[Intel-gfx] [PATCH] drm/atomic: Clear crtcs, connectors and planes when clearing state

[Daniel Vetter]

On Mon, Mar 30, 2015 at 10:41:19AM +0300, Ander Conselvan de Oliveira wrote:
> Users of the atomic state assume that if the pointer to a crtc, plane or
> connector is not NULL in the respective object vector, than the state
> for that object in *_states vector also won't be NULL. That assumption
> was broken by drm_atomic_state_clear(), which would clear the state
> pointer but leave the pointer to the object still set.
> 
> This fixes a NULL pointer dereference in i915 caused by the use of
> drm_atomic_state_clear().
> 
> Cc: dri-devel at lists.freedesktop.org
> Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira at intel.com>

Oops. Applied to topic/drm-misc.

Thanks, Daniel
> ---
>  drivers/gpu/drm/drm_atomic.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index 5d3abe3..00ea881 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -134,6 +134,7 @@ void drm_atomic_state_clear(struct drm_atomic_state *state)
>  
>  		connector->funcs->atomic_destroy_state(connector,
>  						       state->connector_states[i]);
> +		state->connectors[i] = NULL;
>  		state->connector_states[i] = NULL;
>  	}
>  
> @@ -145,6 +146,7 @@ void drm_atomic_state_clear(struct drm_atomic_state *state)
>  
>  		crtc->funcs->atomic_destroy_state(crtc,
>  						  state->crtc_states[i]);
> +		state->crtcs[i] = NULL;
>  		state->crtc_states[i] = NULL;
>  	}
>  
> @@ -156,6 +158,7 @@ void drm_atomic_state_clear(struct drm_atomic_state *state)
>  
>  		plane->funcs->atomic_destroy_state(plane,
>  						   state->plane_states[i]);
> +		state->planes[i] = NULL;
>  		state->plane_states[i] = NULL;
>  	}
>  }
> -- 
> 2.1.0
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch