Messages in this thread | | | Date | Mon, 16 Nov 2020 12:00:04 -0800 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH] rcu: Allow rcu_irq_enter_check_tick() from NMI |
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On Mon, Nov 16, 2020 at 06:24:31PM +0100, Thomas Gleixner wrote: > On Mon, Nov 16 2020 at 13:10, Peter Zijlstra wrote: > > > Any which way around; here's a proper patch... > > > > --- > > > > Subject: rcu: Allow rcu_irq_enter_check_tick() from NMI > > From: Peter Zijlstra <peterz@infradead.org> > > Date: Mon Nov 16 12:54:56 CET 2020 > > > > Eugenio managed to tickle #PF from NMI context which resulted in > > hitting a WARN in RCU through irqentry_enter() -> > > __rcu_irq_enter_check_tick(). > > > > However, this situation is perfectly sane and does not warrant an > > WARN. The #PF will (necessarily) be atomic and not require messing > > with the tick state, so early return is correct. > > > > Fixes: aaf2bc50df1f ("rcu: Abstract out rcu_irq_enter_check_tick() from rcu_nmi_enter()") > > Reported-by: "Eugenio Pérez" <eupm90@gmail.com> > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> > > Reviewed-by: Andy Lutomirski <luto@kernel.org> > > Reviewed-by: Paul E. McKenney <paulmck@kernel.org> > > Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Queued, thank you all!
Thanx, Paul
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