Re: [PATCH 2/6] drm/xen-front: Fix misused IS_ERR_OR_NULL checks

[Dan Carpenter <dan.carpenter@xxxxxxxxxx>]

On Tue, Aug 04, 2020 at 06:35:20AM +0000, Oleksandr Andrushchenko wrote:
> 
> On 8/4/20 9:12 AM, Jürgen Groß wrote:
> > On 31.07.20 14:51, Oleksandr Andrushchenko wrote:
> >> From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
> >>
> >> The patch c575b7eeb89f: "drm/xen-front: Add support for Xen PV
> >> display frontend" from Apr 3, 2018, leads to the following static
> >> checker warning:
> >>
> >>     drivers/gpu/drm/xen/xen_drm_front_gem.c:140 xen_drm_front_gem_create()
> >>     warn: passing zero to 'ERR_CAST'
> >>
> >> drivers/gpu/drm/xen/xen_drm_front_gem.c
> >>     133  struct drm_gem_object *xen_drm_front_gem_create(struct drm_device 
> >> *dev,
> >>     134                                                  size_t size)
> >>     135  {
> >>     136          struct xen_gem_object *xen_obj;
> >>     137
> >>     138          xen_obj = gem_create(dev, size);
> >>     139          if (IS_ERR_OR_NULL(xen_obj))
> >>     140                  return ERR_CAST(xen_obj);
> >>
> >> Fix this and the rest of misused places with IS_ERR_OR_NULL in the
> >> driver.
> >>
> >> Fixes:  c575b7eeb89f: "drm/xen-front: Add support for Xen PV display 
> >> frontend"
> >
> > Again forgot to Cc stable?
> 
> I was just not sure if these minor fixes need to go the stable, but I will add

Correct.  It's still a bug because it's setting the error code
incorrectly on the impossible path.  But fortunately impossible things
don't affect runtime.

regards,
dan carpenter