Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: [PATCH v17 18/23] platform/x86: Intel SGX driver | From | Dave Hansen <> | Date | Mon, 17 Dec 2018 11:09:33 -0800 |
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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?
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