---

yaml
---
r: 121245
b: refs/heads/master
c: 62679ef
h: refs/heads/master
i:
  121243: 8468d0a
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e49dc19c6a19ea112fcb94b7c62ec62cdd5c08aa
+refs/heads/master: 62679efe0a5f02987a621942afc5979a80a6ca5a

trunk/arch/x86/kernel/ftrace.c

@@ -420,13 +420,23 @@ static void pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
 	int index;
 
 	index = current->curr_ret_stack;
+
+	if (unlikely(index < 0)) {
+		ftrace_graph_stop();
+		WARN_ON(1);
+		/* Might as well panic, otherwise we have no where to go */
+		*ret = (unsigned long)panic;
+		return;
+	}
+
 	*ret = current->ret_stack[index].ret;
 	trace->func = current->ret_stack[index].func;
 	trace->calltime = current->ret_stack[index].calltime;
 	trace->overrun = atomic_read(&current->trace_overrun);
 	trace->depth = index;
 	barrier();
 	current->curr_ret_stack--;
+
 }
 
 /*
@@ -442,6 +452,13 @@ unsigned long ftrace_return_to_handler(void)
 	trace.rettime = cpu_clock(raw_smp_processor_id());
 	ftrace_graph_return(&trace);
 
+	if (unlikely(!ret)) {
+		ftrace_graph_stop();
+		WARN_ON(1);
+		/* Might as well panic. What else to do? */
+		ret = (unsigned long)panic;
+	}
+
 	return ret;
 }