KDD：HelloWorld

源文件：

// hello.c
#include <linux/init.h>
#include <linux/module.h>
MODULE_LICENSE("Dual BSD/GPL");

static int hello_init(void){
    printk(KERN_ALERT "hello, world, init\n");
    return 0;
}

static void hello_exit(void){
    printk(KERN_ALERT "goodbye, exit\n");
}

module_init(hello_init);
module_exit(hello_exit);

编译Makefile：

# Makefile
obj-m = hello.o
KVERSION = $(shell uname -r)
all:
	make -C /lib/modules/$(KVERSION)/build M=$(PWD) modules
clean:
	make -C /lib/modules/$(KVERSION)/build M=$(PWD) clean

在centos6下面编译：

[winlin@dev6 helloworld]$ make
make -C /lib/modules/2.6.32-71.el6.x86_64/build M=/home/winlin/smartsystem/trunk/smart-server/research/kdd/helloworld modules
make[1]: Entering directory `/usr/src/kernels/2.6.32-71.el6.x86_64'
  CC [M]  /home/winlin/smartsystem/trunk/smart-server/research/kdd/helloworld/hello.o
  Building modules, stage 2.
  MODPOST 1 modules
  CC      /home/winlin/smartsystem/trunk/smart-server/research/kdd/helloworld/hello.mod.o
  LD [M]  /home/winlin/smartsystem/trunk/smart-server/research/kdd/helloworld/hello.ko.unsigned
  NO SIGN [M] /home/winlin/smartsystem/trunk/smart-server/research/kdd/helloworld/hello.ko
make[1]: Leaving directory `/usr/src/kernels/2.6.32-71.el6.x86_64'

查看生成的文件，有hello.ko：

[winlin@dev6 helloworld]$ ll
total 344
-rw-rw-r-- 1 winlin winlin    312 May 28 09:55 hello.c
-rw-rw-r-- 1 winlin winlin 110242 May 28 09:55 hello.ko
-rw-rw-r-- 1 winlin winlin 110242 May 28 09:55 hello.ko.unsigned
-rw-rw-r-- 1 winlin winlin    690 May 28 09:55 hello.mod.c
-rw-rw-r-- 1 winlin winlin  60360 May 28 09:55 hello.mod.o
-rw-rw-r-- 1 winlin winlin  51423 May 28 09:55 hello.o
-rw-rw-r-- 1 winlin winlin    180 May 28 09:55 Makefile
-rw-rw-r-- 1 winlin winlin     84 May 28 09:57 modules.order
-rw-rw-r-- 1 winlin winlin      0 May 28 09:35 Module.symvers

安装：

[winlin@dev6 helloworld]$ /sbin/lsmod|grep hello
[winlin@dev6 helloworld]$ sudo /sbin/insmod ./hello.ko
[winlin@dev6 helloworld]$ /sbin/lsmod|grep hello
hello                    928  0 

查看打印出来的消息：

[winlin@dev6 helloworld]$ sudo tailf /var/log/messages
May 28 09:58:11 dev6 kernel: hello, world, init

删除模块：

[winlin@dev6 helloworld]$ sudo /sbin/rmmod hello.ko
[winlin@dev6 helloworld]$ /sbin/lsmod|grep hello
[winlin@dev6 helloworld]$ sudo tailf /var/log/messages
May 28 09:59:18 dev6 kernel: goodbye, exit