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authorDavid Hildenbrand2016-05-09 11:22:34 +0200
committerChristian Borntraeger2016-06-10 12:07:28 +0200
commit154c8c19c35b6da94a623cb793458e203572083d (patch)
tree9ca37ad9fa34d1495bb1c770b035192c87a15854
parents390/mm: simplify get_guest_storage_key (diff)
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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>
-rw-r--r--arch/s390/include/asm/pgtable.h3
-rw-r--r--arch/s390/kvm/kvm-s390.c8
-rw-r--r--arch/s390/mm/pgtable.c12
3 files changed, 10 insertions, 13 deletions
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 42b968a85863..91f0e7b79821 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -893,7 +893,8 @@ void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
bool test_and_clear_guest_dirty(struct mm_struct *mm, unsigned long address);
int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
unsigned char key, bool nq);
-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);
/*
* Certain architectures need to do special things when PTEs
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index d0156d7969e0..ad166c6698e0 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1029,7 +1029,6 @@ static long kvm_s390_get_skeys(struct kvm *kvm, struct kvm_s390_skeys *args)
{
uint8_t *keys;
uint64_t hva;
- unsigned long curkey;
int i, r = 0;
if (args->flags != 0)
@@ -1058,12 +1057,9 @@ static long kvm_s390_get_skeys(struct kvm *kvm, struct kvm_s390_skeys *args)
break;
}
- curkey = get_guest_storage_key(current->mm, hva);
- if (IS_ERR_VALUE(curkey)) {
- r = curkey;
+ r = get_guest_storage_key(current->mm, hva, &keys[i]);
+ if (r)
break;
- }
- keys[i] = curkey;
}
up_read(&current->mm->mmap_sem);
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 4c8d572d59cc..3e35298758d6 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -539,9 +539,9 @@ int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
}
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 @@ unsigned long get_guest_storage_key(struct mm_struct *mm, unsigned long addr)
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