tracing/ftrace: Allow for the traceonoff probe be unique to instances

Have the traceon/off function probe triggers affect only the instance they
are set in. This required making the trace_on/off accessible for other files
in the tracing directory.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kernel/trace/trace.c

@@ -757,7 +757,7 @@ __trace_buffer_lock_reserve(struct ring_buffer *buffer,
 	return event;
 }
 
-static void tracer_tracing_on(struct trace_array *tr)
+void tracer_tracing_on(struct trace_array *tr)
 {
 	if (tr->trace_buffer.buffer)
 		ring_buffer_record_on(tr->trace_buffer.buffer);
@@ -1045,7 +1045,7 @@ void tracing_snapshot_alloc(void)
 EXPORT_SYMBOL_GPL(tracing_snapshot_alloc);
 #endif /* CONFIG_TRACER_SNAPSHOT */
 
-static void tracer_tracing_off(struct trace_array *tr)
+void tracer_tracing_off(struct trace_array *tr)
 {
 	if (tr->trace_buffer.buffer)
 		ring_buffer_record_off(tr->trace_buffer.buffer);

kernel/trace/trace.h

@@ -582,6 +582,8 @@ void tracing_reset_all_online_cpus(void);
 int tracing_open_generic(struct inode *inode, struct file *filp);
 bool tracing_is_disabled(void);
 int tracer_tracing_is_on(struct trace_array *tr);
+void tracer_tracing_on(struct trace_array *tr);
+void tracer_tracing_off(struct trace_array *tr);
 struct dentry *trace_create_file(const char *name,
 				 umode_t mode,
 				 struct dentry *parent,

kernel/trace/trace_functions.c

@@ -268,7 +268,8 @@ static struct tracer function_trace __tracer_data =
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 static void update_traceon_count(struct ftrace_probe_ops *ops,
-				 unsigned long ip, bool on,
+				 unsigned long ip,
+				 struct trace_array *tr, bool on,
 				 void *data)
 {
 	struct ftrace_func_mapper *mapper = data;
@@ -313,13 +314,13 @@ static void update_traceon_count(struct ftrace_probe_ops *ops,
 	/* Make sure we see count before checking tracing state */
 	smp_rmb();
 
-	if (on == !!tracing_is_on())
+	if (on == !!tracer_tracing_is_on(tr))
 		return;
 
 	if (on)
-		tracing_on();
+		tracer_tracing_on(tr);
 	else
-		tracing_off();
+		tracer_tracing_off(tr);
 
 	/* Make sure tracing state is visible before updating count */
 	smp_wmb();
@@ -332,7 +333,7 @@ ftrace_traceon_count(unsigned long ip, unsigned long parent_ip,
 		     struct trace_array *tr, struct ftrace_probe_ops *ops,
 		     void *data)
 {
-	update_traceon_count(ops, ip, 1, data);
+	update_traceon_count(ops, ip, tr, 1, data);
 }
 
 static void
@@ -340,7 +341,7 @@ ftrace_traceoff_count(unsigned long ip, unsigned long parent_ip,
 		      struct trace_array *tr, struct ftrace_probe_ops *ops,
 		      void *data)
 {
-	update_traceon_count(ops, ip, 0, data);
+	update_traceon_count(ops, ip, tr, 0, data);
 }
 
 static void
@@ -348,10 +349,10 @@ ftrace_traceon(unsigned long ip, unsigned long parent_ip,
 	       struct trace_array *tr, struct ftrace_probe_ops *ops,
 	       void *data)
 {
-	if (tracing_is_on())
+	if (tracer_tracing_is_on(tr))
 		return;
 
-	tracing_on();
+	tracer_tracing_on(tr);
 }
 
 static void
@@ -359,10 +360,10 @@ ftrace_traceoff(unsigned long ip, unsigned long parent_ip,
 		struct trace_array *tr, struct ftrace_probe_ops *ops,
 		void *data)
 {
-	if (!tracing_is_on())
+	if (!tracer_tracing_is_on(tr))
 		return;
 
-	tracing_off();
+	tracer_tracing_off(tr);
 }
 
 /*