1 files changed, 32 insertions, 13 deletions

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 0f0de30e3e3..e8b6e5b8932 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -623,7 +623,7 @@ static inline pgste_t pgste_get_lock(pte_t *ptep)
 		"	csg	%0,%1,%2\n"
 		"	jl	0b\n"
 		: "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
-		: "Q" (ptep[PTRS_PER_PTE]) : "cc");
+		: "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");
 #endif
 	return __pgste(new);
 }
@@ -635,18 +635,26 @@ static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
 		"	nihh	%1,0xff7f\n"	/* clear RCP_PCL_BIT */
 		"	stg	%1,%0\n"
 		: "=Q" (ptep[PTRS_PER_PTE])
-		: "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE]) : "cc");
+		: "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])
+		: "cc", "memory");
 	preempt_enable();
 #endif
 }
 
+static inline void pgste_set(pte_t *ptep, pgste_t pgste)
+{
+#ifdef CONFIG_PGSTE
+	*(pgste_t *)(ptep + PTRS_PER_PTE) = pgste;
+#endif
+}
+
 static inline pgste_t pgste_update_all(pte_t *ptep, pgste_t pgste)
 {
 #ifdef CONFIG_PGSTE
 	unsigned long address, bits;
 	unsigned char skey;
 
-	if (!pte_present(*ptep))
+	if (pte_val(*ptep) & _PAGE_INVALID)
 		return pgste;
 	address = pte_val(*ptep) & PAGE_MASK;
 	skey = page_get_storage_key(address);
@@ -680,7 +688,7 @@ static inline pgste_t pgste_update_young(pte_t *ptep, pgste_t pgste)
 #ifdef CONFIG_PGSTE
 	int young;
 
-	if (!pte_present(*ptep))
+	if (pte_val(*ptep) & _PAGE_INVALID)
 		return pgste;
 	/* Get referenced bit from storage key */
 	young = page_reset_referenced(pte_val(*ptep) & PAGE_MASK);
@@ -704,17 +712,19 @@ static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry)
 {
 #ifdef CONFIG_PGSTE
 	unsigned long address;
-	unsigned long okey, nkey;
+	unsigned long nkey;
 
-	if (!pte_present(entry))
+	if (pte_val(entry) & _PAGE_INVALID)
 		return;
+	VM_BUG_ON(!(pte_val(*ptep) & _PAGE_INVALID));
 	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 */
-	nkey |= (pgste_val(pgste) & (RCP_ACC_BITS | RCP_FP_BIT)) >> 56;
-	if (okey != nkey)
-		page_set_storage_key(address, nkey, 0);
+	/*
+	 * Set page access key and fetch protection bit from pgste.
+	 * The guest C/R information is still in the PGSTE, set real
+	 * key C/R to 0.
+	 */
+	nkey = (pgste_val(pgste) & (RCP_ACC_BITS | RCP_FP_BIT)) >> 56;
+	page_set_storage_key(address, nkey, 0);
 #endif
 }
 
@@ -1098,6 +1108,11 @@ static inline pte_t ptep_modify_prot_start(struct mm_struct *mm,
 	pte = *ptep;
 	if (!mm_exclusive(mm))
 		__ptep_ipte(address, ptep);
+
+	if (mm_has_pgste(mm)) {
+		pgste = pgste_update_all(&pte, pgste);
+		pgste_set(ptep, pgste);
+	}
 	return pte;
 }
 
@@ -1105,9 +1120,13 @@ static inline void ptep_modify_prot_commit(struct mm_struct *mm,
 					   unsigned long address,
 					   pte_t *ptep, pte_t pte)
 {
+	pgste_t pgste;
+
 	if (mm_has_pgste(mm)) {
+		pgste = *(pgste_t *)(ptep + PTRS_PER_PTE);
+		pgste_set_key(ptep, pgste, pte);
 		pgste_set_pte(ptep, pte);
-		pgste_set_unlock(ptep, *(pgste_t *)(ptep + PTRS_PER_PTE));
+		pgste_set_unlock(ptep, pgste);
 	} else
 		*ptep = pte;
 }