Let's carefully handle the boundary of the function parameter to make
sure that the arguments passed doesn't exceed the address range.

Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Dave Young <dyoung@redhat.com>
Link: https://lore.kernel.org/r/20200804044933.1973-2-lijiang@redhat.com