Re: [PATCH 2/2] powerpc/64s: __find_linux_pte synchronization vs pmdp_invalidate
From: Michael Ellerman <hidden>
Date: 2019-06-12 05:06:23
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 <redacted>
Suggested-by: Aneesh Kumar K.V <redacted>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <redacted>Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/a00196a272161338d4b1d66ec69e3d57 cheers