[for-next][PATCH 00/13] tracing: Updates for v6.19

[for-next][PATCH 00/13] tracing: Updates for v6.19

[Steven Rostedt]

Tracing updates on a full stomach of turkey!

  git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
trace/for-next

Head SHA1: f6ed9c5d3190cf18382ee75e0420602101f53586


Masami Hiramatsu (Google) (2):
      tracing: Show the tracer options in boot-time created instance
      tracing: Add boot-time backup of persistent ring buffer

Menglong Dong (1):
      ftrace: Avoid redundant initialization in register_ftrace_direct

Steven Rostedt (9):
      fgraph: Make fgraph_no_sleep_time signed
      tracing: Remove unused variable in tracing_trace_options_show()
      tracing: Remove get_trigger_ops() and add count_func() from trigger ops
      tracing: Merge struct event_trigger_ops into struct event_command
      tracing: Remove unneeded event_mutex lock in event_trigger_regex_release()
      tracing: Add bulk garbage collection of freeing event_trigger_data
      tracing: Use strim() in trigger_process_regex() instead of skip_spaces()
      ftrace: Allow tracing of some of the tracing code
      overflow: Introduce struct_offset() to get offset of member

pengdonglin (1):
      function_graph: Enable funcgraph-args and funcgraph-retaddr to work simultaneously

----
 include/linux/ftrace.h               |   7 +-
 include/linux/overflow.h             |  12 ++
 kernel/trace/Kconfig                 |  14 ++
 kernel/trace/Makefile                |  17 ++
 kernel/trace/ftrace.c                |   2 +-
 kernel/trace/trace.c                 |  77 +++++--
 kernel/trace/trace.h                 | 153 +++++++------
 kernel/trace/trace_entries.h         |  15 +-
 kernel/trace/trace_eprobe.c          |  19 +-
 kernel/trace/trace_events_hist.c     | 143 +++++-------
 kernel/trace/trace_events_trigger.c  | 408 +++++++++++++++--------------------
 kernel/trace/trace_functions_graph.c |  73 ++++---
 12 files changed, 477 insertions(+), 463 deletions(-)

[for-next][PATCH 01/13] fgraph: Make fgraph_no_sleep_time signed

[Steven Rostedt]

From: Steven Rostedt <rostedt@goodmis.org>

The variable fgraph_no_sleep_time changed from being a boolean to being a
counter. A check is made to make sure that it never goes below zero. But
the variable being unsigned makes the check always fail even if it does go
below zero.

Make the variable a signed int so that checking it going below zero still
works.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20251125104751.4c9c7f28@gandalf.local.home
Fixes: 5abb6ccb58f0 ("tracing: Have function graph tracer option sleep-time be per instance")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/aR1yRQxDmlfLZzoo@stanley.mountain/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace.h                 | 2 +-
 kernel/trace/trace_functions_graph.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 58be6d741d72..da5d9527ebd6 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1113,7 +1113,7 @@ static inline void ftrace_graph_addr_finish(struct fgraph_ops *gops, struct ftra
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
 extern unsigned int fgraph_max_depth;
-extern unsigned int fgraph_no_sleep_time;
+extern int fgraph_no_sleep_time;
 extern bool fprofile_no_sleep_time;
 
 static inline bool
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 44d5dc5031e2..d0513cfcd936 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -20,7 +20,7 @@
 static int ftrace_graph_skip_irqs;
 
 /* Do not record function time when task is sleeping */
-unsigned int fgraph_no_sleep_time;
+int fgraph_no_sleep_time;
 
 struct fgraph_cpu_data {
 	pid_t		last_pid;
-- 
2.51.0

[for-next][PATCH 02/13] tracing: Remove unused variable in tracing_trace_options_show()

[Steven Rostedt]

From: Steven Rostedt <rostedt@goodmis.org>

The flags and opts used in tracing_trace_options_show() now come directly
from the trace array "current_trace_flags" and not the current_trace. The
variable "trace" was still being assigned to tr->current_trace but never
used. This caused a warning in clang.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20251117120637.43ef995d@gandalf.local.home
Reported-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Closes: https://lore.kernel.org/all/aRtHWXzYa8ijUIDa@black.igk.intel.com/
Fixes: 428add559b692 ("tracing: Have tracer option be instance specific")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8ae95800592d..59cd4ed8af6d 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5167,7 +5167,6 @@ static int tracing_trace_options_show(struct seq_file *m, void *v)
 	struct tracer_opt *trace_opts;
 	struct trace_array *tr = m->private;
 	struct tracer_flags *flags;
-	struct tracer *trace;
 	u32 tracer_flags;
 	int i;
 
@@ -5184,8 +5183,6 @@ static int tracing_trace_options_show(struct seq_file *m, void *v)
 	if (!flags || !flags->opts)
 		return 0;
 
-	trace = tr->current_trace;
-
 	tracer_flags = flags->val;
 	trace_opts = flags->opts;
 
-- 
2.51.0

[for-next][PATCH 03/13] ftrace: Avoid redundant initialization in register_ftrace_direct

[Steven Rostedt]

From: Menglong Dong <menglong8.dong@gmail.com>

The FTRACE_OPS_FL_INITIALIZED flag is cleared in register_ftrace_direct,
which can make it initialized by ftrace_ops_init() even if it is already
initialized. It seems that there is no big deal here, but let's still fix
it.

Link: https://patch.msgid.link/20251110121808.1559240-1-dongml2@chinatelecom.cn
Fixes: f64dd4627ec6 ("ftrace: Add multi direct register/unregister interface")
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/ftrace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 7c3bbebeec7a..b4510a6dbf42 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -6069,7 +6069,7 @@ int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
 	new_hash = NULL;
 
 	ops->func = call_direct_funcs;
-	ops->flags = MULTI_FLAGS;
+	ops->flags |= MULTI_FLAGS;
 	ops->trampoline = FTRACE_REGS_ADDR;
 	ops->direct_call = addr;
 
-- 
2.51.0

[for-next][PATCH 04/13] tracing: Show the tracer options in boot-time created instance

[Steven Rostedt]

From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>

Since tracer_init_tracefs_work_func() only updates the tracer options
for the global_trace, the instances created by the kernel cmdline
do not have those options.

Fix to update tracer options for those boot-time created instances
to show those options.

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/176354112555.2356172.3989277078358802353.stgit@mhiramat.tok.corp.google.com
Fixes: 428add559b69 ("tracing: Have tracer option be instance specific")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 59cd4ed8af6d..032bdedca5d9 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -10228,11 +10228,14 @@ static __init int __update_tracer_options(struct trace_array *tr)
 	return ret;
 }
 
-static __init void update_tracer_options(struct trace_array *tr)
+static __init void update_tracer_options(void)
 {
+	struct trace_array *tr;
+
 	guard(mutex)(&trace_types_lock);
 	tracer_options_updated = true;
-	__update_tracer_options(tr);
+	list_for_each_entry(tr, &ftrace_trace_arrays, list)
+		__update_tracer_options(tr);
 }
 
 /* Must have trace_types_lock held */
@@ -10934,7 +10937,7 @@ static __init void tracer_init_tracefs_work_func(struct work_struct *work)
 
 	create_trace_instances(NULL);
 
-	update_tracer_options(&global_trace);
+	update_tracer_options();
 }
 
 static __init int tracer_init_tracefs(void)
-- 
2.51.0

[for-next][PATCH 05/13] tracing: Remove get_trigger_ops() and add count_func() from trigger ops

[Steven Rostedt]

From: Steven Rostedt <rostedt@goodmis.org>

The struct event_command has a callback function called get_trigger_ops().
This callback returns the "trigger_ops" to use for the trigger. These ops
define the trigger function, how to init the trigger, how to print the
trigger and how to free it.

The only reason there's a callback function to get these ops is because
some triggers have two types of operations. One is an "always on"
operation, and the other is a "count down" operation. If a user passes in
a parameter to say how many times the trigger should execute. For example:

  echo stacktrace:5 > events/kmem/kmem_cache_alloc/trigger

It will trigger the stacktrace for the first 5 times the kmem_cache_alloc
event is hit.

Instead of having two different trigger_ops since the only difference
between them is the tigger itself (the print, init and free functions are
all the same), just use a single ops that the event_command points to and
add a function field to the trigger_ops to have a count_func.

When a trigger is added to an event, if there's a count attached to it and
the trigger ops has the count_func field, the data allocated to represent
this trigger will have a new flag set called COUNT.

Then when the trigger executes, it will check if the COUNT data flag is
set, and if so, it will call the ops count_func(). If that returns false,
it returns without executing the trigger.

This removes the need for duplicate event_trigger_ops structures.

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/20251125200932.274566147@kernel.org
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace.h                |  26 ++-
 kernel/trace/trace_eprobe.c         |   8 +-
 kernel/trace/trace_events_hist.c    |  60 +------
 kernel/trace/trace_events_trigger.c | 257 ++++++++++------------------
 4 files changed, 116 insertions(+), 235 deletions(-)

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index da5d9527ebd6..b9c59d9f9a0c 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1791,6 +1791,7 @@ extern void clear_event_triggers(struct trace_array *tr);
 
 enum {
 	EVENT_TRIGGER_FL_PROBE		= BIT(0),
+	EVENT_TRIGGER_FL_COUNT		= BIT(1),
 };
 
 struct event_trigger_data {
@@ -1822,6 +1823,10 @@ struct enable_trigger_data {
 	bool				hist;
 };
 
+bool event_trigger_count(struct event_trigger_data *data,
+			 struct trace_buffer *buffer,  void *rec,
+			 struct ring_buffer_event *event);
+
 extern int event_enable_trigger_print(struct seq_file *m,
 				      struct event_trigger_data *data);
 extern void event_enable_trigger_free(struct event_trigger_data *data);
@@ -1909,6 +1914,11 @@ extern void event_file_put(struct trace_event_file *file);
  *	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
@@ -1936,6 +1946,10 @@ struct event_trigger_ops {
 					   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,
@@ -1962,6 +1976,9 @@ 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
@@ -2013,17 +2030,11 @@ 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).
- *
- * @get_trigger_ops: The callback function invoked to retrieve the
- *	event_trigger_ops implementation associated with the command.
- *	This callback function allows a single event_command to
- *	support multiple trigger implementations via different sets of
- *	event_trigger_ops, depending on the value of the @param
- *	string.
  */
 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,
@@ -2040,7 +2051,6 @@ struct event_command {
 	int			(*set_filter)(char *filter_str,
 					      struct event_trigger_data *data,
 					      struct trace_event_file *file);
-	const struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
 };
 
 /**
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index a1d402124836..14ae896dbe75 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -513,21 +513,15 @@ static void eprobe_trigger_unreg_func(char *glob,
 
 }
 
-static const struct event_trigger_ops *eprobe_trigger_get_ops(char *cmd,
-							      char *param)
-{
-	return &eprobe_trigger_ops;
-}
-
 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,
-	.get_trigger_ops	= eprobe_trigger_get_ops,
 	.set_filter		= NULL,
 };
 
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 1d536219b624..f9cc8d6a215b 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -6363,12 +6363,6 @@ static const struct event_trigger_ops event_hist_trigger_named_ops = {
 	.free			= event_hist_trigger_named_free,
 };
 
-static const struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
-								  char *param)
-{
-	return &event_hist_trigger_ops;
-}
-
 static void hist_clear(struct event_trigger_data *data)
 {
 	struct hist_trigger_data *hist_data = data->private_data;
@@ -6908,11 +6902,11 @@ static struct event_command trigger_hist_cmd = {
 	.name			= "hist",
 	.trigger_type		= ETT_EVENT_HIST,
 	.flags			= EVENT_CMD_FL_NEEDS_REC,
+	.trigger_ops		= &event_hist_trigger_ops,
 	.parse			= event_hist_trigger_parse,
 	.reg			= hist_register_trigger,
 	.unreg			= hist_unregister_trigger,
 	.unreg_all		= hist_unreg_all,
-	.get_trigger_ops	= event_hist_get_trigger_ops,
 	.set_filter		= set_trigger_filter,
 };
 
@@ -6945,29 +6939,9 @@ hist_enable_trigger(struct event_trigger_data *data,
 	}
 }
 
-static void
-hist_enable_count_trigger(struct event_trigger_data *data,
-			  struct trace_buffer *buffer,  void *rec,
-			  struct ring_buffer_event *event)
-{
-	if (!data->count)
-		return;
-
-	if (data->count != -1)
-		(data->count)--;
-
-	hist_enable_trigger(data, buffer, rec, event);
-}
-
 static const struct event_trigger_ops hist_enable_trigger_ops = {
 	.trigger		= hist_enable_trigger,
-	.print			= event_enable_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops hist_enable_count_trigger_ops = {
-	.trigger		= hist_enable_count_trigger,
+	.count_func		= event_trigger_count,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_enable_trigger_free,
@@ -6975,36 +6949,12 @@ static const struct event_trigger_ops hist_enable_count_trigger_ops = {
 
 static const struct event_trigger_ops hist_disable_trigger_ops = {
 	.trigger		= hist_enable_trigger,
+	.count_func		= event_trigger_count,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_enable_trigger_free,
 };
 
-static const struct event_trigger_ops hist_disable_count_trigger_ops = {
-	.trigger		= hist_enable_count_trigger,
-	.print			= event_enable_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops *
-hist_enable_get_trigger_ops(char *cmd, char *param)
-{
-	const struct event_trigger_ops *ops;
-	bool enable;
-
-	enable = (strcmp(cmd, ENABLE_HIST_STR) == 0);
-
-	if (enable)
-		ops = param ? &hist_enable_count_trigger_ops :
-			&hist_enable_trigger_ops;
-	else
-		ops = param ? &hist_disable_count_trigger_ops :
-			&hist_disable_trigger_ops;
-
-	return ops;
-}
-
 static void hist_enable_unreg_all(struct trace_event_file *file)
 {
 	struct event_trigger_data *test, *n;
@@ -7023,22 +6973,22 @@ static void hist_enable_unreg_all(struct trace_event_file *file)
 static struct event_command trigger_hist_enable_cmd = {
 	.name			= ENABLE_HIST_STR,
 	.trigger_type		= ETT_HIST_ENABLE,
+	.trigger_ops		= &hist_enable_trigger_ops,
 	.parse			= event_enable_trigger_parse,
 	.reg			= event_enable_register_trigger,
 	.unreg			= event_enable_unregister_trigger,
 	.unreg_all		= hist_enable_unreg_all,
-	.get_trigger_ops	= hist_enable_get_trigger_ops,
 	.set_filter		= set_trigger_filter,
 };
 
 static struct event_command trigger_hist_disable_cmd = {
 	.name			= DISABLE_HIST_STR,
 	.trigger_type		= ETT_HIST_ENABLE,
+	.trigger_ops		= &hist_disable_trigger_ops,
 	.parse			= event_enable_trigger_parse,
 	.reg			= event_enable_register_trigger,
 	.unreg			= event_enable_unregister_trigger,
 	.unreg_all		= hist_enable_unreg_all,
-	.get_trigger_ops	= hist_enable_get_trigger_ops,
 	.set_filter		= set_trigger_filter,
 };
 
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index cbfc306c0159..576bad18bcdb 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -28,6 +28,20 @@ void trigger_data_free(struct event_trigger_data *data)
 	kfree(data);
 }
 
+static inline void data_ops_trigger(struct event_trigger_data *data,
+				    struct trace_buffer *buffer,  void *rec,
+				    struct ring_buffer_event *event)
+{
+	const struct event_trigger_ops *ops = data->ops;
+
+	if (data->flags & EVENT_TRIGGER_FL_COUNT) {
+		if (!ops->count_func(data, buffer, rec, event))
+			return;
+	}
+
+	ops->trigger(data, buffer, rec, event);
+}
+
 /**
  * event_triggers_call - Call triggers associated with a trace event
  * @file: The trace_event_file associated with the event
@@ -70,7 +84,7 @@ event_triggers_call(struct trace_event_file *file,
 		if (data->paused)
 			continue;
 		if (!rec) {
-			data->ops->trigger(data, buffer, rec, event);
+			data_ops_trigger(data, buffer, rec, event);
 			continue;
 		}
 		filter = rcu_dereference_sched(data->filter);
@@ -80,7 +94,7 @@ event_triggers_call(struct trace_event_file *file,
 			tt |= data->cmd_ops->trigger_type;
 			continue;
 		}
-		data->ops->trigger(data, buffer, rec, event);
+		data_ops_trigger(data, buffer, rec, event);
 	}
 	return tt;
 }
@@ -122,7 +136,7 @@ event_triggers_post_call(struct trace_event_file *file,
 		if (data->paused)
 			continue;
 		if (data->cmd_ops->trigger_type & tt)
-			data->ops->trigger(data, NULL, NULL, NULL);
+			data_ops_trigger(data, NULL, NULL, NULL);
 	}
 }
 EXPORT_SYMBOL_GPL(event_triggers_post_call);
@@ -377,6 +391,36 @@ __init int unregister_event_command(struct event_command *cmd)
 	return -ENODEV;
 }
 
+/**
+ * event_trigger_count - Optional count function for event triggers
+ * @data: Trigger-specific data
+ * @buffer: The ring buffer that the event is being written to
+ * @rec: The trace entry for the event, NULL for unconditional invocation
+ * @event: The event meta data in the ring buffer
+ *
+ * For triggers that can take a count parameter that doesn't do anything
+ * special, they can use this function to assign to their .count_func
+ * field.
+ *
+ * This simply does a count down of the @data->count field.
+ *
+ * If the @data->count is greater than zero, it will decrement it.
+ *
+ * Returns false if @data->count is zero, otherwise true.
+ */
+bool event_trigger_count(struct event_trigger_data *data,
+			 struct trace_buffer *buffer,  void *rec,
+			 struct ring_buffer_event *event)
+{
+	if (!data->count)
+		return false;
+
+	if (data->count != -1)
+		(data->count)--;
+
+	return true;
+}
+
 /**
  * event_trigger_print - Generic event_trigger_ops @print implementation
  * @name: The name of the event trigger
@@ -807,9 +851,13 @@ int event_trigger_separate_filter(char *param_and_filter, char **param,
  * @private_data: User data to associate with the event trigger
  *
  * Allocate an event_trigger_data instance and initialize it.  The
- * @cmd_ops are used along with the @cmd and @param to get the
- * trigger_ops to assign to the event_trigger_data.  @private_data can
- * also be passed in and associated with the event_trigger_data.
+ * @cmd_ops defines how the trigger will operate. If @param is set,
+ * and @cmd_ops->trigger_ops->count_func is non NULL, then the
+ * data->count is set to @param and before the trigger is executed, the
+ * @cmd_ops->trigger_ops->count_func() is called. If that function returns
+ * false, the @cmd_ops->trigger_ops->trigger() function will not be called.
+ * @private_data can also be passed in and associated with the
+ * event_trigger_data.
  *
  * Use trigger_data_free() to free an event_trigger_data object.
  *
@@ -821,18 +869,17 @@ struct event_trigger_data *trigger_data_alloc(struct event_command *cmd_ops,
 					      void *private_data)
 {
 	struct event_trigger_data *trigger_data;
-	const struct event_trigger_ops *trigger_ops;
-
-	trigger_ops = cmd_ops->get_trigger_ops(cmd, param);
 
 	trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
 	if (!trigger_data)
 		return NULL;
 
 	trigger_data->count = -1;
-	trigger_data->ops = trigger_ops;
+	trigger_data->ops = cmd_ops->trigger_ops;
 	trigger_data->cmd_ops = cmd_ops;
 	trigger_data->private_data = private_data;
+	if (param && cmd_ops->trigger_ops->count_func)
+		trigger_data->flags |= EVENT_TRIGGER_FL_COUNT;
 
 	INIT_LIST_HEAD(&trigger_data->list);
 	INIT_LIST_HEAD(&trigger_data->named_list);
@@ -1271,31 +1318,28 @@ traceon_trigger(struct event_trigger_data *data,
 	tracing_on();
 }
 
-static void
-traceon_count_trigger(struct event_trigger_data *data,
-		      struct trace_buffer *buffer, void *rec,
-		      struct ring_buffer_event *event)
+static bool
+traceon_count_func(struct event_trigger_data *data,
+		   struct trace_buffer *buffer, void *rec,
+		   struct ring_buffer_event *event)
 {
 	struct trace_event_file *file = data->private_data;
 
 	if (file) {
 		if (tracer_tracing_is_on(file->tr))
-			return;
+			return false;
 	} else {
 		if (tracing_is_on())
-			return;
+			return false;
 	}
 
 	if (!data->count)
-		return;
+		return false;
 
 	if (data->count != -1)
 		(data->count)--;
 
