On Wed, Aug 19, 2020 at 08:39:13PM +1000, Alexey Kardashevskiy wrote:
> > or current upstream?
>
> The upstream 18445bf405cb (13 hours old) also shows the problem. Yours
> 1/2 still fixes it.
Afaict that just reduces the window.
Isn't the problem that:
arch/powerpc/kernel/exceptions-64e.S
START_EXCEPTION(perfmon);
NORMAL_EXCEPTION_PROLOG(0x260, BOOKE_INTERRUPT_PERFORMANCE_MONITOR,
PROLOG_ADDITION_NONE)
EXCEPTION_COMMON(0x260)
INTS_DISABLE
# RECONCILE_IRQ_STATE
# TRACE_DISABLE_INTS
# TRACE_WITH_FRAME_BUFFER(trace_hardirqs_off)
#
# but we haven't done nmi_enter() yet... whoopsy
CHECK_NAPPING()
addi r3,r1,STACK_FRAME_OVERHEAD
bl performance_monitor_exception
# perf_irq()
# perf_event_interrupt
# __perf_event_interrupt
# nmi_enter()
That is, afaict your entry code is buggered.
