[PATCH v3 7/7] selftests/resctrl: Cleanup benchmark argument parsing

[Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>]

Benchmark argument is handled by custom argument parsing code which is
more complicated than it needs to be.

Process benchmark argument within the normal getopt() handling and drop
entirely unnecessary ben_ind and has_ben variables. If -b is not given,
setup the default benchmark command right after the switch statement
and make -b to goto over it while it terminates the getopt() loop.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
---
 .../testing/selftests/resctrl/resctrl_tests.c | 71 ++++++++++---------
 1 file changed, 36 insertions(+), 35 deletions(-)

diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
index 94516d1f4307..ae9001ef7b0a 100644
--- a/tools/testing/selftests/resctrl/resctrl_tests.c
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -169,28 +169,35 @@ static void run_cat_test(int cpu_no, int no_of_bits)
 
 int main(int argc, char **argv)
 {
-	bool has_ben = false, mbm_test = true, mba_test = true, cmt_test = true;
-	int c, cpu_no = 1, argc_new = argc, i, no_of_bits = 0;
+	bool mbm_test = true, mba_test = true, cmt_test = true;
+	int c, cpu_no = 1, i, no_of_bits = 0;
 	const char *benchmark_cmd[BENCHMARK_ARGS];
-	int ben_ind, tests = 0;
 	char *span_str = NULL;
 	bool cat_test = true;
 	char *skip_reason;
+	int tests = 0;
 	int ret;
 
-	for (i = 0; i < argc; i++) {
-		if (strcmp(argv[i], "-b") == 0) {
-			ben_ind = i + 1;
-			argc_new = ben_ind - 1;
-			has_ben = true;
-			break;
-		}
-	}
-
-	while ((c = getopt(argc_new, argv, "ht:b:n:p:")) != -1) {
+	while ((c = getopt(argc, argv, "ht:b:n:p:")) != -1) {
 		char *token;
 
 		switch (c) {
+		case 'b':
+			/*
+			 * First move optind back to the (first) optarg and
+			 * then build the benchmark command using the
+			 * remaining arguments.
+			 */
+			optind--;
+			if (argc - optind >= BENCHMARK_ARGS - 1)
+				ksft_exit_fail_msg("Too long benchmark command");
+
+			/* Extract benchmark command from command line. */
+			for (i = 0; i < argc - optind; i++)
+				benchmark_cmd[i] = argv[i + optind];
+			benchmark_cmd[i] = NULL;
+
+			goto last_arg;
 		case 't':
 			token = strtok(optarg, ",");
 
@@ -240,6 +247,19 @@ int main(int argc, char **argv)
 		}
 	}
 
+	/* If no benchmark is given by "-b" argument, use fill_buf. */
+	benchmark_cmd[0] = "fill_buf";
+	ret = asprintf(&span_str, "%u", DEFAULT_SPAN);
+	if (ret < 0)
+		ksft_exit_fail_msg("Out of memory!\n");
+	benchmark_cmd[1] = span_str;
+	benchmark_cmd[2] = "1";
+	benchmark_cmd[3] = "0";
+	benchmark_cmd[4] = "false";
+	benchmark_cmd[5] = NULL;
+
+last_arg:
+
 	ksft_print_header();
 
 	/*
@@ -247,28 +267,9 @@ int main(int argc, char **argv)
 	 * 1. We write to resctrl FS
 	 * 2. We execute perf commands
 	 */
-	if (geteuid() != 0)
-		return ksft_exit_skip("Not running as root. Skipping...\n");
-
-	if (has_ben) {
-		if (argc - ben_ind >= BENCHMARK_ARGS - 1)
-			ksft_exit_fail_msg("Too long benchmark command.\n");
-
-		/* Extract benchmark command from command line. */
-		for (i = 0; i < argc - ben_ind; i++)
-			benchmark_cmd[i] = argv[i + ben_ind];
-		benchmark_cmd[i] = NULL;
-	} else {
-		/* If no benchmark is given by "-b" argument, use fill_buf. */
-		benchmark_cmd[0] = "fill_buf";
-		ret = asprintf(&span_str, "%u", DEFAULT_SPAN);
-		if (ret < 0)
-			ksft_exit_fail_msg("Out of memory!\n");
-		benchmark_cmd[1] = span_str;
-		benchmark_cmd[2] = "1";
-		benchmark_cmd[3] = "0";
-		benchmark_cmd[4] = "false";
-		benchmark_cmd[5] = NULL;
+	if (geteuid() != 0) {
+		skip_reason = "Not running as root. Skipping...\n";
+		goto free_span;
 	}
 
 	if (!check_resctrlfs_support()) {
-- 
2.30.2