On 10/12/2018 13:15, Michael Mueller wrote:
On 10.12.18 10:44, Cornelia Huck wrote:
On Mon, 10 Dec 2018 10:27:54 +0100
Pierre Morel <pmorel@xxxxxxxxxxxxx> wrote:
On 03/12/2018 10:48, Michael Mueller wrote:
On 03.12.18 10:21, Cornelia Huck wrote:
On Fri, 30 Nov 2018 15:32:13 +0100
Michael Mueller <mimu@xxxxxxxxxxxxx> wrote:
+int kvm_s390_gisc_unregister(struct kvm *kvm, u32 gisc)
+{
+ int rc = 0;
+
+ if (!kvm->arch.gib_in_use)
+ return -ENODEV;
+ if (gisc > MAX_ISC)
+ return -EINVAL;
+
+ spin_lock(&kvm->arch.iam_ref_lock);
+ if (kvm->arch.iam_ref_count[gisc] == 0) {
+ rc = -EFAULT;
-EFAULT looks odd. -EINVAL?
sure
Can we find some errno return value which is not already used in this
function?
I'm not sure what would be a better fit here (-EINVAL if you try to
unregister something that has never been registered seems reasonable).
Also, I think it is quite reasonable if a function returns the same
error for different reasons, as long as they are all the same class of
error. In this case, both the caller using an out-of-rage gisc or a
gisc that has never been registered indicate some internal mixup in how
the caller handles the gisc.
I think -EPERM is the right choice here. It is not permitted to
decrease the ref counter below zero.
To be anoying I would prefer
-ERANGE if gisc > MAX_ISC
-EINVAL in the second case is OK for me
and I also can agree with the argumentation of Conny.
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
