[PATCH] drm: Zero out DRM object memory upon cleanup

[Benjamin Gaignard]

I have test this patch on my side, plane properties are no more duplicated
so you can add my ack.

Thanks
Benjamin

2014-12-10 12:06 GMT+01:00 Daniel Vetter <daniel at ffwll.ch>:

> On Wed, Dec 10, 2014 at 11:38:49AM +0100, Thierry Reding wrote:
> > From: Thierry Reding <treding at nvidia.com>
> >
> > Drivers where the DRM objects have a lifetime that extends beyond that
> > of the DRM device need to zero out the DRM object memory to void stale
> > data such as properties. The DRM core code expects to operate on newly
> > allocated and zeroed out objects and will behave unexpectedly, such as
> > add duplicate properties, otherwise.
> >
> > Signed-off-by: Thierry Reding <treding at nvidia.com>
>
> Yeah, makes sense imo to do in the core. Reviewed-by: Daniel Vetter <
> daniel.vetter at ffwll.ch>
>
> Also stuffed into drm-misc and I think I'll throw that at Dave today or
> tomorrow.
> -Daniel
>
> > ---
> >  drivers/gpu/drm/drm_crtc.c | 11 ++++++++++-
> >  1 file changed, 10 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> > index 4c9aaf8e6176..4e35d2f74e0f 100644
> > --- a/drivers/gpu/drm/drm_crtc.c
> > +++ b/drivers/gpu/drm/drm_crtc.c
> > @@ -725,6 +725,8 @@ void drm_crtc_cleanup(struct drm_crtc *crtc)
> >       WARN_ON(crtc->state && !crtc->funcs->atomic_destroy_state);
> >       if (crtc->state && crtc->funcs->atomic_destroy_state)
> >               crtc->funcs->atomic_destroy_state(crtc, crtc->state);
> > +
> > +     memset(crtc, 0, sizeof(*crtc));
> >  }
> >  EXPORT_SYMBOL(drm_crtc_cleanup);
> >
> > @@ -927,6 +929,8 @@ void drm_connector_cleanup(struct drm_connector
> *connector)
> >       if (connector->state && connector->funcs->atomic_destroy_state)
> >               connector->funcs->atomic_destroy_state(connector,
> >                                                      connector->state);
> > +
> > +     memset(connector, 0, sizeof(*connector));
> >  }
> >  EXPORT_SYMBOL(drm_connector_cleanup);
> >
> > @@ -1068,6 +1072,8 @@ void drm_bridge_cleanup(struct drm_bridge *bridge)
> >       list_del(&bridge->head);
> >       dev->mode_config.num_bridge--;
> >       drm_modeset_unlock_all(dev);
> > +
> > +     memset(bridge, 0, sizeof(*bridge));
> >  }
> >  EXPORT_SYMBOL(drm_bridge_cleanup);
> >
> > @@ -1134,10 +1140,11 @@ void drm_encoder_cleanup(struct drm_encoder
> *encoder)
> >       drm_modeset_lock_all(dev);
> >       drm_mode_object_put(dev, &encoder->base);
> >       kfree(encoder->name);
> > -     encoder->name = NULL;
> >       list_del(&encoder->head);
> >       dev->mode_config.num_encoder--;
> >       drm_modeset_unlock_all(dev);
> > +
> > +     memset(encoder, 0, sizeof(*encoder));
> >  }
> >  EXPORT_SYMBOL(drm_encoder_cleanup);
> >
> > @@ -1257,6 +1264,8 @@ void drm_plane_cleanup(struct drm_plane *plane)
> >       WARN_ON(plane->state && !plane->funcs->atomic_destroy_state);
> >       if (plane->state && plane->funcs->atomic_destroy_state)
> >               plane->funcs->atomic_destroy_state(plane, plane->state);
> > +
> > +     memset(plane, 0, sizeof(*plane));
> >  }
> >  EXPORT_SYMBOL(drm_plane_cleanup);
> >
> > --
> > 2.1.3
> >
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch
>



-- 

Benjamin Gaignard

Graphic Working Group

Linaro.org <http://www.linaro.org/> *│ *Open source software for ARM SoCs

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