lkml.org 
[lkml]   [2008]   [Jul]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC 00/15] x86_64: Optimize percpu accesses

* Jeremy Fitzhardinge <jeremy@goop.org> wrote:

>> Further -fstack-protector-all only seems to detect against buffer
>> overflows and thus corruption of the stack. Not stack overflows. So
>> it doesn't appear especially useful.
>
> It's a bit useful. But at the cost of preventing a pile of more
> useful unification work, not to mention making all access to per-cpu
> variables more expensive.

well, stackprotector is near zero maintenance trouble. It mostly binds
in places that are fundamentally non-unifiable anyway. (nobody is going
to unify the assembly code in switch_to())

i had zero-based percpu problems (early crashes) with a 4.2.3 gcc that
had --fstack-protect compiled out, so there's no connection there.

In its fixed form in tip/core/stackprotector it can catch the splice
exploit which makes it quite a bit useful. It would be rather silly to
not offer that feature.

Ingo


\
 
 \ /
  Last update: 2008-07-09 22:17    [W:0.246 / U:3.352 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site