On Wed, Dec 01, 2021 at 11:23:01AM -0800, Reinette Chatre wrote: > === Summary === > > An SGX VMA can only be created if its permissions are the same or > weaker than the Enclave Page Cache Map (EPCM) permissions. After VMA > creation this rule continues to be enforced by the page fault handler. > > With SGX2 the EPCM permissions of a page can change after VMA > creation resulting in the VMA exceeding the EPCM permissions and the > page fault handler incorrectly blocking access. > > Enable the VMA's pages to remain accessible while ensuring that > the page table entries are installed to match the EPCM permissions > without exceeding the VMA perms issions. I don't understand what the short summary means in English, and the commit message is way too bloated to make any conclusions. It really needs a rewrite. These were the questions I could not find answer for: 1. Why it would be by any means safe to remove a permission check? 2. Why not re-issuing mmap()'s is unfeasible? I.e. close existing VMA's and mmap() new ones. /Jarkko
