5.15-stable review patch. If anyone has any objections, please let me know.
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From: Benjamin Peterson benjamin@engflow.com
[ 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 --- 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 6755370483b06..b179995cef96a 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -2766,7 +2766,7 @@ 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,