2 files changed, 17 insertions, 41 deletions

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 2d5964119885..3651fdc3bec9 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -27,6 +27,19 @@
 #define ARCH_SUPPORTS_FTRACE_OPS 0
 #endif
 
+/*
+ * If the arch's mcount caller does not support all of ftrace's
+ * features, then it must call an indirect function that
+ * does. Or at least does enough to prevent any unwelcomed side effects.
+ */
+#if !defined(CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST) || \
+        !ARCH_SUPPORTS_FTRACE_OPS
+# define FTRACE_FORCE_LIST_FUNC 1
+#else
+# define FTRACE_FORCE_LIST_FUNC 0
+#endif
+
+
 struct module;
 struct ftrace_hash;
 
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 4f2ab9352a68..4cbca2e6eb70 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -97,8 +97,6 @@ static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end;
 static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end;
 static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
-static ftrace_func_t __ftrace_trace_function_delay __read_mostly = ftrace_stub;
-ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
 ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
 static struct ftrace_ops global_ops;
 static struct ftrace_ops control_ops;
@@ -162,26 +160,9 @@ static void set_ftrace_pid_function(ftrace_func_t func)
 void clear_ftrace_function(void)
 {
         ftrace_trace_function = ftrace_stub;
-        __ftrace_trace_function = ftrace_stub;
-        __ftrace_trace_function_delay = ftrace_stub;
         ftrace_pid_function = ftrace_stub;
 }
 
-#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
-/*
- * For those archs that do not test ftrace_trace_stop in their
- * mcount call site, we need to do it from C.
- */
-static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip,
-                                  struct ftrace_ops *op)
-{
-        if (function_trace_stop)
-                return;
-
-        __ftrace_trace_function(ip, parent_ip, op);
-}
-#endif
-
 static void control_ops_disable_all(struct ftrace_ops *ops)
 {
         int cpu;
@@ -246,7 +227,7 @@ static void update_ftrace_function(void)
         if (ftrace_ops_list == &ftrace_list_end ||
             (ftrace_ops_list->next == &ftrace_list_end &&
              !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) &&
-             ARCH_SUPPORTS_FTRACE_OPS)) {
+             !FTRACE_FORCE_LIST_FUNC)) {
                 /* Set the ftrace_ops that the arch callback uses */
                 if (ftrace_ops_list == &global_ops)
                         function_trace_op = ftrace_global_list;
@@ -259,18 +240,7 @@ static void update_ftrace_function(void)
                 func = ftrace_ops_list_func;
         }
 
-#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
         ftrace_trace_function = func;
-#else
-#ifdef CONFIG_DYNAMIC_FTRACE
-        /* do not update till all functions have been modified */
-        __ftrace_trace_function_delay = func;
-#else
-        __ftrace_trace_function = func;
-#endif
-        ftrace_trace_function =
-                (func == ftrace_stub) ? func : ftrace_test_stop_func;
-#endif
 }
 
 static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
@@ -1902,16 +1872,6 @@ static void ftrace_run_update_code(int command)
          */
         arch_ftrace_update_code(command);
 
-#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
-        /*
-         * For archs that call ftrace_test_stop_func(), we must
-         * wait till after we update all the function callers
-         * before we update the callback. This keeps different
-         * ops that record different functions from corrupting
-         * each other.
-         */
-        __ftrace_trace_function = __ftrace_trace_function_delay;
-#endif
         function_trace_stop--;
 
         ret = ftrace_arch_code_modify_post_process();
@@ -3996,6 +3956,9 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
 {
         struct ftrace_ops *op;
 
+        if (function_trace_stop)
+                return;
+
         if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT)))
                 return;