[PATCH 4/4] drm/i915: Use CPU mapping for userspace dma-buf mmap()

[Daniel Vetter]

On Tue, Aug 11, 2015 at 11:20:46PM +0100, Chris Wilson wrote:
> On Tue, Aug 11, 2015 at 05:59:23PM -0300, Tiago Vignatti wrote:
> > Userspace is the one in charge of flush CPU by wrapping mmap with
> > begin{,end}_cpu_access.
> > 
> > v2: Remove LLC check cause we have dma-buf sync providers now. Also, fix return
> > before transferring ownership when mmap fails.
> > v3: Fix return values.
> > 
> > Signed-off-by: Tiago Vignatti <tiago.vignatti at intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_gem_dmabuf.c | 18 +++++++++++++++++-
> >  1 file changed, 17 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> > index 8447ba4..8b87c86 100644
> > --- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> > +++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> > @@ -193,7 +193,23 @@ static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_n
> >  
> >  static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
> >  {
> > -	return -EINVAL;
> > +	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
> > +	int ret;
> > +
> > +	if (obj->base.size < vma->vm_end - vma->vm_start)
> > +		return -EINVAL;
> > +
> > +	if (WARN_ON(!obj->base.filp))
> > +		return -ENODEV;
> 
> That's user triggerable, mmap(dma_buf_export(userptr)), so remove the

Sounds like we need another testcase here ;-)
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch