lkml.org 
[lkml]   [2018]   [Jan]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH 06/18] x86, barrier: stop speculation for failed access_ok
On Fri, Jan 5, 2018 at 6:52 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> The fact is, we have to stop speculating when access_ok() does *not*
> fail - because that's when we'll actually do the access. And it's that
> access that needs to be non-speculative.

I also suspect we should probably do this entirely differently.

Maybe the whole lfence can be part of uaccess_begin() instead (ie
currently 'stac()'). That would fit the existing structure better, I
think. And it would avoid any confusion about the whole "when to stop
speculation".

Linus

\
 
 \ /
  Last update: 2018-01-06 04:09    [W:0.600 / U:0.000 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site