Re: [PATCH 1/2][next] vfio/ccw: Replace one-element array with flexible-array member

[Marion & Christophe JAILLET]

Le 23/05/2023 à 19:45, Christophe JAILLET a écrit :
> Le 23/05/2023 à 03:35, Gustavo A. R. Silva a écrit :
> > One-element arrays are deprecated, and we are replacing them with 
> > flexible
> > array members instead. So, replace one-element array with flexible-array
> > member in struct vfio_ccw_parent and refactor the the rest of the code
> > accordingly.
> >
> > Link: https://github.com/KSPP/linux/issues/79
> > Link: https://github.com/KSPP/linux/issues/297
> > Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
> > ---
> >   drivers/s390/cio/vfio_ccw_drv.c     | 3 ++-
> >   drivers/s390/cio/vfio_ccw_private.h | 2 +-
> >   2 files changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/s390/cio/vfio_ccw_drv.c 
> > b/drivers/s390/cio/vfio_ccw_drv.c
> > index ff538a086fc7..57906a9c6324 100644
> > --- a/drivers/s390/cio/vfio_ccw_drv.c
> > +++ b/drivers/s390/cio/vfio_ccw_drv.c
> > @@ -171,7 +171,8 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
> >           return -ENODEV;
> >       }
> > -    parent = kzalloc(sizeof(*parent), GFP_KERNEL);
> > +    parent = kzalloc(sizeof(*parent) + sizeof(struct mdev_type *),
>
> Hi, wouldn't:
>
>     parent = kzalloc(struct_size(parent, mdev_types, 1)),
>
> be more informative and in the spirit of flexible array use?

Ok, patch 2/2.

Sorry for the noise.

CJ

> Just my 2c,
>
> CJ
>
> > +             GFP_KERNEL);
> >       if (!parent)
> >           return -ENOMEM;
> > diff --git a/drivers/s390/cio/vfio_ccw_private.h 
> > b/drivers/s390/cio/vfio_ccw_private.h
> > index b441ae6700fd..b62bbc5c6376 100644
> > --- a/drivers/s390/cio/vfio_ccw_private.h
> > +++ b/drivers/s390/cio/vfio_ccw_private.h
> > @@ -79,7 +79,7 @@ struct vfio_ccw_parent {
> >       struct mdev_parent    parent;
> >       struct mdev_type    mdev_type;
> > -    struct mdev_type    *mdev_types[1];
> > +    struct mdev_type    *mdev_types[];
> >   };
> >   /**