On Wed, Oct 02, 2024 at 05:00:03PM +0200, Frederic Weisbecker wrote:
> Le Wed, Oct 02, 2024 at 04:57:38PM +0200, Frederic Weisbecker a écrit :
> > Callbacks enqueued after rcutree_report_cpu_dead() fall into RCU barrier
> > blind spot. Report any potential misuse.
> >
> > Reported-by: Paul E. McKenney <paul...@kernel.org>
> > Signed-off-by: Frederic Weisbecker <frede...@kernel.org>
> > ---
> > kernel/rcu/tree.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> > index a60616e69b66..36070b6bf4a1 100644
> > --- a/kernel/rcu/tree.c
> > +++ b/kernel/rcu/tree.c
> > @@ -3084,8 +3084,11 @@ __call_rcu_common(struct rcu_head *head,
> > rcu_callback_t func, bool lazy_in)
> > head->func = func;
> > head->next = NULL;
> > kasan_record_aux_stack_noalloc(head);
> > +
> > local_irq_save(flags);
> > rdp = this_cpu_ptr(&rcu_data);
> > + RCU_LOCKDEP_WARN(rcu_rdp_cpu_online(rdp), "Callback enqueued on offline
> > CPU!");
>
> This should be !rcu_rdp_cpu_online(rdp)
>
> Sigh...
I am pulling this in for testing with this change, thank you!
Thanx, Paul
> > +
> > lazy = lazy_in && !rcu_async_should_hurry();
> >
> > /* Add the callback to our list. */
> > --
> > 2.46.0
> >
> >
