kerie

#include<linux/module.h>
#include<linux/kernel.h>
#include<linux/proc_fs.h>
#include<linux/sched.h>
#include<linux/uaccess.h>

#define STRINGLEN 1024

char global_buffer[STRINGLEN];
struct proc_dir_entry *example_dir,*zhang_file,*keke_file;

kerie

#include<stdio.h>
#include<stdlib.h>
#include<sys/unistd.h>

#include<fcntl.h>

int main()
{
	char yourmsg[1000];

kerie

static int rwbuf_ioctl(struct inode *node, struct file * filep, unsigned int cmd, unsigned long arg)
{
	if(cmd==RWBUF_CLEAR)
	{
		rwlen = 0;
		printk(KERN_ALERT "rwbuf in kernel zero-ed\n");
		return 0;
	}
	else if(cmd==RWBUF_LENGTH)
	{

kerie

static ssize_t rwbuf_read(struct file* filp, char *buf , size_t count, loff_t *ppos)
{
		printk(KERN_ALERT "read\n");
		count=rwlen;
		copy_to_user(buf,rwbuf,count);
		printk(KERN_ALERT "read ok\n");
		return count;
}

kerie

static ssize_t rwbuf_write(struct file *filep, const char *buf, size_t count, loff_t *ppos)
{
	if(count<=1024)
	{
		writenum++;
		//printk(KERN_ALERT "write1\n");
		copy_from_user(rwbuf,buf,count);
		//printk(KERN_ALERT "write2\n");
		rwlen = count;
		//printk(KERN_ALERT "write ok\n");

kerie

static int rwbuf_open(struct inode *node, struct file *filep)
{
	if(inuse==1)
		return -1;

	inuse=1;
	printk(KERN_ALERT "open ok\n");
	return 0;
}

kerie

int init_module_rwbuf()
{
	register_chrdev(277,DEVICE_NAME,&rwbuf_fops);
	printk(KERN_ALERT "register ok\n");
	return 0;
}

kerie

obj-m := rwbuf.o
PWD := $(shell pwd) 
KDIR=/usr/src/linux-headers-2.6.35-22-generic
default:
	make -C $(KDIR) M=$(PWD) modules

kerie

static struct file_operations rwbuf_fops =
{
	read:  rwbuf_read,
	write: rwbuf_write,
	ioctl: rwbuf_ioctl,
	open:  rwbuf_open,
	release: rwbuf_close,
};

kerie

#include<linux/kernel.h>
#include<linux/module.h>
#include<linux/fs.h>
#include<linux/errno.h>
#include<linux/uaccess.h>
#include<linux/init.h>

#define RWBUF_SIZE 2048
#define DEVICE_NAME "ChrDev" //修改为自己喜欢的名字
#define RWBUF_CLEAR 0x909090