tracing: Merge struct event_trigger_ops into struct event_command

Now that there's pretty much a one to one mapping between the struct
event_trigger_ops and struct event_command, there's no reason to have two
different structures. Merge the function pointers of event_trigger_ops
into event_command.

There's one exception in trace_events_hist.c for the
event_hist_trigger_named_ops. This has special logic for the init and free
function pointers for "named histograms". In this case, allocate the
cmd_ops of the event_trigger_data and set it to the proper init and free
functions, which are used to initialize and free the event_trigger_data
respectively. Have the free function and the init function (on failure)
free the cmd_ops of the data element.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://patch.msgid.link/20251125200932.446322765@kernel.org
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Author: rostedt

kernel/trace/trace.h

@@ -1798,7 +1798,6 @@ struct event_trigger_data {
 	unsigned long			count;
 	int				ref;
 	int				flags;
-	const struct event_trigger_ops	*ops;
 	struct event_command		*cmd_ops;
 	struct event_filter __rcu	*filter;
 	char				*filter_str;
@@ -1889,73 +1888,6 @@ extern void event_trigger_unregister(struct event_command *cmd_ops,
 extern void event_file_get(struct trace_event_file *file);
 extern void event_file_put(struct trace_event_file *file);
 
-/**
- * struct event_trigger_ops - callbacks for trace event triggers
- *
- * The methods in this structure provide per-event trigger hooks for
- * various trigger operations.
- *
- * The @init and @free methods are used during trigger setup and
- * teardown, typically called from an event_command's @parse()
- * function implementation.
- *
- * The @print method is used to print the trigger spec.
- *
- * The @trigger method is the function that actually implements the
- * trigger and is called in the context of the triggering event
- * whenever that event occurs.
- *
- * All the methods below, except for @init() and @free(), must be
- * implemented.
- *
- * @trigger: The trigger 'probe' function called when the triggering
- *	event occurs.  The data passed into this callback is the data
- *	that was supplied to the event_command @reg() function that
- *	registered the trigger (see struct event_command) along with
- *	the trace record, rec.
- *
- * @count_func: If defined and a numeric parameter is passed to the
- *	trigger, then this function will be called before @trigger
- *	is called. If this function returns false, then @trigger is not
- *	executed.
- *
- * @init: An optional initialization function called for the trigger
- *	when the trigger is registered (via the event_command reg()
- *	function).  This can be used to perform per-trigger
- *	initialization such as incrementing a per-trigger reference
- *	count, for instance.  This is usually implemented by the
- *	generic utility function @event_trigger_init() (see
- *	trace_event_triggers.c).
- *
- * @free: An optional de-initialization function called for the
- *	trigger when the trigger is unregistered (via the
- *	event_command @reg() function).  This can be used to perform
- *	per-trigger de-initialization such as decrementing a
- *	per-trigger reference count and freeing corresponding trigger
- *	data, for instance.  This is usually implemented by the
- *	generic utility function @event_trigger_free() (see
- *	trace_event_triggers.c).
- *
- * @print: The callback function invoked to have the trigger print
- *	itself.  This is usually implemented by a wrapper function
- *	that calls the generic utility function @event_trigger_print()
- *	(see trace_event_triggers.c).
- */
-struct event_trigger_ops {
-	void			(*trigger)(struct event_trigger_data *data,
-					   struct trace_buffer *buffer,
-					   void *rec,
-					   struct ring_buffer_event *rbe);
-	bool			(*count_func)(struct event_trigger_data *data,
-					      struct trace_buffer *buffer,
-					      void *rec,
-					      struct ring_buffer_event *rbe);
-	int			(*init)(struct event_trigger_data *data);
-	void			(*free)(struct event_trigger_data *data);
-	int			(*print)(struct seq_file *m,
-					 struct event_trigger_data *data);
-};
-
 /**
  * struct event_command - callbacks and data members for event commands
  *
@@ -1976,9 +1908,6 @@ struct event_trigger_ops {
  * @name: The unique name that identifies the event command.  This is
  *	the name used when setting triggers via trigger files.
  *
- * @trigger_ops: The event_trigger_ops implementation associated with
- *	the command.
- *
  * @trigger_type: A unique id that identifies the event command
  *	'type'.  This value has two purposes, the first to ensure that
  *	only one trigger of the same type can be set at a given time
@@ -2008,7 +1937,7 @@ struct event_trigger_ops {
  *
  * @reg: Adds the trigger to the list of triggers associated with the
  *	event, and enables the event trigger itself, after
- *	initializing it (via the event_trigger_ops @init() function).
+ *	initializing it (via the event_command @init() function).
  *	This is also where commands can use the @trigger_type value to
  *	make the decision as to whether or not multiple instances of
  *	the trigger should be allowed.  This is usually implemented by
@@ -2017,7 +1946,7 @@ struct event_trigger_ops {
  *
  * @unreg: Removes the trigger from the list of triggers associated
  *	with the event, and disables the event trigger itself, after
- *	initializing it (via the event_trigger_ops @free() function).
+ *	initializing it (via the event_command @free() function).
  *	This is usually implemented by the generic utility function
  *	@unregister_trigger() (see trace_event_triggers.c).
  *
@@ -2030,11 +1959,46 @@ struct event_trigger_ops {
  *	event command, filters set by the user for the command will be
  *	ignored.  This is usually implemented by the generic utility
  *	function @set_trigger_filter() (see trace_event_triggers.c).
+ *
+ * All the methods below, except for @init() and @free(), must be
+ * implemented.
+ *
+ * @trigger: The trigger 'probe' function called when the triggering
+ *	event occurs.  The data passed into this callback is the data
+ *	that was supplied to the event_command @reg() function that
+ *	registered the trigger (see struct event_command) along with
+ *	the trace record, rec.
+ *
+ * @count_func: If defined and a numeric parameter is passed to the
+ *	trigger, then this function will be called before @trigger
+ *	is called. If this function returns false, then @trigger is not
+ *	executed.
+ *
+ * @init: An optional initialization function called for the trigger
+ *	when the trigger is registered (via the event_command reg()
+ *	function).  This can be used to perform per-trigger
+ *	initialization such as incrementing a per-trigger reference
+ *	count, for instance.  This is usually implemented by the
+ *	generic utility function @event_trigger_init() (see
+ *	trace_event_triggers.c).
+ *
+ * @free: An optional de-initialization function called for the
+ *	trigger when the trigger is unregistered (via the
+ *	event_command @reg() function).  This can be used to perform
+ *	per-trigger de-initialization such as decrementing a
+ *	per-trigger reference count and freeing corresponding trigger
+ *	data, for instance.  This is usually implemented by the
+ *	generic utility function @event_trigger_free() (see
+ *	trace_event_triggers.c).
+ *
+ * @print: The callback function invoked to have the trigger print
+ *	itself.  This is usually implemented by a wrapper function
+ *	that calls the generic utility function @event_trigger_print()
+ *	(see trace_event_triggers.c).
  */
 struct event_command {
 	struct list_head	list;
 	char			*name;
-	const struct event_trigger_ops *trigger_ops;
 	enum event_trigger_type	trigger_type;
 	int			flags;
 	int			(*parse)(struct event_command *cmd_ops,
@@ -2051,6 +2015,18 @@ struct event_command {
 	int			(*set_filter)(char *filter_str,
 					      struct event_trigger_data *data,
 					      struct trace_event_file *file);
+	void			(*trigger)(struct event_trigger_data *data,
+					   struct trace_buffer *buffer,
+					   void *rec,
+					   struct ring_buffer_event *rbe);
+	bool			(*count_func)(struct event_trigger_data *data,
+					      struct trace_buffer *buffer,
+					      void *rec,
+					      struct ring_buffer_event *rbe);
+	int			(*init)(struct event_trigger_data *data);
+	void			(*free)(struct event_trigger_data *data);
+	int			(*print)(struct seq_file *m,
+					 struct event_trigger_data *data);
 };
 
