[bpf-next 3/4] selftests/bpf: report failed subtest count in test_progs summary

[Vineet Gupta <vineet.gupta@linux.dev>]

The final summary line is asymmetric: the PASSED field reports both the
number of top-level tests and the number of subtests within them, while
the FAILED field reports only top-level tests:

  Summary: 640/5750 PASSED, 7760 SKIPPED, 100 FAILED

There is no way to tell whether those 100 failing tests amount to 100
broken subtests or 1000. So count subtests with a non-zero error_cnt
into a new sub_fail_cnt and print it alongside fail_cnt:

  Summary: 640/5750 PASSED, 7760 SKIPPED, 100/342 FAILED
                                             ^^^^^

This is correct for -j runs, as subtest_states[] is populated both in
sequential and parallel modes.

A test that fails without declaring any subtests contributes 0 to
sub_fail_cnt. That mirrors the existing behaviour of sub_succ_cnt for
tests that pass without subtests, keeping the two numerators
comparable.

Also emit the new count as a "failed_subtest" field in the JSON output,
for parity with the existing "success_subtest".

Note that this changes the trailing field of the summary line from a bare
integer to "A/B", so anything scraping "N FAILED" out of it needs updating.
While here, fix the fail_cnt comment in struct test_env, which claims it
counts "total failed tests + sub-tests".

Signed-off-by: Vineet Gupta <vineet.gupta@linux.dev>
---
 tools/testing/selftests/bpf/test_progs.c | 21 +++++++++++++--------
 tools/testing/selftests/bpf/test_progs.h |  2 +-
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index 8ee46745e2e8..5e2f6ec2e212 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -1656,8 +1656,8 @@ static void *dispatch_thread(void *ctx)
 
 static void calculate_summary_and_print_errors(struct test_env *env)
 {
-	int i;
-	int succ_cnt = 0, fail_cnt = 0, sub_succ_cnt = 0, skip_cnt = 0;
+	int i, j;
+	int succ_cnt = 0, fail_cnt = 0, sub_succ_cnt = 0, sub_fail_cnt = 0, skip_cnt = 0;
 	json_writer_t *w = NULL;
 
 	for (i = 0; i < prog_test_cnt; i++) {
@@ -1670,10 +1670,14 @@ static void calculate_summary_and_print_errors(struct test_env *env)
 		sub_succ_cnt += state->sub_succ_cnt;
 		skip_cnt += state->skip_cnt;
 
-		if (state->error_cnt)
+		if (state->error_cnt) {
 			fail_cnt++;
-		else if (!test->not_built)
+			for (j = 0; j < state->subtest_num; j++)
+				if (state->subtest_states[j].error_cnt)
+					sub_fail_cnt++;
+		} else if (!test->not_built) {
 			succ_cnt++;
+		}
 	}
 
 	if (env->json) {
@@ -1688,6 +1692,7 @@ static void calculate_summary_and_print_errors(struct test_env *env)
 		jsonw_uint_field(w, "success_subtest", sub_succ_cnt);
 		jsonw_uint_field(w, "skipped", skip_cnt);
 		jsonw_uint_field(w, "failed", fail_cnt);
+		jsonw_uint_field(w, "failed_subtest", sub_fail_cnt);
 		jsonw_name(w, "results");
 		jsonw_start_array(w);
 	}
@@ -1726,12 +1731,12 @@ static void calculate_summary_and_print_errors(struct test_env *env)
 		fclose(env->json);
 
 	if (env->not_built_cnt)
-		printf("Summary: %d/%d PASSED, %d SKIPPED (%d not built), %d FAILED\n",
+		printf("Summary: %d/%d PASSED, %d SKIPPED (%d not built), %d/%d FAILED\n",
 		       succ_cnt, sub_succ_cnt, skip_cnt, env->not_built_cnt,
-		       fail_cnt);
+		       fail_cnt, sub_fail_cnt);
 	else
-		printf("Summary: %d/%d PASSED, %d SKIPPED, %d FAILED\n",
-		       succ_cnt, sub_succ_cnt, skip_cnt, fail_cnt);
+		printf("Summary: %d/%d PASSED, %d SKIPPED, %d/%d FAILED\n",
+		       succ_cnt, sub_succ_cnt, skip_cnt, fail_cnt, sub_fail_cnt);
 
 	env->succ_cnt = succ_cnt;
 	env->sub_succ_cnt = sub_succ_cnt;
diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h
index e66d5c457901..ea493c477fbd 100644
--- a/tools/testing/selftests/bpf/test_progs.h
+++ b/tools/testing/selftests/bpf/test_progs.h
@@ -124,7 +124,7 @@ struct test_env {
 
 	int succ_cnt; /* successful tests */
 	int sub_succ_cnt; /* successful sub-tests */
-	int fail_cnt; /* total failed tests + sub-tests */
+	int fail_cnt; /* failed tests */
 	int skip_cnt; /* skipped tests */
 	int not_built_cnt; /* tests not built */
 
-- 
2.55.0