[PATCH] drm/i915/gvt/scheduler: fix potential NULL pointer dereference

[Chris Wilson]

Quoting Gustavo A. R. Silva (2018-03-19 20:50:12)
> Hi Chris,
> 
> On 03/19/2018 03:38 PM, Chris Wilson wrote:
> > Quoting Gustavo A. R. Silva (2018-03-19 19:30:53)
> >> _workload_ is being dereferenced before it is null checked, hence
> >> there is a potential null pointer dereference.
> >>
> >> Fix this by moving the pointer dereference after _workload_ has
> >> been null checked.
> > 
> > The checks are misleading and not required.
> 
> All of them?
> 
> if (!workload || !reg_state || workload->ring_id != RCS)
>         return;

workload can not be NULL (dereference in caller), reg_state can not be
NULL (by construct from kmap()).

It may be not an RCS ring through.
-Chris