#define PGDIR_MASK (~(PGDIR_SIZE - 1))
#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
-#define FIRST_USER_ADDRESS 0
+#define FIRST_USER_ADDRESS 0UL
#define USER_PGD_PTRS (PAGE_OFFSET >> PGDIR_SHIFT)
#define KERNEL_PGD_PTRS (PTRS_PER_PGD - USER_PGD_PTRS)