Re: [PATCH bpf-next v2 1/5] selftests/bpf: Replace CHECK with ASSERT macros for ksyms test

[Yonghong Song <yonghong.song@linux.dev>]

On 3/22/24 9:13 AM, Andrii Nakryiko wrote:
> On Thu, Mar 21, 2024 at 1:01 PM Yonghong Song <yonghong.song@linux.dev> wrote:
>> I am going to modify ksyms test later so take this opportunity
>> to replace old CHECK macros with new ASSERT macros.
>> No functionality change.
>>
>> Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
>> ---
>>   .../testing/selftests/bpf/prog_tests/ksyms.c  | 30 ++++++-------------
>>   1 file changed, 9 insertions(+), 21 deletions(-)
>>
>> diff --git a/tools/testing/selftests/bpf/prog_tests/ksyms.c b/tools/testing/selftests/bpf/prog_tests/ksyms.c
>> index b295969b263b..6a86d1f07800 100644
>> --- a/tools/testing/selftests/bpf/prog_tests/ksyms.c
>> +++ b/tools/testing/selftests/bpf/prog_tests/ksyms.c
>> @@ -5,8 +5,6 @@
>>   #include "test_ksyms.skel.h"
>>   #include <sys/stat.h>
>>
>> -static int duration;
>> -
>>   void test_ksyms(void)
>>   {
>>          const char *btf_path = "/sys/kernel/btf/vmlinux";
>> @@ -18,43 +16,33 @@ void test_ksyms(void)
>>          int err;
>>
>>          err = kallsyms_find("bpf_link_fops", &link_fops_addr);
>> -       if (CHECK(err == -EINVAL, "kallsyms_fopen", "failed to open: %d\n", errno))
>> -               return;
>> -       if (CHECK(err == -ENOENT, "ksym_find", "symbol 'bpf_link_fops' not found\n"))
>> +       if (!ASSERT_TRUE(err != -EINVAL && err != -ENOENT, "bpf_link_fops"))
>>                  return;
> it's best to keep each individual equality test as ASSERT_EQ(), that
> way we get more specific and detailed error (with expected vs actual
> value), which here we'll just get "wanted true but got false", and
> then we'd have to debug some more which of the conditions it is. So
> please keep the original granularity of checks everywhere.

Do you mean

         if (ASSERT_EQ(err, -EINVAL, "..."))
                 return;
         if (ASSERT_EQ(err, -ENOENT, "..."))
                 return;

This does not really work, for example if err = 0, it will declare test 
failure.


>
>>          err = kallsyms_find("__per_cpu_start", &per_cpu_start_addr);
>> -       if (CHECK(err == -EINVAL, "kallsyms_fopen", "failed to open: %d\n", errno))
>> -               return;
>> -       if (CHECK(err == -ENOENT, "ksym_find", "symbol 'per_cpu_start' not found\n"))
>> +       if (!ASSERT_TRUE(err != -EINVAL && err != -ENOENT, "__per_cpu_start"))
>>                  return;
>>
>> -       if (CHECK(stat(btf_path, &st), "stat_btf", "err %d\n", errno))
>> +       if (!ASSERT_OK(stat(btf_path, &st), "stat_btf"))
>>                  return;
>>          btf_size = st.st_size;
>>
>>          skel = test_ksyms__open_and_load();
>> -       if (CHECK(!skel, "skel_open", "failed to open and load skeleton\n"))
>> +       if (!ASSERT_OK_PTR(skel, "test_ksyms__open_and_load"))
>>                  return;
>>
>>          err = test_ksyms__attach(skel);
>> -       if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
>> +       if (!ASSERT_OK(err, "test_ksyms__attach"))
>>                  goto cleanup;
>>
>>          /* trigger tracepoint */
>>          usleep(1);
>>
>>          data = skel->data;
>> -       CHECK(data->out__bpf_link_fops != link_fops_addr, "bpf_link_fops",
>> -             "got 0x%llx, exp 0x%llx\n",
>> -             data->out__bpf_link_fops, link_fops_addr);
>> -       CHECK(data->out__bpf_link_fops1 != 0, "bpf_link_fops1",
>> -             "got %llu, exp %llu\n", data->out__bpf_link_fops1, (__u64)0);
>> -       CHECK(data->out__btf_size != btf_size, "btf_size",
>> -             "got %llu, exp %llu\n", data->out__btf_size, btf_size);
>> -       CHECK(data->out__per_cpu_start != per_cpu_start_addr, "__per_cpu_start",
>> -             "got %llu, exp %llu\n", data->out__per_cpu_start,
>> -             per_cpu_start_addr);
>> +       ASSERT_EQ(data->out__bpf_link_fops, link_fops_addr, "bpf_link_fops");
>> +       ASSERT_EQ(data->out__bpf_link_fops1, 0, "bpf_link_fops1");
>> +       ASSERT_EQ(data->out__btf_size, btf_size, "btf_size");
>> +       ASSERT_EQ(data->out__per_cpu_start, per_cpu_start_addr, "__per_cpu_start");
>>
>>   cleanup:
>>          test_ksyms__destroy(skel);
>> --
>> 2.43.0
>>