Re: [PATCH 03/21] rcu: Add a note about noinstr VS unsafe eqs functions

From: Peter Zijlstra
Date: Thu May 19 2022 - 11:02:59 EST


On Tue, May 03, 2022 at 12:00:33PM +0200, Frederic Weisbecker wrote:
> @@ -895,6 +899,10 @@ static void noinstr rcu_eqs_exit(bool user)
> *
> * If you add or remove a call to rcu_idle_exit(), be sure to test with
> * CONFIG_RCU_EQS_DEBUG=y.
> + *
> + * FIXME: This function should be noinstr but the below local_irq_save() is
> + * unsafe because it involves illegal RCU uses through tracing and lockdep.
> + * This must be fixed first.
> */
> void rcu_idle_exit(void)
> {

Urgh, except this one... I'm sure I fixed that at some point. Clearly
that never made it in :/