kernel: Create kernel-devel squashfs and bind into host containers

macros/shared

@@ -42,6 +42,7 @@
 %_cross_sysusersdir %{_cross_rootdir}%{_sysusersdir}
 %_cross_sysctldir %{_cross_rootdir}%{_sysctldir}
 %_cross_templatedir %{_cross_datadir}/templates
+%_cross_usrsrc %{_cross_prefix}/src
 %_cross_licensedir %{_cross_datadir}/licenses
 %_defaultlicensedir %{_cross_licensedir}
 

packages/kernel/kernel.spec

@@ -28,7 +28,8 @@ BuildRequires: hostname
 BuildRequires: kmod
 BuildRequires: openssl-devel
 
-%global kernel_sourcedir %{_usrsrc}/kernels/%{version}
+%global kernel_sourcedir %{_cross_usrsrc}/kernels
+%global kernel_libdir %{_cross_libdir}/modules/%{version}
 
 %description
 %{summary}.
@@ -113,11 +114,21 @@ find %{buildroot}%{_cross_prefix} \
 # remove x86 intermediate files like generated/asm/.syscalls_32.h.cmd
 sed -i '/asm\/.*\.cmd$/d' kernel_devel_files
 
-install -d %{buildroot}%{kernel_sourcedir}
+## Create squashfs of kernel-devel files (ie. /usr/src/kernels/<version>)
+mkdir src_squashfs
 for file in $(cat kernel_devel_files); do
-  install -D ${file} %{buildroot}%{kernel_sourcedir}/${file}
-
+  install -D ${file} src_squashfs/%{version}/${file}
 done
+mksquashfs src_squashfs kernel-devel.squashfs
+install -D kernel-devel.squashfs %{buildroot}%{_cross_datadir}/thar/kernel-devel.squashfs
+install -d %{buildroot}%{kernel_sourcedir}
+
+# Replace the incorrect links from modules_install. These will be bound
+# into a host container (and unused in the host) so they must not point
+# to %{_cross_usrsrc} (eg. /x86_64-thar-linux-gnu/sys-root/...)
+rm -f %{buildroot}%{kernel_libdir}/build %{buildroot}%{kernel_libdir}/source
+ln -sf %{_usrsrc}/kernels/%{version} %{buildroot}%{kernel_libdir}/build
+ln -sf %{_usrsrc}/kernels/%{version} %{buildroot}%{kernel_libdir}/source
 
 %files
 %license COPYING LICENSES/preferred/GPL-2.0 LICENSES/exceptions/Linux-syscall-note
@@ -156,7 +167,6 @@ done
 
 %files devel
 %dir %{kernel_sourcedir}
-%{kernel_sourcedir}/*
-%{kernel_sourcedir}/.config
+%{_cross_datadir}/thar/kernel-devel.squashfs
 
 %changelog

packages/release/release.spec

@@ -19,6 +19,7 @@ Source1002: configured.target
 Source1006: prepare-local.service
 Source1007: var.mount
 Source1008: opt.mount
+Source1009: usr-src-kernels.mount.in
 Source1010: var-lib-thar.mount
 
 BuildArch: noarch
@@ -38,6 +39,7 @@ Requires: %{_cross_os}grub
 Requires: %{_cross_os}iproute
 Requires: %{_cross_os}kernel
 Requires: %{_cross_os}kernel-modules
+Requires: %{_cross_os}kernel-devel
 Requires: %{_cross_os}bork
 Requires: %{_cross_os}moondog
 Requires: %{_cross_os}netdog
@@ -84,6 +86,10 @@ EOF
 
 install -d %{buildroot}%{_cross_unitdir}
 install -p -m 0644 %{S:1002} %{S:1006} %{S:1007} %{S:1008} %{S:1010} %{buildroot}%{_cross_unitdir}
+# Mounting on usr/src/kernels requires using the real path: %{_cross_usrsrc}/kernels
+KERNELPATH=$(systemd-escape --path %{_cross_usrsrc}/kernels)
+sed -e 's|PREFIX|%{_cross_prefix}|' %{S:1009} > ${KERNELPATH}.mount
+install -p -m 0644 ${KERNELPATH}.mount %{buildroot}%{_cross_unitdir}
 
 install -d %{buildroot}%{_cross_templatedir}
 install -p -m 0644 %{S:200} %{buildroot}%{_cross_templatedir}/hostname
@@ -99,6 +105,7 @@ install -p -m 0644 %{S:200} %{buildroot}%{_cross_templatedir}/hostname
 %{_cross_unitdir}/prepare-local.service
 %{_cross_unitdir}/var.mount
 %{_cross_unitdir}/opt.mount
+%{_cross_unitdir}/*-kernels.mount
 %{_cross_unitdir}/var-lib-thar.mount
 %dir %{_cross_templatedir}
 %{_cross_templatedir}/hostname

packages/release/usr-src-kernels.mount.in

@@ -0,0 +1,13 @@
+[Unit]
+Description=Kernel Development Sources
+Conflicts=umount.target
+Before=local-fs.target umount.target
+
+[Mount]
+What=PREFIX/share/thar/kernel-devel.squashfs
+Where=PREFIX/src/kernels
+Type=squashfs
+Options=defaults,ro,loop
+
+[Install]
+WantedBy=local-fs.target

workspaces/host-ctr/cmd/host-ctr/main.go

@@ -307,6 +307,16 @@ func withSuperpowered(superpowered bool) oci.SpecOpts {
 				Options:     []string{"rbind", "ro"},
 				Destination: "/.thar/rootfs",
 				Source:      "/",
+			},
+			{
+				Options:     []string{"rbind", "ro"},
+				Destination: "/lib/modules",
+				Source:      "/lib/modules",
+			},
+			{
+				Options:     []string{"rbind", "ro"},
+				Destination: "/usr/src/kernels",
+				Source:      "/usr/src/kernels",
 			}}),
 	)
 }