Re: [PATCH v2] powerpc: Fix struct termio related ioctl macros

[Justin Forbes <jforbes@fedoraproject.org>]

On Tue, May 20, 2025 at 08:36:18PM +1000, Michael Ellerman wrote:
> Madhavan Srinivasan <maddy@linux.ibm.com> writes:
> > Since termio interface is now obsolete, include/uapi/asm/ioctls.h
> > has some constant macros referring to "struct termio", this caused
> > build failure at userspace.
> >
> > In file included from /usr/include/asm/ioctl.h:12,
> >                  from /usr/include/asm/ioctls.h:5,
> >                  from tst-ioctls.c:3:
> > tst-ioctls.c: In function 'get_TCGETA':
> > tst-ioctls.c:12:10: error: invalid application of 'sizeof' to incomplete type 'struct termio'
> >    12 |   return TCGETA;
> >       |          ^~~~~~
> >
> > Even though termios.h provides "struct termio", trying to juggle definitions around to
> > make it compile could introduce regressions. So better to open code it.
> >
> > Reported-by: Tulio Magno <tuliom@ascii.art.br>
> > Closes: https://lore.kernel.org/linuxppc-dev/8734dji5wl.fsf@ascii.art.br/
> > Suggested-by: Nicholas Piggin <npiggin@gmail.com>
> > Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
> > ---
> > Changelog v1:
> > - mpe pointing out mistake in hardcoded values.
> >   Fixed the same.
> >
> >  arch/powerpc/include/uapi/asm/ioctls.h | 8 ++++----
> >  1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/powerpc/include/uapi/asm/ioctls.h b/arch/powerpc/include/uapi/asm/ioctls.h
> > index 2c145da3b774..b5211e413829 100644
> > --- a/arch/powerpc/include/uapi/asm/ioctls.h
> > +++ b/arch/powerpc/include/uapi/asm/ioctls.h
> > @@ -23,10 +23,10 @@
> >  #define TCSETSW		_IOW('t', 21, struct termios)
> >  #define TCSETSF		_IOW('t', 22, struct termios)
> >  
> > -#define TCGETA		_IOR('t', 23, struct termio)
> > -#define TCSETA		_IOW('t', 24, struct termio)
> > -#define TCSETAW		_IOW('t', 25, struct termio)
> > -#define TCSETAF		_IOW('t', 28, struct termio)
> > +#define TCGETA		0x40147417 /* _IOR('t', 23, struct termio) */
> > +#define TCSETA		0x80147418 /* _IOW('t', 24, struct termio) */
> > +#define TCSETAW		0x80147419 /* _IOW('t', 25, struct termio) */
> > +#define TCSETAF		0x8014741c /* _IOW('t', 28, struct termio) */
> 
> These values look right to me. And the values should never change, so
> hard-coding them is a reasonable solution.
> 
> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au>

Has this been forgotten? We are having to carry it for userspace to
continue, and this should really be pushed to Linus.

Tested-by: Justin M. Forbes <jforbes@fedoraproject.org>

> 
> cheers
>