[PATCH v4 7/8] ARM: mm: allow non-text sections to be non-executable

[Rabin Vincent]

On Fri, Aug 29, 2014 at 09:04:41AM -0700, Kees Cook wrote:
> On Tue, Aug 26, 2014 at 7:43 AM, Will Deacon <will.deacon at arm.com> wrote:
> > Hmm, so do you mandate that preemption is disabled during sections of code
> > where the permissions must be changed after boot? (e.g. ftrace patching)
> 
> I guess it's not enforced (how do I make sure preempt is off?), but
> it's only used during the ftrace patching. I'm open to suggestions! (I
> had avoided going the fixmap route since I would have expected that to
> be much slower.)

For ftrace patching this is called under stop_machine() so preemption is
already off there.