Here's the patch I applied to build the modified module referenced
above.

Ben.

-- 
Ben Hutchings
Power corrupts.  Absolute power is kind of neat.
                           - John Lehman, Secretary of the US Navy 1981-1987
commit aa735263241c7ae1ce9d3b6fd957b02819468f99
Author: Ben Hutchings <b...@decadent.org.uk>
Date:   Sat Aug 15 19:22:39 2009 +0100

    r128: Add test for initialisation to all ioctls that require it
    
    Almost all r128's private ioctls require that the CCE state has
    already been initialised.  However, most do not test that this has
    been done, and will proceed to dereference a null pointer.  This may
    result in a security vulnerability, since some ioctls are
    unprivileged.
    
    This adds a macro for the common initialisation test and changes all
    ioctl implementations that require prior initialisation to use that
    macro.
    
    Also, r128_do_init_cce() does not test that the CCE state has not
    been initialised already.  Repeated initialisation may lead to a crash
    or resource leak.  This adds that test.

diff --git a/drivers/gpu/drm/r128/r128_cce.c b/drivers/gpu/drm/r128/r128_cce.c
index c75fd35..ebf9f63 100644
--- a/drivers/gpu/drm/r128/r128_cce.c
+++ b/drivers/gpu/drm/r128/r128_cce.c
@@ -353,6 +353,11 @@ static int r128_do_init_cce(struct drm_device * dev, drm_r128_init_t * init)
 
 	DRM_DEBUG("\n");
 
+	if (dev->dev_private) {
+		DRM_DEBUG("called when already initialized\n");
+		return -EINVAL;
+	}
+
 	dev_priv = drm_alloc(sizeof(drm_r128_private_t), DRM_MEM_DRIVER);
 	if (dev_priv == NULL)
 		return -ENOMEM;
@@ -649,6 +654,8 @@ int r128_cce_start(struct drm_device *dev, void *data, struct drm_file *file_pri
 
 	LOCK_TEST_WITH_RETURN(dev, file_priv);
 
+	DEV_INIT_TEST_WITH_RETURN(dev_priv);
+
 	if (dev_priv->cce_running || dev_priv->cce_mode == R128_PM4_NONPM4) {
 		DRM_DEBUG("while CCE running\n");
 		return 0;
@@ -671,6 +678,8 @@ int r128_cce_stop(struct drm_device *dev, void *data, struct drm_file *file_priv
 
 	LOCK_TEST_WITH_RETURN(dev, file_priv);
 
+	DEV_INIT_TEST_WITH_RETURN(dev_priv);
+
 	/* Flush any pending CCE commands.  This ensures any outstanding
 	 * commands are exectuted by the engine before we turn it off.
 	 */
@@ -708,10 +717,7 @@ int r128_cce_reset(struct drm_device *dev, void *data, struct drm_file *file_pri
 
 	LOCK_TEST_WITH_RETURN(dev, file_priv);
 
-	if (!dev_priv) {
-		DRM_DEBUG("called before init done\n");
-		return -EINVAL;
-	}
+	DEV_INIT_TEST_WITH_RETURN(dev_priv);
 
 	r128_do_cce_reset(dev_priv);
 
@@ -728,6 +734,8 @@ int r128_cce_idle(struct drm_device *dev, void *data, struct drm_file *file_priv
 
 	LOCK_TEST_WITH_RETURN(dev, file_priv);
 
+	DEV_INIT_TEST_WITH_RETURN(dev_priv);
+
 	if (dev_priv->cce_running) {
 		r128_do_cce_flush(dev_priv);
 	}
@@ -741,6 +749,8 @@ int r128_engine_reset(struct drm_device *dev, void *data, struct drm_file *file_
 
 	LOCK_TEST_WITH_RETURN(dev, file_priv);
 
+	DEV_INIT_TEST_WITH_RETURN(dev->dev_private);
+
 	return r128_do_engine_reset(dev);
 }
 
diff --git a/drivers/gpu/drm/r128/r128_drv.h b/drivers/gpu/drm/r128/r128_drv.h
index 797a26c..3c60829 100644
--- a/drivers/gpu/drm/r128/r128_drv.h
+++ b/drivers/gpu/drm/r128/r128_drv.h
@@ -422,6 +422,14 @@ static __inline__ void r128_update_ring_snapshot(drm_r128_private_t * dev_priv)
  * Misc helper macros
  */
 
+#define DEV_INIT_TEST_WITH_RETURN(_dev_priv)				\
+do {									\
+	if (!_dev_priv) {						\
+		DRM_ERROR("called with no initialization\n");		\
+		return -EINVAL;						\
+	}								\
+} while (0)
+
 #define RING_SPACE_TEST_WITH_RETURN( dev_priv )				\
 do {									\
 	drm_r128_ring_buffer_t *ring = &dev_priv->ring; int i;		\
diff --git a/drivers/gpu/drm/r128/r128_state.c b/drivers/gpu/drm/r128/r128_state.c
index 026a48c..af2665c 100644
--- a/drivers/gpu/drm/r128/r128_state.c
+++ b/drivers/gpu/drm/r128/r128_state.c
@@ -1244,14 +1244,18 @@ static void r128_cce_dispatch_stipple(struct drm_device * dev, u32 * stipple)
 static int r128_cce_clear(struct drm_device *dev, void *data, struct drm_file *file_priv)
 {
 	drm_r128_private_t *dev_priv = dev->dev_private;
-	drm_r128_sarea_t *sarea_priv = dev_priv->sarea_priv;
+	drm_r128_sarea_t *sarea_priv;
 	drm_r128_clear_t *clear = data;
 	DRM_DEBUG("\n");
 