 /**
@@ -2071,7 +2047,7 @@ struct event_command {
  *	either committed or discarded.  At that point, if any commands
  *	have deferred their triggers, those commands are finally
  *	invoked following the close of the current event.  In other
- *	words, if the event_trigger_ops @func() probe implementation
+ *	words, if the event_command @func() probe implementation
  *	itself logs to the trace buffer, this flag should be set,
  *	otherwise it can be left unspecified.
  *

kernel/trace/trace_eprobe.c

@@ -484,13 +484,6 @@ static void eprobe_trigger_func(struct event_trigger_data *data,
 	__eprobe_trace_func(edata, rec);
 }
 
-static const struct event_trigger_ops eprobe_trigger_ops = {
-	.trigger		= eprobe_trigger_func,
-	.print			= eprobe_trigger_print,
-	.init			= eprobe_trigger_init,
-	.free			= eprobe_trigger_free,
-};
-
 static int eprobe_trigger_cmd_parse(struct event_command *cmd_ops,
 				    struct trace_event_file *file,
 				    char *glob, char *cmd,
@@ -517,12 +510,15 @@ static struct event_command event_trigger_cmd = {
 	.name			= "eprobe",
 	.trigger_type		= ETT_EVENT_EPROBE,
 	.flags			= EVENT_CMD_FL_NEEDS_REC,
-	.trigger_ops		= &eprobe_trigger_ops,
 	.parse			= eprobe_trigger_cmd_parse,
 	.reg			= eprobe_trigger_reg_func,
 	.unreg			= eprobe_trigger_unreg_func,
 	.unreg_all		= NULL,
 	.set_filter		= NULL,
+	.trigger		= eprobe_trigger_func,
+	.print			= eprobe_trigger_print,
+	.init			= eprobe_trigger_init,
+	.free			= eprobe_trigger_free,
 };
 
 static struct event_trigger_data *
@@ -542,7 +538,6 @@ new_eprobe_trigger(struct trace_eprobe *ep, struct trace_event_file *file)
 
 	trigger->flags = EVENT_TRIGGER_FL_PROBE;
 	trigger->count = -1;
-	trigger->ops = &eprobe_trigger_ops;
 
 	/*
 	 * EVENT PROBE triggers are not registered as commands with