Re: [PATCH] Fix argument passing in sysvipc/test-sysvsem

[Florian Weimer <fweimer at redhat dot com>]

On 01/02/2017 07:14 PM, Tulio Magno Quites Machado Filho wrote:
> Florian Weimer <fweimer@redhat.com> writes:
>
> > On 12/31/2016 05:04 PM, Zack Weinberg wrote:
> > > On Sat, Dec 31, 2016 at 1:07 AM, Florian Weimer <fweimer@redhat.com> wrote:
> > > > On 12/30/2016 09:43 PM, Tulio Magno Quites Machado Filho wrote:
> > > > > +/* Confirm if sys/sem.h defines semun.  */
> > > > > +#ifdef _SEM_SEMUN_UNDEFINED
> > > > > +union semun
> > > > > +{
> > > > > +  int val;
> > > > > +  struct semid_ds *buf;
> > > > > +    unsigned short int *array;
> > > > > +  struct seminfo *__buf;
> > > > > +};
> > > > > +#endif
> > > >
> > > >
> > > > Sorry, I don't understand the comment.  Why is this definition not provided
> > > > by the installed headers if IPC_STAT needs it?
> > >
> > > sys/sem.h is required *not* to declare union semun; applications are
> > > required to declare it themselves.  See
> > > http://pubs.opengroup.org/onlinepubs/9699919799/functions/semctl.html.
> > > Yes, this is ridiculous.  I can only guess that it was omitted by
> > > mistake from the original incarnation of SysV semaphores, so
> > > applications started declaring it themselves, and then POSIX was over
> > > a barrel since redundant complete aggregate definitions aren't
> > > allowed.
> >
> > This still doesn't make sense.  POSIX could have standardized the union
> > under a different name.  The existence struct sockaddr_storage strongly
> > suggests that implementations must be able to cope with this kind of
> > aliasing violation.
>
> Florian, could elaborate what your proposing here?
>
> It isn't clear whether you're suggesting that this test should be changed or
> if POSIX should be changed.

My comments are not relevant to the test case change.

Florian