 	LOCK_TEST_WITH_RETURN(dev, file_priv);
 
+	DEV_INIT_TEST_WITH_RETURN(dev_priv);
+
 	RING_SPACE_TEST_WITH_RETURN(dev_priv);
 
+	sarea_priv = dev_priv->sarea_priv;
+
 	if (sarea_priv->nbox > R128_NR_SAREA_CLIPRECTS)
 		sarea_priv->nbox = R128_NR_SAREA_CLIPRECTS;
 
@@ -1312,6 +1316,8 @@ static int r128_cce_flip(struct drm_device *dev, void *data, struct drm_file *fi
 
 	LOCK_TEST_WITH_RETURN(dev, file_priv);
 
+	DEV_INIT_TEST_WITH_RETURN(dev_priv);
+
 	RING_SPACE_TEST_WITH_RETURN(dev_priv);
 
 	if (!dev_priv->page_flipping)
@@ -1331,6 +1337,8 @@ static int r128_cce_swap(struct drm_device *dev, void *data, struct drm_file *fi
 
 	LOCK_TEST_WITH_RETURN(dev, file_priv);
 
+	DEV_INIT_TEST_WITH_RETURN(dev_priv);
+
 	RING_SPACE_TEST_WITH_RETURN(dev_priv);
 
 	if (sarea_priv->nbox > R128_NR_SAREA_CLIPRECTS)
@@ -1354,10 +1362,7 @@ static int r128_cce_vertex(struct drm_device *dev, void *data, struct drm_file *
 
 	LOCK_TEST_WITH_RETURN(dev, file_priv);
 
-	if (!dev_priv) {
-		DRM_ERROR("called with no initialization\n");
-		return -EINVAL;
-	}
+	DEV_INIT_TEST_WITH_RETURN(dev_priv);
 
 	DRM_DEBUG("pid=%d index=%d count=%d discard=%d\n",
 		  DRM_CURRENTPID, vertex->idx, vertex->count, vertex->discard);
@@ -1410,10 +1415,7 @@ static int r128_cce_indices(struct drm_device *dev, void *data, struct drm_file
 
 	LOCK_TEST_WITH_RETURN(dev, file_priv);
 
-	if (!dev_priv) {
-		DRM_ERROR("called with no initialization\n");
-		return -EINVAL;
-	}
+	DEV_INIT_TEST_WITH_RETURN(dev_priv);
 
 	DRM_DEBUG("pid=%d buf=%d s=%d e=%d d=%d\n", DRM_CURRENTPID,
 		  elts->idx, elts->start, elts->end, elts->discard);
@@ -1476,6 +1478,8 @@ static int r128_cce_blit(struct drm_device *dev, void *data, struct drm_file *fi
 
 	LOCK_TEST_WITH_RETURN(dev, file_priv);
 
+	DEV_INIT_TEST_WITH_RETURN(dev_priv);
+
 	DRM_DEBUG("pid=%d index=%d\n", DRM_CURRENTPID, blit->idx);
 
 	if (blit->idx < 0 || blit->idx >= dma->buf_count) {
@@ -1501,6 +1505,8 @@ static int r128_cce_depth(struct drm_device *dev, void *data, struct drm_file *f
 
 	LOCK_TEST_WITH_RETURN(dev, file_priv);
 
+	DEV_INIT_TEST_WITH_RETURN(dev_priv);
+
 	RING_SPACE_TEST_WITH_RETURN(dev_priv);
 
 	ret = -EINVAL;
@@ -1531,6 +1537,8 @@ static int r128_cce_stipple(struct drm_device *dev, void *data, struct drm_file
 
 	LOCK_TEST_WITH_RETURN(dev, file_priv);
 
+	DEV_INIT_TEST_WITH_RETURN(dev_priv);
+
 	if (DRM_COPY_FROM_USER(&mask, stipple->mask, 32 * sizeof(u32)))
 		return -EFAULT;
 
@@ -1555,10 +1563,7 @@ static int r128_cce_indirect(struct drm_device *dev, void *data, struct drm_file
 
 	LOCK_TEST_WITH_RETURN(dev, file_priv);
 
-	if (!dev_priv) {
-		DRM_ERROR("called with no initialization\n");
-		return -EINVAL;
-	}
+	DEV_INIT_TEST_WITH_RETURN(dev_priv);
 
 	DRM_DEBUG("idx=%d s=%d e=%d d=%d\n",
 		  indirect->idx, indirect->start, indirect->end,
@@ -1620,10 +1625,7 @@ static int r128_getparam(struct drm_device *dev, void *data, struct drm_file *fi
 	drm_r128_getparam_t *param = data;
 	int value;
 
-	if (!dev_priv) {
-		DRM_ERROR("called with no initialization\n");
-		return -EINVAL;
-	}
+	DEV_INIT_TEST_WITH_RETURN(dev_priv);
 
 	DRM_DEBUG("pid=%d\n", DRM_CURRENTPID);
 

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