Re: [PATCH] ipmi: fix potential deadlock on &kcs_bmc->lock

From: Corey Minyard
Date: Tue Jul 04 2023 - 10:28:07 EST


On Fri, Jun 30, 2023 at 10:31:02AM +0930, Andrew Jeffery wrote:
> Hi Corey, Chengfeng,
>
> On Wed, 28 Jun 2023, at 21:17, Corey Minyard wrote:
> > Indeed, this looks like an issue.
> >
> > Andrew, any opinions on this? The attached patch will work, the other
> > option would be to disable interrupts when calling
> > kcs_bmc_handle_event() in the timer handler. But then you have to worry
> > about RT.
>
> Right, I think we'd do best to not over-complicate things.
> spin_lock_irq{save,restore}() are the intuitive choice to me.
>
> I'll follow up with R-b/T-b tags once I've booted the patch
> and done some testing.

Thanks. This is in my for-next tree, I'd like to get this in the merge
window, which I believe ends this Sunday.

> >> This flaw was found using an experimental static analysis tool we are
> >> developing for irq-related deadlock.

Will this tool be available for general use? It's obviously quite
handy.

-corey