Re: [PATCH 00/23] KAISER: unmap most of the kernel from userspace page tables

From: Andy Lutomirski
Date: Thu Nov 02 2017 - 03:32:44 EST


On Wed, Nov 1, 2017 at 1:33 PM, Andy Lutomirski <luto@xxxxxxxxxx> wrote:
> On Wed, Nov 1, 2017 at 12:05 PM, Linus Torvalds
> <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>> On Wed, Nov 1, 2017 at 11:46 AM, Dave Hansen
>> <dave.hansen@xxxxxxxxxxxxxxx> wrote:
>>>
>>> The vmalloc()'d stacks definitely need the page table walk.
>>
>> Ugh, yes. Nasty.
>>
>> Andy at some point mentioned a per-cpu initial stack trampoline thing
>> for his exception patches, but I'm not sure he actually ever did that.
>>
>> Andy?
>
> I'm going to push it to kernel.org very shortly (like twenty minutes
> maybe). Then the 0day bot can chew on it. With the proposed LDT
> rework, we don't need to do any of dynamic mapping stuff, I think.

FWIW, I pushed all but the actual stack switching part. Something
broke in the rebase and it doesn't boot right now :(