tracing: Pass the trace_array into ftrace_probe_ops functions

Pass the trace_array associated to a ftrace_probe_ops into the probe_ops
func(), init() and free() functions. The trace_array is the descriptor that
describes a tracing instance. This will help create the infrastructure that
will allow having function probes unique to tracing instances.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kernel/trace/ftrace.c

@@ -3791,6 +3791,7 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
 				      struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
 	struct ftrace_probe_ops *probe_ops;
+	struct trace_array *tr = op->private;
 
 	probe_ops = container_of(op, struct ftrace_probe_ops, ops);
 
@@ -3800,7 +3801,7 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
 	 * on the hash. rcu_read_lock is too dangerous here.
 	 */
 	preempt_disable_notrace();
-	probe_ops->func(ip, parent_ip, probe_ops, NULL);
+	probe_ops->func(ip, parent_ip, tr, probe_ops, NULL);
 	preempt_enable_notrace();
 }
 
@@ -3969,6 +3970,7 @@ register_ftrace_function_probe(char *glob, struct trace_array *tr,
 		ops->ops.func = function_trace_probe_call;
 		ftrace_ops_init(&ops->ops);
 		INIT_LIST_HEAD(&ops->list);
+		ops->ops.private = tr;
 	}
 
 	mutex_lock(&ops->ops.func_hash->regex_lock);
@@ -3997,7 +3999,7 @@ register_ftrace_function_probe(char *glob, struct trace_array *tr,
 			 * to give the caller an opportunity to do so.
 			 */
 			if (ops->init) {
-				ret = ops->init(ops, entry->ip, data);
+				ret = ops->init(ops, tr, entry->ip, data);
 				if (ret < 0)
 					goto out;
 			}
@@ -4038,7 +4040,7 @@ register_ftrace_function_probe(char *glob, struct trace_array *tr,
 		hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
 			if (ftrace_lookup_ip(old_hash, entry->ip))
 				continue;
-			ops->free(ops, entry->ip, NULL);
+			ops->free(ops, tr, entry->ip, NULL);
 		}
 	}
 	goto out_unlock;
@@ -4055,6 +4057,7 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
 	struct ftrace_hash *hash = NULL;
 	struct hlist_node *tmp;
 	struct hlist_head hhd;
+	struct trace_array *tr;
 	char str[KSYM_SYMBOL_LEN];
 	int i, ret;
 	int size;
@@ -4062,6 +4065,8 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
 	if (!(ops->ops.flags & FTRACE_OPS_FL_INITIALIZED))
 		return -EINVAL;
 
+	tr = ops->ops.private;
+
 	if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
 		func_g.search = NULL;
 	else if (glob) {
@@ -4139,7 +4144,7 @@ unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
 	hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
 		hlist_del(&entry->hlist);
 		if (ops->free)
-			ops->free(ops, entry->ip, NULL);
+			ops->free(ops, tr, entry->ip, NULL);
 		kfree(entry);
 	}
 	mutex_unlock(&ftrace_lock);

kernel/trace/trace.c

@@ -6736,14 +6736,16 @@ static const struct file_operations tracing_dyn_info_fops = {
 #if defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE)
 static void
 ftrace_snapshot(unsigned long ip, unsigned long parent_ip,
-		struct ftrace_probe_ops *ops, void **data)
+		struct trace_array *tr, struct ftrace_probe_ops *ops,
+		void **data)
 {
 	tracing_snapshot();
 }
 
 static void
 ftrace_count_snapshot(unsigned long ip, unsigned long parent_ip,
-		      struct ftrace_probe_ops *ops, void **data)
+		      struct trace_array *tr, struct ftrace_probe_ops *ops,
+		      void **data)
 {
 	struct ftrace_func_mapper *mapper = ops->private_data;
 	long *count = NULL;
@@ -6785,8 +6787,8 @@ ftrace_snapshot_print(struct seq_file *m, unsigned long ip,
 }
 
 static int
-ftrace_snapshot_init(struct ftrace_probe_ops *ops, unsigned long ip,
-		     void *data)
+ftrace_snapshot_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
+		     unsigned long ip, void *data)
 {
 	struct ftrace_func_mapper *mapper = ops->private_data;
 
