mm: hugetlbfs: skip shared VMAs when unmapping private pages to satisfy a fault

[pandora-kernel.git] / mm / hugetlb.c

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 26922da..776c630 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2501,6 +2501,14 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
                if (iter_vma == vma)
                        continue;
 
+               /*
+                * Shared VMAs have their own reserves and do not affect
+                * MAP_PRIVATE accounting but it is possible that a shared
+                * VMA is using the same page so check and skip such VMAs.
+                */
+               if (iter_vma->vm_flags & VM_MAYSHARE)
+                       continue;
+
                /*
                 * Unmap the page from other VMAs without their own reserves.
                 * They get marked to be SIGKILLed if they fault in these