[for-linus][PATCH 17/20] tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()

[Steven Rostedt <rostedt@kernel.org>]

From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <thomas.weissschuh@linutronix.de>

While ftrace_set_clr_event() modifies its input buffer during parsing,
before returning to the caller the buffer is supposed to be restored
to its original state.

This works correctly for the colon between the subsystem and event
but not the colon at the beginning of :mod:.

Restore the colon, so the :mod: trailer is not stripped after
ftrace_set_clr_event().

Cc: stable@vger.kernel.org
Fixes: 4c86bc531e60 ("tracing: Add :mod: command to enabled module events")
Link: https://patch.msgid.link/20260908-tracing-cli-event-filter-v2-1-05396a3fb663@linutronix.de
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_events.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 9dbc2441763b..30c0ddf90887 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1489,6 +1489,8 @@ int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
 	/* Put back the colon to allow this to be called again */
 	if (buf)
 		*(buf - 1) = ':';
+	if (mod)
+		*(mod - 5) = ':';
 
 	return ret;
 }
-- 
2.53.0