From 154c8c19c35b6da94a623cb793458e203572083d Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Mon, 9 May 2016 11:22:34 +0200 Subject: [PATCH] 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 Signed-off-by: David Hildenbrand Signed-off-by: Christian Borntraeger --- arch/s390/include/asm/pgtable.h | 3 ++- arch/s390/kvm/kvm-s390.c | 8 ++------ arch/s390/mm/pgtable.c | 12 ++++++------ 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(¤t->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 -- 2.20.1