Thank you. I fix it 

EXTRA_CFLAGS += -DDEBUG


2014-06-25 17:50 GMT+08:00 Varka Bhadram <varkabhadram@gmail.com>:
On 06/25/2014 03:17 PM, lx wrote:
thank you.
But the Makefile is so simple and Not use "cc".
#################################
obj-m   := task_01.o

 CFLAGS_task_01.o := -DDEBUG
KDIR:=/lib/modules/`uname -r`/build
PWD:=$(shell pwd)

default:
    echo $KDIR
    $(MAKE) -C $(KDIR) M=$(PWD) modules
#################################

So, how to add "CFLAGS"?