mips/kvm: fix ioctl error handling

Returning directly whatever copy_to_user(...) or copy_from_user(...)
returns may not do the right thing if there's a pagefault:
copy_to_user/copy_from_user return the number of bytes not copied in
this case, but ioctls need to return -EFAULT instead.

Fix up kvm on mips to do
	return copy_to_user(...)) ?  -EFAULT : 0;
and
	return copy_from_user(...)) ?  -EFAULT : 0;

everywhere.

Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 8bc3977576e6af5f7b5c1a17f306da0f21b26937..3110447ab1e9bffc37fa8572f5ce62d44d4a5fd9 100644 (file)
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -702,7 +702,7 @@ static int kvm_mips_get_reg(struct kvm_vcpu *vcpu,
        } else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U128) {
                void __user *uaddr = (void __user *)(long)reg->addr;
 
-               return copy_to_user(uaddr, vs, 16);
+               return copy_to_user(uaddr, vs, 16) ? -EFAULT : 0;
        } else {
                return -EINVAL;
        }
@@ -732,7 +732,7 @@ static int kvm_mips_set_reg(struct kvm_vcpu *vcpu,
        } else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U128) {
                void __user *uaddr = (void __user *)(long)reg->addr;
 
-               return copy_from_user(vs, uaddr, 16);
+               return copy_from_user(vs, uaddr, 16) ? -EFAULT : 0;
        } else {
                return -EINVAL;
        }