6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Benjamin Peterson <benjamin@xxxxxxxxxxx>
[ Upstream commit 5fb8e56542a3cf469fdf25d77f50e21cbff3ae7e ]
trace__fprintf_tp_fields may not print any tracepoint arguments. E.g., if the
argument values are all zero. Previously, this would result in a totally
uninitialized buffer being passed to fprintf, which could lead to garbage on the
console. Fix the problem by passing the number of initialized bytes fprintf.
Fixes: f11b2803bb88 ("perf trace: Allow choosing how to augment the tracepoint arguments")
Signed-off-by: Benjamin Peterson <benjamin@xxxxxxxxxxx>
Tested-by: Howard Chu <howardchu95@xxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20241103204816.7834-1-benjamin@xxxxxxxxxxx
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/perf/builtin-trace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 4cc942f7fec7d..4f47fe3b211d9 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -3087,7 +3087,7 @@ static size_t trace__fprintf_tp_fields(struct trace *trace, struct evsel *evsel,
printed += syscall_arg_fmt__scnprintf_val(arg, bf + printed, size - printed, &syscall_arg, val);
}
- return printed + fprintf(trace->output, "%s", bf);
+ return printed + fprintf(trace->output, "%.*s", (int)printed, bf);
}
static int trace__event_handler(struct trace *trace, struct evsel *evsel,
--
2.43.0
