Merge branch 'akpm' (fixes from Andrew)

Pull misc fixes from Andrew Morton:
 "Ten fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kernel/signal.c: stop info leak via the tkill and the tgkill syscalls
  mm/vmscan: fix error return in kswapd_run()
  hfsplus: fix potential overflow in hfsplus_file_truncate()
  avr32: fix build error in atstk1006_defconfig
  hugetlbfs: add swap entry check in follow_hugetlb_page()
  fs/binfmt_elf.c: fix hugetlb memory check in vma_dump_size()
  hugetlbfs: stop setting VM_DONTDUMP in initializing vma(VM_HUGETLB)
  checkpatch: fix stringification macro defect
  drivers/video/mmp/core.c: fix use-after-free bug
  thinkpad-acpi: kill hotkey_thread_mutex

1 files changed, 11 insertions, 1 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index ca9a7c6d7e97..1a12f5b9a0ab 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2961,7 +2961,17 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
                         break;
                 }
 
-                if (absent ||
+                /*
+                 * We need call hugetlb_fault for both hugepages under migration
+                 * (in which case hugetlb_fault waits for the migration,) and
+                 * hwpoisoned hugepages (in which case we need to prevent the
+                 * caller from accessing to them.) In order to do this, we use
+                 * here is_swap_pte instead of is_hugetlb_entry_migration and
+                 * is_hugetlb_entry_hwpoisoned. This is because it simply covers
+                 * both cases, and because we can't follow correct pages
+                 * directly from any kind of swap entries.
+                 */
+                if (absent || is_swap_pte(huge_ptep_get(pte)) ||
                     ((flags & FOLL_WRITE) && !pte_write(huge_ptep_get(pte)))) {
                         int ret;