[for-next][PATCH 4/5] function_graph: Use a ftrace_graph_ret_stub() for return

[Steven Rostedt <rostedt@goodmis.org>]

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

There's a unique ftrace_graph_entry_stub() for the entryfunc of a
fgraph_ops, but the ftrace_stub is used for the retfunc(). To be consistent
and also to use the same type of function as the type being called for
retfunc(), create and use ftrace_graph_ret_stub().

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/fgraph.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 8dfd5021b933..580ce7534a49 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -327,14 +327,17 @@ void ftrace_graph_sleep_time_control(bool enable)
 	fgraph_sleep_time = enable;
 }
 
+static void ftrace_graph_ret_stub(struct ftrace_graph_ret *trace)
+{
+}
+
 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
 {
 	return 0;
 }
 
 /* The callbacks that hook a function */
-trace_func_graph_ret_t ftrace_graph_return =
-			(trace_func_graph_ret_t)ftrace_stub;
+trace_func_graph_ret_t ftrace_graph_return = ftrace_graph_ret_stub;
 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
 static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
 
@@ -614,7 +617,7 @@ void unregister_ftrace_graph(struct fgraph_ops *gops)
 		goto out;
 
 	ftrace_graph_active--;
-	ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
+	ftrace_graph_return = ftrace_graph_ret_stub;
 	ftrace_graph_entry = ftrace_graph_entry_stub;
 	__ftrace_graph_entry = ftrace_graph_entry_stub;
 	ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);
-- 
2.20.1