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From: Thorsten Blum <thorsten.blum@toblux.com>
To: Steven Rostedt <rostedt@goodmis.org>,
	Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	linux-kernel@vger.kernel.org,
	linux-trace-kernel@vger.kernel.org,
	Thorsten Blum <thorsten.blum@toblux.com>
Subject: [PATCH] synthetic tracing: Fix trace_string() return value
Date: Wed, 14 Feb 2024 23:05:56 +0100
Message-Id: <20240214220555.711598-1-thorsten.blum@toblux.com>
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Fix trace_string() by assigning the string length to the return variable
which got lost in commit ddeea494a16f ("tracing/synthetic: Use union
instead of casts") and caused trace_string() to always return 0.

Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
---
 kernel/trace/trace_events_synth.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index e7af286af4f1..c82b401a294d 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -441,8 +441,9 @@ static unsigned int trace_string(struct synth_trace_event *entry,
 	if (is_dynamic) {
 		union trace_synth_field *data = &entry->fields[*n_u64];
 
+		len = fetch_store_strlen((unsigned long)str_val);
 		data->as_dynamic.offset = struct_size(entry, fields, event->n_u64) + data_size;
-		data->as_dynamic.len = fetch_store_strlen((unsigned long)str_val);
+		data->as_dynamic.len = len;
 
 		ret = fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry);
 
-- 
2.39.2