ftrace: add trace pipe header pluggin

This patch adds a method for open_pipe and open_read to the pluggins
so that they can add a header to the trace pipe call.

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, 5 insertions, 0 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index c1ec134ac356..ee53d706066f 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -135,9 +135,13 @@ struct tracer {
         void                    (*init)(struct trace_array *tr);
         void                    (*reset)(struct trace_array *tr);
         void                    (*open)(struct trace_iterator *iter);
+        void                    (*pipe_open)(struct trace_iterator *iter);
         void                    (*close)(struct trace_iterator *iter);
         void                    (*start)(struct trace_iterator *iter);
         void                    (*stop)(struct trace_iterator *iter);
+        ssize_t                 (*read)(struct trace_iterator *iter,
+                                        struct file *filp, char __user *ubuf,
+                                        size_t cnt, loff_t *ppos);
         void                    (*ctrl_update)(struct trace_array *tr);
 #ifdef CONFIG_FTRACE_STARTUP_TEST
         int                     (*selftest)(struct tracer *trace,
@@ -160,6 +164,7 @@ struct trace_seq {
 struct trace_iterator {
         struct trace_array      *tr;
         struct tracer           *trace;
+        void                    *private;
         long                    last_overrun[NR_CPUS];
         long                    overrun[NR_CPUS];