Re: [PATCH] x86 NMI: Be smarter about invoking panic() inside NMI handler.

From: Andrei E. Warkentin
Date: Tue Mar 20 2012 - 13:57:44 EST


Hi,

2012/3/1 Andrei Warkentin <andrey.warkentin@xxxxxxxxx>:
> If two (or more) unknown NMIs arrive on different CPUs, there
> is a large chance both CPUs will wind up inside panic(). This
> is fine, unless you want to enter KDB - KDB cannot round up
> all CPUs, because some of them are stuck inside
> panic_smp_self_stop with NMI latched. This is
> easy to replicate with QEMU. Boot with -smp 4 and
> send NMI using the monitor.
>
> Solution for this - attempt to enter panic() from NMI
> handler. If panic() is already active in the system,
> just exit out of the NMI handler. This lets KDB round
> up CPUs.
>
> Signed-off-by: Andrei Warkentin <andrey.warkentin@xxxxxxxxx>
> ---

Any feedback on this? Who are the right maintainers to bug about this?

A
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