[PATCH 01/12] evtchn: refuse EVTCHNOP_status for Xen-bound event channels

[Jan Beulich <jbeulich@xxxxxxxx>]

Callers have no business knowing the state of the Xen end of an event
channel.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -933,6 +933,11 @@ int evtchn_status(evtchn_status_t *statu
     }
 
     chn = evtchn_from_port(d, port);
+    if ( consumer_is_xen(chn) )
+    {
+        rc = -EACCES;
+        goto out;
+    }
 
     rc = xsm_evtchn_status(XSM_TARGET, d, chn);
     if ( rc )