[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: David S. Miller <davem@davemloft.net>
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 5f16008..4128fc7 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -727,6 +727,13 @@
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 @@
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 @@
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 @@
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 @@
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;
}