Re: [PATCH v5 3/4] net: socket: simplify dev_ifconf handling

[Arnd Bergmann <arnd@kernel.org>]

On Wed, Jul 21, 2021 at 9:32 AM Christoph Hellwig <hch@lst.de> wrote:
>
> > The implementation can be simplified further, based on the
> > knowledge that the dynamic registration is only ever used
> > > for IPv4.
>
> I think dropping register_gifconf (which seems like a nice cleanup!)
> needs to be a separate prep patch to not make this too confusing.

Right, good idea.

> > index e6231837aff5..4727c7a3a988 100644
> > --- a/include/linux/compat.h
> > +++ b/include/linux/compat.h
> > @@ -104,6 +104,11 @@ struct compat_ifmap {
> >       unsigned char port;
> >  };
> >
> > +struct compat_ifconf {
> > +     compat_int_t    ifc_len;                /* size of buffer */
> > +     compat_uptr_t   ifcbuf;
> > +};
> > +
> >  #ifdef CONFIG_COMPAT
> >
> >  #ifndef compat_user_stack_pointer
> > @@ -326,12 +331,6 @@ typedef struct compat_sigevent {
> >       } _sigev_un;
> >  } compat_sigevent_t;
> >
> > -struct compat_if_settings {
> > -     unsigned int type;      /* Type of physical device or protocol */
> > -     unsigned int size;      /* Size of the data allocated by the caller */
> > -     compat_uptr_t ifs_ifsu; /* union of pointers */
> > -};
>
> Does this actually compile as-is?  It adds a second definition of
> compat_ifconf but removes the still used compat_if_settings?

Indeed it does not. I must have applied a hunk to the wrong patch
in an earlier rebase, and the build bots never picked up on it because
the series was fine in the end.

> Maybe it would be a better idea to add a prep patch that makes as much
> as possible of compat.h available unconditionally instead of all these
> little moves.

Ok, I'll figure something out.

        Arnd