sched: numa: skip inaccessible VMAs

Inaccessible VMA should not be trapping NUMA hint faults. Skip them.

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, 7 insertions, 0 deletions

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 9030da7bcb15..c7395d97e4cb 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1738,6 +1738,13 @@ void task_numa_work(struct callback_head *work)
                     (vma->vm_file && (vma->vm_flags & (VM_READ|VM_WRITE)) == (VM_READ)))
                         continue;
 
+                /*
+                 * Skip inaccessible VMAs to avoid any confusion between
+                 * PROT_NONE and NUMA hinting ptes
+                 */
+                if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
+                        continue;
+
                 do {
                         start = max(start, vma->vm_start);
                         end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE);