D28836.diff
No OneTemporary
Actions

Size

1 KB

Referenced Files

None

Subscribers

None

D28836.diff
View Options

	diff --git a/sys/net/if.c b/sys/net/if.c
	--- a/sys/net/if.c
	+++ b/sys/net/if.c
	@@ -359,7 +359,8 @@
	ifp = ifnet_byindex(idx);
	if (ifp == NULL \|\| (ifp->if_flags & IFF_DYING))
	return (NULL);
	- if_ref(ifp);
	+ if (!if_try_ref(ifp))
	+ return (NULL);
	return (ifp);
	}

	@@ -738,9 +739,18 @@
	void
	if_ref(struct ifnet *ifp)
	{
	+ u_int old;

	/* We don't assert the ifnet list lock here, but arguably should. */
	- refcount_acquire(&ifp->if_refcount);
	+ old = refcount_acquire(&ifp->if_refcount);
	+ KASSERT(old > 0, ("%s: ifp %p has 0 refs", __func__, ifp));
	+}
	+
	+bool
	+if_try_ref(struct ifnet *ifp)
	+{
	+ NET_EPOCH_ASSERT();
	+ return (refcount_acquire_if_not_zero(&ifp->if_refcount));
	}

	void
	diff --git a/sys/net/if_var.h b/sys/net/if_var.h
	--- a/sys/net/if_var.h
	+++ b/sys/net/if_var.h
	@@ -661,6 +661,7 @@
	int if_printf(struct ifnet , const char , ...) __printflike(2, 3);
	void if_ref(struct ifnet *);
	void if_rele(struct ifnet *);
	+bool if_try_ref(struct ifnet *);
	int if_setlladdr(struct ifnet , const u_char , int);
	int if_tunnel_check_nesting(struct ifnet , struct mbuf , uint32_t, int);
	void if_up(struct ifnet *);