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| author | Benjamin Peterson <benjamin@engflow.com> | 2024-11-03 20:48:16 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-12-05 14:02:24 +0100 |
| commit | 660ea0db314df4dcdf2f6ff438e908f7d8b844f5 (patch) | |
| tree | cc31a2350377e1423b1f2de55d2c3d44f3b9dac3 | |
| parent | bbe48e47b978558a58ddec8888e217a74dfbc14c (diff) | |
| download | linux-660ea0db314df4dcdf2f6ff438e908f7d8b844f5.tar.gz linux-660ea0db314df4dcdf2f6ff438e908f7d8b844f5.tar.bz2 linux-660ea0db314df4dcdf2f6ff438e908f7d8b844f5.zip | |
perf trace: avoid garbage when not printing a trace event's arguments
[ 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@engflow.com>
Tested-by: Howard Chu <howardchu95@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20241103204816.7834-1-benjamin@engflow.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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 4cc942f7fec7..4f47fe3b211d 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, |