Subject: Re: [PATCH 2/2] powerpc/64s: __find_linux_pte synchronization vs pmdp_invalidate

From: Michael Ellerman <[email-masked]>
Date: Wed, 12 Jun 2019 14:59:12 +1000 (AEST)

On Fri, 2019-06-07 at 03:56:36 UTC, Nicholas Piggin wrote:
> The change to pmdp_invalidate to mark the pmd with _PAGE_INVALID broke
> the synchronisation against lock free lookups, __find_linux_pte's
> pmd_none check no longer returns true for such cases.
> 
> Fix this by adding a check for this condition as well.
> 
> Fixes: da7ad366b497 ("powerpc/mm/book3s: Update pmd_present to look at _PAGE_PRESENT bit")
> Cc: Christophe Leroy <[email-masked]>
> Suggested-by: Aneesh Kumar K.V <[email-masked]>
> Signed-off-by: Nicholas Piggin <[email-masked]>
> Reviewed-by: Aneesh Kumar K.V <[email-masked]>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/a00196a272161338d4b1d66ec69e3d57

cheers