1 files changed, 26 insertions, 7 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 783098f6cf8..41b1038f76d 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -27,6 +27,29 @@ static struct list_head hugepage_freelists[MAX_NUMNODES];
 static unsigned int nr_huge_pages_node[MAX_NUMNODES];
 static unsigned int free_huge_pages_node[MAX_NUMNODES];
 
+static void clear_huge_page(struct page *page, unsigned long addr)
+{
+	int i;
+
+	might_sleep();
+	for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) {
+		cond_resched();
+		clear_user_highpage(page + i, addr);
+	}
+}
+
+static void copy_huge_page(struct page *dst, struct page *src,
+			   unsigned long addr)
+{
+	int i;
+
+	might_sleep();
+	for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) {
+		cond_resched();
+		copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE);
+	}
+}
+
 /*
  * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages
  */
@@ -98,7 +121,6 @@ void free_huge_page(struct page *page)
 struct page *alloc_huge_page(struct vm_area_struct *vma, unsigned long addr)
 {
 	struct page *page;
-	int i;
 
 	spin_lock(&hugetlb_lock);
 	page = dequeue_huge_page(vma, addr);
@@ -108,8 +130,6 @@ struct page *alloc_huge_page(struct vm_area_struct *vma, unsigned long addr)
 	}
 	spin_unlock(&hugetlb_lock);
 	set_page_refcounted(page);
-	for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); ++i)
-		clear_user_highpage(&page[i], addr);
 	return page;
 }
 
@@ -367,7 +387,7 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
 			unsigned long address, pte_t *ptep, pte_t pte)
 {
 	struct page *old_page, *new_page;
-	int i, avoidcopy;
+	int avoidcopy;
 
 	old_page = pte_page(pte);
 
@@ -388,9 +408,7 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
 	}
 
 	spin_unlock(&mm->page_table_lock);
-	for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++)
-		copy_user_highpage(new_page + i, old_page + i,
-				   address + i*PAGE_SIZE);
+	copy_huge_page(new_page, old_page, address);
 	spin_lock(&mm->page_table_lock);
 
 	ptep = huge_pte_offset(mm, address & HPAGE_MASK);
@@ -435,6 +453,7 @@ retry:
 			ret = VM_FAULT_OOM;
 			goto out;
 		}
+		clear_huge_page(page, address);
 
 		if (vma->vm_flags & VM_SHARED) {
 			int err;