Re: [PATCH bpf v2 2/2] selftests/bpf: Test that a drained css iterator keeps returning NULL

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Low] selftests/bpf: standalone css_iter files duplicate existing
  iters_css tests
--

commit 2e186e543b0b323cd0fe5abfcf3d4268a7d8d9cd
Author: Kang Chen <k.chen@smail.nju.edu.cn>

selftests/bpf: Test that a drained css iterator keeps returning NULL

This commit adds a BPF selftest verifying that calling bpf_iter_css_next()
on an already drained css iterator continues to return NULL.

> diff --git a/tools/testing/selftests/bpf/prog_tests/css_iter.c b/tools/testing/selftests/bpf/prog_tests/css_iter.c
> new file mode 100644
> index 0000000000000..9bf8f056d3cd0
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/css_iter.c
> @@ -0,0 +1,35 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <test_progs.h>
> +#include <bpf/libbpf.h>
> +#include "css_iter.skel.h"

[ ... ]

> +void test_css_iter(void)
> +{
> +	if (test__start_subtest("next_after_drain"))
> +		test_css_iter_next_after_drain();
> +}

[Severity: Low]
This isn't a bug, but could this test case be added to the existing css
iterator test suite in tools/testing/selftests/bpf/prog_tests/iters.c
(subtest_css_iters()) and tools/testing/selftests/bpf/progs/iters_css.c
instead of introducing new standalone files?  iters_css.c already exercises
bpf_iter_css_new(), bpf_iter_css_next(), and bpf_iter_css_destroy() with
the same ksym declarations and cgroup/RCU setup.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261113024453.922726-1-k.chen@smail.nju.edu.cn?part=2