mm/hugetlb.c: fix virtual address handling in hugetlb fault

handle_mm_fault() passes 'faulted' address to hugetlb_fault().  This
address is not aligned to a hugepage boundary.

Most of the functions for hugetlb pages are aware of that and calculate an
alignment themselves.  However some functions such as
copy_user_huge_page() and clear_huge_page() don't handle alignment by
themselves.

This patch make hugeltb_fault() fix the alignment and pass an aligned
addresss (to address of a faulted hugepage) to functions.

[akpm@linux-foundation.org: use &=]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 49e693b7fd0c..ab89d6f382d1 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2640,6 +2640,8 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
         static DEFINE_MUTEX(hugetlb_instantiation_mutex);
         struct hstate *h = hstate_vma(vma);
 
+        address &= huge_page_mask(h);
+
         ptep = huge_pte_offset(mm, address);
         if (ptep) {
                 entry = huge_ptep_get(ptep);