Re: [PATCH batadv] batman-adv: mark functions inheriting critical sections

[Sven Eckelmann <sven@narfation.org>]

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On Thursday, 15 October 2026 09:22:30 CEST sashiko-bot@kernel.org wrote:
[...]
> [Severity: Low]
> Does adding this capability annotation break the type signature when passed
> as a function pointer?
> 
> In net/batman-adv/originator.c, batadv_frag_check_entry() is passed as the
> check_cb argument to batadv_frag_purge_orig():
> 
> 			batadv_frag_purge_orig(orig_node,
> 					       batadv_frag_check_entry);
> 
> Because the check_cb function pointer definition lacks the corresponding
> capability annotation, this creates a capability type mismatch that leads to
> a static analysis warning or error during context analysis.

No, it doesn't in my tests.

> 
> [ ... ]
> 
> > diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c
> > index 22dd28d5e1abc..6ebab4eb1382e 100644
> > --- a/net/batman-adv/multicast.c
> > +++ b/net/batman-adv/multicast.c
> > @@ -683,6 +685,7 @@ static void batadv_mcast_mla_list_free(struct hlist_head *mcast_list)
> >   */
> >  static void batadv_mcast_mla_tt_retract(struct batadv_priv *bat_priv,
> >  					struct hlist_head *mcast_list)
> > +	__must_hold(&bat_priv->mcast.mla_lock)
> >  {
> 
> [Severity: Low]
> Is it possible this annotation is violated during teardown?
> 
> In batadv_mcast_free(), the code intentionally skips acquiring mla_lock
> because it relies on implicit serialization after the worker is canceled:
> 
> 	/* safely calling outside of worker, as worker was canceled above */
> 	batadv_mcast_mla_tt_retract(bat_priv, NULL);
> 
> However, batadv_mcast_mla_tt_retract() is now strictly annotated to require
> the lock, which will cause a build warning or error when compiled with
> CONFIG_WARN_CONTEXT_ANALYSIS=y. Is this one of the corner cases preventing
> the enablement of CONTEXT_ANALYSIS := y?

Yes, it is one one of the corner cases.

Regards,
	Sven

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