@@ -46,6 +46,9 @@ int sbusfb_mmap_helper(struct sbus_mmap_map *map,
unsigned long off;
int i;
+ if (!(vma->vm_flags & (VM_SHARED | VM_MAYSHARE)))
+ return -EINVAL;
+
size = vma->vm_end - vma->vm_start;
if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
return -EINVAL;