ftrace: add a buffer for output

Later patches will need to print the same things as the seq output
does. But those outputs will not use the seq utility. This patch
adds a buffer to the iterator, that can be used by either the
seq utility or other output.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 6 insertions, 0 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 0ce127455b4b..f5b32ca0b457 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -111,11 +111,17 @@ struct tracer {
         int                     print_max;
 };
 
+struct trace_seq {
+        unsigned char           buffer[PAGE_SIZE];
+        unsigned int            len;
+};
+
 /*
  * Trace iterator - used by printout routines who present trace
  * results to users and which routines might sleep, etc:
  */
 struct trace_iterator {
+        struct trace_seq        seq;
         struct trace_array      *tr;
         struct tracer           *trace;