mm/hmm/mirror: helper to snapshot CPU page table

[sfrench/cifs-2.6.git] / mm / pgtable-generic.c

diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index c99d9512a45b8a1599f0d679ec92d9e4511b3d68..1175f6a24fdb09d49af7ab93061b56b527d554a1 100644 (file)
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -124,7 +124,8 @@ pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address,
 {
        pmd_t pmd;
        VM_BUG_ON(address & ~HPAGE_PMD_MASK);
-       VM_BUG_ON(!pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp));
+       VM_BUG_ON((pmd_present(*pmdp) && !pmd_trans_huge(*pmdp) &&
+                          !pmd_devmap(*pmdp)) || !pmd_present(*pmdp));
        pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
        flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
        return pmd;