Some CO-RE negative testcases are buggy

[Lorenz Bauer <lmb@cloudflare.com>]

Hi Andrii,

I was looking at some CORE testcases, and noticed two problems:

* The checks for negative test cases use an incorrect CHECK(false) 
  invocation. This means negative test cases don't fail when they
  should.
* Some existence tests use incorrect file names, but the test harness
  is unable to detect this. Basically, failure to load due to a failed
  CORE relocation is not distinguished from ENOENT. I found the CHECK
  issue when investigating this problem.

I've written the patch attached below, but there are now 12 failures.
I don't understand the tests well enough to fix them, maybe you can
take a look?

Best
Lorenz

---
 .../selftests/bpf/prog_tests/core_reloc.c        | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
index d94dcead72e6..bd759290347c 100644
--- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c
+++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
@@ -644,12 +644,12 @@ static struct core_reloc_test_case test_cases[] = {
 		.output_len = sizeof(struct core_reloc_existence_output),
 	},
 
-	FIELD_EXISTS_ERR_CASE(existence__err_int_sz),
-	FIELD_EXISTS_ERR_CASE(existence__err_int_type),
-	FIELD_EXISTS_ERR_CASE(existence__err_int_kind),
-	FIELD_EXISTS_ERR_CASE(existence__err_arr_kind),
-	FIELD_EXISTS_ERR_CASE(existence__err_arr_value_type),
-	FIELD_EXISTS_ERR_CASE(existence__err_struct_type),
+	FIELD_EXISTS_ERR_CASE(existence___err_wrong_int_sz),
+	FIELD_EXISTS_ERR_CASE(existence___err_wrong_int_type),
+	FIELD_EXISTS_ERR_CASE(existence___err_wrong_int_kind),
+	FIELD_EXISTS_ERR_CASE(existence___err_wrong_arr_kind),
+	FIELD_EXISTS_ERR_CASE(existence___err_wrong_arr_value_type),
+	FIELD_EXISTS_ERR_CASE(existence___err_wrong_struct_type),
 
 	/* bitfield relocation checks */
 	BITFIELDS_CASE(bitfields, {
@@ -864,7 +864,7 @@ void test_core_reloc(void)
 		err = bpf_object__load_xattr(&load_attr);
 		if (err) {
 			if (!test_case->fails)
-				CHECK(false, "obj_load", "failed to load prog '%s': %d\n", probe_name, err);
+				CHECK(true, "obj_load", "failed to load prog '%s': %d\n", probe_name, err);
 			goto cleanup;
 		}
 
@@ -904,7 +904,7 @@ void test_core_reloc(void)
 		}
 
 		if (test_case->fails) {
-			CHECK(false, "obj_load_fail", "should fail to load prog '%s'\n", probe_name);
+			CHECK(true, "obj_load_fail", "should fail to load prog '%s'\n", probe_name);
 			goto cleanup;
 		}
 
-- 
2.27.0