Re: [PATCH v2 0/2] bus: CCN/CCI: Fix use of smp_processor_id()

From: Mark Rutland
Date: Tue Oct 03 2017 - 13:20:22 EST

On Tue, Oct 03, 2017 at 06:14:11PM +0100, Marc Zyngier wrote:
> I've just noticed that both the CCI and CCN drivers have a small
> buglet in that they call smp_processor_id() from preemptible context,
> which is frown upon (having just booted a 4.13 kernel with
> DEBUG_PREEMPT on my Seattle, I was surprised to be greeted with a nice
> backtrace...).
> I've tested the CCN patch on the same Seatle box, but I've only
> compile-tested the equivalent CCI patch (which is obviously correct --
> famous last words...).
> Thanks,
> M.
> * From v1: Keep the current CPU refcount until we have registered the
> CPU notifiers, making sure we don't race against a surprise hotplug
> off.
> Marc Zyngier (2):
> bus: arm-ccn: Fix use of smp_processor_id() in preemptible context
> bus: arm-cci: Fix use of smp_processor_id() in preemptible context

For both:

Acked-by: Mark Rutland <mark.rutland@xxxxxxx>