Re: [RFC][PATCH v2 11/21] x86/pti: Extend PTI user mappings

[Andy Lutomirski]

On Mon, Nov 16, 2020 at 6:49 AM Alexandre Chartre
<alexandre.chartre@xxxxxxxxxx> wrote:
>
> Extend PTI user mappings so that more kernel entry code can be executed
> with the user page-table. To do so, we need to map syscall and interrupt
> entry code, per cpu offsets (__per_cpu_offset, which is used some in
> entry code), the stack canary, and the PTI stack (which is defined per
> task).

Does anything unmap the PTI stack?  Mapping is easy, and unmapping
could be a pretty big mess.

--Andy