdir {} + || die

-	local relfile=${ED}${kernel_dir}/include/config/kernel.release
-	local module_ver
-	module_ver=$(<"${relfile}") || die
-
  	# warn when trying to "make" a dist-kernel
  	cat <<-EOF >> "${ED}${kernel_dir}/Makefile" || die

@@ -399,12 +403,12 @@ kernel-build_src_install() {
  	echo "${CATEGORY}/${PF}:${SLOT}" > "${ED}${kernel_dir}/dist-kernel" 
|| die

  	# fix source tree and build dir symlinks
-	dosym "../../../${kernel_dir}" "/lib/modules/${module_ver}/build"
-	dosym "../../../${kernel_dir}" "/lib/modules/${module_ver}/source"
+	dosym "../../../${kernel_dir}" "/lib/modules/${KV_FULL}/build"
+	dosym "../../../${kernel_dir}" "/lib/modules/${KV_FULL}/source"
  	if [[ "${image_path}" == *vmlinux* ]]; then
-		dosym "../../../${kernel_dir}/${image_path}" 
"/lib/modules/${module_ver}/vmlinux"
+		dosym "../../../${kernel_dir}/${image_path}" 
"/lib/modules/${KV_FULL}/vmlinux"
  	else
-		dosym "../../../${kernel_dir}/${image_path}" 
"/lib/modules/${module_ver}/vmlinuz"
+		dosym "../../../${kernel_dir}/${image_path}" 
"/lib/modules/${KV_FULL}/vmlinuz"
  	fi

  	if [[ ${KERNEL_IUSE_MODULES_SIGN} ]]; then
@@ -435,7 +439,7 @@ kernel-build_src_install() {
  				--conf "${T}/empty-file"
  				--confdir "${T}/empty-directory"
  				--kernel-image "${image}"
-				--kmoddir "${ED}/lib/modules/${dir_ver}"
+				--kmoddir "${ED}/lib/modules/${KV_FULL}"
  				--kver "${dir_ver}"
  				--verbose
  				--compress="xz -9e --check=crc32"
@@ -462,7 +466,7 @@ kernel-build_src_install() {
  				--linux="${image}"
  				--initrd="${image%/*}/initrd"
  				--cmdline="${KERNEL_GENERIC_UKI_CMDLINE}"
-				--uname="${dir_ver}"
+				--uname="${KV_FULL}"
  				--output="${image%/*}/uki.efi"
  			)

@@ -520,7 +524,7 @@ kernel-build_pkg_postinst() {
  			ewarn
  			ewarn "MODULES_SIGN_KEY was not set, this means the kernel build 
system"
  			ewarn "automatically generated the signing key. This key was installed"
-			ewarn "in ${EROOT}/usr/src/linux-${PV}${KV_LOCALVERSION}/certs"
+			ewarn "in ${EROOT}/usr/src/linux-${KV_FULL}/certs"
  			ewarn "and will also be included in any binary packages."
  			ewarn "Please take appropriate action to protect the key!"
  			ewarn
diff --git a/eclass/kernel-install.eclass b/eclass/kernel-install.eclass
index f512d815fe098..e0716b63a2489 100644
--- a/eclass/kernel-install.eclass
+++ b/eclass/kernel-install.eclass
@@ -28,6 +28,15 @@
  # If set to a non-null value, adds IUSE=generic-uki and required
  # logic to install a generic unified kernel image.

+# @ECLASS_VARIABLE: KV_FULL
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# A string containing the full kernel release version, e.g.
+# '6.9.6-gentoo-dist'. Defaults to ${PV}${KV_LOCALVERSION},
+# but can be set by the ebuild when this default value does
+# not match the kernel release. kernel-build.eclass sets this
+# to whatever is in the built kernel's kernel.release file.
+
  # @ECLASS_VARIABLE: KV_LOCALVERSION
  # @DEFAULT_UNSET
  # @DESCRIPTION:
@@ -569,40 +578,40 @@ kernel-install_src_test() {
  kernel-install_pkg_preinst() {
  	debug-print-function ${FUNCNAME} "${@}"

-	local dir_ver=${PV}${KV_LOCALVERSION}
-	local kernel_dir=${ED}/usr/src/linux-${dir_ver}
-	local relfile=${kernel_dir}/include/config/kernel.release
+	# Set KV_FULL to ${PV}${KV_LOCALVERSION} if it hasn't
+	# been set elsewhere for backward compatibility with existing
+	# bin-kernel packages
+	if [[ -z ${KV_FULL} ]]; then
+		KV_FULL=${PV}${KV_LOCALVERSION}
+	fi
+
+	local kernel_dir=${ED}/usr/src/linux-${KV_FULL}
  	local image_path=$(dist-kernel_get_image_path)
  	[[ ! -d ${kernel_dir} ]] &&
  		die "Kernel directory ${kernel_dir} not installed!"
-	[[ ! -f ${relfile} ]] &&
-		die "Release file ${relfile} not installed!"
-	local release
-	release="$(<"${relfile}")" || die
-	DIST_KERNEL_RELEASE="${release}"