-	if (file)
-		tracer_tracing_on(file->tr);
-	else
-		tracing_on();
+	return true;
 }
 
 static void
@@ -1319,31 +1363,28 @@ traceoff_trigger(struct event_trigger_data *data,
 	tracing_off();
 }
 
-static void
-traceoff_count_trigger(struct event_trigger_data *data,
-		       struct trace_buffer *buffer, void *rec,
-		       struct ring_buffer_event *event)
+static bool
+traceoff_count_func(struct event_trigger_data *data,
+		    struct trace_buffer *buffer, void *rec,
+		    struct ring_buffer_event *event)
 {
 	struct trace_event_file *file = data->private_data;
 
 	if (file) {
 		if (!tracer_tracing_is_on(file->tr))
-			return;
+			return false;
 	} else {
 		if (!tracing_is_on())
-			return;
+			return false;
 	}
 
 	if (!data->count)
-		return;
+		return false;
 
 	if (data->count != -1)
 		(data->count)--;
 
-	if (file)
-		tracer_tracing_off(file->tr);
-	else
-		tracing_off();
+	return true;
 }
 
 static int
@@ -1362,13 +1403,7 @@ traceoff_trigger_print(struct seq_file *m, struct event_trigger_data *data)
 
 static const struct event_trigger_ops traceon_trigger_ops = {
 	.trigger		= traceon_trigger,
-	.print			= traceon_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_trigger_free,
-};
-
-static const struct event_trigger_ops traceon_count_trigger_ops = {
-	.trigger		= traceon_count_trigger,
+	.count_func		= traceon_count_func,
 	.print			= traceon_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
@@ -1376,41 +1411,19 @@ static const struct event_trigger_ops traceon_count_trigger_ops = {
 
 static const struct event_trigger_ops traceoff_trigger_ops = {
 	.trigger		= traceoff_trigger,
+	.count_func		= traceoff_count_func,
 	.print			= traceoff_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static const struct event_trigger_ops traceoff_count_trigger_ops = {
-	.trigger		= traceoff_count_trigger,
-	.print			= traceoff_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_trigger_free,
-};
-
-static const struct event_trigger_ops *
-onoff_get_trigger_ops(char *cmd, char *param)
-{
-	const struct event_trigger_ops *ops;
-
-	/* we register both traceon and traceoff to this callback */
-	if (strcmp(cmd, "traceon") == 0)
-		ops = param ? &traceon_count_trigger_ops :
-			&traceon_trigger_ops;
-	else
-		ops = param ? &traceoff_count_trigger_ops :
-			&traceoff_trigger_ops;
-
-	return ops;
-}
-
 static struct event_command trigger_traceon_cmd = {
 	.name			= "traceon",
 	.trigger_type		= ETT_TRACE_ONOFF,
+	.trigger_ops		= &traceon_trigger_ops,
 	.parse			= event_trigger_parse,
 	.reg			= register_trigger,
 	.unreg			= unregister_trigger,
-	.get_trigger_ops	= onoff_get_trigger_ops,
 	.set_filter		= set_trigger_filter,
 };
 
@@ -1418,10 +1431,10 @@ static struct event_command trigger_traceoff_cmd = {
 	.name			= "traceoff",
 	.trigger_type		= ETT_TRACE_ONOFF,
 	.flags			= EVENT_CMD_FL_POST_TRIGGER,
+	.trigger_ops		= &traceoff_trigger_ops,
 	.parse			= event_trigger_parse,
 	.reg			= register_trigger,
 	.unreg			= unregister_trigger,
-	.get_trigger_ops	= onoff_get_trigger_ops,
 	.set_filter		= set_trigger_filter,
 };
 
@@ -1439,20 +1452,6 @@ snapshot_trigger(struct event_trigger_data *data,
 		tracing_snapshot();
 }
 
-static void
-snapshot_count_trigger(struct event_trigger_data *data,
-		       struct trace_buffer *buffer, void *rec,
-		       struct ring_buffer_event *event)
-{
-	if (!data->count)
-		return;
-
-	if (data->count != -1)
-		(data->count)--;
-
-	snapshot_trigger(data, buffer, rec, event);
-}
-
 static int
 register_snapshot_trigger(char *glob,
 			  struct event_trigger_data *data,
@@ -1486,31 +1485,19 @@ snapshot_trigger_print(struct seq_file *m, struct event_trigger_data *data)
 
 static const struct event_trigger_ops snapshot_trigger_ops = {
 	.trigger		= snapshot_trigger,
+	.count_func		= event_trigger_count,
 	.print			= snapshot_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static const struct event_trigger_ops snapshot_count_trigger_ops = {
-	.trigger		= snapshot_count_trigger,
-	.print			= snapshot_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_trigger_free,
-};
-
-static const struct event_trigger_ops *
-snapshot_get_trigger_ops(char *cmd, char *param)
-{
-	return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
-}
-
 static struct event_command trigger_snapshot_cmd = {
 	.name			= "snapshot",
 	.trigger_type		= ETT_SNAPSHOT,
+	.trigger_ops		= &snapshot_trigger_ops,
 	.parse			= event_trigger_parse,
 	.reg			= register_snapshot_trigger,
 	.unreg			= unregister_snapshot_trigger,
-	.get_trigger_ops	= snapshot_get_trigger_ops,
 	.set_filter		= set_trigger_filter,
 };
 
@@ -1558,20 +1545,6 @@ stacktrace_trigger(struct event_trigger_data *data,
 		trace_dump_stack(STACK_SKIP);
 }
 
-static void
-stacktrace_count_trigger(struct event_trigger_data *data,
-			 struct trace_buffer *buffer, void *rec,
-			 struct ring_buffer_event *event)
-{
-	if (!data->count)
-		return;
-
-	if (data->count != -1)
-		(data->count)--;
-
-	stacktrace_trigger(data, buffer, rec, event);
-}
-
 static int
 stacktrace_trigger_print(struct seq_file *m, struct event_trigger_data *data)
 {
@@ -1581,32 +1554,20 @@ stacktrace_trigger_print(struct seq_file *m, struct event_trigger_data *data)
 
 static const struct event_trigger_ops stacktrace_trigger_ops = {
 	.trigger		= stacktrace_trigger,
+	.count_func		= event_trigger_count,
 	.print			= stacktrace_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static const struct event_trigger_ops stacktrace_count_trigger_ops = {
-	.trigger		= stacktrace_count_trigger,
-	.print			= stacktrace_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_trigger_free,
-};
-
-static const struct event_trigger_ops *
-stacktrace_get_trigger_ops(char *cmd, char *param)
-{
-	return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
-}
-
 static struct event_command trigger_stacktrace_cmd = {
 	.name			= "stacktrace",
 	.trigger_type		= ETT_STACKTRACE,
+	.trigger_ops		= &stacktrace_trigger_ops,
 	.flags			= EVENT_CMD_FL_POST_TRIGGER,
 	.parse			= event_trigger_parse,
 	.reg			= register_trigger,
 	.unreg			= unregister_trigger,
-	.get_trigger_ops	= stacktrace_get_trigger_ops,
 	.set_filter		= set_trigger_filter,
 };
 
@@ -1642,24 +1603,24 @@ event_enable_trigger(struct event_trigger_data *data,
 		set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
 }
 
-static void
-event_enable_count_trigger(struct event_trigger_data *data,
-			   struct trace_buffer *buffer,  void *rec,
-			   struct ring_buffer_event *event)
+static bool
+event_enable_count_func(struct event_trigger_data *data,
+			struct trace_buffer *buffer,  void *rec,
+			struct ring_buffer_event *event)
 {
 	struct enable_trigger_data *enable_data = data->private_data;
 
 	if (!data->count)
-		return;
+		return false;
 
 	/* Skip if the event is in a state we want to switch to */
 	if (enable_data->enable == !(enable_data->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
-		return;
+		return false;
 
 	if (data->count != -1)
 		(data->count)--;
 
-	event_enable_trigger(data, buffer, rec, event);
+	return true;
 }
 
 int event_enable_trigger_print(struct seq_file *m,
@@ -1706,13 +1667,7 @@ void event_enable_trigger_free(struct event_trigger_data *data)
 
 static const struct event_trigger_ops event_enable_trigger_ops = {
 	.trigger		= event_enable_trigger,
-	.print			= event_enable_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops event_enable_count_trigger_ops = {
-	.trigger		= event_enable_count_trigger,
+	.count_func		= event_enable_count_func,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_enable_trigger_free,
@@ -1720,13 +1675,7 @@ static const struct event_trigger_ops event_enable_count_trigger_ops = {
 
 static const struct event_trigger_ops event_disable_trigger_ops = {
 	.trigger		= event_enable_trigger,
-	.print			= event_enable_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops event_disable_count_trigger_ops = {
-	.trigger		= event_enable_count_trigger,
+	.count_func		= event_enable_count_func,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_enable_trigger_free,
@@ -1906,45 +1855,23 @@ void event_enable_unregister_trigger(char *glob,
 		data->ops->free(data);
 }
 
-static const struct event_trigger_ops *
-event_enable_get_trigger_ops(char *cmd, char *param)
-{
-	const struct event_trigger_ops *ops;
-	bool enable;
-
-#ifdef CONFIG_HIST_TRIGGERS
-	enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
-		  (strcmp(cmd, ENABLE_HIST_STR) == 0));
-#else
-	enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
-#endif
-	if (enable)
-		ops = param ? &event_enable_count_trigger_ops :
-			&event_enable_trigger_ops;
-	else
-		ops = param ? &event_disable_count_trigger_ops :
-			&event_disable_trigger_ops;
-
-	return ops;
-}
-
 static struct event_command trigger_enable_cmd = {
 	.name			= ENABLE_EVENT_STR,
 	.trigger_type		= ETT_EVENT_ENABLE,
+	.trigger_ops		= &event_enable_trigger_ops,
 	.parse			= event_enable_trigger_parse,
 	.reg			= event_enable_register_trigger,
 	.unreg			= event_enable_unregister_trigger,
-	.get_trigger_ops	= event_enable_get_trigger_ops,
 	.set_filter		= set_trigger_filter,
 };
 
 static struct event_command trigger_disable_cmd = {
 	.name			= DISABLE_EVENT_STR,
 	.trigger_type		= ETT_EVENT_ENABLE,
+	.trigger_ops		= &event_disable_trigger_ops,
 	.parse			= event_enable_trigger_parse,
 	.reg			= event_enable_register_trigger,
 	.unreg			= event_enable_unregister_trigger,
-	.get_trigger_ops	= event_enable_get_trigger_ops,
 	.set_filter		= set_trigger_filter,
 };
 
