1 files changed, 13 insertions, 7 deletions

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 34ede0ea85a9..4f289ff0b7fe 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -593,14 +593,16 @@ static inline pgste_t pgste_update_all(pte_t *ptep, pgste_t pgste)
         unsigned long address, bits;
         unsigned char skey;
 
+        if (!pte_present(*ptep))
+                return pgste;
         address = pte_val(*ptep) & PAGE_MASK;
         skey = page_get_storage_key(address);
         bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
         /* Clear page changed & referenced bit in the storage key */
-        if (bits) {
-                skey ^= bits;
-                page_set_storage_key(address, skey, 1);
-        }
+        if (bits & _PAGE_CHANGED)
+                page_set_storage_key(address, skey ^ bits, 1);
+        else if (bits)
+                page_reset_referenced(address);
         /* Transfer page changed & referenced bit to guest bits in pgste */
         pgste_val(pgste) |= bits << 48;         /* RCP_GR_BIT & RCP_GC_BIT */
         /* Get host changed & referenced bits from pgste */
@@ -625,6 +627,8 @@ static inline pgste_t pgste_update_young(pte_t *ptep, pgste_t pgste)
 #ifdef CONFIG_PGSTE
         int young;
 
+        if (!pte_present(*ptep))
+                return pgste;
         young = page_reset_referenced(pte_val(*ptep) & PAGE_MASK);
         /* Transfer page referenced bit to pte software bit (host view) */
         if (young || (pgste_val(pgste) & RCP_HR_BIT))
@@ -638,13 +642,15 @@ static inline pgste_t pgste_update_young(pte_t *ptep, pgste_t pgste)
 
 }
 
-static inline void pgste_set_pte(pte_t *ptep, pgste_t pgste)
+static inline void pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry)
 {
 #ifdef CONFIG_PGSTE
         unsigned long address;
         unsigned long okey, nkey;
 
-        address = pte_val(*ptep) & PAGE_MASK;
+        if (!pte_present(entry))
+                return;
+        address = pte_val(entry) & PAGE_MASK;
         okey = nkey = page_get_storage_key(address);
         nkey &= ~(_PAGE_ACC_BITS | _PAGE_FP_BIT);
         /* Set page access key and fetch protection bit from pgste */
@@ -712,7 +718,7 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 
         if (mm_has_pgste(mm)) {
                 pgste = pgste_get_lock(ptep);
-                pgste_set_pte(ptep, pgste);
+                pgste_set_pte(ptep, pgste, entry);
                 *ptep = entry;
                 pgste_set_unlock(ptep, pgste);
         } else