6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Thorsten Blum <thorsten.blum@xxxxxxxxxx>
commit 9b6326354cf9a41521b79287da3bfab022ae0b6d upstream.
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.
Link: https://lore.kernel.org/linux-trace-kernel/20240214220555.711598-1-thorsten.blum@xxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Fixes: ddeea494a16f ("tracing/synthetic: Use union instead of casts")
Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Signed-off-by: Thorsten Blum <thorsten.blum@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);
--
2.43.2
