ftrace: add trace_special()

for ad-hoc tracing.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 15 insertions, 0 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 27fa2d06f499..7bdfef35c05a 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -26,6 +26,15 @@ struct ctx_switch_entry {
 };
 
 /*
+ * Special (free-form) trace entry:
+ */
+struct special_entry {
+        unsigned long           arg1;
+        unsigned long           arg2;
+        unsigned long           arg3;
+};
+
+/*
  * The trace entry - the most basic unit of tracing. This is what
  * is printed in the end as a single line in the trace output, such as:
  *
@@ -41,6 +50,7 @@ struct trace_entry {
         union {
                 struct ftrace_entry             fn;
                 struct ctx_switch_entry         ctx;
+                struct special_entry            special;
         };
 };
 
@@ -154,6 +164,11 @@ void tracing_sched_switch_trace(struct trace_array *tr,
                                 struct task_struct *next,
                                 unsigned long flags);
 void tracing_record_cmdline(struct task_struct *tsk);
+void trace_special(struct trace_array *tr,
+                   struct trace_array_cpu *data,
+                   unsigned long arg1,
+                   unsigned long arg2,
+                   unsigned long arg3);
 
 void tracing_start_function_trace(void);
 void tracing_stop_function_trace(void);