Re: [PATCH] kcsan: Treat runtime as NMI-like with interrupt tracing

From: peterz
Date: Mon Aug 10 2020 - 10:06:59 EST


On Mon, Aug 10, 2020 at 10:07:44AM +0200, Marco Elver wrote:
> On Fri, 7 Aug 2020 at 19:06, Paul E. McKenney <paulmck@xxxxxxxxxx> wrote:
> > On Fri, Aug 07, 2020 at 11:00:31AM +0200, Marco Elver wrote:
> > > Since KCSAN instrumentation is everywhere, we need to treat the hooks
> > > NMI-like for interrupt tracing. In order to present an as 'normal' as
> > > possible context to the code called by KCSAN when reporting errors, we
> > > need to update the IRQ-tracing state.
> > >
> > > Tested: Several runs through kcsan-test with different configuration
> > > (PROVE_LOCKING on/off), as well as hours of syzbot testing with the
> > > original config that caught the problem (without CONFIG_PARAVIRT=y,
> > > which appears to cause IRQ state tracking inconsistencies even when
> > > KCSAN remains off, see Link).
> > >
> > > Link: https://lkml.kernel.org/r/0000000000007d3b2d05ac1c303e@xxxxxxxxxx
> > > Fixes: 248591f5d257 ("kcsan: Make KCSAN compatible with new IRQ state tracking")
> > > Reported-by: syzbot+8db9e1ecde74e590a657@xxxxxxxxxxxxxxxxxxxxxxxxx
> > > Co-developed-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
>
> Peter, if you're fine with it, I think we'll require your
> Signed-off-by (since Co-developed-by).

Sure:

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>