s390/mm: return key via pointer in get_guest_storage_key
Let's just split returning the key and reporting errors. This makes calling
code easier and avoids bugs as happened already.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 4c8d572..3e35298 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -539,9 +539,9 @@
}
EXPORT_SYMBOL(set_guest_storage_key);
-unsigned long get_guest_storage_key(struct mm_struct *mm, unsigned long addr)
+int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
+ unsigned char *key)
{
- unsigned char key;
spinlock_t *ptl;
pgste_t pgste;
pte_t *ptep;
@@ -551,14 +551,14 @@
return -EFAULT;
pgste = pgste_get_lock(ptep);
- key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
+ *key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
if (!(pte_val(*ptep) & _PAGE_INVALID))
- key = page_get_storage_key(pte_val(*ptep) & PAGE_MASK);
+ *key = page_get_storage_key(pte_val(*ptep) & PAGE_MASK);
/* Reflect guest's logical view, not physical */
- key |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
+ *key |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
pgste_set_unlock(ptep, pgste);
pte_unmap_unlock(ptep, ptl);
- return key;
+ return 0;
}
EXPORT_SYMBOL(get_guest_storage_key);
#endif