Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "13 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm, thp: do not cause memcg oom for thp
  mm/vmscan: wake up flushers for legacy cgroups too
  Revert "mm: page_alloc: skip over regions of invalid pfns where possible"
  mm/shmem: do not wait for lock_page() in shmem_unused_huge_shrink()
  mm/thp: do not wait for lock_page() in deferred_split_scan()
  mm/khugepaged.c: convert VM_BUG_ON() to collapse fail
  x86/mm: implement free pmd/pte page interfaces
  mm/vmalloc: add interfaces to free unmapped page table
  h8300: remove extraneous __BIG_ENDIAN definition
  hugetlbfs: check for pgoff value overflow
  lockdep: fix fs_reclaim warning
  MAINTAINERS: update Mark Fasheh's e-mail
  mm/mempolicy.c: avoid use uninitialized preferred_node

1 files changed, 14 insertions, 3 deletions

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 8fe1b0aa2896..b9a254dcc0e7 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -108,6 +108,16 @@ static void huge_pagevec_release(struct pagevec *pvec)
 	pagevec_reinit(pvec);
 }
 
+/*
+ * Mask used when checking the page offset value passed in via system
+ * calls.  This value will be converted to a loff_t which is signed.
+ * Therefore, we want to check the upper PAGE_SHIFT + 1 bits of the
+ * value.  The extra bit (- 1 in the shift value) is to take the sign
+ * bit into account.
+ */
+#define PGOFF_LOFFT_MAX \
+	(((1UL << (PAGE_SHIFT + 1)) - 1) <<  (BITS_PER_LONG - (PAGE_SHIFT + 1)))
+
 static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
 {
 	struct inode *inode = file_inode(file);
@@ -127,12 +137,13 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
 	vma->vm_ops = &hugetlb_vm_ops;
 
 	/*
-	 * Offset passed to mmap (before page shift) could have been
-	 * negative when represented as a (l)off_t.
+	 * page based offset in vm_pgoff could be sufficiently large to
+	 * overflow a (l)off_t when converted to byte offset.
 	 */
-	if (((loff_t)vma->vm_pgoff << PAGE_SHIFT) < 0)
+	if (vma->vm_pgoff & PGOFF_LOFFT_MAX)
 		return -EINVAL;
 
+	/* must be huge page aligned */
 	if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT))
 		return -EINVAL;