netboot: systemd must mount /tmp and /run

When using netboot, the initrd script mounts /tmp and /run before pivoting on
the new rootfs and then running systemd. As a consequence, systemd doesn't try
to remount /tmp or /run (and the correct smack labels are not applied on /tmp
and /run, leading to many issues).

This patch unmounts /tmp and /run just before running systemd which will
then mount them with correct labels.

Bug-AGL: SPEC-2596

Change-Id: I4cd7b67f04c232a6e48c777fb5fefa6c46f6744a
Signed-off-by: Stephane Desneux <stephane.desneux@iot.bzh>

diff --git a/meta-netboot/recipes-core/initramfs-netboot/files/init.sh b/meta-netboot/recipes-core/initramfs-netboot/files/init.sh
index 2def28e..7064314 100644 (file)
--- a/meta-netboot/recipes-core/initramfs-netboot/files/init.sh
+++ b/meta-netboot/recipes-core/initramfs-netboot/files/init.sh
@@ -126,8 +126,8 @@ done
 
 # switch to new rootfs
 log_info "Switching to new rootfs"
-mkdir -p run/initramfs
-pivot_root . run/initramfs || bail_out "pivot_root failed."
+mkdir -p boot/initramfs
+pivot_root . boot/initramfs || bail_out "pivot_root failed."
 
 # workaround for connman (avoid bringing down the network interface used for booting, disable DNS proxy)
 if [[ -f /lib/systemd/system/connman.service ]]; then
@@ -137,8 +137,14 @@ if [[ -f /lib/systemd/system/connman.service ]]; then
 fi
 
 # also use /proc/net/pnp to generate /etc/resolv.conf
+rm -f /etc/resolv.conf
 grep -v bootserver /proc/net/pnp | sed 's/^domain/search/g' >/etc/resolv.conf
 
+# unmount tmp and run to let systemd remount them with correct smack labels (SPEC-2596)
+log_info "Unmounting /tmp and /run"
+umount /tmp
+umount /run
+
 # finally, run systemd
 check_debug "Debug point 2. Exit to continue initrd script (run systemd)."