lkml.org 
[lkml]   [2016]   [Feb]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch 01/20] idle: Move x86ism out of generic code
On Mon, 29 Feb 2016, Will Deacon wrote:

> On Mon, Feb 29, 2016 at 08:35:41PM +0100, Thomas Gleixner wrote:
> > On Sat, 27 Feb 2016, Brian Gerst wrote:
> > > > arch_cpu_idle_prepare();
> > > > cpu_idle_loop();
> > > > }
> > >
> > > Does this actually work with stack protector enabled?
> > > boot_init_stack_canary() is inlined while arch_cpu_idle_prepare() is
> > > not.
> >
> > Stupid me. No it does of course not. I could have sworn that I tested that,
> > but obvioulsy not.
> >
> > I drop that patch, but actually the real question is whether we can drop that
> > '#ifdef x86' around that boot_init_stack_canary() invocation.
> >
> > AFAICT, neither arm, arm64 nor mips and sh call it on anything else than the
> > boot cpu. I can't see why that would be an issue on those architectures and
> > why it would be a problem if the boot cpu calls it again here.
> >
> > CC'ed the relevant maintainers. Is there any issue with the patch below?
>
> On arm[64], the canary is unfortunately global, so I don't think it would
> be safe to update it live like this without effectively stopping the
> machine and forcing everybody into idle.

Thanks for clarification.

Thomas


\
 
 \ /
  Last update: 2016-02-29 22:01    [W:0.074 / U:0.432 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site