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

[Petr Vorel]

Hi Xu,

...
> >> +	TEST(kcmp(getpid(), pid, KCMP_FILE, remotefd, targetfd));
> >> +	if (TST_RET != 0)
> >> +		tst_res(TFAIL, "pidfd_getfd() didn't get the same open file description");
> > Maybe just:
> >         TST_EXP_PASS_SILENT(kcmp(getpid(), pid, KCMP_FILE, remotefd, targetfd));
> I think we can't use this macro here see below(kcmp manpage about return 
> value):
> 0 v1 is equal to v2; in other words, the two processes share the resource.

> 1   v1 is less than v2.

> 2   v1 is greater than v2.

> 3   v1 is not equal to v2, but ordering information is unavailable.

> On error, -1 is returned, and errno is set appropriately.

> So 1,2,3 are not invalid return value.
I'm sorry, you're right.

> 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).

Kind regards,
Petr

> 	tst_res(TFAIL, "kcmp invalid return value %ld", TST_RET);
> 	goto free;
> }

> free:
>   ....