Re: [PATCH bpf-next v5 7/9] selftests/bpf: Add tests to verify verifier log for global percpu data

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] `RUN_TESTS` macro is incorrectly wrapped inside `test__start_subtest()`, which breaks the subtest hierarchy.
--

commit 1dcc43260f6040ba128a20fe56dd3f75bb90a451
Author: Leon Hwang <leon.hwang@linux.dev>

selftests/bpf: Add tests to verify verifier log for global percpu data

This patch adds two tests to verify the verifier log output when a
percpu_array map is incorrectly used as a const string.

> diff --git a/tools/testing/selftests/bpf/prog_tests/global_data_init.c b/tools/testing/selftests/bpf/prog_tests/global_data_init.c
> --- a/tools/testing/selftests/bpf/prog_tests/global_data_init.c
> +++ b/tools/testing/selftests/bpf/prog_tests/global_data_init.c
[ ... ]
> @@ -244,6 +244,11 @@ static void test_global_percpu_data_lskel(void)
>  	free(online);
>  }
>  
> +static void test_global_percpu_data_verifier_log(void)
> +{
> +	RUN_TESTS(test_global_percpu_data);
> +}
> +
>  void test_global_percpu_data(void)
>  {
[ ... ]
> @@ -255,4 +260,6 @@ void test_global_percpu_data(void)
>  		test_global_percpu_data_init();
>  	if (test__start_subtest("lskel"))
>  		test_global_percpu_data_lskel();
> +	if (test__start_subtest("verifier_log"))
> +		test_global_percpu_data_verifier_log();

[Severity: Medium]
Does this accidentally break the subtest hierarchy?

The BPF selftests framework does not support nested subtests, and
test__start_subtest_with_desc() explicitly calls test__end_subtest() if a
subtest is already active.

Because RUN_TESTS() internally creates a new subtest for each program in the
skeleton, invoking test_global_percpu_data_verifier_log() while the
"verifier_log" subtest is active will immediately terminate the "verifier_log"
subtest.

This causes the parent subtest to falsely report as passing with zero
assertions, and the skeleton tests will run as flat peer subtests rather than
being logically grouped.

Could RUN_TESTS() be used directly here without wrapping it in
test__start_subtest()?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260608145113.65857-1-leon.hwang@linux.dev?part=7