-- 
2.51.0

[for-next][PATCH 06/13] tracing: Merge struct event_trigger_ops into struct event_command

[Steven Rostedt]

From: Steven Rostedt <rostedt@goodmis.org>

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>
---
 kernel/trace/trace.h                | 126 +++++++++++-----------------
 kernel/trace/trace_eprobe.c         |  13 +--
 kernel/trace/trace_events_hist.c    |  93 ++++++++++----------
 kernel/trace/trace_events_trigger.c | 121 +++++++++++---------------
 4 files changed, 151 insertions(+), 202 deletions(-)

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index b9c59d9f9a0c..901aad30099b 100644
--- a/kernel/trace/trace.h
+++ b/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.
  *
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 14ae896dbe75..f3e0442c3b96 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/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
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index f9cc8d6a215b..f0dafc1f2787 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -5694,7 +5694,7 @@ static void hist_trigger_show(struct seq_file *m,
 		seq_puts(m, "\n\n");
 
 	seq_puts(m, "# event histogram\n#\n# trigger info: ");
-	data->ops->print(m, data);
+	data->cmd_ops->print(m, data);
 	seq_puts(m, "#\n\n");
 
 	hist_data = data->private_data;
@@ -6016,7 +6016,7 @@ static void hist_trigger_debug_show(struct seq_file *m,
 		seq_puts(m, "\n\n");
 
 	seq_puts(m, "# event histogram\n#\n# trigger info: ");
-	data->ops->print(m, data);
+	data->cmd_ops->print(m, data);
 	seq_puts(m, "#\n\n");
 
 	hist_data = data->private_data;
@@ -6326,20 +6326,21 @@ static void event_hist_trigger_free(struct event_trigger_data *data)
 	free_hist_pad();
 }
 
-static const struct event_trigger_ops event_hist_trigger_ops = {
-	.trigger		= event_hist_trigger,
-	.print			= event_hist_trigger_print,
-	.init			= event_hist_trigger_init,
-	.free			= event_hist_trigger_free,
-};
-
 static int event_hist_trigger_named_init(struct event_trigger_data *data)
 {
+	int ret;
+
 	data->ref++;
 
 	save_named_trigger(data->named_data->name, data);
 
-	return event_hist_trigger_init(data->named_data);
+	ret = event_hist_trigger_init(data->named_data);
+	if (ret < 0) {
+		kfree(data->cmd_ops);
+		data->cmd_ops = &trigger_hist_cmd;
+	}
+
+	return ret;
 }
 
 static void event_hist_trigger_named_free(struct event_trigger_data *data)
@@ -6351,18 +6352,14 @@ static void event_hist_trigger_named_free(struct event_trigger_data *data)
 
 	data->ref--;
 	if (!data->ref) {
+		struct event_command *cmd_ops = data->cmd_ops;
+
 		del_named_trigger(data);
 		trigger_data_free(data);
+		kfree(cmd_ops);
 	}
 }
 
-static const struct event_trigger_ops event_hist_trigger_named_ops = {
-	.trigger		= event_hist_trigger,
-	.print			= event_hist_trigger_print,
-	.init			= event_hist_trigger_named_init,
-	.free			= event_hist_trigger_named_free,
-};
-
 static void hist_clear(struct event_trigger_data *data)
 {
 	struct hist_trigger_data *hist_data = data->private_data;
@@ -6556,13 +6553,24 @@ static int hist_register_trigger(char *glob,
 		data->paused = true;
 
 	if (named_data) {
+		struct event_command *cmd_ops;
+
 		data->private_data = named_data->private_data;
 		set_named_trigger_data(data, named_data);
-		data->ops = &event_hist_trigger_named_ops;
+		/* Copy the command ops and update some of the functions */
+		cmd_ops = kmalloc(sizeof(*cmd_ops), GFP_KERNEL);
+		if (!cmd_ops) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		*cmd_ops = *data->cmd_ops;
+		cmd_ops->init = event_hist_trigger_named_init;
+		cmd_ops->free = event_hist_trigger_named_free;
+		data->cmd_ops = cmd_ops;
 	}
 
-	if (data->ops->init) {
-		ret = data->ops->init(data);
+	if (data->cmd_ops->init) {
+		ret = data->cmd_ops->init(data);
 		if (ret < 0)
 			goto out;
 	}
@@ -6676,8 +6684,8 @@ static void hist_unregister_trigger(char *glob,
 		}
 	}
 
-	if (test && test->ops->free)
-		test->ops->free(test);
+	if (test && test->cmd_ops->free)
+		test->cmd_ops->free(test);
 
 	if (hist_data->enable_timestamps) {
 		if (!hist_data->remove || test)
@@ -6729,8 +6737,8 @@ static void hist_unreg_all(struct trace_event_file *file)
 			update_cond_flag(file);
 			if (hist_data->enable_timestamps)
 				tracing_set_filter_buffering(file->tr, false);
-			if (test->ops->free)
-				test->ops->free(test);
+			if (test->cmd_ops->free)
+				test->cmd_ops->free(test);
 		}
 	}
 }
@@ -6902,12 +6910,15 @@ static struct event_command trigger_hist_cmd = {
 	.name			= "hist",
 	.trigger_type		= ETT_EVENT_HIST,
 	.flags			= EVENT_CMD_FL_NEEDS_REC,
-	.trigger_ops		= &event_hist_trigger_ops,
 	.parse			= event_hist_trigger_parse,
 	.reg			= hist_register_trigger,
 	.unreg			= hist_unregister_trigger,
 	.unreg_all		= hist_unreg_all,
 	.set_filter		= set_trigger_filter,
+	.trigger		= event_hist_trigger,
+	.print			= event_hist_trigger_print,
+	.init			= event_hist_trigger_init,
+	.free			= event_hist_trigger_free,
 };
 
 __init int register_trigger_hist_cmd(void)
@@ -6939,22 +6950,6 @@ hist_enable_trigger(struct event_trigger_data *data,
 	}
 }
 
-static const struct event_trigger_ops hist_enable_trigger_ops = {
-	.trigger		= hist_enable_trigger,
-	.count_func		= event_trigger_count,
-	.print			= event_enable_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops hist_disable_trigger_ops = {
-	.trigger		= hist_enable_trigger,
-	.count_func		= event_trigger_count,
-	.print			= event_enable_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_enable_trigger_free,
-};
-
 static void hist_enable_unreg_all(struct trace_event_file *file)
 {
 	struct event_trigger_data *test, *n;
@@ -6964,8 +6959,8 @@ static void hist_enable_unreg_all(struct trace_event_file *file)
 			list_del_rcu(&test->list);
 			update_cond_flag(file);
 			trace_event_trigger_enable_disable(file, 0);
-			if (test->ops->free)
-				test->ops->free(test);
+			if (test->cmd_ops->free)
+				test->cmd_ops->free(test);
 		}
 	}
 }
@@ -6973,23 +6968,31 @@ static void hist_enable_unreg_all(struct trace_event_file *file)
 static struct event_command trigger_hist_enable_cmd = {
 	.name			= ENABLE_HIST_STR,
 	.trigger_type		= ETT_HIST_ENABLE,
-	.trigger_ops		= &hist_enable_trigger_ops,
 	.parse			= event_enable_trigger_parse,
 	.reg			= event_enable_register_trigger,
 	.unreg			= event_enable_unregister_trigger,
 	.unreg_all		= hist_enable_unreg_all,
 	.set_filter		= set_trigger_filter,
+	.trigger		= hist_enable_trigger,
+	.count_func		= event_trigger_count,
+	.print			= event_enable_trigger_print,
+	.init			= event_trigger_init,
+	.free			= event_enable_trigger_free,
 };
 
 static struct event_command trigger_hist_disable_cmd = {
 	.name			= DISABLE_HIST_STR,
 	.trigger_type		= ETT_HIST_ENABLE,
-	.trigger_ops		= &hist_disable_trigger_ops,
 	.parse			= event_enable_trigger_parse,
 	.reg			= event_enable_register_trigger,
 	.unreg			= event_enable_unregister_trigger,
 	.unreg_all		= hist_enable_unreg_all,
 	.set_filter		= set_trigger_filter,
+	.trigger		= hist_enable_trigger,
+	.count_func		= event_trigger_count,
+	.print			= event_enable_trigger_print,
+	.init			= event_trigger_init,
+	.free			= event_enable_trigger_free,
 };
 
 static __init void unregister_trigger_hist_enable_disable_cmds(void)
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 576bad18bcdb..7795af600466 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -32,14 +32,14 @@ static inline void data_ops_trigger(struct event_trigger_data *data,
 				    struct trace_buffer *buffer,  void *rec,
 				    struct ring_buffer_event *event)
 {
-	const struct event_trigger_ops *ops = data->ops;
+	const struct event_command *cmd_ops = data->cmd_ops;
 
 	if (data->flags & EVENT_TRIGGER_FL_COUNT) {
-		if (!ops->count_func(data, buffer, rec, event))
+		if (!cmd_ops->count_func(data, buffer, rec, event))
 			return;
 	}
 
-	ops->trigger(data, buffer, rec, event);
+	cmd_ops->trigger(data, buffer, rec, event);
 }
 
 /**
@@ -205,7 +205,7 @@ static int trigger_show(struct seq_file *m, void *v)
 	}
 
 	data = list_entry(v, struct event_trigger_data, list);
-	data->ops->print(m, data);
+	data->cmd_ops->print(m, data);
 
 	return 0;
 }
@@ -422,7 +422,7 @@ bool event_trigger_count(struct event_trigger_data *data,
 }
 
 /**
- * event_trigger_print - Generic event_trigger_ops @print implementation
+ * event_trigger_print - Generic event_command @print implementation
  * @name: The name of the event trigger
  * @m: The seq_file being printed to
  * @data: Trigger-specific data
@@ -457,7 +457,7 @@ event_trigger_print(const char *name, struct seq_file *m,
 }
 
