[PATCH] KVM: ia64: fix the error code of ioctl KVM_IA64_VCPU_GET_STACK failure

[Wei Yongjun <yjwei@cn.fujitsu.com>]

The ioctl KVM_IA64_VCPU_GET_STACK does not set the error code if
copy_to_user() fail, and 0 will be return, we should use -EFAULT
instead of 0 in this case, so this patch fixed it.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
---
 arch/ia64/kvm/kvm-ia64.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 26e0e08..bc07c81 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -1535,8 +1535,10 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 			goto out;
 
 		if (copy_to_user(user_stack, stack,
-				 sizeof(struct kvm_ia64_vcpu_stack)))
+				 sizeof(struct kvm_ia64_vcpu_stack))) {
+			r = -EFAULT;
 			goto out;
+		}
 
 		break;
 	}
-- 
1.6.3.3