@@ -6794,8 +6796,8 @@ ftrace_snapshot_init(struct ftrace_probe_ops *ops, unsigned long ip,
 }
 
 static void
-ftrace_snapshot_free(struct ftrace_probe_ops *ops, unsigned long ip,
-		     void **_data)
+ftrace_snapshot_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
+		     unsigned long ip, void **data)
 {
 	struct ftrace_func_mapper *mapper = ops->private_data;
 

kernel/trace/trace.h

@@ -943,11 +943,14 @@ struct ftrace_probe_ops {
 	struct list_head	list;
 	void			(*func)(unsigned long ip,
 					unsigned long parent_ip,
+					struct trace_array *tr,
 					struct ftrace_probe_ops *ops,
 					void **data);
 	int			(*init)(struct ftrace_probe_ops *ops,
+					struct trace_array *tr,
 					unsigned long ip, void *data);
 	void			(*free)(struct ftrace_probe_ops *ops,
+					struct trace_array *tr,
 					unsigned long ip, void **data);
 	int			(*print)(struct seq_file *m,
 					 unsigned long ip,

kernel/trace/trace_events.c

@@ -2470,7 +2470,8 @@ static void update_event_probe(struct event_probe_data *data)
 
 static void
 event_enable_probe(unsigned long ip, unsigned long parent_ip,
-		   struct ftrace_probe_ops *ops, void **_data)
+		   struct trace_array *tr, struct ftrace_probe_ops *ops,
+		   void **_data)
 {
 	struct ftrace_func_mapper *mapper = ops->private_data;
 	struct event_probe_data *data;
@@ -2486,7 +2487,8 @@ event_enable_probe(unsigned long ip, unsigned long parent_ip,
 
 static void
 event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
-			 struct ftrace_probe_ops *ops, void **_data)
+			 struct trace_array *tr, struct ftrace_probe_ops *ops,
+			 void **_data)
 {
 	struct ftrace_func_mapper *mapper = ops->private_data;
 	struct event_probe_data *data;
@@ -2513,7 +2515,7 @@ event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
 
 static int
 event_enable_print(struct seq_file *m, unsigned long ip,
-		      struct ftrace_probe_ops *ops, void *_data)
+		   struct ftrace_probe_ops *ops, void *_data)
 {
 	struct ftrace_func_mapper *mapper = ops->private_data;
 	struct event_probe_data *data;
@@ -2542,8 +2544,8 @@ event_enable_print(struct seq_file *m, unsigned long ip,
 }
 
 static int
-event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
-		  void *_data)
+event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
+		  unsigned long ip, void *_data)
 {
 	struct ftrace_func_mapper *mapper = ops->private_data;
 	struct event_probe_data *data = _data;
@@ -2559,8 +2561,8 @@ event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
 }
 
 static void
-event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
-		  void **_data)
+event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
+		  unsigned long ip, void **_data)
 {
 	struct ftrace_func_mapper *mapper = ops->private_data;
 	struct event_probe_data *data;

kernel/trace/trace_functions.c

@@ -328,21 +328,24 @@ static void update_traceon_count(struct ftrace_probe_ops *ops,
 
 static void
 ftrace_traceon_count(unsigned long ip, unsigned long parent_ip,
-		     struct ftrace_probe_ops *ops, void **data)
+		     struct trace_array *tr, struct ftrace_probe_ops *ops,
+		     void **data)
 {
 	update_traceon_count(ops, ip, 1);
 }
 
