Nicholas Piggin <npig...@gmail.com> writes: > If the boot CPU tries to access per-cpu data of other CPUs before > per cpu areas are set up, it will unexpectedly use offset 0. > > Try to catch such accesses by poisoning the __per_cpu_offset array.
I wasn't sure about this. On bare metal it's just an instant checkstop which is very user hostile. I worry it's just going to cause unusual configurations/options to crash for folks, like eg. booting with page_poison=1 did a while back. Can we put it behind a debug option? Maybe CONFIG_DEBUG_VM ? cheers
