Re: [PATCH] drm/i915: add sanity check for partial view creation

From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
To: "Ville Syrjälä" <ville.syrjala@linux.intel.com>,
	"Matthew Auld" <matthew.auld@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH] drm/i915: add sanity check for partial view creation
Date: Wed, 02 Mar 2016 15:37:50 +0200	[thread overview]
Message-ID: <1456925870.6260.4.camel@linux.intel.com> (raw)
In-Reply-To: <20160229175721.GC15993@intel.com>

On ma, 2016-02-29 at 19:57 +0200, Ville Syrjälä wrote:
> On Mon, Feb 29, 2016 at 05:11:02PM +0000, Matthew Auld wrote:
> > 
> > When binding pages for a partial view we should check that the offset +
> > size is valid relative to the size of the gem object.
> > 
> > Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> > Signed-off-by: Matthew Auld <matthew.auld@intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_gem_gtt.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> > index 49e4f26..a477bb2 100644
> > --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> > +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> > @@ -3500,6 +3500,10 @@ intel_partial_pages(const struct i915_ggtt_view *view,
> >  	struct sg_page_iter obj_sg_iter;
> >  	int ret = -ENOMEM;
> >  
> > +	if (view->params.partial.offset + view->params.partial.size >
> > +	    obj->pages->nents)
> > +		return ERR_PTR(-EINVAL);
> It seems to me that if we hit this, there must a bug somewhere higher
> up.
> 

Currently yes. This is in preparation of the more widespread support
for partial views and was chosen as a good get-to-know-GEM-code
candidate.

Regards, Joonas

> > 
> > +
> >  	st = kmalloc(sizeof(*st), GFP_KERNEL);
> >  	if (!st)
> >  		goto err_st_alloc;
> > -- 
> > 2.4.3
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx