Re: [PATCH][drm-next] drm/i915/gvt: ensure -ve return value is handled correctly

From: Joe Perches
Date: Tue Sep 19 2017 - 22:35:35 EST


On Wed, 2017-09-20 at 05:46 +0800, Zhenyu Wang wrote:
> On 2017.09.19 16:55:34 +0100, Colin King wrote:
> > From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> >
> > An earlier fix changed the return type from find_bb_size however the
> > integer return is being assigned to a unsigned int so the -ve error
> > check will never be detected. Make bb_size an int to fix this.
> >
> > Detected by CoverityScan CID#1456886 ("Unsigned compared against 0")
> >
> > Fixes: 1e3197d6ad73 ("drm/i915/gvt: Refine error handling for perform_bb_shadow")
> > Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/gvt/cmd_parser.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gvt/cmd_parser.c b/drivers/gpu/drm/i915/gvt/cmd_parser.c
> > index 2c0ccbb817dc..f41cbf664b69 100644
> > --- a/drivers/gpu/drm/i915/gvt/cmd_parser.c
> > +++ b/drivers/gpu/drm/i915/gvt/cmd_parser.c
> > @@ -1628,7 +1628,7 @@ static int perform_bb_shadow(struct parser_exec_state *s)
> > struct intel_shadow_bb_entry *entry_obj;
> > struct intel_vgpu *vgpu = s->vgpu;
> > unsigned long gma = 0;
> > - uint32_t bb_size;
> > + int bb_size;
> > void *dst = NULL;
> > int ret = 0;
> >
>
> Applied this, thanks!

Is it possible for bb_size to be both >= 2g and valid?