From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Date: Mon, 10 Nov 2025 15:48:20 +0000 (+0900)
Subject: tracing: Report wrong dynamic event command
X-Git-Tag: v6.19-rc1~119^2~21
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7157062bb46c8bcfba3a7d77f91fc4795bff1316;p=thirdparty%2Fkernel%2Flinux.git

tracing: Report wrong dynamic event command

Report wrong dynamic event type in the command via error_log.
-----
 # echo "z hoge" > /sys/kernel/tracing/dynamic_events
 sh: write error: Invalid argument
 # cat /sys/kernel/tracing/error_log
 [   22.977022] dynevent: error: No matching dynamic event type
   Command: z hoge
            ^
-----

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/176278970056.343441.10528135217342926645.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---

diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c
index d06854bd32b35..c4dfbc293baee 100644
--- a/kernel/trace/trace_dynevent.c
+++ b/kernel/trace/trace_dynevent.c
@@ -144,9 +144,16 @@ static int create_dyn_event(const char *raw_command)
 		if (!ret || ret != -ECANCELED)
 			break;
 	}
-	mutex_unlock(&dyn_event_ops_mutex);
-	if (ret == -ECANCELED)
+	if (ret == -ECANCELED) {
+		static const char *err_msg[] = {"No matching dynamic event type"};
+
+		/* Wrong dynamic event. Leave an error message. */
+		tracing_log_err(NULL, "dynevent", raw_command, err_msg,
+				0, 0);
 		ret = -EINVAL;
+	}
+
+	mutex_unlock(&dyn_event_ops_mutex);
 
 	return ret;
 }