Re: Addition of ppoll(2), a wrapper around pollts(2)

[Joerg Sonnenberger <joerg%bec.de@localhost>]

On Tue, May 26, 2020 at 06:50:32AM +0200, Martin Husemann wrote:
> On Tue, May 26, 2020 at 01:37:41AM +0200, Kamil Rytarowski wrote:
> > I agree here with Joerg.
> > 
> > At this point it's good to just add a wrapper as in the proposed patch.
> > Once we will bump libc major, we can rename the syscall and remove
> > pollts references.
> > 
> > Weak alias would still be nicer, but it might be not worth the
> > complexity of tweaking the syscall stab code generation.
> > 
> > I think it's good to test t_pollts and t_ppoll as in theory they are
> > different APIs. Long term t_pollts can be removed, after libc major bump.
> 
> I don't think it is that complex, see the already existing
> 
> /*
>  * WSYSCALL(weak,strong) is like RSYSCALL(weak), except that weak is
>  * a weak internal alias for the strong symbol.
>  */
> 
> (which is of course used for something totaly different right now, but
> should work for this case too) and probably all it would take is a
> special clause in lib/libc/sys/Makefile.inc.
> 
> I would 
> 
>  - rename the syscall
>  - either make an alias for the old name or use a wrapper as suggested (but
>    the other way around)
>  - check if there is a good place for a SYS_... define and add that as
>    an alias for syscall(2)
>  - rename the uses in the test case (just like the syscal has been renamed)
>  - add an entry in the libc TODO file for the mythical bump

I'm quite against the useless churn of renaming the existing system
call. It doesn't add any value. It might make sense if ppoll was a
cancellation point, but it isn't and quite unlikely to become one.
This literally should be a two line change and nothing more.

Joerg