arm64: don't kill the kernel on a bad esr from el0

arm64: don't kill the kernel on a bad esr from el0

commit 9955ac47f4ba1c95ecb6092aeaefb40a22e99268 upstream.

Rather than completely killing the kernel if we receive an esr value we
can't deal with in the el0 handlers, send the process a SIGILL and log
the esr value in the hope that we can debug it. If we receive a bad esr
from el1, we'll die() as before.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>