1 files changed, 44 insertions, 1 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 17b95a492948..4b93b8412252 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -297,6 +297,12 @@ static void ftrace_sync_ipi(void *data)
         smp_rmb();
 }
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static void update_function_graph_func(void);
+#else
+static inline void update_function_graph_func(void) { }
+#endif
+
 static void update_ftrace_function(void)
 {
         ftrace_func_t func;
@@ -329,6 +335,8 @@ static void update_ftrace_function(void)
         if (ftrace_trace_function == func)
                 return;
 
+        update_function_graph_func();
+
         /*
          * If we are using the list function, it doesn't care
          * about the function_trace_ops.
@@ -4810,6 +4818,7 @@ int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
 trace_func_graph_ret_t ftrace_graph_return =
                         (trace_func_graph_ret_t)ftrace_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;
 
 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
@@ -4951,6 +4960,30 @@ static struct ftrace_ops fgraph_ops __read_mostly = {
                                 FTRACE_OPS_FL_RECURSION_SAFE,
 };
 
+static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
+{
+        if (!ftrace_ops_test(&global_ops, trace->func, NULL))
+                return 0;
+        return __ftrace_graph_entry(trace);
+}
+
+/*
+ * The function graph tracer should only trace the functions defined
+ * by set_ftrace_filter and set_ftrace_notrace. If another function
+ * tracer ops is registered, the graph tracer requires testing the
+ * function against the global ops, and not just trace any function
+ * that any ftrace_ops registered.
+ */
+static void update_function_graph_func(void)
+{
+        if (ftrace_ops_list == &ftrace_list_end ||
+            (ftrace_ops_list == &global_ops &&
+             global_ops.next == &ftrace_list_end))
+                ftrace_graph_entry = __ftrace_graph_entry;
+        else
+                ftrace_graph_entry = ftrace_graph_entry_test;
+}
+
 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
                         trace_func_graph_ent_t entryfunc)
 {
@@ -4975,7 +5008,16 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
         }
 
         ftrace_graph_return = retfunc;
-        ftrace_graph_entry = entryfunc;
+
+        /*
+         * Update the indirect function to the entryfunc, and the
+         * function that gets called to the entry_test first. Then
+         * call the update fgraph entry function to determine if
+         * the entryfunc should be called directly or not.
+         */
+        __ftrace_graph_entry = entryfunc;
+        ftrace_graph_entry = ftrace_graph_entry_test;
+        update_function_graph_func();
 
         ret = ftrace_startup(&fgraph_ops, FTRACE_START_FUNC_RET);
 
@@ -4994,6 +5036,7 @@ void unregister_ftrace_graph(void)
         ftrace_graph_active--;
         ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
         ftrace_graph_entry = ftrace_graph_entry_stub;
+        __ftrace_graph_entry = ftrace_graph_entry_stub;
         ftrace_shutdown(&fgraph_ops, FTRACE_STOP_FUNC_RET);
         unregister_pm_notifier(&ftrace_suspend_notifier);
         unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);