[LTP] [PATCH 1/4] syscalls/sync01: Remove it

[Petr Vorel]

Hi,

> On Mon, 2020-11-09 at 13:42 +0100, Cyril Hrubis wrote:
> > Hi!
> > > 1) open(2) will return -1 if an error occur.
> > >      Is it necessary to check invalid return value(except -1) if
> > > an 
> > > error occur?

> > Well if there are values that are never supposed to be returned it
> > makes
> > sense to catch these and return a TBROK or TFAIL.

> > If we are expecially testing a syscall() I would say that we should
> > check for all kinds of errors including the values that shall not be
> > returned e.g.:

> > 	TEST(open(...));

> > 	if (TST_RET == -1) {
> > 		tst_ret(TFAIL | TTERRNO, "open() failed");
> > 		return;
> > 	}

> > 	if (TST_RET < 0) {
> > 		tst_ret(TFAIL | TTERRNO, "Invalid open() retval %ld",
> > TST_RET);
> > 		return;
> > 	}

> > 	...

> I see no downside in checking for this unexpected negative value,
> except copy/pasting this test condition in every syscall testcase.

> I don't know the LTP codebase well enough yet, but what would you say
> is a good way to have this somewhere in the library. A TEST_SYSCALL
> macro, or something else, which fails if the return value is < -1?
LGTM. I was thinking about adding it directly into TEST() and define _TEST()
which would not do that and be used in that few cases which ret < -1 is valid,
but that would be ugly.

Another candidate is macro for new API tst_syscall() defined in
include/lapi/syscalls.h (generated in include/lapi/syscalls/regen.sh).

Kind regards,
Petr