Commit 154c8c19 authored by David Hildenbrand's avatar David Hildenbrand Committed by Christian Borntraeger
Browse files

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: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 8d6037a7

arch/s390/include/asm/pgtable.h

+2 −1
Original line number Diff line number Diff line
@@ -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

arch/s390/kvm/kvm-s390.c

+2 −6
Original line number Diff line number Diff line
@@ -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)
@@ -1058,13 +1057,10 @@ 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);



	if (!r) {

arch/s390/mm/pgtable.c

+6 −6
Original line number Diff line number Diff line
@@ -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