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

Tao Chen <chen.dylane@xxxxxxxxx> · Sat, 25 Jan 2025 23:07:14 +0800

在 2025/1/25 02:48, Andrii Nakryiko 写道:
On Fri, Jan 24, 2025 at 6:44 AM Tao Chen <chen.dylane@xxxxxxxxx> 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@xxxxxxxxx>
---
  .../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







