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Date:   Fri, 6 Apr 2018 18:34:50 +0100
From:   Mark Rutland <mark.rutland@arm.com>
To:     James Morse <james.morse@arm.com>
Cc:     Yury Norov <ynorov@caviumnetworks.com>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Will Deacon <will.deacon@arm.com>,
        Chris Metcalf <cmetcalf@mellanox.com>,
        Christopher Lameter <cl@linux.com>,
        Russell King - ARM Linux <linux@armlinux.org.uk>,
        Steven Rostedt <rostedt@goodmis.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
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        Michael Ellerman <mpe@ellerman.id.au>,
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Subject: Re: [PATCH 1/5] arm64: entry: isb in el1_irq
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On Fri, Apr 06, 2018 at 06:30:50PM +0100, James Morse wrote:
> Hi Mark,
> 
> On 06/04/18 18:22, Mark Rutland wrote:
> > Digging a bit, I also thing that our ct_user_exit and ct_user_enter
> > usage is on dodgy ground today.
> 
> [...]
> 
> > I think similar applies to SDEI; we don't negotiate with RCU prior to
> > invoking handlers, which might need RCU.
> 
> The arch code's __sdei_handler() calls nmi_enter() -> rcu_nmi_enter(), which
> does a rcu_dynticks_eqs_exit().

Ah, sorry. I missed that!

Thanks,
Mark.