tracing/events: Add trace_define_common_fields()

Extract duplicate code. Also prepare for the later patch.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A8BAFB8.1010304@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

4 files changed, 29 insertions, 17 deletions

diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 35b3a4a5ba86..427cbae47f84 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -142,6 +142,7 @@ extern int filter_current_check_discard(struct ftrace_event_call *call,
 
 extern int trace_define_field(struct ftrace_event_call *call, char *type,
                               char *name, int offset, int size, int is_signed);
+extern int trace_define_common_fields(struct ftrace_event_call *call);
 
 #define is_signed_type(type)    (((type)(-1)) < 0)
 
@@ -166,11 +167,4 @@ do {									\
                 __trace_printk(ip, fmt, ##args);                        \
 } while (0)
 
-#define __common_field(type, item, is_signed)                           \
-        ret = trace_define_field(event_call, #type, "common_" #item,    \
-                                 offsetof(typeof(field.ent), item),     \
-                                 sizeof(field.ent.item), is_signed);    \
-        if (ret)                                                        \
-                return ret;
-
 #endif /* _LINUX_FTRACE_EVENT_H */
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 4e81c9b37515..127400255e4c 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -299,11 +299,9 @@ ftrace_define_fields_##call(struct ftrace_event_call *event_call)	\
         struct ftrace_raw_##call field;                                 \
         int ret;                                                        \
                                                                         \
-        __common_field(int, type, 1);                                   \
-        __common_field(unsigned char, flags, 0);                        \
-        __common_field(unsigned char, preempt_count, 0);                \
-        __common_field(int, pid, 1);                                    \
-        __common_field(int, tgid, 1);                                   \
+        ret = trace_define_common_fields(event_call);                   \
+        if (ret)                                                        \
+                return ret;                                             \
                                                                         \
         tstruct;                                                        \
                                                                         \
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index af8fb8ebef0b..9c7ecfb3416f 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -62,6 +62,28 @@ err:
 }
 EXPORT_SYMBOL_GPL(trace_define_field);
 
+#define __common_field(type, item)                                      \
+        ret = trace_define_field(call, #type, "common_" #item,          \
+                                 offsetof(typeof(ent), item),           \
+                                 sizeof(ent.item),                      \
+                                 is_signed_type(type));                 \
+        if (ret)                                                        \
+                return ret;
+
+int trace_define_common_fields(struct ftrace_event_call *call)
+{
+        int ret;
+        struct trace_entry ent;
+
+        __common_field(unsigned short, type);
+        __common_field(unsigned char, flags);
+        __common_field(unsigned char, preempt_count);
+        __common_field(int, pid);
+        __common_field(int, tgid);
+
+        return ret;
+}
+
 #ifdef CONFIG_MODULES
 
 static void trace_destroy_fields(struct ftrace_event_call *call)
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index cf2c752a25bf..70875303ae46 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -189,11 +189,9 @@ ftrace_define_fields_##call(struct ftrace_event_call *event_call)	\
         struct args field;                                              \
         int ret;                                                        \
                                                                         \
-        __common_field(unsigned char, type, 0);                         \
-        __common_field(unsigned char, flags, 0);                        \
-        __common_field(unsigned char, preempt_count, 0);                \
-        __common_field(int, pid, 1);                                    \
-        __common_field(int, tgid, 1);                                   \
+        ret = trace_define_common_fields(event_call);                   \
+        if (ret)                                                        \
+                return ret;                                             \
                                                                         \
         tstruct;                                                        \
                                                                         \