x86, ftrace: call trace->open() before stopping tracing; add trace->print_header()

Add a callback to allow an ftrace plug-in to write its own header.

Move the call to trace->open() up a few lines.

The changes are required by the BTS ftrace plug-in.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1 insertions, 0 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 28c15c2ebc22..717f9f045c6f 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -311,6 +311,7 @@ struct tracer {
         int                     (*selftest)(struct tracer *trace,
                                             struct trace_array *tr);
 #endif
+        void                    (*print_header)(struct seq_file *m);
         enum print_line_t       (*print_line)(struct trace_iterator *iter);
         /* If you handled the flag setting, return 0 */
         int                     (*set_flag)(u32 old_flags, u32 bit, int set);