hugetlb: fix metadata corruption in hugetlb_fault()

[platform/adaptation/renesas_rcar/renesas_kernel.git] / mm / hugetlb.c

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index c032738..bd031a4 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2515,22 +2515,19 @@ retry:
                        hugepage_add_new_anon_rmap(page, vma, address);
                }
        } else {
+               /*
+                * If memory error occurs between mmap() and fault, some process
+                * don't have hwpoisoned swap entry for errored virtual address.
+                * So we need to block hugepage fault by PG_hwpoison bit check.
+                */
+               if (unlikely(PageHWPoison(page))) {
+                       ret = VM_FAULT_HWPOISON;
+                       goto backout_unlocked;
+               }
                page_dup_rmap(page);
        }
 
        /*
-        * Since memory error handler replaces pte into hwpoison swap entry
-        * at the time of error handling, a process which reserved but not have
-        * the mapping to the error hugepage does not have hwpoison swap entry.
-        * So we need to block accesses from such a process by checking
-        * PG_hwpoison bit here.
-        */
-       if (unlikely(PageHWPoison(page))) {
-               ret = VM_FAULT_HWPOISON;
-               goto backout_unlocked;
-       }
-
-       /*
         * If we are going to COW a private mapping later, we examine the
         * pending reservations for this page now. This will ensure that
         * any allocations necessary to record that reservation occur outside