Driver to hide files in Linux OS

#include "device_file.h"
#include <linux/fs.h>       /* file stuff */
#include <linux/kernel.h>    /* printk() */
#include <linux/errno.h>     /* error codes */
#include <linux/module.h>    /* THIS_MODULE */
#include <linux/cdev.h>      /* char device stuff */
#include <asm/uaccess.h>     /* strncpy_from_user() */
#define SUCCESS 0

static int g_device_open = 0;

static ssize_t device_file_write ( struct file *file_ptr
                        , const char *buffer
                        , size_t length
                        , loff_t *offset)
{
	char* pFile_Path;

	pFile_Path=(char *)kmalloc(sizeof(char *)*length,GFP_KERNEL);

	if ( strncpy_from_user(pFile_Path,buffer,length)== -EFAULT) 
	{
	
		printk( KERN_NOTICE "Entered in fault get_user state");

		length=-1;
		goto finish;
	}

	if (strstr(pFile_Path,"\n"))
	{
		pFile_Path[length - 1] = 0;

		printk( KERN_NOTICE "Entered in end line filter");
	}
	
	printk( KERN_NOTICE "File path is %s without EOF", pFile_Path);

	if (hook_functions(pFile_Path)==-1) 
	{	
		length=-2;
	}
finish:
	kfree(pFile_Path);

	return length;
}

static int device_file_open(struct inode *inode, struct file *file)
{

   if (g_device_open)

   return -EBUSY;

   g_device_open++;
   try_module_get(THIS_MODULE);

   return SUCCESS;

}

static int device_file_release(struct inode *inode, struct file *file)
{

  g_device_open--;

  module_put(THIS_MODULE);
  return SUCCESS;
}

/*===============================================================================================*/
static struct file_operations hide_driver_fops = 
{
   .owner   = THIS_MODULE,
   .write   = device_file_write,
   .open    = device_file_open,
   .release = device_file_release,
};

static int device_file_major_number = 0;

static const char device_name[] = "Hide_Driver";

/*===============================================================================================*/
int register_device(void)
{
      int result = 0;

      printk( KERN_NOTICE "Hide-driver: register_device() is called." );

      result = register_chrdev( 0, device_name, &hide_driver_fops );
      if( result < 0 )
      {
         printk( KERN_WARNING "Hide-driver:  can\'t register character device with errorcode = %i", result );
         return result;
      }

      device_file_major_number = result;
      printk( KERN_NOTICE "Hide-driver: registered character device with major number = %i and minor numbers 0...255"
                  , device_file_major_number );

      return 0;
}
/*-----------------------------------------------------------------------------------------------*/
void unregister_device(void)
{
   printk( KERN_NOTICE "Hide-driver: unregister_device() is called" );
   if(device_file_major_number != 0)
   {
      unregister_chrdev(device_file_major_number, device_name);
   }
}