mkdire.c

一个驱动程序开发 一个系统调用 内附文档 非常详细

#ifndef __KERNEL__
#define __KERNEL__

#endif
#ifndef MODULE
#define MODULE
#endif

#include	<linux/init.h>
#include	<linux/module.h>
#include <linux/kernel.h>
#include <linux/unistd.h>
#include <linux/time.h>
#include <asm/uaccess.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>

#define __NR_mk 223

#define MODULE_NAME "haozi"

MODULE_DESCRIPTION("My sys_mk()");
MODULE_AUTHOR("haozi:)");
static int ( *anything_saved) (void);

extern long* sys_call_table;

static struct proc_dir_entry * haozi_dir;

static int sys_mk (void)
{
	
	int rv=0;
	
	haozi_dir = proc_mkdir(MODULE_NAME,NULL);

	haozi_dir ->owner = THIS_MODULE;

	if(haozi_dir == NULL) {
		rv = -ENOMEM;
		goto out;
	}
	else {
		printk( KERN_ALERT"success!\n");
		printk( KERN_ALERT"Pid %ld called proc_mkdir(). \n", (long)current->pid);
	}

	out:
		return rv;

}

static int mk_init(void) {

	anything_saved = (int(*) (void) ) (sys_call_table [__NR_mk]);

	sys_call_table[__NR_mk]= (unsigned long) sys_mk;

	printk("this is my addmkdir\n");

	return 0;
}


static void mk_exit(void) {

	sys_call_table[__NR_mk] = (unsigned long) anything_saved;

	printk("I'm leaving.\n");
}


module_init(mk_init);
module_exit(mk_exit);

MODULE_LICENSE("Dual BSD/GPL");