On 12/17/18 10:48 AM, Sean Christopherson wrote: > We can't set mm to NULL as we need it to unregister the notifier, and > I'm fairly certain attempting to unregister in the release callback > will deadlock. Suggestion: It looks like you only expect one VMA per enclave. Things go bonkers if this is not true. So, instead of storing encl->mm, don't. You can get the mm from vma->vm_mm and you could just store encl->vma instead. Doing that, you could even axe encl->base and encl->size, I think because you just get those from the VMA itself. That makes the relationship clearer: 1 VMA per enclave. We also implicitly understand that if you have a VMA, you implicitly have a ref to the mm *and* the VMA is immutable. If there were ever a path where encl->vma wasn't immutable, we'd have a bug (or load of bugs) somewhere, right?
