Attach:
splassert: sowakeup: want 1 have 0
Starting stack trace...
sowakeup() at sowakeup+0x41
sorwakeup() at sorwakeup+0xb4
route_input() at route_input+0x2d7
if_attach() at if_attach+0x58
xnf_attach() at xnf_attach+0x45f
config_attach() at config_attach+0x1bc
xen_attach_device() at xen_attach_device+0x146
xen_hotplug() at xen_hotplug+0x23f
taskq_thread() at taskq_thread+0x6c
end trace frame: 0x0, count: 248
End of stack trace.
Detach:
splassert: sowakeup: want 1 have 0
Starting stack trace...
sowakeup() at sowakeup+0x41
sorwakeup() at sorwakeup+0xb4
route_input() at route_input+0x2d7
if_detach() at if_detach+0x27e
xnf_detach() at xnf_detach+0x4d
config_detach() at config_detach+0x13c
xen_hotplug() at xen_hotplug+0x2e5
taskq_thread() at taskq_thread+0x6c
end trace frame: 0x0, count: 249
End of stack trace.
xnf2 detached
The taskq running xen_hotplug is KERNEL_LOCK'ed. The diff below solves
the issue, but is it any good?
diff --git sys/net/if.c sys/net/if.c
index 1e103564710..a5c25b89560 100644
--- sys/net/if.c
+++ sys/net/if.c
@@ -525,11 +525,11 @@ if_attach(struct ifnet *ifp)
{
int s;
- s = splsoftnet();
+ NET_LOCK(s);
if_attach_common(ifp);
TAILQ_INSERT_TAIL(&ifnet, ifp, if_list);
if_attachsetup(ifp);
- splx(s);
+ NET_UNLOCK(s);
}
void
@@ -941,6 +941,7 @@ if_detach(struct ifnet *ifp)
ifq_clr_oactive(&ifp->if_snd);
+ rw_enter_write(&netlock);
s = splnet();
/* Other CPUs must not have a reference before we start destroying. */
if_idxmap_remove(ifp);
@@ -1017,6 +1018,7 @@ if_detach(struct ifnet *ifp)
/* Announce that the interface is gone. */
rt_ifannouncemsg(ifp, IFAN_DEPARTURE);
splx(s);
+ rw_exit_write(&netlock);
ifq_destroy(&ifp->if_snd);
}
