1 files changed, 38 insertions, 22 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 92376aeac4a7..08aca65d709a 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -68,8 +68,12 @@
 #define INIT_OPS_HASH(opsname)  \
         .func_hash              = &opsname.local_hash,                  \
         .local_hash.regex_lock  = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
+#define ASSIGN_OPS_HASH(opsname, val) \
+        .func_hash              = val, \
+        .local_hash.regex_lock  = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
 #else
 #define INIT_OPS_HASH(opsname)
+#define ASSIGN_OPS_HASH(opsname, val)
 #endif
 
 static struct ftrace_ops ftrace_list_end __read_mostly = {
@@ -4663,7 +4667,6 @@ void __init ftrace_init(void)
 static struct ftrace_ops global_ops = {
         .func                   = ftrace_stub,
         .flags                  = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
-        INIT_OPS_HASH(global_ops)
 };
 
 static int __init ftrace_nodyn_init(void)
@@ -5197,6 +5200,17 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
+static struct ftrace_ops graph_ops = {
+        .func                   = ftrace_stub,
+        .flags                  = FTRACE_OPS_FL_RECURSION_SAFE |
+                                   FTRACE_OPS_FL_INITIALIZED |
+                                   FTRACE_OPS_FL_STUB,
+#ifdef FTRACE_GRAPH_TRAMP_ADDR
+        .trampoline             = FTRACE_GRAPH_TRAMP_ADDR,
+#endif
+        ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
+};
+
 static int ftrace_graph_active;
 
 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
@@ -5359,12 +5373,28 @@ static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
  */
 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
+        struct ftrace_ops *op;
+        bool do_test = false;
+
+        /*
+         * The graph and global ops share the same set of functions
+         * to test. If any other ops is on the list, then
+         * the graph tracing needs to test if its the function
+         * it should call.
+         */
+        do_for_each_ftrace_op(op, ftrace_ops_list) {
+                if (op != &global_ops && op != &graph_ops &&
+                    op != &ftrace_list_end) {
+                        do_test = true;
+                        /* in double loop, break out with goto */
+                        goto out;
+                }
+        } while_for_each_ftrace_op(op);
+ out:
+        if (do_test)
                 ftrace_graph_entry = ftrace_graph_entry_test;
+        else
+                ftrace_graph_entry = __ftrace_graph_entry;
 }
 
 static struct notifier_block ftrace_suspend_notifier = {
@@ -5405,16 +5435,7 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
         ftrace_graph_entry = ftrace_graph_entry_test;
         update_function_graph_func();
 
-        /* Function graph doesn't use the .func field of global_ops */
-        global_ops.flags |= FTRACE_OPS_FL_STUB;
-
-#ifdef CONFIG_DYNAMIC_FTRACE
-        /* Optimize function graph calling (if implemented by arch) */
-        if (FTRACE_GRAPH_TRAMP_ADDR != 0)
-                global_ops.trampoline = FTRACE_GRAPH_TRAMP_ADDR;
-#endif
-
-        ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
+        ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET);
 
 out:
         mutex_unlock(&ftrace_lock);
@@ -5432,12 +5453,7 @@ void unregister_ftrace_graph(void)
         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(&global_ops, FTRACE_STOP_FUNC_RET);
-        global_ops.flags &= ~FTRACE_OPS_FL_STUB;
-#ifdef CONFIG_DYNAMIC_FTRACE
-        if (FTRACE_GRAPH_TRAMP_ADDR != 0)
-                global_ops.trampoline = 0;
-#endif
+        ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);
         unregister_pm_notifier(&ftrace_suspend_notifier);
         unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);