UBUNTU: SAUCE: proc: hide kernel addresses via %pK in /proc/<pid>/stack

UBUNTU: SAUCE: proc: hide kernel addresses via %pK in /proc/<pid>/stack

[in -mm as proc-hide-kernel-addresses-via-%pk-in-proc-pid-stack.patch]

OriginalAuthor: Konstantin Khlebnikov <khlebnikov@openvz.org>

This file is readable for the task owner.  Hide kernel addresses from
unprivileged users, leave them function names and offsets.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Kees Cook <kees.cook@canonical.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andy Whitcroft <apw@canonical.com>