On Thu, Jun 06, 2019 at 06:37:10PM +0300, Jarkko Sakkinen wrote: > On Wed, Jun 05, 2019 at 01:14:04PM -0700, Andy Lutomirski wrote: > > > > > > > On Jun 5, 2019, at 8:17 AM, Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> wrote: > > > > > >> On Tue, Jun 04, 2019 at 10:10:22PM +0000, Xing, Cedric wrote: > > >> A bit off topic here. This mmap()/mprotect() discussion reminds me a > > >> question (guess for Jarkko): Now that vma->vm_file->private_data keeps > > >> a pointer to the enclave, why do we store it again in vma->vm_private? > > >> It isn't a big deal but non-NULL vm_private does prevent mprotect() > > >> from merging adjacent VMAs. > > > > > > Same semantics as with a regular mmap i.e. you can close the file and > > > still use the mapping. > > > > > > > > > > The file should be properly refcounted — vm_file should not go away while it’s mapped. mm already takes care of that so vm_file does not go away. Still we need an internal refcount for enclaves to synchronize with the swapper. In summary nothing needs to be done. > Right, makes sense. It is easy one to change essentially just removing > internal refcount from sgx_encl and using file for the same. I'll update > this to my tree along with the changes to remove LKM/ACPI bits ASAP. /Jarkko
