Re: [PATCH bpf-next v4 19/20] selftests/bpf: Cover the exception cleanup shapes the chain does not reach

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] bpf: multi-line comments do not follow mandatory style
--

commit 0b5284880fa55ebb7577505990c5eb80e76e625a
Author: Yonghong Song <yonghong.song@linux.dev>

selftests/bpf: Cover the exception cleanup shapes the chain does not reach

This commit adds end-to-end tests for exception cleanup shapes that the main
call chain does not reach. It introduces various edge cases in new BPF
programs and verifies their exception handling and cleanup behaviors.

> diff --git a/tools/testing/selftests/bpf/prog_tests/exceptions_cleanup.c b/tools/testing/selftests/bpf/prog_tests/exceptions_cleanup.c
> index c932da7cbec16..2825dbb53b1c6 100644
> --- a/tools/testing/selftests/bpf/prog_tests/exceptions_cleanup.c
> +++ b/tools/testing/selftests/bpf/prog_tests/exceptions_cleanup.c
[ ... ]
> @@ -36,6 +40,346 @@ static void run(struct exceptions_cleanup *skel, __u64 input, __u32 retval,
[ ... ]
> +	/* The same call site either way: the subprogram's throw unwinds into
> +	 * this frame and runs its pad, an extension's stops at its own boundary.
> +	 */

[Severity: Low]
This isn't a bug, but does this multi-line comment follow the required style?
The BPF subsystem guidelines strictly require that multi-line comments must
have the opening /* on its own line, with the comment text starting on the
next line.

> +	if (test__start_subtest("freplace_subprog_throws"))
> +		run_shape(skel, skel->progs.entry_freplace, 7, THROW_COOKIE,
> +			  RAN_FREPLACE);
[ ... ]
> diff --git a/tools/testing/selftests/bpf/progs/exceptions_cleanup_shapes.c b/tools/testing/selftests/bpf/progs/exceptions_cleanup_shapes.c
> new file mode 100644
> index 0000000000000..5e8ca799d9d2a
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/exceptions_cleanup_shapes.c
> @@ -0,0 +1,982 @@
[ ... ]
> +__u64 pads_ran = 0;
> +__u64 pad_runs = 0;
> +
> +/* 1. Everything a cleanup table leaves dead: a throw's continuation, the tail
> + * after a resume with an ld_imm64 and a branch in it, and the block only that
> + * continuation reaches.
> + */

[Severity: Low]
This isn't a bug either, but here is another instance where the multi-line
comment rule is violated ahead of sweep_frame(). Could we update these to
have the opening /* on its own line?

> +static __used __naked __noinline __u64 sweep_frame(void)
> +{

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Sashiko AI review · https://sashiko.dev/#/patchset/20260921210033.1715000-1-yonghong.song@linux.dev?part=19