powerpc/thp: Fix crash on mremap

[~andy/linux] / include / asm-generic / pgtable.h

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index b12079afbd5f2757440a054e984dcd9f9e1b1547..8e4f41d9af4d47279e13a33edd317ce5de32e451 100644 (file)
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -558,6 +558,18 @@ static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
 }
 #endif
 
+#ifndef pmd_move_must_withdraw
+static inline int pmd_move_must_withdraw(spinlock_t *new_pmd_ptl,
+                                        spinlock_t *old_pmd_ptl)
+{
+       /*
+        * With split pmd lock we also need to move preallocated
+        * PTE page table if new_pmd is on different PMD page table.
+        */
+       return new_pmd_ptl != old_pmd_ptl;
+}
+#endif
+
 /*
  * This function is meant to be used by sites walking pagetables with
  * the mmap_sem hold in read mode to protect against MADV_DONTNEED and
@@ -599,11 +611,10 @@ static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd)
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
        barrier();
 #endif
-       if (pmd_none(pmdval))
+       if (pmd_none(pmdval) || pmd_trans_huge(pmdval))
                return 1;
        if (unlikely(pmd_bad(pmdval))) {
-               if (!pmd_trans_huge(pmdval))
-                       pmd_clear_bad(pmd);
+               pmd_clear_bad(pmd);
                return 1;
        }
        return 0;