[PATCH 3/4] KVM: s390: replace bitmap_copy with bitmap_{from,to}_arr64 where appropriate

Yury Norov
2022-04-20T22:25:50Z

Copying bitmaps from/to 64-bit arrays with bitmap_copy is not safe
in general case. Use designated functions instead.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
arch/s390/kvm/kvm-s390.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 156d1c25a3c1..a353bb43ee48 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1332,8 +1332,7 @@ static int kvm_s390_set_processor_feat(struct kvm *kvm,
mutex_unlock(&kvm->lock);
return -EBUSY;
}
- bitmap_copy(kvm->arch.cpu_feat, (unsigned long *) data.feat,
- KVM_S390_VM_CPU_FEAT_NR_BITS);
+ bitmap_from_arr64(kvm->arch.cpu_feat, data.feat, KVM_S390_VM_CPU_FEAT_NR_BITS);
mutex_unlock(&kvm->lock);
VM_EVENT(kvm, 3, "SET: guest feat: 0x%16.16llx.0x%16.16llx.0x%16.16llx",
data.feat[0],
@@ -1504,8 +1503,7 @@ static int kvm_s390_get_processor_feat(struct kvm *kvm,
{
struct kvm_s390_vm_cpu_feat data;

- bitmap_copy((unsigned long *) data.feat, kvm->arch.cpu_feat,
- KVM_S390_VM_CPU_FEAT_NR_BITS);
+ bitmap_to_arr64(data.feat, kvm->arch.cpu_feat, KVM_S390_VM_CPU_FEAT_NR_BITS);
if (copy_to_user((void __user *)attr->addr, &data, sizeof(data)))
return -EFAULT;
VM_EVENT(kvm, 3, "GET: guest feat: 0x%16.16llx.0x%16.16llx.0x%16.16llx",
@@ -1520,9 +1518,7 @@ static int kvm_s390_get_machine_feat(struct kvm *kvm,
{
struct kvm_s390_vm_cpu_feat data;

- bitmap_copy((unsigned long *) data.feat,
- kvm_s390_available_cpu_feat,
- KVM_S390_VM_CPU_FEAT_NR_BITS);
+ bitmap_to_arr64(data.feat, kvm_s390_available_cpu_feat, KVM_S390_VM_CPU_FEAT_NR_BITS);
if (copy_to_user((void __user *)attr->addr, &data, sizeof(data)))
return -EFAULT;
VM_EVENT(kvm, 3, "GET: host feat: 0x%16.16llx.0x%16.16llx.0x%16.16llx",
--
2.32.0