 /**
- * event_trigger_init - Generic event_trigger_ops @init implementation
+ * event_trigger_init - Generic event_command @init implementation
  * @data: Trigger-specific data
  *
  * Common implementation of event trigger initialization.
@@ -474,7 +474,7 @@ int event_trigger_init(struct event_trigger_data *data)
 }
 
 /**
- * event_trigger_free - Generic event_trigger_ops @free implementation
+ * event_trigger_free - Generic event_command @free implementation
  * @data: Trigger-specific data
  *
  * Common implementation of event trigger de-initialization.
@@ -536,8 +536,8 @@ clear_event_triggers(struct trace_array *tr)
 		list_for_each_entry_safe(data, n, &file->triggers, list) {
 			trace_event_trigger_enable_disable(file, 0);
 			list_del_rcu(&data->list);
-			if (data->ops->free)
-				data->ops->free(data);
+			if (data->cmd_ops->free)
+				data->cmd_ops->free(data);
 		}
 	}
 }
@@ -600,8 +600,8 @@ static int register_trigger(char *glob,
 			return -EEXIST;
 	}
 
-	if (data->ops->init) {
-		ret = data->ops->init(data);
+	if (data->cmd_ops->init) {
+		ret = data->cmd_ops->init(data);
 		if (ret < 0)
 			return ret;
 	}
@@ -639,8 +639,8 @@ static bool try_unregister_trigger(char *glob,
 	}
 
 	if (data) {
-		if (data->ops->free)
-			data->ops->free(data);
+		if (data->cmd_ops->free)
+			data->cmd_ops->free(data);
 
 		return true;
 	}
@@ -875,10 +875,9 @@ struct event_trigger_data *trigger_data_alloc(struct event_command *cmd_ops,
 		return NULL;
 
 	trigger_data->count = -1;
-	trigger_data->ops = cmd_ops->trigger_ops;
 	trigger_data->cmd_ops = cmd_ops;
 	trigger_data->private_data = private_data;
-	if (param && cmd_ops->trigger_ops->count_func)
+	if (param && cmd_ops->count_func)
 		trigger_data->flags |= EVENT_TRIGGER_FL_COUNT;
 
 	INIT_LIST_HEAD(&trigger_data->list);
@@ -1401,41 +1400,33 @@ traceoff_trigger_print(struct seq_file *m, struct event_trigger_data *data)
 				   data->filter_str);
 }
 
-static const struct event_trigger_ops traceon_trigger_ops = {
-	.trigger		= traceon_trigger,
-	.count_func		= traceon_count_func,
-	.print			= traceon_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_trigger_free,
-};
-
-static const struct event_trigger_ops traceoff_trigger_ops = {
-	.trigger		= traceoff_trigger,
-	.count_func		= traceoff_count_func,
-	.print			= traceoff_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_trigger_free,
-};
-
 static struct event_command trigger_traceon_cmd = {
 	.name			= "traceon",
 	.trigger_type		= ETT_TRACE_ONOFF,
-	.trigger_ops		= &traceon_trigger_ops,
 	.parse			= event_trigger_parse,
 	.reg			= register_trigger,
 	.unreg			= unregister_trigger,
 	.set_filter		= set_trigger_filter,
+	.trigger		= traceon_trigger,
+	.count_func		= traceon_count_func,
+	.print			= traceon_trigger_print,
+	.init			= event_trigger_init,
+	.free			= event_trigger_free,
 };
 
 static struct event_command trigger_traceoff_cmd = {
 	.name			= "traceoff",
 	.trigger_type		= ETT_TRACE_ONOFF,
 	.flags			= EVENT_CMD_FL_POST_TRIGGER,
-	.trigger_ops		= &traceoff_trigger_ops,
 	.parse			= event_trigger_parse,
 	.reg			= register_trigger,
 	.unreg			= unregister_trigger,
 	.set_filter		= set_trigger_filter,
+	.trigger		= traceoff_trigger,
+	.count_func		= traceoff_count_func,
+	.print			= traceoff_trigger_print,
+	.init			= event_trigger_init,
+	.free			= event_trigger_free,
 };
 
 #ifdef CONFIG_TRACER_SNAPSHOT
@@ -1483,22 +1474,18 @@ snapshot_trigger_print(struct seq_file *m, struct event_trigger_data *data)
 				   data->filter_str);
 }
 
-static const struct event_trigger_ops snapshot_trigger_ops = {
-	.trigger		= snapshot_trigger,
-	.count_func		= event_trigger_count,
-	.print			= snapshot_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_trigger_free,
-};
-
 static struct event_command trigger_snapshot_cmd = {
 	.name			= "snapshot",
 	.trigger_type		= ETT_SNAPSHOT,
-	.trigger_ops		= &snapshot_trigger_ops,
 	.parse			= event_trigger_parse,
 	.reg			= register_snapshot_trigger,
 	.unreg			= unregister_snapshot_trigger,
 	.set_filter		= set_trigger_filter,
+	.trigger		= snapshot_trigger,
+	.count_func		= event_trigger_count,
+	.print			= snapshot_trigger_print,
+	.init			= event_trigger_init,
+	.free			= event_trigger_free,
 };
 
 static __init int register_trigger_snapshot_cmd(void)
@@ -1552,23 +1539,19 @@ stacktrace_trigger_print(struct seq_file *m, struct event_trigger_data *data)
 				   data->filter_str);
 }
 
-static const struct event_trigger_ops stacktrace_trigger_ops = {
-	.trigger		= stacktrace_trigger,
-	.count_func		= event_trigger_count,
-	.print			= stacktrace_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_trigger_free,
-};
-
 static struct event_command trigger_stacktrace_cmd = {
 	.name			= "stacktrace",
 	.trigger_type		= ETT_STACKTRACE,
-	.trigger_ops		= &stacktrace_trigger_ops,
 	.flags			= EVENT_CMD_FL_POST_TRIGGER,
 	.parse			= event_trigger_parse,
 	.reg			= register_trigger,
 	.unreg			= unregister_trigger,
 	.set_filter		= set_trigger_filter,
+	.trigger		= stacktrace_trigger,
+	.count_func		= event_trigger_count,
+	.print			= stacktrace_trigger_print,
+	.init			= event_trigger_init,
+	.free			= event_trigger_free,
 };
 
 static __init int register_trigger_stacktrace_cmd(void)
@@ -1665,22 +1648,6 @@ void event_enable_trigger_free(struct event_trigger_data *data)
 	}
 }
 
-static const struct event_trigger_ops event_enable_trigger_ops = {
-	.trigger		= event_enable_trigger,
-	.count_func		= event_enable_count_func,
-	.print			= event_enable_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops event_disable_trigger_ops = {
-	.trigger		= event_enable_trigger,
-	.count_func		= event_enable_count_func,
-	.print			= event_enable_trigger_print,
-	.init			= event_trigger_init,
-	.free			= event_enable_trigger_free,
-};
-
 int event_enable_trigger_parse(struct event_command *cmd_ops,
 			       struct trace_event_file *file,
 			       char *glob, char *cmd, char *param_and_filter)
@@ -1810,8 +1777,8 @@ int event_enable_register_trigger(char *glob,
 		}
 	}
 
-	if (data->ops->init) {
-		ret = data->ops->init(data);
+	if (data->cmd_ops->init) {
+		ret = data->cmd_ops->init(data);
 		if (ret < 0)
 			return ret;
 	}
@@ -1851,28 +1818,36 @@ void event_enable_unregister_trigger(char *glob,
 		}
 	}
 
-	if (data && data->ops->free)
-		data->ops->free(data);
+	if (data && data->cmd_ops->free)
+		data->cmd_ops->free(data);
 }
 
 static struct event_command trigger_enable_cmd = {
 	.name			= ENABLE_EVENT_STR,
 	.trigger_type		= ETT_EVENT_ENABLE,
-	.trigger_ops		= &event_enable_trigger_ops,
 	.parse			= event_enable_trigger_parse,
 	.reg			= event_enable_register_trigger,
 	.unreg			= event_enable_unregister_trigger,
 	.set_filter		= set_trigger_filter,
+	.trigger		= event_enable_trigger,
+	.count_func		= event_enable_count_func,
+	.print			= event_enable_trigger_print,
+	.init			= event_trigger_init,
+	.free			= event_enable_trigger_free,
 };
 
 static struct event_command trigger_disable_cmd = {
 	.name			= DISABLE_EVENT_STR,
 	.trigger_type		= ETT_EVENT_ENABLE,
-	.trigger_ops		= &event_disable_trigger_ops,
 	.parse			= event_enable_trigger_parse,
 	.reg			= event_enable_register_trigger,
 	.unreg			= event_enable_unregister_trigger,
 	.set_filter		= set_trigger_filter,
+	.trigger		= event_enable_trigger,
+	.count_func		= event_enable_count_func,
+	.print			= event_enable_trigger_print,
+	.init			= event_trigger_init,
+	.free			= event_enable_trigger_free,
 };
 
 static __init void unregister_trigger_enable_disable_cmds(void)
-- 
2.51.0

[for-next][PATCH 07/13] tracing: Remove unneeded event_mutex lock in event_trigger_regex_release()

[Steven Rostedt]

From: Steven Rostedt <rostedt@goodmis.org>

In event_trigger_regex_release(), the only code is:

	mutex_lock(&event_mutex);
	if (file->f_mode & FMODE_READ)
		seq_release(inode, file);
	mutex_unlock(&event_mutex);

	return 0;

There's nothing special about the file->f_mode or the seq_release() that
requires any locking. Remove the unnecessary locks.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://patch.msgid.link/20251125214031.975879283@kernel.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace_events_trigger.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 7795af600466..e5dcfcbb2cd5 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -314,13 +314,9 @@ static ssize_t event_trigger_regex_write(struct file *file,
 
 static int event_trigger_regex_release(struct inode *inode, struct file *file)
 {
-	mutex_lock(&event_mutex);
-
 	if (file->f_mode & FMODE_READ)
 		seq_release(inode, file);
 
-	mutex_unlock(&event_mutex);
-
 	return 0;
 }
 
-- 
2.51.0

[for-next][PATCH 08/13] tracing: Add bulk garbage collection of freeing event_trigger_data

[Steven Rostedt]

From: Steven Rostedt <rostedt@goodmis.org>

The event trigger data requires a full tracepoint_synchronize_unregister()
call before freeing. That call can take 100s of milliseconds to complete.
In order to allow for bulk freeing of the trigger data, it can not call
the tracepoint_synchronize_unregister() for every individual trigger data
being free.

