[PATCH -v2 7/8] kexec jump: ftrace_enabled_save/restore

[Huang Ying <ying.huang@intel.com>]

Add ftrace_enabled_save/restore, used to disable ftrace for a
while. This is used by kexec jump.

Signed-off-by: Huang Ying <ying.huang@intel.com>

---
 include/linux/ftrace.h |   18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -98,6 +98,24 @@ static inline void tracer_disable(void)
 #endif
 }
 
+static inline int ftrace_enabled_save(void)
+{
+#ifdef CONFIG_FTRACE
+	int saved_ftrace_enabled = ftrace_enabled;
+	ftrace_enabled = 0;
+	return saved_ftrace_enabled;
+#else
+	return 0;
+#endif
+}
+
+static inline void ftrace_enabled_restore(int enabled)
+{
+#ifdef CONFIG_FTRACE
+	ftrace_enabled = enabled;
+#endif
+}
+
 #ifdef CONFIG_FRAME_POINTER
 /* TODO: need to fix this for ARM */
 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))