tracing: use union for multi-usages field

Impact: cleanup

struct dyn_ftrace::ip has different usages in his lifecycle,
we use union for it. And also for struct dyn_ftrace::flags.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <49C871BE.3080405@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 9 insertions, 3 deletions

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 1141248c84ee..015a3d22cf74 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -145,9 +145,15 @@ enum {
 };
 
 struct dyn_ftrace {
-        unsigned long           ip; /* address of mcount call-site */
-        unsigned long           flags;
-        struct dyn_arch_ftrace  arch;
+        union {
+                unsigned long           ip; /* address of mcount call-site */
+                struct dyn_ftrace       *freelist;
+        };
+        union {
+                unsigned long           flags;
+                struct dyn_ftrace       *newlist;
+        };
+        struct dyn_arch_ftrace          arch;
 };
 
 int ftrace_force_update(void);