On Mon, Jun 17, 2019 at 3:24 PM Sean Christopherson
<sean.j.christopherson@xxxxxxxxx> wrote:
>
> The enclave mm tracking is currently broken:
>
> - Adding current->mm during ECREATE is wrong as there is no guarantee
> that the current process has mmap()'d the enclave, i.e. there may
> never be an associated sgx_vma_close() to drop the encl_mm.
>
> - Adding mm's at sgx_vma_open() is wrong as vm_ops->open is called
> only when splitting or duplicating a vma. If userspace performs a
> single mmap() on the enclave then SGX will fail to track the mm.
> This bug is partially hidden by tracking current->mm at ECREATE.
>
> Rework the tracking to get/add the mm at mmap(). A side effect of the
> bug fix is that sgx_vma_{open,close}() should never encounter a vma with
> an associated enclave and no associated encl_mm, i.e. WARN if an encl_mm
> cannot be found in either condition.
>
It would be nifty if you could also kill .vm_close, since then VMAs
could be merged properly. Would this be straightforward?
--Andy
