lkml.org 
[lkml]   [2019]   [May]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] ptrace: restore smp_rmb() in __ptrace_may_access()
On 05/29, Jann Horn wrote:
>
> > (I am wondering if smp_acquire__after_ctrl_dep() could be used instead, just to
> > make this code look more confusing)
>
> Uuh, I had no idea that that barrier type exists. The helper isn't
> even explicitly mentioned in Documentation/memory-barriers.rst. I
> don't really want to use dark magic in the middle of ptrace access
> logic...

Yes. and if it was not clear I didn't try to seriously suggest to use this
barrier. I was just curious if it can be used or not in this particular case.

> Anyway, looking at it, I think smp_acquire__after_ctrl_dep() doesn't
> make sense here;

Well I still _think_ it should work, it provides the LOAD-LOAD ordering
and this is what we need.

But I can be easily wrong, and again, I wasn't serious.

Oleg.

\
 
 \ /
  Last update: 2019-05-30 14:06    [W:0.145 / U:0.176 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site