Commit 667347f1 authored by David S. Miller's avatar David S. Miller
Browse files

[NEIGH]: Add debugging check when adding timers. 



If we double-add a neighbour entry timer, which should be
impossible but has been reported, dump the current state of
the entry so that we can debug this.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 56e9b263

net/core/neighbour.c

+14 −9
Original line number Diff line number Diff line
@@ -727,6 +727,13 @@ static __inline__ int neigh_max_probes(struct neighbour *n) 
		p->ucast_probes + p->app_probes + p->mcast_probes);

}



static inline void neigh_add_timer(struct neighbour *n, unsigned long when)

{

	if (unlikely(mod_timer(&n->timer, when))) {

		printk("NEIGH: BUG, double timer add, state is %x\n",

		       n->nud_state);

	}

}



/* Called when a timer expires for a neighbour entry. */
@@ -811,8 +818,7 @@ static void neigh_timer_handler(unsigned long arg) 
		neigh_hold(neigh);

		if (time_before(next, jiffies + HZ/2))

			next = jiffies + HZ/2;

		neigh->timer.expires = next;

		add_timer(&neigh->timer);

		neigh_add_timer(neigh, next);

	}

	if (neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) {

		struct sk_buff *skb = skb_peek(&neigh->arp_queue);
@@ -854,8 +860,7 @@ int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 
			atomic_set(&neigh->probes, neigh->parms->ucast_probes);

			neigh->nud_state     = NUD_INCOMPLETE;

			neigh_hold(neigh);

			neigh->timer.expires = now + 1;

			add_timer(&neigh->timer);

			neigh_add_timer(neigh, now + 1);

		} else {

			neigh->nud_state = NUD_FAILED;

			write_unlock_bh(&neigh->lock);
@@ -868,8 +873,8 @@ int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 
		NEIGH_PRINTK2("neigh %p is delayed.\n", neigh);

		neigh_hold(neigh);

		neigh->nud_state = NUD_DELAY;

		neigh->timer.expires = jiffies + neigh->parms->delay_probe_time;

		add_timer(&neigh->timer);

		neigh_add_timer(neigh,

				jiffies + neigh->parms->delay_probe_time);

	}



	if (neigh->nud_state == NUD_INCOMPLETE) {
@@ -1015,10 +1020,10 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, 
		neigh_del_timer(neigh);

		if (new & NUD_IN_TIMER) {

			neigh_hold(neigh);

			neigh->timer.expires = jiffies + 

			neigh_add_timer(neigh, (jiffies + 

						((new & NUD_REACHABLE) ? 

						 neigh->parms->reachable_time : 0);

			add_timer(&neigh->timer);

						 neigh->parms->reachable_time :

						 0)));

		}

		neigh->nud_state = new;

	}