Re: [PATCH RFC v1 1/3] ARM: Add irq disabled version of soft_restart.

[Sebastian Capella <sebastian.capella@linaro.org>]

Quoting Russell King - ARM Linux (2014-02-22 02:26:17)
> On Tue, Feb 18, 2014 at 05:52:07PM -0800, Sebastian Capella wrote:
> > From: Russ Dill <Russ.Dill@ti.com>
> > 
> > This adds the ability to run soft_restart with local_irq/fiq_disable
> > already called. This is helpful for the hibernation code paths.
> 
> I'd rather keep this simple.  There's no problem with calling soft_restart
> with interrupts already disabled.  local_irq_disable()/local_fiq_disable()
> there should be harmless.

Hi Russell,

I'm observing a data abort loop when I replace this call:

In the local_irq_disable, it ends up calling trace_hardirqs_off
(CONFIG_TRACE_IRQFLAGS_SUPPORT is enabled), which calls
trace_hardirqs_off_caller which checks lockdep_recursion in the
current task, but we've switched to a temporary stack with the
call_with_stack, and get_current is returning NULL.  This
triggers a data abort, which calls trace_hardirqs_off
again and so on.

Do you have any suggestions here?

Thanks,

Sebastian