lkml.org 
[lkml]   [2015]   [Sep]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] x86: Use entire page for the per-cpu GDT only if paravirt-enabled
From
Date
On 09/29/2015 11:02 AM, Andy Lutomirski wrote:
> On Tue, Sep 29, 2015 at 10:50 AM, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
>> On Tue, Sep 29, 2015 at 1:35 PM, Andy Lutomirski <luto@amacapital.net> wrote:
>>>
>>> Does anyone know what happens if you stick a non-accessed segment in
>>> the GDT, map the GDT RO, and access it?
>>
>> You should get a #PF, as you guess, but go ahead and test it if you
>> want to make sure.
>
> Then I think that, if we do this, the patch series should first make
> it percpu and fixmapped but RW and then flip it RO as a separate patch
> in case we need to revert the actual RO bit. I don't want to break
> Wine or The Witcher 2 because of this, and we might need various
> fixups. I really hope that no one uses get_thread_area to check
> whether TLS has been accessed.
>

Of course.

-hpa




\
 
 \ /
  Last update: 2015-09-29 22:41    [W:0.089 / U:0.044 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site