Re: [PATCH 0/8] tracing vs rcu vs nmi

[Peter Zijlstra]

On Wed, Feb 12, 2020 at 10:32:10AM +0100, Peter Zijlstra wrote:
> Hi all,
> 
> These here patches are the result of Mathieu and Steve trying to get commit
> 865e63b04e9b2 ("tracing: Add back in rcu_irq_enter/exit_irqson() for rcuidle
> tracepoints") reverted again.
> 
> One of the things discovered is that tracing MUST NOT happen before nmi_enter()
> or after nmi_exit(). I've only fixed x86, but quickly gone through other
> architectures and there is definitely more stuff to be fixed (simply grep for
> nmi_enter in your arch).

For ARM64:

 - apei_claim_sea()
 - __sdei_handler()
 - do_serror()
 - debug_exception_enter() / do_debug_exception()

all look dodgy.