tracing/events: add export symbols for trace events in modules

Impact: let modules add trace events

The trace event code requires some functions to be exported to allow
modules to use TRACE_EVENT. This patch adds EXPORT_SYMBOL_GPL to the
necessary functions.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/trace.c

@@ -176,6 +176,7 @@ int filter_current_check_discard(struct ftrace_event_call *call, void *rec,
 {
 	return filter_check_discard(call, rec, global_trace.buffer, event);
 }
+EXPORT_SYMBOL_GPL(filter_current_check_discard);
 
 cycle_t ftrace_now(int cpu)
 {
@@ -886,6 +887,7 @@ trace_current_buffer_lock_reserve(unsigned char type, unsigned long len,
 	return trace_buffer_lock_reserve(&global_trace,
 					 type, len, flags, pc);
 }
+EXPORT_SYMBOL(trace_current_buffer_lock_reserve);
 
 void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
 					unsigned long flags, int pc)
@@ -903,6 +905,7 @@ void trace_current_buffer_discard_commit(struct ring_buffer_event *event)
 {
 	ring_buffer_discard_commit(global_trace.buffer, event);
 }
+EXPORT_SYMBOL_GPL(trace_nowake_buffer_unlock_commit);
 
 void
 trace_function(struct trace_array *tr,

kernel/trace/trace_events.c

@@ -53,6 +53,7 @@ err:
 
 	return -ENOMEM;
 }
+EXPORT_SYMBOL_GPL(trace_define_field);
 
 static void ftrace_clear_events(void)
 {

kernel/trace/trace_events_filter.c

@@ -110,6 +110,7 @@ int filter_match_preds(struct ftrace_event_call *call, void *rec)
 
 	return 1;
 }
+EXPORT_SYMBOL_GPL(filter_match_preds);
 
 void filter_print_preds(struct filter_pred **preds, int n_preds,
 			struct trace_seq *s)
@@ -220,6 +221,7 @@ oom:
 
 	return -ENOMEM;
 }
+EXPORT_SYMBOL_GPL(init_preds);
 
 void filter_free_subsystem_preds(struct event_subsystem *system)
 {

kernel/trace/trace_output.c

@@ -94,6 +94,7 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
 
 	return len;
 }
+EXPORT_SYMBOL_GPL(trace_seq_printf);
 
 int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
 {
@@ -538,6 +539,7 @@ int register_ftrace_event(struct trace_event *event)
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(register_ftrace_event);
 
 /**
  * unregister_ftrace_event - remove a no longer used event
@@ -551,6 +553,7 @@ int unregister_ftrace_event(struct trace_event *event)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(unregister_ftrace_event);
 
 /*
  * Standard events