Re: [PATCH 25/43] x86/mm/kaiser: Unmap kernel from userspace page tables (core patch)

From: Dave Hansen
Date: Fri Nov 24 2017 - 11:33:15 EST


On 11/24/2017 04:16 AM, Peter Zijlstra wrote:
> On Fri, Nov 24, 2017 at 10:14:30AM +0100, Ingo Molnar wrote:
>> +The minimalistic kernel portion of the user page tables try to
>> +map only what is needed to enter/exit the kernel such as the
>> +entry/exit functions themselves and the interrupt descriptor
>> +table (IDT).
>
> There are a few unnecessary things that get mapped
>> +such as the first C function when entering an interrupt (see
>> +comments in kaiser.c).
>
> If I understood Andy's patches correctly, this should no longer be
> required. Is this text still correct?

It is out of date. We were able to remove the irq handler mappings.