diff options
| author | Benjamin Peterson <[email protected]> | 2024-11-03 20:48:16 +0000 |
|---|---|---|
| committer | Namhyung Kim <[email protected]> | 2024-11-05 23:27:17 -0800 |
| commit | 5fb8e56542a3cf469fdf25d77f50e21cbff3ae7e (patch) | |
| tree | 4437134c288a0dafcb85be2db61cd7ec90bad7d7 | |
| parent | 29bf07bc9ad2eca06a14d78f7f4dc5dc8f10aae3 (diff) | |
perf trace: avoid garbage when not printing a trace event's arguments
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 <[email protected]>
Tested-by: Howard Chu <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>
| -rw-r--r-- | tools/perf/builtin-trace.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index c1e9e14c8686..a661fbd870e7 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, |