proc_rw.c

/*
  Le e escree no /proc/hello

*/

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

int len,temp;
char *msg;

static ssize_t  read_proc(struct file *filp,char __user *buf,size_t count,loff_t *offp ) 
{
	if(count>temp)
    {
		count=temp;
	}
	temp=temp-count;
	copy_to_user(buf,msg, count);
	if(count==0)
	temp=len;
   
	return count;
}
 
static ssize_t  write_proc(struct file *filp,const char __user *buf,size_t count,loff_t *offp)
{
	copy_from_user(msg,buf,count);
	len=count;
	temp=len;
	return count;
}

static struct file_operations proc_fops = {
   .read = read_proc,
   .write = write_proc
};


int proc_init (void) 
{
	proc_create("hello",0,NULL,&proc_fops);
	msg=kmalloc(GFP_KERNEL,10*sizeof(char));
	return 0;
}

void proc_cleanup(void) 
{
	 remove_proc_entry("hello",NULL);
}

MODULE_LICENSE("GPL"); 
module_init(proc_init);
module_exit(proc_cleanup);