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>

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 9030da7..c7395d9 100644 (file)
--- 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);