[PATCH] tracing: Use more common error handling code in event_enable_trigger_parse()

[PATCH] tracing: Use more common error handling code in event_enable_trigger_parse()

[Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Tue, 16 Jun 2026 22:22:52 +0200

Use an additional label so that a bit of exception handling can be better
reused at the end of this function implementation.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 kernel/trace/trace_events_trigger.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 655db2e82513..7e17dd6d5b50 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -1789,17 +1789,14 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
 	enable_data->file = event_enable_file;
 
 	trigger_data = trigger_data_alloc(cmd_ops, cmd, param, enable_data);
-	if (!trigger_data) {
-		kfree(enable_data);
-		return ret;
-	}
+	if (!trigger_data)
+		goto out_free_enable_data;
 
 	if (remove) {
 		event_trigger_unregister(cmd_ops, file, glob+1, trigger_data);
 		kfree(trigger_data);
-		kfree(enable_data);
 		ret = 0;
-		return ret;
+		goto out_free_enable_data;
 	}
 
 	/* Up the trigger_data count to make sure nothing frees it on failure */
@@ -1837,6 +1834,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
  out_free:
 	event_trigger_reset_filter(cmd_ops, trigger_data);
 	event_trigger_free(trigger_data);
+out_free_enable_data:
 	kfree(enable_data);
 
 	return ret;
-- 
2.54.0

Re: [PATCH] tracing: Use more common error handling code in event_enable_trigger_parse()

[Steven Rostedt]

On Tue, 16 Jun 2026 22:33:17 +0200
Markus Elfring <Markus.Elfring@web.de> wrote:

> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Tue, 16 Jun 2026 22:22:52 +0200
> 
> Use an additional label so that a bit of exception handling can be better
> reused at the end of this function implementation.
> 
> This issue was detected by using the Coccinelle software.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
>  kernel/trace/trace_events_trigger.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
> index 655db2e82513..7e17dd6d5b50 100644
> --- a/kernel/trace/trace_events_trigger.c
> +++ b/kernel/trace/trace_events_trigger.c
> @@ -1789,17 +1789,14 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
>  	enable_data->file = event_enable_file;
>  
>  	trigger_data = trigger_data_alloc(cmd_ops, cmd, param, enable_data);
> -	if (!trigger_data) {
> -		kfree(enable_data);
> -		return ret;
> -	}
> +	if (!trigger_data)
> +		goto out_free_enable_data;
>  
>  	if (remove) {
>  		event_trigger_unregister(cmd_ops, file, glob+1, trigger_data);
>  		kfree(trigger_data);
> -		kfree(enable_data);
>  		ret = 0;
> -		return ret;
> +		goto out_free_enable_data;
>  	}
>  
>  	/* Up the trigger_data count to make sure nothing frees it on failure */
> @@ -1837,6 +1834,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
>   out_free:
>  	event_trigger_reset_filter(cmd_ops, trigger_data);
>  	event_trigger_free(trigger_data);
> +out_free_enable_data:
>  	kfree(enable_data);

Ug, let's not add more error labels now that we have cleanup code.

Untested, but this would be cleaner:

diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 655db2e82513..7da096acaf2b 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -1739,7 +1739,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
 			       char *glob, char *cmd, char *param_and_filter)
 {
 	struct trace_event_file *event_enable_file;
-	struct enable_trigger_data *enable_data;
+	struct enable_trigger_data *enable_data __free(kfree) = NULL;
 	struct event_trigger_data *trigger_data;
 	struct trace_array *tr = file->tr;
 	char *param, *filter;
@@ -1789,17 +1789,13 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
 	enable_data->file = event_enable_file;
 
 	trigger_data = trigger_data_alloc(cmd_ops, cmd, param, enable_data);
-	if (!trigger_data) {
-		kfree(enable_data);
+	if (!trigger_data)
 		return ret;
-	}
 
 	if (remove) {
 		event_trigger_unregister(cmd_ops, file, glob+1, trigger_data);
 		kfree(trigger_data);
-		kfree(enable_data);
-		ret = 0;
-		return ret;
+		return 0;
 	}
 
 	/* Up the trigger_data count to make sure nothing frees it on failure */
@@ -1829,6 +1825,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
 		goto out_disable;
 
 	event_trigger_free(trigger_data);
+	no_free_ptr(enable_free);
 	return ret;
  out_disable:
 	trace_event_enable_disable(event_enable_file, 0, 1);
@@ -1837,7 +1834,6 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
  out_free:
 	event_trigger_reset_filter(cmd_ops, trigger_data);
 	event_trigger_free(trigger_data);
-	kfree(enable_data);
 
 	return ret;
 }

-- Steve