Re: [PATCH] x86/mm/pti: Move user W+X check into pti_finalize()

From: Dave Hansen
Date: Wed Aug 08 2018 - 11:54:41 EST


On 08/08/2018 04:16 AM, Joerg Roedel wrote:
> But with CONFIG_DEBUG_WX enabled, the user page-table is
> already checked in mark_readonly() for insecure mappings.
> This causes false-positive warnings, because the user
> page-table did not get the updated mappings yet.

One bit of information missing from the changelog: Could you clarify how
there are any entries in the user page tables for the code to complain?
Before pti_init(), I would have expected the user page tables to be empty.

That causes a different problem, but it would not have resulted in
warnings, so I think I'm missing something.