Merge /spare/repo/linux-2.6/

1 files changed, 10 insertions, 1 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index fbd1111ea119..6bf720bc662c 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -301,6 +301,7 @@ void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
 {
         struct mm_struct *mm = vma->vm_mm;
         unsigned long address;
+        pte_t *ptep;
         pte_t pte;
         struct page *page;
 
@@ -309,9 +310,17 @@ void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
         BUG_ON(end & ~HPAGE_MASK);
 
         for (address = start; address < end; address += HPAGE_SIZE) {
-                pte = huge_ptep_get_and_clear(mm, address, huge_pte_offset(mm, address));
+                ptep = huge_pte_offset(mm, address);
+                if (! ptep)
+                        /* This can happen on truncate, or if an
+                         * mmap() is aborted due to an error before
+                         * the prefault */
+                        continue;
+
+                pte = huge_ptep_get_and_clear(mm, address, ptep);
                 if (pte_none(pte))
                         continue;
+
                 page = pte_page(pte);
                 put_page(page);
         }