static void ion_vm_open(struct vm_area_struct *vma)
{
	struct ion_buffer *buffer = vma->vm_private_data;
	struct ion_vma_list *vma_list;

	vma_list = kmalloc(sizeof(struct ion_vma_list), GFP_KERNEL);
	if (!vma_list)
		return;
	vma_list->vma = vma;
	mutex_lock(&buffer->lock);
	list_add(&vma_list->list, &buffer->vmas);
	mutex_unlock(&buffer->lock);
	pr_debug("%s: adding %p\n", __func__, vma);
}
static void ion_vm_open(struct vm_area_struct *vma)
{
	struct ion_buffer *buffer = vma->vm_private_data;
	struct ion_vma_list *vma_list;

	vma_list = kmalloc(sizeof(struct ion_vma_list), GFP_KERNEL);
	if (!vma_list)
		return;
	vma_list->vma = vma;
	mutex_lock(&buffer->lock);
	list_add(&vma_list->list, &buffer->vmas);
	mutex_unlock(&buffer->lock);
	pr_debug("%s: adding %p\n", __func__, vma);
}