disp: msm: Fix a null pointer access in msm_gem_shrinker_count()

This change moves the point at which msm_gem_object is added to
inactive list. Moving this ensures that initialization will be
complete before adding the object to the list. This change also
removes unused functions from msm_gem.c.

Change-Id: Id8fa04cc88a21e04108ae21b18d5acc761ef4c6e
Signed-off-by: Bruce Hoo <bingchua@codeaurora.org>
Signed-off-by: Jeykumar Sankaran <jsanka@codeaurora.org>

msm/msm_gem.c

@@ -1085,10 +1085,8 @@ int msm_gem_new_handle(struct drm_device *dev, struct drm_file *file,
 static int msm_gem_new_impl(struct drm_device *dev,
 		uint32_t size, uint32_t flags,
 		struct dma_resv *resv,
-		struct drm_gem_object **obj,
+		struct drm_gem_object **obj)
-		bool struct_mutex_locked)
 {
-	struct msm_drm_private *priv = dev->dev_private;
 	struct msm_gem_object *msm_obj;
 
 	switch (flags & MSM_BO_CACHE_MASK) {
@@ -1128,19 +1126,15 @@ static int msm_gem_new_impl(struct drm_device *dev,
 	msm_obj->in_active_list = false;
 	msm_obj->obj_dirty = false;
 
-	mutex_lock(&priv->mm_lock);
-	list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
-	mutex_unlock(&priv->mm_lock);
-
 	*obj = &msm_obj->base;
 
 	return 0;
 }
 
-static struct drm_gem_object *_msm_gem_new(struct drm_device *dev,
+struct drm_gem_object *msm_gem_new(struct drm_device *dev, uint32_t size, uint32_t flags)
-		uint32_t size, uint32_t flags, bool struct_mutex_locked)
 {
 	struct msm_drm_private *priv = dev->dev_private;
+	struct msm_gem_object *msm_obj;
 	struct drm_gem_object *obj = NULL;
 	bool use_vram = false;
 	int ret;
@@ -1161,14 +1155,15 @@ static struct drm_gem_object *_msm_gem_new(struct drm_device *dev,
 	if (size == 0)
 		return ERR_PTR(-EINVAL);
 
-	ret = msm_gem_new_impl(dev, size, flags, NULL, &obj, struct_mutex_locked);
+	ret = msm_gem_new_impl(dev, size, flags, NULL, &obj);
 	if (ret)
 		goto fail;
 
+	msm_obj = to_msm_bo(obj);
+
 	if (use_vram) {
 		struct msm_gem_vma *vma;
 		struct page **pages;
-		struct msm_gem_object *msm_obj = to_msm_bo(obj);
 
 		mutex_lock(&msm_obj->lock);
 
@@ -1196,6 +1191,10 @@ static struct drm_gem_object *_msm_gem_new(struct drm_device *dev,
 			goto fail;
 	}
 
+	mutex_lock(&dev->struct_mutex);
+	list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
+	mutex_unlock(&dev->struct_mutex);
+
 	return obj;
 
 fail:
@@ -1203,18 +1202,6 @@ fail:
 	return ERR_PTR(ret);
 }
 
-struct drm_gem_object *msm_gem_new_locked(struct drm_device *dev,
-		uint32_t size, uint32_t flags)
-{
-	return _msm_gem_new(dev, size, flags, true);
-}
-
-struct drm_gem_object *msm_gem_new(struct drm_device *dev,
-		uint32_t size, uint32_t flags)
-{
-	return _msm_gem_new(dev, size, flags, false);
-}
-
 int msm_gem_delayed_import(struct drm_gem_object *obj)
 {
 	struct dma_buf_attachment *attach;
@@ -1258,6 +1245,7 @@ fail_import:
 struct drm_gem_object *msm_gem_import(struct drm_device *dev,
 		struct dma_buf *dmabuf, struct sg_table *sgt)
 {
+	struct msm_drm_private *priv = dev->dev_private;
 	struct msm_gem_object *msm_obj;
 	struct drm_gem_object *obj = NULL;
 	uint32_t size;
@@ -1266,8 +1254,7 @@ struct drm_gem_object *msm_gem_import(struct drm_device *dev,
 
 	size = PAGE_ALIGN(dmabuf->size);
 
-	ret = msm_gem_new_impl(dev, size, MSM_BO_WC, dmabuf->resv, &obj,
+	ret = msm_gem_new_impl(dev, size, MSM_BO_WC, dmabuf->resv, &obj);
-			false);
 	if (ret)
 		goto fail;
 
@@ -1294,6 +1281,11 @@ struct drm_gem_object *msm_gem_import(struct drm_device *dev,
 		DRM_ERROR("dma_buf_get_flags failure, err=%d\n", ret);
 
 	mutex_unlock(&msm_obj->lock);
+
+	mutex_lock(&dev->struct_mutex);
+	list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
+	mutex_unlock(&dev->struct_mutex);
+
 	return obj;
 
 fail:
@@ -1301,12 +1293,12 @@ fail:
 	return ERR_PTR(ret);
 }
 
-static void *_msm_gem_kernel_new(struct drm_device *dev, uint32_t size,
+void *msm_gem_kernel_new(struct drm_device *dev, uint32_t size,
 		uint32_t flags, struct msm_gem_address_space *aspace,
-		struct drm_gem_object **bo, uint64_t *iova, bool locked)
+		struct drm_gem_object **bo, uint64_t *iova)
 {
 	void *vaddr;
-	struct drm_gem_object *obj = _msm_gem_new(dev, size, flags, locked);
+	struct drm_gem_object *obj = msm_gem_new(dev, size, flags);
 	int ret;
 
 	if (IS_ERR(obj))
@@ -1330,31 +1322,14 @@ static void *_msm_gem_kernel_new(struct drm_device *dev, uint32_t size,
 
 	return vaddr;
 err:
-	if (locked)
-		drm_gem_object_put_locked(obj);
-	else
 	drm_gem_object_put(obj);
 
 	return ERR_PTR(ret);
 
 }
 
-void *msm_gem_kernel_new(struct drm_device *dev, uint32_t size,
-		uint32_t flags, struct msm_gem_address_space *aspace,
-		struct drm_gem_object **bo, uint64_t *iova)
-{
-	return _msm_gem_kernel_new(dev, size, flags, aspace, bo, iova, false);
-}
-
-void *msm_gem_kernel_new_locked(struct drm_device *dev, uint32_t size,
-		uint32_t flags, struct msm_gem_address_space *aspace,
-		struct drm_gem_object **bo, uint64_t *iova)
-{
-	return _msm_gem_kernel_new(dev, size, flags, aspace, bo, iova, true);
-}
-
 void msm_gem_kernel_put(struct drm_gem_object *bo,
-		struct msm_gem_address_space *aspace, bool locked)
+		struct msm_gem_address_space *aspace)
 {
 	if (IS_ERR_OR_NULL(bo))
 		return;
@@ -1362,9 +1337,6 @@ void msm_gem_kernel_put(struct drm_gem_object *bo,
 	msm_gem_put_vaddr(bo);
 	msm_gem_unpin_iova(bo, aspace);
 
-	if (locked)
-		drm_gem_object_put_locked(bo);
-	else
 	drm_gem_object_put(bo);
 }