  	# perform the version check for release ebuilds only
  	if [[ ${PV} != *9999 ]]; then
  		local expected_ver=$(dist-kernel_PV_to_KV "${PV}")

-		if [[ ${release} != ${expected_ver}* ]]; then
+		if [[ ${KV_FULL} != ${expected_ver}* ]]; then
  			eerror "Kernel release mismatch!"
  			eerror "  expected (PV): ${expected_ver}*"
-			eerror "          found: ${release}"
+			eerror "          found: ${KV_FULL}"
  			eerror "Please verify that you are applying the correct patches."
-			die "Kernel release mismatch (${release} instead of ${expected_ver}*)"
+			die "Kernel release mismatch (${KV_FULL} instead of ${expected_ver}*)"
  		fi
  	fi

  	if [[ -L ${EROOT}/lib && ${EROOT}/lib -ef ${EROOT}/usr/lib ]]; then
  		# Adjust symlinks for merged-usr.
-		rm "${ED}/lib/modules/${release}"/{build,source} || die
-		dosym "../../../src/linux-${dir_ver}" "/usr/lib/modules/${release}/build"
-		dosym "../../../src/linux-${dir_ver}" 
"/usr/lib/modules/${release}/source"
+		rm "${ED}/lib/modules/${KV_FULL}"/{build,source} || die
+		dosym "../../../src/linux-${KV_FULL}" "/usr/lib/modules/${KV_FULL}/build"
+		dosym "../../../src/linux-${KV_FULL}" 
"/usr/lib/modules/${KV_FULL}/source"
  		for file in vmlinux vmlinuz; do
-			if [[ -L "${ED}/lib/modules/${release}/${file}" ]]; then
-				rm "${ED}/lib/modules/${release}/${file}" || die
-				dosym "../../../src/linux-${dir_ver}/${image_path}" 
"/usr/lib/modules/${release}/${file}"
+			if [[ -L "${ED}/lib/modules/${KV_FULL}/${file}" ]]; then
+				rm "${ED}/lib/modules/${KV_FULL}/${file}" || die
+				dosym "../../../src/linux-${KV_FULL}/${image_path}" 
"/usr/lib/modules/${KV_FULL}/${file}"
  			fi
  		done
  	fi
@@ -695,13 +704,12 @@ kernel-install_install_all() {
  kernel-install_pkg_postinst() {
  	debug-print-function ${FUNCNAME} "${@}"

-	local dir_ver=${PV}${KV_LOCALVERSION}
-	kernel-install_update_symlink "${EROOT}/usr/src/linux" "${dir_ver}"
+	kernel-install_update_symlink "${EROOT}/usr/src/linux" "${KV_FULL}"
  	dist-kernel_compressed_module_cleanup \
-		"${EROOT}/lib/modules/${DIST_KERNEL_RELEASE}"
+		"${EROOT}/lib/modules/${KV_FULL}"

  	if [[ -z ${ROOT} ]]; then
-		kernel-install_install_all "${dir_ver}"
+		kernel-install_install_all "${KV_FULL}"
  	fi

  	if [[ ${KERNEL_IUSE_GENERIC_UKI} ]] && use generic-uki; then
@@ -734,8 +742,7 @@ kernel-install_pkg_postrm() {
  	debug-print-function ${FUNCNAME} "${@}"

  	if [[ -z ${ROOT} && ! ${KERNEL_IUSE_GENERIC_UKI} ]]; then
-		local dir_ver=${PV}${KV_LOCALVERSION}
-		local kernel_dir=${EROOT}/usr/src/linux-${dir_ver}
+		local kernel_dir=${EROOT}/usr/src/linux-${KV_FULL}
  		local image_path=$(dist-kernel_get_image_path)
  		ebegin "Removing initramfs"
  		rm -f "${kernel_dir}/${image_path%/*}"/{initrd,uki.efi} &&
@@ -750,7 +757,11 @@ kernel-install_pkg_postrm() {
  kernel-install_pkg_config() {
  	[[ -z ${ROOT} ]] || die "ROOT!=/ not supported currently"

-	kernel-install_install_all "${PV}${KV_LOCALVERSION}"
+	if [[ -z ${KV_FULL} ]]; then
+		KV_FULL=${PV}${KV_LOCALVERSION}
+	fi
+
+	kernel-install_install_all "${KV_FULL}"
  }

  # @FUNCTION: kernel-install_compress_modules