Re: BUG: sleeping function called from invalid context at include/linux/sched/mm.h:256

[Paul Menzel]

Dear Paul,


Am 13.02.22 um 15:45 schrieb Paul E. McKenney:
> On Sun, Feb 13, 2022 at 08:39:13AM +0100, Paul Menzel wrote:

> > Am 13.02.22 um 00:48 schrieb Paul E. McKenney:
> > > On Sun, Feb 13, 2022 at 12:05:50AM +0100, Paul Menzel wrote:
> >
> > […]
> >
> > > > Running rcutorture on the POWER8 system IBM S822LC with Ubuntu 20.10, it
> > > > found the bug below. I more or less used rcu/dev (0ba8896d2fd7
> > > > (lib/irq_poll: Declare IRQ_POLL softirq vector as ksoftirqd-parking safe))
> > > > [1]. The bug manifested for the four configurations below.
> > > >
> > > > 1.  results-rcutorture-kasan/SRCU-T
> > > > 2.  results-rcutorture-kasan/TINY02
> > > > 3.  results-rcutorture/SRCU-T
> > > > 4.  results-rcutorture/TINY02
> > >
> > > Adding Frederic on CC...
> > >
> > > I am dropping these three for the moment:
> > >
> > > 0ba8896d2fd75 lib/irq_poll: Declare IRQ_POLL softirq vector as ksoftirqd-parking safe
> > > efa8027149a1f tick/rcu: Stop allowing RCU_SOFTIRQ in idle
> > > d338d22b9d338 tick/rcu: Remove obsolete rcu_needs_cpu() parameters
> > >
> > > Though it might be that these are victims of circumstance, in other
> > > words, that the original bug that Paul Menzel reported was caused by
> > > something else.
> >
> > Even without these three patches, the issue is reproducible. I tested commit
> > 7a935b7ac61b (tools/nolibc/stdlib: implement abort()).
>
> Ah, I thought you were saying that the issue was caused by them.
>
> I will put them back.  And apologies to Frederic for kicking his
> patches out!

Sorry for being unclear.

> Are you able to bisect to see what commit introduced the problem?

I have not checked yet, if it’s a regression. I am going to test it next 
week.

[…]


Kind regards,