Re: [PATCH] drivers/perf: arm_spe: Use perf_allow_kernel() for permissions

[James Clark]

On 07/08/2024 12:15 pm, Peter Zijlstra wrote:
> On Wed, Aug 07, 2024 at 11:54:41AM +0100, James Clark wrote:
> > diff --git a/kernel/events/core.c b/kernel/events/core.c
> > index aa3450bdc227..4a69583e329a 100644
> > --- a/kernel/events/core.c
> > +++ b/kernel/events/core.c
> > @@ -417,6 +417,7 @@ static struct kmem_cache *perf_event_cache;
> >    *   2 - disallow kernel profiling for unpriv
> >    */
> >   int sysctl_perf_event_paranoid __read_mostly = 2;
> > +EXPORT_SYMBOL_GPL(sysctl_perf_event_paranoid);
>
> I'm never a fan of exporting variables. Perhaps create a helper function
> that returns the value and use that where required?
>
> That avoids modules getting the idea it would be okay to change this
> valie themselves.

I could also remove the inline from perf_allow_kernel() and export that 
instead. I don't think it really needs to be inlined but I gave it the 
benefit of the doubt because it was added that way.