[PATCH bpf-next v2 3/4] selftests: bpf: make reuseport test output more legible

[Lorenz Bauer <lmb@cloudflare.com>]

Include the name of the mismatching result in human readable format
when reporting an error. The new output looks like the following:

  unexpected result
   result: [1, 0, 0, 0, 0, 0]
  expected: [0, 0, 0, 0, 0, 0]
  mismatch on DROP_ERR_INNER_MAP (bpf_prog_linum:153)
  check_results:FAIL:382

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
---
 .../bpf/prog_tests/select_reuseport.c         | 28 ++++++++++++++++---
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/select_reuseport.c b/tools/testing/selftests/bpf/prog_tests/select_reuseport.c
index 2c37ae7dc214..e7e56929751c 100644
--- a/tools/testing/selftests/bpf/prog_tests/select_reuseport.c
+++ b/tools/testing/selftests/bpf/prog_tests/select_reuseport.c
@@ -316,6 +316,26 @@ static void check_data(int type, sa_family_t family, const struct cmd *cmd,
 		       expected.len, result.len, get_linum());
 }
 
+static const char *result_to_str(enum result res)
+{
+	switch (res) {
+	case DROP_ERR_INNER_MAP:
+		return "DROP_ERR_INNER_MAP";
+	case DROP_ERR_SKB_DATA:
+		return "DROP_ERR_SKB_DATA";
+	case DROP_ERR_SK_SELECT_REUSEPORT:
+		return "DROP_ERR_SK_SELECT_REUSEPORT";
+	case DROP_MISC:
+		return "DROP_MISC";
+	case PASS:
+		return "PASS";
+	case PASS_ERR_SK_SELECT_REUSEPORT:
+		return "PASS_ERR_SK_SELECT_REUSEPORT";
+	default:
+		return "UNKNOWN";
+	}
+}
+
 static void check_results(void)
 {
 	__u32 results[NR_RESULTS];
@@ -351,10 +371,10 @@ static void check_results(void)
 		printf(", %u", expected_results[i]);
 	printf("]\n");
 
-	RET_IF(expected_results[broken] != results[broken],
-	       "unexpected result",
-	       "expected_results[%u] != results[%u] bpf_prog_linum:%ld\n",
-	       broken, broken, get_linum());
+	printf("mismatch on %s (bpf_prog_linum:%ld)\n", result_to_str(broken),
+	       get_linum());
+
+	CHECK_FAIL(true);
 }
 
 static int send_data(int type, sa_family_t family, void *data, size_t len,
-- 
2.20.1