Re: [PATCH v6 03/11] mm, x86: Add support for eXclusive Page Frame Ownership (XPFO)

[Dave Hansen]

At a high level, does this approach keep an attacker from being able to
determine the address of data in the linear map, or does it keep them
from being able to *exploit* it?  Can you have a ret2dir attack if the
attacker doesn't know the address, for instance?