[LTP] [PATCH] posix/conformance/interfaces/sem_timedwait/2-1: add _GNU_SOURCE define

[Cyril Hrubis]

Hi!
> > That does not sound right, the open posix testsuite must not depend on anything
> > GNU specific.
> 
> I see. Thanks.
> But I tested both on Fedora and Ubuntu, they reported the same error
> if using the params " -std=c99 -D_POSIX_C_SOURCE=200809L
> -D_XOPEN_SOURCE=700" for gcc.

That is certainly unexpected. I managed to reproduce this on Debian 12.

Looks that on certain systems the MMAP_ANONYMOUS seems to be guarded by
__USE_MISC. The __USE_MISC is defined in /usr/include/features.h and set
if _DEFAULT_SOURCE is set which is set by _GNU_SOURCE.

I did double check the POSIX and I was probably confusing MAP_PRIVATE
and MAP_ANONYMOUS, sorry. Looks like MAP_ANONYMOUS is indeed not a part
of POSIX.

> How about manually defining MAP_ANONYMOUS like below?

Does not seem to be a good solution either, that will work only on
Linux. The open posix testsuite is supposed to run on any POSIX
compatible OS.

I'm afraid that the only solution we can use is to allocate the shared
memory via the posix shm. That means to get the file descriptor for
mmap() from shm_open() (followed by shm_unlink()).

-- 
Cyril Hrubis
chrubis@suse.cz