第一个内核模块

hello.c

#include<linux/module.h>
#include<linux/init.h>
#include<linux/kernel.h>
   
int init_module(){
     printk("<1>hello world!
");
     return 0;
  }
void cleanup_module(){
  printk("<1>godbye");
 }
  
MODULE_LICENSE("GPL");

　　Makefile

   linux_kernel=$(shell uname -r)
   linux_kernel_path=/usr/src/linux-headers-$(linux_kernel)
   curr_path=$(shell pwd)
   obj-m += hello.o
   all:
       make -C $(linux_kernel_path)    M=$(curr_path) modules
  clean:
      make -C $(linux_kernel_path)    M=$(curr_path) clean                       

root下执行make后

make -C /usr/src/linux-headers-3.13.0-67-generic    M=/home/hugh/myfs/ws modules
make[1]: Entering directory `/usr/src/linux-headers-3.13.0-67-generic'
  Building modules, stage 2.
  MODPOST 1 modules
make[1]: Leaving directory `/usr/src/linux-headers-3.13.0-67-generic'

插入模块

insmod hello.ko

卸载模块

rmmod hello

dmesg查看日志

……
[113392.319719] hello: module verification failed: signature and/or  required key missing - tainting kernel
[113392.321763] hello world!
[113561.149510] <1>hello world!
[113487.425871] godbye
[113571.386171] <1>godbye

yep,it's done!