On Wed, 11 Nov 2020 22:01:51 +1000, Nicholas Piggin wrote:
> read_user_stack_slow that walks user address translation by hand is
> only required on hash, because a hash fault can not be serviced from
> "NMI" context (to avoid re-entering the hash code) so the user stack
> can be mapped into Linux page tables but not accessible by the CPU.
>
> Radix MMU mode does not have this restriction. A page fault failure
> would indicate the page is not accessible via get_user_pages either,
> so avoid this on radix.
Applied to powerpc/next.
[1/1] powerpc/64s/perf: perf interrupt does not have to get_user_pages to
access user memory
https://git.kernel.org/powerpc/c/987c426320cce72d1b28f55c8603b239e4f7187c
cheers
