Re: 4.12-RC2 BUG: scheduling while atomic: irq/47-iwlwifi

On 23-5-2017 9:22, Johannes Berg wrote:

On Tue, 2017-05-23 at 09:19 +0200, Arend Van Spriel wrote:

quoted

quoted

	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());

Thought about something like this after sending the email. So there
are two call sites. One for scheduled scan results notification and
one in scheduled scan stop scenario. So for the latter it is not
needed to use the rcu_read_lock() as it should have RTNL lock hence
the two checks above?

Right. The latter can't even really use rcu_read_lock() since it also
wants to modify the list, and that's not sufficient protection for
modifying.

Hence the name ;-)

Regards,
Arend