[LTP] [PATCH 4/5] Add pidfd_getfd01 test

[xuyang2018.jy@fujitsu.com]

Hi Petr
> Hi Xu,
>
> ...
>>>> TEST(kcmp(getpid(), pid, KCMP_FILE, remotefd, targetfd));
>>>> if (TST_RET==-1) {
>>>> 	tst_res(TFAIL | TTERRNO, "kcmp failed unexpectedly");
>>>> 	goto free;
>>>> } else {
>>>> 	if (TST_RET<   0 || TST_RET>   3)
>>> +1 (very nit: instead of if/else I'd use 2x if and (TST_RET<   -1 || TST_RET>   3)
>>> - readability).
>> Good catch. I add the last "if" otherwise 1,2,3 are ignored.
>
>> TEST(kcmp(getpid(), pid, KCMP_FILE, remotefd, targetfd));
>>           if (TST_RET == -1) {
>>                   tst_res(TFAIL | TTERRNO, "kcmp failed unexpectedly");
>>                   goto free;
>>           }
>>           if (TST_RET<  0 || TST_RET>  3) {
>>                   tst_res(TFAIL, "kcmp invalid returns value(%d)",
>> (int)TST_RET);
>>                   goto free;
>>           }
>>           if (TST_RET != 0) {
>>                   tst_res(TFAIL, "kcmp returns unexpected value(%d)
>> instead of 0",
>>                                   (int)TST_RET);
>>                   goto free;
>>           }
>
>>           tst_res(TPASS, "pidfd_getfd(%d, %d, 0) passed", pidfd, targetfd);
>
> FYI Unless we want to have explanations why it failed, we could use TST_EXP_VAL() or
> TST_EXP_VAL_SILENT().
Ok, I will use TST_EXP_VAL_SILENT.

Best Regards
Yang Xu
>
> Kind regards,
> Petr