mm: numa: clear numa hinting information on mprotect

On a protection change it is no longer clear if the page should be still
accessible.  This patch clears the NUMA hinting fault bits on a
protection change.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 1291a053b167..f8421722acb9 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -54,6 +54,8 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 
                         if (!prot_numa) {
                                 ptent = ptep_modify_prot_start(mm, addr, pte);
+                                if (pte_numa(ptent))
+                                        ptent = pte_mknonnuma(ptent);
                                 ptent = pte_modify(ptent, newprot);
                                 updated = true;
                         } else {