BugLink: http://bugs.launchpad.net/bugs/1572722

commit a67cc9aa upstream.

Disabling pagefault makes little sense there, preemption disabling is
what was meant.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>