On Fri, Jul 20, 2018 at 3:20 PM Andy Lutomirski <l...@amacapital.net> wrote:
> Thanks for digging! The problem was presumably that vmalloc_fault() will
> IRET and re-enable NMIs on the way out.
> But we’ve supported page faults on user memory in NMI handlers on 32-bit and
> 64-bit for quite a while, and it’s fine now.
>
> I would remove the warning, re-test, and revert the other patch.
Agreed. I don't think we have any issues with page faults during NMI
any more. Afaik the kprobe people depend on it.
That said, 64-bit mode has that scary PV-op case
(arch_flush_lazy_mmu_mode). Being PV mode, I can't find it in myself
to worry about it, I'm assuming it's ok.
Linus
