UBUNTU: SAUCE: (efi-lockdown) bpf: Restrict kernel image access functions when the...

UBUNTU: SAUCE: (efi-lockdown) bpf: Restrict kernel image access functions when the kernel is locked down

There are some bpf functions can be used to read kernel memory:
bpf_probe_read, bpf_probe_write_user and bpf_trace_printk.  These allow
private keys in kernel memory (e.g. the hibernation image signing key) to
be read by an eBPF program.  Prohibit those functions when the kernel is
locked down.

Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
Signed-off-by: David Howells <dhowells@redhat.com>
(cherry picked from commit 59e44bdc67df6cdcd4627f2b5b0b4d7e735c23fc
 git://git.kernel.org/pub/scm/linux/kernel/git/jwboyer/fedora.git)
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>