1 files changed, 34 insertions, 10 deletions

diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c
index c1f20a147462..12c3b3ab84aa 100644
--- a/tools/testing/selftests/bpf/bench.c
+++ b/tools/testing/selftests/bpf/bench.c
@@ -287,10 +287,11 @@ static const struct argp_child bench_parsers[] = {
 	{},
 };
 
+/* Make pos_args global, so that we can run argp_parse twice, if necessary */
+static int pos_args;
+
 static error_t parse_arg(int key, char *arg, struct argp_state *state)
 {
-	static int pos_args;
-
 	switch (key) {
 	case 'v':
 		env.verbose = true;
@@ -359,7 +360,7 @@ static error_t parse_arg(int key, char *arg, struct argp_state *state)
 	return 0;
 }
 
-static void parse_cmdline_args(int argc, char **argv)
+static void parse_cmdline_args_init(int argc, char **argv)
 {
 	static const struct argp argp = {
 		.options = opts,
@@ -369,9 +370,25 @@ static void parse_cmdline_args(int argc, char **argv)
 	};
 	if (argp_parse(&argp, argc, argv, 0, NULL, NULL))
 		exit(1);
-	if (!env.list && !env.bench_name) {
-		argp_help(&argp, stderr, ARGP_HELP_DOC, "bench");
-		exit(1);
+}
+
+static void parse_cmdline_args_final(int argc, char **argv)
+{
+	struct argp_child bench_parsers[2] = {};
+	const struct argp argp = {
+		.options = opts,
+		.parser = parse_arg,
+		.doc = argp_program_doc,
+		.children = bench_parsers,
+	};
+
+	/* Parse arguments the second time with the correct set of parsers */
+	if (bench->argp) {
+		bench_parsers[0].argp = bench->argp;
+		bench_parsers[0].header = bench->name;
+		pos_args = 0;
+		if (argp_parse(&argp, argc, argv, 0, NULL, NULL))
+			exit(1);
 	}
 }
 
@@ -531,15 +548,14 @@ static const struct bench *benchs[] = {
 	&bench_local_storage_tasks_trace,
 };
 
-static void setup_benchmark()
+static void find_benchmark(void)
 {
-	int i, err;
+	int i;
 
 	if (!env.bench_name) {
 		fprintf(stderr, "benchmark name is not specified\n");
 		exit(1);
 	}
-
 	for (i = 0; i < ARRAY_SIZE(benchs); i++) {
 		if (strcmp(benchs[i]->name, env.bench_name) == 0) {
 			bench = benchs[i];
@@ -550,6 +566,11 @@ static void setup_benchmark()
 		fprintf(stderr, "benchmark '%s' not found\n", env.bench_name);
 		exit(1);
 	}
+}
+
+static void setup_benchmark(void)
+{
+	int i, err;
 
 	printf("Setting up benchmark '%s'...\n", bench->name);
 
@@ -621,7 +642,7 @@ static void collect_measurements(long delta_ns) {
 
 int main(int argc, char **argv)
 {
-	parse_cmdline_args(argc, argv);
+	parse_cmdline_args_init(argc, argv);
 
 	if (env.list) {
 		int i;
@@ -633,6 +654,9 @@ int main(int argc, char **argv)
 		return 0;
 	}
 
+	find_benchmark();
+	parse_cmdline_args_final(argc, argv);
+
 	setup_benchmark();
 
 	setup_timer();