Re: [PATCH bpf-next v3 3/3] selftests/bpf: Add libbpf_probe_bpf_kfunc API selftests

[Tao Chen <chen.dylane@gmail.com>]

在 2025/1/25 02:48, Andrii Nakryiko 写道:
> On Fri, Jan 24, 2025 at 6:44 AM Tao Chen <chen.dylane@gmail.com> wrote:
>>
>> Add selftests for prog_kfunc feature probing.
>>   ./test_progs -t libbpf_probe_kfuncs
>>   #153     libbpf_probe_kfuncs:OK
>>   Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED
>>
>> Signed-off-by: Tao Chen <chen.dylane@gmail.com>
>> ---
>>   .../selftests/bpf/prog_tests/libbpf_probes.c  | 35 +++++++++++++++++++
>>   1 file changed, 35 insertions(+)
>>
>> diff --git a/tools/testing/selftests/bpf/prog_tests/libbpf_probes.c b/tools/testing/selftests/bpf/prog_tests/libbpf_probes.c
>> index 4ed46ed58a7b..d9d69941f694 100644
>> --- a/tools/testing/selftests/bpf/prog_tests/libbpf_probes.c
>> +++ b/tools/testing/selftests/bpf/prog_tests/libbpf_probes.c
>> @@ -126,3 +126,38 @@ void test_libbpf_probe_helpers(void)
>>                  ASSERT_EQ(res, d->supported, buf);
>>          }
>>   }
>> +
>> +void test_libbpf_probe_kfuncs(void)
>> +{
>> +       int ret, kfunc_id;
>> +       char *kfunc = "bpf_cpumask_create";
>> +       struct btf *btf;
>> +
>> +       btf = btf__parse("/sys/kernel/btf/vmlinux", NULL);
>> +       if (!ASSERT_OK_PTR(btf, "btf_parse"))
>> +               return;
>> +
>> +       kfunc_id = btf__find_by_name_kind(btf, kfunc, BTF_KIND_FUNC);
>> +       if (!ASSERT_GT(kfunc_id, 0, kfunc))
>> +               goto cleanup;
>> +
>> +       /* prog BPF_PROG_TYPE_SYSCALL supports kfunc bpf_cpumask_create */
>> +       ret = libbpf_probe_bpf_kfunc(BPF_PROG_TYPE_SYSCALL, kfunc_id, 0, NULL);
>> +       ASSERT_EQ(ret, 1, kfunc);
>> +
>> +       /* prog BPF_PROG_TYPE_KPROBE does not support kfunc bpf_cpumask_create */
>> +       ret = libbpf_probe_bpf_kfunc(BPF_PROG_TYPE_KPROBE, kfunc_id, 0, NULL);
>> +       ASSERT_EQ(ret, 0, kfunc);
>> +
>> +       /* invalid kfunc id */
>> +       ret = libbpf_probe_bpf_kfunc(BPF_PROG_TYPE_KPROBE, -1, 0, NULL);
>> +       ASSERT_EQ(ret, 0, "invalid kfunc id:-1");
>> +
>> +       /* invalid prog type */
>> +       ret = libbpf_probe_bpf_kfunc(100000, kfunc_id, 0, NULL);
>> +       if (!ASSERT_LE(ret, 0, "invalid prog type:100000"))
> 
> we have ASSERT_ERR(), wouldn't it work here?
> 
> 
> let's also add a test for kfunc in module (we have bpf_testmod, we
> should be able to test something out of there)

Ok, i will add it in v4.

> 
>> +               goto cleanup;
>> +
>> +cleanup:
>> +       btf__free(btf);
>> +}
>> --
>> 2.43.0
>>


-- 
Best Regards
Dylane Chen