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From:   sunliming <sunliming@kylinos.cn>
To:     rostedt@goodmis.org, mhiramat@kernel.org, beaub@linux.microsoft.com
Cc:     linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org, sunliming <sunliming@kylinos.cn>
Subject: [PATCH] tracing/user_events: Handle matching arguments that is null from dyn_events
Date:   Mon, 29 May 2023 14:51:10 +0800
Message-Id: <20230529065110.303440-1-sunliming@kylinos.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

When A registering user event from dyn_events has no argments, it will pass the
matching check, regardless of whether there is a user event with the same name
and arguments. Add the matching check when the arguments of registering user
event is null.

Signed-off-by: sunliming <sunliming@kylinos.cn>
---
 kernel/trace/trace_events_user.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index e90161294698..0d91dac206ff 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -1712,6 +1712,8 @@ static bool user_event_match(const char *system, const char *event,
 
 	if (match && argc > 0)
 		match = user_fields_match(user, argc, argv);
+	else if (match && argc == 0)
+		match = list_empty(&user->fields);
 
 	return match;
 }
-- 
2.25.1