Bug#734193: Please mount selinuxfs as read-only

[Laurent Bigonville]

Hi,

As explained in #734454 (which is different but somewhat related), the
selinuxfs on the chroot should probably be mounted as readonly so the
userspace in the chroot would think that selinux is disabled.

The proper way to set the fs read-only without interfering with the
selinuxfs from the host is to bind mount it from the host and then set
it as ro like this:

mount --bind /sys/fs/selinux /var/chroot/sys/fs/selinux
mount -o remount,ro,bind /var/chroot/sys/fs/selinux

Cheers,

Laurent Bigonville