Re: [PATCH] selftests/bpf: remove unused duration variable from cgroup_attach_multi

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] selftests/bpf: build failure from removing duration required by CHECK macro
--

commit d7de4f4763b56d10ac8f8dca1287b007d98057b7
Author: Palak Raval <pdsj2807@gmail.com>

selftests/bpf: remove unused duration variable from cgroup_attach_multi

This commit removes the duration variable from serial_test_cgroup_attach_multi()
under the assumption that it is unused.

> diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c b/tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c
> index db0b7bac78d15..9037e98f6f760 100644
> --- a/tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c
> +++ b/tools/testing/selftests/bpf/prog_tests/cgroup_attach_multi.c
> @@ -81,7 +81,6 @@ void serial_test_cgroup_attach_multi(void)
>  	DECLARE_LIBBPF_OPTS(bpf_prog_attach_opts, attach_opts);
>  	int allow_prog[7] = {-1};
>  	unsigned long long value;
> -	__u32 duration = 0;
>  	int i = 0;
>  
>  	for (i = 0; i < ARRAY_SIZE(allow_prog); i++) {

[Severity: Low]
Will removing this variable cause a build failure? 

The BPF selftest framework's deprecated CHECK() macro implicitly requires the
duration variable to be present in the caller's scope, as it expands to
_CHECK(condition, tag, duration, format...).

Because serial_test_cgroup_attach_multi() uses CHECK() right below this, and
extensively throughout its body:

	for (i = 0; i < ARRAY_SIZE(allow_prog); i++) {
		allow_prog[i] = prog_load_cnt(1, 1 << i);
		if (CHECK(allow_prog[i] < 0, "prog_load",
			  "verifier output:\n%s\n-------\n", bpf_log_buf))
			goto err;
	}

removing the duration variable causes an undeclared identifier compilation
error.

To safely remove the duration variable, the test must first be migrated to the
modern ASSERT_*() macros.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261015175022.1370503-1-pdsj2807@gmail.com?part=1