Create a kthread that gets created the first time a trigger data is freed,
and have it use the lockless llist to get the list of data to free, run
the tracepoint_synchronize_unregister() then free everything in the list.

By freeing hundreds of event_trigger_data elements together, it only
requires two runs of the synchronization function, and not hundreds of
runs. This speeds up the operation by orders of magnitude (milliseconds
instead of several seconds).

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://patch.msgid.link/20251125214032.151674992@kernel.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace.h                |  2 ++
 kernel/trace/trace_events_trigger.c | 55 +++++++++++++++++++++++++++--
 2 files changed, 54 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 901aad30099b..a3aa225ed50a 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -22,6 +22,7 @@
 #include <linux/ctype.h>
 #include <linux/once_lite.h>
 #include <linux/ftrace_regs.h>
+#include <linux/llist.h>
 
 #include "pid_list.h"
 
@@ -1808,6 +1809,7 @@ struct event_trigger_data {
 	char				*name;
 	struct list_head		named_list;
 	struct event_trigger_data	*named_data;
+	struct llist_node		llist;
 };
 
 /* Avoid typos */
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index e5dcfcbb2cd5..3b97c242b795 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/security.h>
+#include <linux/kthread.h>
 #include <linux/module.h>
 #include <linux/ctype.h>
 #include <linux/mutex.h>
@@ -17,15 +18,63 @@
 static LIST_HEAD(trigger_commands);
 static DEFINE_MUTEX(trigger_cmd_mutex);
 
+static struct task_struct *trigger_kthread;
+static struct llist_head trigger_data_free_list;
+static DEFINE_MUTEX(trigger_data_kthread_mutex);
+
+/* Bulk garbage collection of event_trigger_data elements */
+static int trigger_kthread_fn(void *ignore)
+{
+	struct event_trigger_data *data, *tmp;
+	struct llist_node *llnodes;
+
+	/* Once this task starts, it lives forever */
+	for (;;) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (llist_empty(&trigger_data_free_list))
+			schedule();
+
+		__set_current_state(TASK_RUNNING);
+
+		llnodes = llist_del_all(&trigger_data_free_list);
+
+		/* make sure current triggers exit before free */
+		tracepoint_synchronize_unregister();
+
+		llist_for_each_entry_safe(data, tmp, llnodes, llist)
+			kfree(data);
+	}
+
+	return 0;
+}
+
 void trigger_data_free(struct event_trigger_data *data)
 {
 	if (data->cmd_ops->set_filter)
 		data->cmd_ops->set_filter(NULL, data, NULL);
 
-	/* make sure current triggers exit before free */
-	tracepoint_synchronize_unregister();
+	if (unlikely(!trigger_kthread)) {
+		guard(mutex)(&trigger_data_kthread_mutex);
+		/* Check again after taking mutex */
+		if (!trigger_kthread) {
+			struct task_struct *kthread;
+
+			kthread = kthread_create(trigger_kthread_fn, NULL,
+						 "trigger_data_free");
+			if (!IS_ERR(kthread))
+				WRITE_ONCE(trigger_kthread, kthread);
+		}
+	}
+
+	if (!trigger_kthread) {
+		/* Do it the slow way */
+		tracepoint_synchronize_unregister();
+		kfree(data);
+		return;
+	}
 
-	kfree(data);
+	llist_add(&data->llist, &trigger_data_free_list);
+	wake_up_process(trigger_kthread);
 }
 
 static inline void data_ops_trigger(struct event_trigger_data *data,
-- 
2.51.0

[for-next][PATCH 09/13] tracing: Use strim() in trigger_process_regex() instead of skip_spaces()

[Steven Rostedt]

From: Steven Rostedt <rostedt@goodmis.org>

The function trigger_process_regex() is called by a few functions, where
only one calls strim() on the buffer passed to it. That leaves the other
functions not trimming the end of the buffer passed in and making it a
little inconsistent.

Remove the strim() from event_trigger_regex_write() and have
trigger_process_regex() use strim() instead of skip_spaces(). The buff
variable is not passed in as const, so it can be modified.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://patch.msgid.link/20251125214032.323747707@kernel.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace_events_trigger.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 3b97c242b795..96aad82b1628 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -308,7 +308,8 @@ int trigger_process_regex(struct trace_event_file *file, char *buff)
 	char *command, *next;
 	struct event_command *p;
 
-	next = buff = skip_spaces(buff);
+	next = buff = strim(buff);
+
 	command = strsep(&next, ": \t");
 	if (next) {
 		next = skip_spaces(next);
@@ -345,8 +346,6 @@ static ssize_t event_trigger_regex_write(struct file *file,
 	if (IS_ERR(buf))
 		return PTR_ERR(buf);
 
-	strim(buf);
-
 	guard(mutex)(&event_mutex);
 
 	event_file = event_file_file(file);
-- 
2.51.0

[for-next][PATCH 10/13] ftrace: Allow tracing of some of the tracing code

[Steven Rostedt]

From: Steven Rostedt <rostedt@goodmis.org>

There is times when tracing the tracing infrastructure can be useful for
debugging the tracing code. Currently all files in the tracing directory
are set to "notrace" the functions.

Add a new config option FUNCTION_SELF_TRACING that will allow some of the
files in the tracing infrastructure to be traced. It requires a config to
enable because it will add noise to the function tracer if events and
other tracing features are enabled. Tracing functions and events together
is quite common, so not tracing the event code should be the default.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://patch.msgid.link/20251120181514.736f2d5f@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/Kconfig  | 14 ++++++++++++++
 kernel/trace/Makefile | 17 +++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 99283b2dcfd6..e1214b9dc990 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -330,6 +330,20 @@ config DYNAMIC_FTRACE_WITH_ARGS
 	depends on DYNAMIC_FTRACE
 	depends on HAVE_DYNAMIC_FTRACE_WITH_ARGS
 
+config FUNCTION_SELF_TRACING
+	bool "Function trace tracing code"
+	depends on FUNCTION_TRACER
+	help
+	  Normally all the tracing code is set to notrace, where the function
+	  tracer will ignore all the tracing functions. Sometimes it is useful
+	  for debugging to trace some of the tracing infratructure itself.
+	  Enable this to allow some of the tracing infrastructure to be traced
+	  by the function tracer. Note, this will likely add noise to function
+	  tracing if events and other tracing features are enabled along with
+	  function tracing.
+
+	  If unsure, say N.
+
 config FPROBE
 	bool "Kernel Function Probe (fprobe)"
 	depends on HAVE_FUNCTION_GRAPH_FREGS && HAVE_FTRACE_GRAPH_FUNC
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index dcb4e02afc5f..fc5dcc888e13 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -16,6 +16,23 @@ obj-y += trace_selftest_dynamic.o
 endif
 endif
 
+# Allow some files to be function traced
+ifdef CONFIG_FUNCTION_SELF_TRACING
+CFLAGS_trace_output.o = $(CC_FLAGS_FTRACE)
+CFLAGS_trace_seq.o = $(CC_FLAGS_FTRACE)
+CFLAGS_trace_stat.o = $(CC_FLAGS_FTRACE)
+CFLAGS_tracing_map.o = $(CC_FLAGS_FTRACE)
+CFLAGS_synth_event_gen_test.o = $(CC_FLAGS_FTRACE)
+CFLAGS_trace_events.o = $(CC_FLAGS_FTRACE)
+CFLAGS_trace_syscalls.o = $(CC_FLAGS_FTRACE)
+CFLAGS_trace_events_filter.o = $(CC_FLAGS_FTRACE)
+CFLAGS_trace_events_trigger.o = $(CC_FLAGS_FTRACE)
+CFLAGS_trace_events_synth.o = $(CC_FLAGS_FTRACE)
+CFLAGS_trace_events_hist.o = $(CC_FLAGS_FTRACE)
+CFLAGS_trace_events_user.o = $(CC_FLAGS_FTRACE)
+CFLAGS_trace_dynevent.o = $(CC_FLAGS_FTRACE)
+endif
+
 ifdef CONFIG_FTRACE_STARTUP_TEST
 CFLAGS_trace_kprobe_selftest.o = $(CC_FLAGS_FTRACE)
 obj-$(CONFIG_KPROBE_EVENTS) += trace_kprobe_selftest.o
-- 
2.51.0

[for-next][PATCH 11/13] tracing: Add boot-time backup of persistent ring buffer

[Steven Rostedt]

From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>

Currently, the persistent ring buffer instance needs to be read before
using it. This means we have to wait for boot up user space and dump
the persistent ring buffer. However, in that case we can not start
tracing on it from the kernel cmdline.

To solve this limitation, this adds an option which allows to create
a trace instance as a backup of the persistent ring buffer at boot.
If user specifies trace_instance=<BACKUP>=<PERSIST_RB> then the
<BACKUP> instance is made as a copy of the <PERSIST_RB> instance.

For example, the below kernel cmdline records all syscalls, scheduler
and interrupt events on the persistent ring buffer `boot_map` but
before starting the tracing, it makes a `backup` instance from the
`boot_map`. Thus, the `backup` instance has the previous boot events.

'reserve_mem=12M:4M:trace trace_instance=boot_map@trace,syscalls:*,sched:*,irq:* trace_instance=backup=boot_map'

As you can see, this just make a copy of entire reserved area and
make a backup instance on it. So you can release (or shrink) the
backup instance after use it to save the memory usage.

  /sys/kernel/tracing/instances # free
                total        used        free      shared  buff/cache   available
  Mem:        1999284       55704     1930520       10132       13060     1914628
  Swap:             0           0           0
  /sys/kernel/tracing/instances # rmdir backup/
  /sys/kernel/tracing/instances # free
                total        used        free      shared  buff/cache   available
  Mem:        1999284       40640     1945584       10132       13060     1929692
  Swap:             0           0           0

Note: since there is no reason to make a copy of empty buffer, this
backup only accepts a persistent ring buffer as the original instance.
Also, since this backup is based on vmalloc(), it does not support
user-space mmap().

