Re: [PATCH -rcu] kcsan: Make KCSAN compatible with lockdep

From: Paul E. McKenney
Date: Wed Jan 15 2020 - 11:37:57 EST


On Wed, Jan 15, 2020 at 05:26:55PM +0100, Marco Elver wrote:
> On Tue, 14 Jan 2020 at 18:24, Alexander Potapenko <glider@xxxxxxxxxx> wrote:
> >
> > > --- a/kernel/kcsan/core.c
> > > +++ b/kernel/kcsan/core.c
> > > @@ -337,7 +337,7 @@ kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type)
> > > * detection point of view) to simply disable preemptions to ensure
> > > * as many tasks as possible run on other CPUs.
> > > */
> > > - local_irq_save(irq_flags);
> > > + raw_local_irq_save(irq_flags);
> >
> > Please reflect the need to use raw_local_irq_save() in the comment.
> >
> > >
> > > watchpoint = insert_watchpoint((unsigned long)ptr, size, is_write);
> > > if (watchpoint == NULL) {
> > > @@ -429,7 +429,7 @@ kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type)
> > >
> > > kcsan_counter_dec(KCSAN_COUNTER_USED_WATCHPOINTS);
> > > out_unlock:
> > > - local_irq_restore(irq_flags);
> > > + raw_local_irq_restore(irq_flags);
> >
> > Ditto
>
> Done. v2: http://lkml.kernel.org/r/20200115162512.70807-1-elver@xxxxxxxxxx

Alexander and Qian, could you please let me know if this fixes things
up for you?

Thanx, Paul