Re: RFC: [PATCH] Enable olddelta to be NULL in adjtime(3)

[Svante Signell]

On Tue, 2016-08-30 at 23:14 +0200, Samuel Thibault wrote:
> Hello,
> 
> Svante Signell, on Tue 30 Aug 2016 14:32:32 +0200, wrote:
> > 
> > The gnumach patch, 80_mach_clock.patch sets the old_adjustment to oadj only
> > if
> > old_adjustment is non-null. This patch is probably redundant but included
> > here
> > anyway.
> It's not only redundant, but actually useless (and thus not fixing
> anything).  See the RPC server stub in ./kern/mach_host.server.c:
> 
> OutP->RetCode =
> host_adjust_time((host_t)convert_port_to_host_priv((ipc_port_t) In0P-
> >Head.msgh_request_port), In0P->new_adjustment, &OutP->old_adjustment);
> 
> i.e. on the server side, mig always provides a room for the RPC to
> provide the result, so the pointer is never NULL.

That's what I assumed. Now confirmed by you (and the code). Thanks, good to know
:)

> > 
> > TODO: EINVAL should also be returned if the supplied delta is too large, as
> > described in adjtime(3).
> This manual talks about the Linux kernel limitation. There is no reason
> to introduce the same limitation.

OK, your choice.