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/176377150002.219692.9425536150438129267.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 63 +++++++++++++++++++++++++++++++++++++++-----
 kernel/trace/trace.h |  1 +
 2 files changed, 58 insertions(+), 6 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 032bdedca5d9..73f8b79f1b0c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -9004,8 +9004,8 @@ static int tracing_buffers_mmap(struct file *filp, struct vm_area_struct *vma)
 	struct trace_iterator *iter = &info->iter;
 	int ret = 0;
 
-	/* A memmap'ed buffer is not supported for user space mmap */
-	if (iter->tr->flags & TRACE_ARRAY_FL_MEMMAP)
+	/* A memmap'ed and backup buffers are not supported for user space mmap */
+	if (iter->tr->flags & (TRACE_ARRAY_FL_MEMMAP | TRACE_ARRAY_FL_VMALLOC))
 		return -ENODEV;
 
 	ret = get_snapshot_map(iter->tr);
@@ -10520,6 +10520,8 @@ static int __remove_instance(struct trace_array *tr)
 		reserve_mem_release_by_name(tr->range_name);
 		kfree(tr->range_name);
 	}
+	if (tr->flags & TRACE_ARRAY_FL_VMALLOC)
+		vfree((void *)tr->range_addr_start);
 
 	for (i = 0; i < tr->nr_topts; i++) {
 		kfree(tr->topts[i].topts);
@@ -11325,6 +11327,42 @@ __init static void do_allocate_snapshot(const char *name)
 static inline void do_allocate_snapshot(const char *name) { }
 #endif
 
+__init static int backup_instance_area(const char *backup,
+				       unsigned long *addr, phys_addr_t *size)
+{
+	struct trace_array *backup_tr;
+	void *allocated_vaddr = NULL;
+
+	backup_tr = trace_array_get_by_name(backup, NULL);
+	if (!backup_tr) {
+		pr_warn("Tracing: Instance %s is not found.\n", backup);
+		return -ENOENT;
+	}
+
+	if (!(backup_tr->flags & TRACE_ARRAY_FL_BOOT)) {
+		pr_warn("Tracing: Instance %s is not boot mapped.\n", backup);
+		trace_array_put(backup_tr);
+		return -EINVAL;
+	}
+
+	*size = backup_tr->range_addr_size;
+
+	allocated_vaddr = vzalloc(*size);
+	if (!allocated_vaddr) {
+		pr_warn("Tracing: Failed to allocate memory for copying instance %s (size 0x%lx)\n",
+			backup, (unsigned long)*size);
+		trace_array_put(backup_tr);
+		return -ENOMEM;
+	}
+
+	memcpy(allocated_vaddr,
+		(void *)backup_tr->range_addr_start, (size_t)*size);
+	*addr = (unsigned long)allocated_vaddr;
+
+	trace_array_put(backup_tr);
+	return 0;
+}
+
 __init static void enable_instances(void)
 {
 	struct trace_array *tr;
@@ -11347,11 +11385,15 @@ __init static void enable_instances(void)
 		char *flag_delim;
 		char *addr_delim;
 		char *rname __free(kfree) = NULL;
+		char *backup;
 
 		tok = strsep(&curr_str, ",");
 
-		flag_delim = strchr(tok, '^');
-		addr_delim = strchr(tok, '@');
+		name = strsep(&tok, "=");
+		backup = tok;
+
+		flag_delim = strchr(name, '^');
+		addr_delim = strchr(name, '@');
 
 		if (addr_delim)
 			*addr_delim++ = '\0';
@@ -11359,7 +11401,10 @@ __init static void enable_instances(void)
 		if (flag_delim)
 			*flag_delim++ = '\0';
 
-		name = tok;
+		if (backup) {
+			if (backup_instance_area(backup, &addr, &size) < 0)
+				continue;
+		}
 
 		if (flag_delim) {
 			char *flag;
@@ -11455,7 +11500,13 @@ __init static void enable_instances(void)
 			tr->ref++;
 		}
 
-		if (start) {
+		/*
+		 * Backup buffers can be freed but need vfree().
+		 */
+		if (backup)
+			tr->flags |= TRACE_ARRAY_FL_VMALLOC;
+
+		if (start || backup) {
 			tr->flags |= TRACE_ARRAY_FL_BOOT | TRACE_ARRAY_FL_LAST_BOOT;
 			tr->range_name = no_free_ptr(rname);
 		}
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index a3aa225ed50a..666f9a2c189d 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -454,6 +454,7 @@ enum {
 	TRACE_ARRAY_FL_LAST_BOOT	= BIT(2),
 	TRACE_ARRAY_FL_MOD_INIT		= BIT(3),
 	TRACE_ARRAY_FL_MEMMAP		= BIT(4),
+	TRACE_ARRAY_FL_VMALLOC		= BIT(5),
 };
 
 #ifdef CONFIG_MODULES
-- 
2.51.0

[for-next][PATCH 12/13] function_graph: Enable funcgraph-args and funcgraph-retaddr to work simultaneously

[Steven Rostedt]

From: pengdonglin <pengdonglin@xiaomi.com>

Currently, the funcgraph-args and funcgraph-retaddr features are
mutually exclusive. This patch resolves this limitation by allowing
funcgraph-retaddr to have an args array.

To verify the change, use perf to trace vfs_write with both options
enabled:

Before:
 # perf ftrace -G vfs_write --graph-opts args,retaddr
   ......
   down_read() { /* <-n_tty_write+0xa3/0x540 */
     __cond_resched(); /* <-down_read+0x12/0x160 */
     preempt_count_add(); /* <-down_read+0x3b/0x160 */
     preempt_count_sub(); /* <-down_read+0x8b/0x160 */
   }

After:
 # perf ftrace -G vfs_write --graph-opts args,retaddr
   ......
   down_read(sem=0xffff8880100bea78) { /* <-n_tty_write+0xa3/0x540 */
     __cond_resched(); /* <-down_read+0x12/0x160 */
     preempt_count_add(val=1); /* <-down_read+0x3b/0x160 */
     preempt_count_sub(val=1); /* <-down_read+0x8b/0x160 */
   }

Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Xiaoqin Zhang <zhangxiaoqin@xiaomi.com>
Link: https://patch.msgid.link/20251125093425.2563849-1-dolinux.peng@gmail.com
Signed-off-by: pengdonglin <pengdonglin@xiaomi.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 include/linux/ftrace.h               |  7 +--
 kernel/trace/trace.h                 | 24 +++++++++-
 kernel/trace/trace_entries.h         | 15 +++---
 kernel/trace/trace_functions_graph.c | 71 ++++++++++++++++++----------
 4 files changed, 80 insertions(+), 37 deletions(-)

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 7ded7df6e9b5..6ca9c6229d93 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -1126,17 +1126,14 @@ static inline void ftrace_init(void) { }
  */
 struct ftrace_graph_ent {
 	unsigned long func; /* Current function */
-	int depth;
+	unsigned long depth;
 } __packed;
 
 /*
  * Structure that defines an entry function trace with retaddr.
- * It's already packed but the attribute "packed" is needed
- * to remove extra padding at the end.
  */
 struct fgraph_retaddr_ent {
-	unsigned long func; /* Current function */
-	int depth;
+	struct ftrace_graph_ent ent;
 	unsigned long retaddr;  /* Return address */
 } __packed;
 
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 666f9a2c189d..c2b61bcd912f 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -964,7 +964,8 @@ extern int __trace_graph_entry(struct trace_array *tr,
 extern int __trace_graph_retaddr_entry(struct trace_array *tr,
 				struct ftrace_graph_ent *trace,
 				unsigned int trace_ctx,
-				unsigned long retaddr);
+				unsigned long retaddr,
+				struct ftrace_regs *fregs);
 extern void __trace_graph_return(struct trace_array *tr,
 				 struct ftrace_graph_ret *trace,
 				 unsigned int trace_ctx,
@@ -2276,4 +2277,25 @@ static inline int rv_init_interface(void)
  */
 #define FTRACE_TRAMPOLINE_MARKER  ((unsigned long) INT_MAX)
 
+/*
+ * This is used to get the address of the args array based on
+ * the type of the entry.
+ */
+#define FGRAPH_ENTRY_ARGS(e)						\
+	({								\
+		unsigned long *_args;					\
+		struct ftrace_graph_ent_entry *_e = e;			\
+									\
+		if (IS_ENABLED(CONFIG_FUNCTION_GRAPH_RETADDR) &&	\
+			e->ent.type == TRACE_GRAPH_RETADDR_ENT) {	\
+			struct fgraph_retaddr_ent_entry *_re;		\
+									\
+			_re = (typeof(_re))_e;				\
+			_args = _re->args;				\
+		} else {						\
+			_args = _e->args;				\
+		}							\
+		_args;							\
+	})
+
 #endif /* _LINUX_KERNEL_TRACE_H */
diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
index de294ae2c5c5..f6a8d29c0d76 100644
--- a/kernel/trace/trace_entries.h
+++ b/kernel/trace/trace_entries.h
@@ -80,11 +80,11 @@ FTRACE_ENTRY(funcgraph_entry, ftrace_graph_ent_entry,
 	F_STRUCT(
 		__field_struct(	struct ftrace_graph_ent,	graph_ent	)
 		__field_packed(	unsigned long,	graph_ent,	func		)
-		__field_packed(	unsigned int,	graph_ent,	depth		)
+		__field_packed(	unsigned long,	graph_ent,	depth		)
 		__dynamic_array(unsigned long,	args				)
 	),
 
-	F_printk("--> %ps (%u)", (void *)__entry->func, __entry->depth)
+	F_printk("--> %ps (%lu)", (void *)__entry->func, __entry->depth)
 );
 
 #ifdef CONFIG_FUNCTION_GRAPH_RETADDR
@@ -95,13 +95,14 @@ FTRACE_ENTRY_PACKED(fgraph_retaddr_entry, fgraph_retaddr_ent_entry,
 	TRACE_GRAPH_RETADDR_ENT,
 
 	F_STRUCT(
-		__field_struct(	struct fgraph_retaddr_ent,	graph_ent	)
-		__field_packed(	unsigned long,	graph_ent,	func		)
-		__field_packed(	unsigned int,	graph_ent,	depth		)
-		__field_packed(	unsigned long,	graph_ent,	retaddr		)
+		__field_struct(	struct fgraph_retaddr_ent,	graph_rent	)
+		__field_packed(	unsigned long,	graph_rent.ent,	func		)
+		__field_packed(	unsigned long,	graph_rent.ent,	depth		)
+		__field_packed(	unsigned long,	graph_rent,	retaddr		)
+		__dynamic_array(unsigned long,	args				)
 	),
 
-	F_printk("--> %ps (%u) <- %ps", (void *)__entry->func, __entry->depth,
+	F_printk("--> %ps (%lu) <- %ps", (void *)__entry->func, __entry->depth,
 		(void *)__entry->retaddr)
 );
 
