Merge branch 'upstream/bugfix' of git://github.com/jsgf/linux-xen

* 'upstream/bugfix' of git://github.com/jsgf/linux-xen:
  xen: use non-tracing preempt in xen_clocksource_read()

arch/x86/xen/time.c

@@ -168,9 +168,10 @@ cycle_t xen_clocksource_read(void)
         struct pvclock_vcpu_time_info *src;
 	cycle_t ret;
 
-	src = &get_cpu_var(xen_vcpu)->time;
+	preempt_disable_notrace();
+	src = &__get_cpu_var(xen_vcpu)->time;
 	ret = pvclock_clocksource_read(src);
-	put_cpu_var(xen_vcpu);
+	preempt_enable_notrace();
 	return ret;
 }