Re: [PATCH v4 2/5] x86, traps: Track entry into and exit from IST context

Andy Lutomirski
2014-12-11T00:25:12Z

On Wed, Dec 10, 2014 at 4:22 PM, Tony Luck <tony.luck@gmail.com> wrote:
> On Tue, Nov 25, 2014 at 10:58 AM, Borislav Petkov <bp@alien8.de> wrote:
>> On Mon, Nov 24, 2014 at 03:52:10PM -0800, Andy Lutomirski wrote:
>>> Dunno. Tony and Borislav -- when do you want the IST stack switching
>>> stuff?
>>
>> I'd leave that up to Tony and his testbench. I mean, we can hammer on
>> it as much as we can and it can pass all testing locally but the real
>> fun starts once it hits upstream and for that it doesn't matter which
>> release... IMHO.
>
> So what was the net result of all the mode/RCU discussions?
>
> Do I need some extra magic incantations in the final version
> of do_machine_check() beyond what was in this patch:
>
> https://lkml.kernel.org/r/546d169211835aded@agluck-desk.sc.intel.com
>
> to make everything happy?
>

I think you need ist_begin_non_atomic() before local_irq_enable() and
ist_end_non_atomic() after local_irq_disable(). Otherwise it should
be good.

--Andy

> -Tony

--
Andy Lutomirski
AMA Capital Management, LLC