Enable signature checking within build environment

* bind /sys and /dev/pts from host
* drop support for devtmpfs as it is no longer needed
* add /run and /dev/rtc0
* clone own ipc, uts and mount namespaces for chroot
* set localtime, timezone and locale within chroot environment
* copy /etc/pacman.d/gnupg from host

1 files changed, 32 insertions, 26 deletions

diff --git a/mkarchroot.in b/mkarchroot.in
index 3eb7464..1b02e0e 100644
--- a/mkarchroot.in
+++ b/mkarchroot.in
@@ -30,7 +30,6 @@ usage() {
 	echo '    -M <file>     Location of a makepkg config file'
 	echo '    -n            Do not copy config files into the chroot'
 	echo '    -c <dir>      Set pacman cache. Default: /var/cache/pacman/pkg'
-	echo '    -d            Use devtmpfs instead of minimal /dev (tmpfs)'
 	echo '    -h            This message'
 	exit 1
 }
@@ -87,38 +86,40 @@ fi
 # {{{ functions
 chroot_mount() {
 	[[ -e "${working_dir}/sys" ]] || mkdir "${working_dir}/sys"
-	mount -t sysfs sysfs "${working_dir}/sys"
+	mount -o bind /sys "${working_dir}/sys"
+	mount -o remount,ro,bind "${working_dir}/sys"
 
 	[[ -e "${working_dir}/proc" ]] || mkdir "${working_dir}/proc"
-	mount -t proc proc "${working_dir}/proc"
+	mount -t proc proc -o nosuid,noexec,nodev "${working_dir}/proc"
+	mount -o bind /proc/sys "${working_dir}/proc/sys"
+	mount -o remount,ro,bind "${working_dir}/proc/sys"
 
 	[[ -e "${working_dir}/dev" ]] || mkdir "${working_dir}/dev"
-	if [[ ${USE_DEVTMPFS} = "y" ]]; then
-		mount -t devtmpfs dev "${working_dir}/dev" -o mode=0755,nosuid
-	else
-		mount -t tmpfs dev "${working_dir}/dev" -o mode=0755,size=10M,nosuid
-		mknod -m 666 "${working_dir}/dev/null" c 1 3
-		mknod -m 666 "${working_dir}/dev/zero" c 1 5
-		mknod -m 600 "${working_dir}/dev/console" c 5 1
-		mknod -m 644 "${working_dir}/dev/random" c 1 8
-		mknod -m 644 "${working_dir}/dev/urandom" c 1 9
-		mknod -m 666 "${working_dir}/dev/tty" c 5 0
-		mknod -m 666 "${working_dir}/dev/ptmx" c 5 2
-		mknod -m 666 "${working_dir}/dev/tty0" c 4 0
-		mknod -m 666 "${working_dir}/dev/full" c 1 7
-		ln -s /proc/kcore "${working_dir}/dev/core"
-		ln -s /proc/self/fd "${working_dir}/dev/fd"
-		ln -s /proc/self/fd/0 "${working_dir}/dev/stdin"
-		ln -s /proc/self/fd/1 "${working_dir}/dev/stdout"
-		ln -s /proc/self/fd/2 "${working_dir}/dev/stderr"
-	fi
+	mount -t tmpfs dev "${working_dir}/dev" -o mode=0755,size=10M,nosuid,strictatime
+	mknod -m 666 "${working_dir}/dev/null" c 1 3
+	mknod -m 666 "${working_dir}/dev/zero" c 1 5
+	mknod -m 600 "${working_dir}/dev/console" c 5 1
+	mknod -m 644 "${working_dir}/dev/random" c 1 8
+	mknod -m 644 "${working_dir}/dev/urandom" c 1 9
+	mknod -m 666 "${working_dir}/dev/tty" c 5 0
+	mknod -m 666 "${working_dir}/dev/ptmx" c 5 2
+	mknod -m 666 "${working_dir}/dev/tty0" c 4 0
+	mknod -m 666 "${working_dir}/dev/full" c 1 7
+	mknod -m 666 "${working_dir}/dev/rtc0" c 254 0
+	ln -s /proc/kcore "${working_dir}/dev/core"
+	ln -s /proc/self/fd "${working_dir}/dev/fd"
+	ln -s /proc/self/fd/0 "${working_dir}/dev/stdin"
+	ln -s /proc/self/fd/1 "${working_dir}/dev/stdout"
+	ln -s /proc/self/fd/2 "${working_dir}/dev/stderr"
 
 	[[ -e "${working_dir}/dev/shm" ]] || mkdir "${working_dir}/dev/shm"
 	mount -t tmpfs shm "${working_dir}/dev/shm" -o nodev,nosuid,size=128M
 
 	[[ -e "${working_dir}/dev/pts" ]] || mkdir "${working_dir}/dev/pts"
-	mount -t devpts devpts "${working_dir}/dev/pts" -o newinstance,ptmxmode=666
-	mount -o bind "${working_dir}/dev/pts/ptmx" "${working_dir}/dev/ptmx"
+	mount -o bind /dev/pts "${working_dir}/dev/pts"
+
+	[[ -e "${working_dir}/run" ]] || mkdir "${working_dir}/run"
+	mount -t tmpfs tmpfs "${working_dir}/run" -o nodev,nosuid,strictatime,size=64M
 
 	[[ -e $cache_dir ]] || mkdir -p "${cache_dir}"
 	[[ -e "${working_dir}/${cache_dir}" ]] || mkdir -p "${working_dir}/${cache_dir}"
@@ -135,6 +136,7 @@ chroot_mount() {
 
 copy_hostconf () {
 	cp /etc/resolv.conf "${working_dir}/etc/resolv.conf"
+	cp -a /etc/pacman.d/gnupg "${working_dir}/etc/pacman.d"
 	echo "Server = ${host_mirror}" > ${working_dir}/etc/pacman.d/mirrorlist
 
 	if [[ -n $pac_conf && $NOCOPY = 'n' ]]; then
@@ -147,12 +149,13 @@ copy_hostconf () {
 }
 
 chroot_umount () {
+	umount "${working_dir}/proc/sys"
 	umount "${working_dir}/proc"
 	umount "${working_dir}/sys"
-	umount "${working_dir}/dev/ptmx"
 	umount "${working_dir}/dev/pts"
 	umount "${working_dir}/dev/shm"
 	umount "${working_dir}/dev"
+	umount "${working_dir}/run"
 	umount "${working_dir}/${cache_dir}"
 	[[ -n $host_mirror_path ]] && umount "${working_dir}/${host_mirror_path}"
 }
@@ -184,7 +187,7 @@ if [[ -n $RUN ]]; then
 	chroot_mount
 	copy_hostconf
 
-	eval chroot "${working_dir}" ${RUN}
+	eval unshare -mui -- chroot "${working_dir}" ${RUN}
 
 	# }}}
 else
@@ -226,6 +229,9 @@ else
 		sed -i 's@^#\(en_US\|de_DE\)\(\.UTF-8\)@\1\2@' "${working_dir}/etc/locale.gen"
 		chroot "${working_dir}" /usr/sbin/locale-gen
 	fi
+	echo 'UTC' > "${working_dir}/etc/timezone"
+	ln -s /usr/share/zoneinfo/UTC "${working_dir}/etc/localtime"
+	echo 'LANG=C' > "${working_dir}/etc/locale.conf"
 
 	copy_hostconf