Re: [PATCH bpf-next v3 18/20] selftests/bpf: Add an end-to-end .bpf_cleanup exception test

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] bpf: multi-line comments violate mandatory subsystem style
--

commit f500599d1234044cd45952e76c1ac50f7c35ab78
Author: Yonghong Song <yonghong.song@linux.dev>

selftests/bpf: Add an end-to-end .bpf_cleanup exception test

This commit introduces end-to-end tests for the .bpf_cleanup exception
handling mechanism. It verifies both successful cleanup paths and various
scenarios where the kernel correctly rejects invalid landing pads or unwind
behaviors.

> diff --git a/tools/testing/selftests/bpf/prog_tests/exceptions_cleanup.c b/tools/testing/selftests/bpf/prog_tests/exceptions_cleanup.c
> new file mode 100644
> index 0000000000000..a951045d21355
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/exceptions_cleanup.c
[ ... ]
> @@ -58,11 +58,11 @@ void test_exceptions_cleanup(void)
> +
> +	/* foo3 throws; every pad runs and the cookie is delivered at entry. */
> +	if (test__start_subtest("throw_from_foo3"))
> +		run(skel, 101, THROW_COOKIE, PADS_FOO3_THREW);
> +
> +	/* foo3 returns 2 ^ 1 == 3, so foo2 throws from its own second region;
> +	 * foo3's frame is long gone, so its pad must not run.
> +	 */

[Severity: Low]
This isn't a bug, but does this violate the BPF subsystem's multi-line
comment style in test_exceptions_cleanup()? The guidelines require the
opening /* to be on its own line.

> +	if (test__start_subtest("throw_from_foo2"))
> +		run(skel, 2, THROW_COOKIE, PADS_FOO2_THREW);
> +
> +	exceptions_cleanup__destroy(skel);

[ ... ]
> diff --git a/tools/testing/selftests/bpf/progs/exceptions_cleanup_fail.c b/tools/testing/selftests/bpf/progs/exceptions_cleanup_fail.c
> new file mode 100644
> index 0000000000000..db6ac7d8bd6de
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/exceptions_cleanup_fail.c
[ ... ]
> @@ -15,10 +15,10 @@ static __used __noinline void __kfunc_btf_anchor(void)
> +	bpf_preempt_enable();
> +	bpf_unwind_resume();
> +}
> +
> +/* 1. A subprogram that may unwind, also used as a helper callback:
> + * bpf_loop()'s own kernel frame would end the walk before it found a
> + * boundary.
> + */

[Severity: Low]
This isn't a bug, but does this multi-line comment format violate the BPF
subsystem style just above throwing_cb()? Similar to the above, the opening
/* should be on its own line. It appears several other comments in this file
follow this same pattern.

> +static int throwing_cb(__u32 idx, void *ctx)
> +{
> +	bpf_throw(0xbad);
> +	return 0;

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260920054225.864535-1-yonghong.song@linux.dev?part=18