 static void
 ftrace_traceoff_count(unsigned long ip, unsigned long parent_ip,
-		      struct ftrace_probe_ops *ops, void **data)
+		      struct trace_array *tr, struct ftrace_probe_ops *ops,
+		      void **data)
 {
 	update_traceon_count(ops, ip, 0);
 }
 
 static void
 ftrace_traceon(unsigned long ip, unsigned long parent_ip,
-	       struct ftrace_probe_ops *ops, void **data)
+	       struct trace_array *tr, struct ftrace_probe_ops *ops,
+	       void **data)
 {
 	if (tracing_is_on())
 		return;
@@ -352,7 +355,8 @@ ftrace_traceon(unsigned long ip, unsigned long parent_ip,
 
 static void
 ftrace_traceoff(unsigned long ip, unsigned long parent_ip,
-		struct ftrace_probe_ops *ops, void **data)
+		struct trace_array *tr, struct ftrace_probe_ops *ops,
+		void **data)
 {
 	if (!tracing_is_on())
 		return;
@@ -371,14 +375,16 @@ ftrace_traceoff(unsigned long ip, unsigned long parent_ip,
 
 static void
 ftrace_stacktrace(unsigned long ip, unsigned long parent_ip,
-		  struct ftrace_probe_ops *ops, void **data)
+		  struct trace_array *tr, struct ftrace_probe_ops *ops,
+		  void **data)
 {
 	trace_dump_stack(STACK_SKIP);
 }
 
 static void
 ftrace_stacktrace_count(unsigned long ip, unsigned long parent_ip,
-			struct ftrace_probe_ops *ops, void **data)
+			struct trace_array *tr, struct ftrace_probe_ops *ops,
+			void **data)
 {
 	struct ftrace_func_mapper *mapper = ops->private_data;
 	long *count;
@@ -436,7 +442,8 @@ static int update_count(struct ftrace_probe_ops *ops, unsigned long ip)
 
 static void
 ftrace_dump_probe(unsigned long ip, unsigned long parent_ip,
-	struct ftrace_probe_ops *ops, void **data)
+		  struct trace_array *tr, struct ftrace_probe_ops *ops,
+		  void **data)
 {
 	if (update_count(ops, ip))
 		ftrace_dump(DUMP_ALL);
@@ -445,7 +452,8 @@ ftrace_dump_probe(unsigned long ip, unsigned long parent_ip,
 /* Only dump the current CPU buffer. */
 static void
 ftrace_cpudump_probe(unsigned long ip, unsigned long parent_ip,
-	struct ftrace_probe_ops *ops, void **data)
+		     struct trace_array *tr, struct ftrace_probe_ops *ops,
+		     void **data)
 {
 	if (update_count(ops, ip))
 		ftrace_dump(DUMP_ORIG);
@@ -473,7 +481,8 @@ ftrace_probe_print(const char *name, struct seq_file *m,
 
 static int
 ftrace_traceon_print(struct seq_file *m, unsigned long ip,
-			 struct ftrace_probe_ops *ops, void *data)
+		     struct ftrace_probe_ops *ops,
+		     void *data)
 {
 	return ftrace_probe_print("traceon", m, ip, ops);
 }
@@ -508,8 +517,8 @@ ftrace_cpudump_print(struct seq_file *m, unsigned long ip,
 
 
 static int
-ftrace_count_init(struct ftrace_probe_ops *ops, unsigned long ip,
-		     void *data)
+ftrace_count_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
+		  unsigned long ip, void *data)
 {
 	struct ftrace_func_mapper *mapper = ops->private_data;
 
@@ -517,8 +526,8 @@ ftrace_count_init(struct ftrace_probe_ops *ops, unsigned long ip,
 }
 
 static void
-ftrace_count_free(struct ftrace_probe_ops *ops, unsigned long ip,
-		  void **_data)
+ftrace_count_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
+		  unsigned long ip, void **_data)
 {
 	struct ftrace_func_mapper *mapper = ops->private_data;