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index d0513cfcd936..17c75cf2348e 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -36,14 +36,19 @@ struct fgraph_ent_args {
 	unsigned long			args[FTRACE_REGS_MAX_ARGS];
 };
 
+struct fgraph_retaddr_ent_args {
+	struct fgraph_retaddr_ent_entry	ent;
+	/* Force the sizeof of args[] to have FTRACE_REGS_MAX_ARGS entries */
+	unsigned long			args[FTRACE_REGS_MAX_ARGS];
+};
+
 struct fgraph_data {
 	struct fgraph_cpu_data __percpu *cpu_data;
 
 	/* Place to preserve last processed entry. */
 	union {
 		struct fgraph_ent_args		ent;
-		/* TODO allow retaddr to have args */
-		struct fgraph_retaddr_ent_entry	rent;
+		struct fgraph_retaddr_ent_args	rent;
 	};
 	struct ftrace_graph_ret_entry	ret;
 	int				failed;
@@ -160,20 +165,32 @@ int __trace_graph_entry(struct trace_array *tr,
 int __trace_graph_retaddr_entry(struct trace_array *tr,
 				struct ftrace_graph_ent *trace,
 				unsigned int trace_ctx,
-				unsigned long retaddr)
+				unsigned long retaddr,
+				struct ftrace_regs *fregs)
 {
 	struct ring_buffer_event *event;
 	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	struct fgraph_retaddr_ent_entry *entry;
+	int size;
+
+	/* If fregs is defined, add FTRACE_REGS_MAX_ARGS long size words */
+	size = sizeof(*entry) + (FTRACE_REGS_MAX_ARGS * !!fregs * sizeof(long));
 
 	event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RETADDR_ENT,
-					  sizeof(*entry), trace_ctx);
+					  size, trace_ctx);
 	if (!event)
 		return 0;
 	entry	= ring_buffer_event_data(event);
-	entry->graph_ent.func = trace->func;
-	entry->graph_ent.depth = trace->depth;
-	entry->graph_ent.retaddr = retaddr;
+	entry->graph_rent.ent = *trace;
+	entry->graph_rent.retaddr = retaddr;
+
+#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
+	if (fregs) {
+		for (int i = 0; i < FTRACE_REGS_MAX_ARGS; i++)
+			entry->args[i] = ftrace_regs_get_argument(fregs, i);
+	}
+#endif
+
 	trace_buffer_unlock_commit_nostack(buffer, event);
 
 	return 1;
@@ -182,7 +199,8 @@ int __trace_graph_retaddr_entry(struct trace_array *tr,
 int __trace_graph_retaddr_entry(struct trace_array *tr,
 				struct ftrace_graph_ent *trace,
 				unsigned int trace_ctx,
-				unsigned long retaddr)
+				unsigned long retaddr,
+				struct ftrace_regs *fregs)
 {
 	return 1;
 }
@@ -267,7 +285,8 @@ static int graph_entry(struct ftrace_graph_ent *trace,
 	if (IS_ENABLED(CONFIG_FUNCTION_GRAPH_RETADDR) &&
 	    tracer_flags_is_set(tr, TRACE_GRAPH_PRINT_RETADDR)) {
 		unsigned long retaddr = ftrace_graph_top_ret_addr(current);
-		ret = __trace_graph_retaddr_entry(tr, trace, trace_ctx, retaddr);
+		ret = __trace_graph_retaddr_entry(tr, trace, trace_ctx,
+						  retaddr, fregs);
 	} else {
 		ret = __graph_entry(tr, trace, trace_ctx, fregs);
 	}
@@ -654,13 +673,9 @@ get_return_for_leaf(struct trace_iterator *iter,
 			 * Save current and next entries for later reference
 			 * if the output fails.
 			 */
-			if (unlikely(curr->ent.type == TRACE_GRAPH_RETADDR_ENT)) {
-				data->rent = *(struct fgraph_retaddr_ent_entry *)curr;
-			} else {
-				int size = min((int)sizeof(data->ent), (int)iter->ent_size);
+			int size = min_t(int, sizeof(data->rent), iter->ent_size);
 
-				memcpy(&data->ent, curr, size);
-			}
+			memcpy(&data->rent, curr, size);
 			/*
 			 * If the next event is not a return type, then
 			 * we only care about what type it is. Otherwise we can
@@ -838,7 +853,7 @@ static void print_graph_retaddr(struct trace_seq *s, struct fgraph_retaddr_ent_e
 		trace_seq_puts(s, " /*");
 
 	trace_seq_puts(s, " <-");
-	seq_print_ip_sym_offset(s, entry->graph_ent.retaddr, trace_flags);
+	seq_print_ip_sym_offset(s, entry->graph_rent.retaddr, trace_flags);
 
 	if (comment)
 		trace_seq_puts(s, " */");
@@ -984,7 +999,7 @@ print_graph_entry_leaf(struct trace_iterator *iter,
 		trace_seq_printf(s, "%ps", (void *)ret_func);
 
 		if (args_size >= FTRACE_REGS_MAX_ARGS * sizeof(long)) {
-			print_function_args(s, entry->args, ret_func);
+			print_function_args(s, FGRAPH_ENTRY_ARGS(entry), ret_func);
 			trace_seq_putc(s, ';');
 		} else
 			trace_seq_puts(s, "();");
@@ -1036,7 +1051,7 @@ print_graph_entry_nested(struct trace_iterator *iter,
 	args_size = iter->ent_size - offsetof(struct ftrace_graph_ent_entry, args);
 
 	if (args_size >= FTRACE_REGS_MAX_ARGS * sizeof(long))
-		print_function_args(s, entry->args, func);
+		print_function_args(s, FGRAPH_ENTRY_ARGS(entry), func);
 	else
 		trace_seq_puts(s, "()");
 
@@ -1218,11 +1233,14 @@ print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
 	/*
 	 * print_graph_entry() may consume the current event,
 	 * thus @field may become invalid, so we need to save it.
-	 * sizeof(struct ftrace_graph_ent_entry) is very small,
-	 * it can be safely saved at the stack.
+	 * This function is shared by ftrace_graph_ent_entry and
+	 * fgraph_retaddr_ent_entry, the size of the latter one
+	 * is larger, but it is very small and can be safely saved
+	 * at the stack.
 	 */
 	struct ftrace_graph_ent_entry *entry;
-	u8 save_buf[sizeof(*entry) + FTRACE_REGS_MAX_ARGS * sizeof(long)];
+	struct fgraph_retaddr_ent_entry *rentry;
+	u8 save_buf[sizeof(*rentry) + FTRACE_REGS_MAX_ARGS * sizeof(long)];
 
 	/* The ent_size is expected to be as big as the entry */
 	if (iter->ent_size > sizeof(save_buf))
@@ -1451,12 +1469,17 @@ print_graph_function_flags(struct trace_iterator *iter, u32 flags)
 	}
 #ifdef CONFIG_FUNCTION_GRAPH_RETADDR
 	case TRACE_GRAPH_RETADDR_ENT: {
-		struct fgraph_retaddr_ent_entry saved;
+		/*
+		 * ftrace_graph_ent_entry and fgraph_retaddr_ent_entry have
+		 * similar functions and memory layouts. The only difference
+		 * is that the latter one has an extra retaddr member, so
+		 * they can share most of the logic.
+		 */
 		struct fgraph_retaddr_ent_entry *rfield;
 
 		trace_assign_type(rfield, entry);
-		saved = *rfield;
-		return print_graph_entry((struct ftrace_graph_ent_entry *)&saved, s, iter, flags);
+		return print_graph_entry((struct ftrace_graph_ent_entry *)rfield,
+					  s, iter, flags);
 	}
 #endif
 	case TRACE_GRAPH_RET: {
-- 
2.51.0

[for-next][PATCH 13/13] overflow: Introduce struct_offset() to get offset of member

[Steven Rostedt]

From: Steven Rostedt <rostedt@goodmis.org>

The trace_marker_raw file in tracefs takes a buffer from user space that
contains an id as well as a raw data string which is usually a binary
structure. The structure used has the following:

	struct raw_data_entry {
		struct trace_entry	ent;
		unsigned int		id;
		char			buf[];
	};

Since the passed in "cnt" variable is both the size of buf as well as the
size of id, the code to allocate the location on the ring buffer had:

   size = struct_size(entry, buf, cnt - sizeof(entry->id));

Which is quite ugly and hard to understand. Instead, add a helper macro
called struct_offset() which then changes the above to a simple and easy
to understand:

   size = struct_offset(entry, id) + cnt;

This will likely come in handy for other use cases too.

Link: https://lore.kernel.org/all/CAHk-=whYZVoEdfO1PmtbirPdBMTV9Nxt9f09CK0k6S+HJD3Zmg@mail.gmail.com/

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Link: https://patch.msgid.link/20251126145249.05b1770a@gandalf.local.home
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 include/linux/overflow.h | 12 ++++++++++++
 kernel/trace/trace.c     |  2 +-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/include/linux/overflow.h b/include/linux/overflow.h
index 725f95f7e416..736f633b2d5f 100644
--- a/include/linux/overflow.h
+++ b/include/linux/overflow.h
@@ -458,6 +458,18 @@ static inline size_t __must_check size_sub(size_t minuend, size_t subtrahend)
 #define struct_size_t(type, member, count)					\
 	struct_size((type *)NULL, member, count)
 
+/**
+ * struct_offset() - Calculate the offset of a member within a struct
+ * @p: Pointer to the struct
+ * @member: Name of the member to get the offset of
+ *
+ * Calculates the offset of a particular @member of the structure pointed
+ * to by @p.
+ *
+ * Return: number of bytes to the location of @member.
+ */
+#define struct_offset(p, member) (offsetof(typeof(*(p)), member))
+
 /**
  * __DEFINE_FLEX() - helper macro for DEFINE_FLEX() family.
  * Enables caller macro to pass arbitrary trailing expressions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 73f8b79f1b0c..3d433a426e5f 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -7642,7 +7642,7 @@ static ssize_t write_raw_marker_to_buffer(struct trace_array *tr,
 	size_t size;
 
 	/* cnt includes both the entry->id and the data behind it. */
-	size = struct_size(entry, buf, cnt - sizeof(entry->id));
+	size = struct_offset(entry, id) + cnt;
 
 	buffer = tr->array_buffer.buffer;
 
-- 
2.51.0