diff --git a/linux/kernel/sys.c b/linux/kernel/sys.c
index 8b4d8d1..872ce19 100644
--- a/linux/kernel/sys.c
+++ b/linux/kernel/sys.c
@@ -179,11 +179,7 @@ unsigned int sys_sleep(unsigned int seconds)
 	return 0;
 }
 
-int sys_clone()
-{
 
-	return -1;
-}
 
 int sys_ftime()
 {
@@ -463,183 +459,4 @@ int sys_umask(int mask)
 	return (old);
 }
 
-static int my_share(unsigned long address, struct task_struct * p)
-{
-	unsigned long from;
-	unsigned long to;
-	unsigned long from_page;
-	unsigned long to_page;
-	unsigned long phys_addr;
-
-	from_page = to_page = ((address>>20) & 0xffc);
-	from_page += ((current->start_code>>20) & 0xffc);
-	to_page += ((p->start_code>>20) & 0xffc);
-
-	from = *(unsigned long *) from_page;
-	from &= 0xfffff000;
-	from_page = from + ((address>>10) & 0xffc);
-	phys_addr = *(unsigned long *) from_page;
-	to = *(unsigned long *) to_page;
-	if (!(to & 1))
-		if (to = get_free_page())
-			*(unsigned long *) to_page = to | 7;
-		else
-			return 0;
-	to &= 0xfffff000;
-	to_page = to + ((address>>10) & 0xffc);
-	if (1 & *(unsigned long *) to_page)
-		return 0;
-	/* share them: write-protect */
-	*(unsigned long *) to_page = *(unsigned long *) from_page;
-	phys_addr -= LOW_MEM;
-	phys_addr >>= 12;
-	mem_map[phys_addr]++;
-	return 1;
-}
-
-// rememeber to sync when munmap exit manual 
-
-long sys_mmap(void * start,size_t len,...)// int prot,int flags,int fd,off_t off
-{
-	printk("start mmaping\n");
-	/* va_list args;
-	va_start(args,len); */
-	int prot=3,flags=1,fd=3,off=0;
-	/* prot=va_arg(args,int);flags=va_arg(args,int);fd=va_arg(args,int);
-	off_t off=va_arg(args,off_t);
-	int *ll=&len;printk("%d,%d,%d,%d,%d\n",*ll,*(ll+1),*(ll+2),*(ll+3),*(ll+4));
-	va_end(args);
-	printk("%d,%d,%d,%ld\n",prot,flags,fd,off); */
-	
-	int block;
-	size_t l=len;
-	struct buffer_head * bh;
-	char *temp,*p1,*p2;
-	void * buf=start;
-	int tempprot=0;
-	
-	//因为new.h和namei.c定义不一样，要修改
-	if(prot &PROT_READ) tempprot |=4;
-	if(prot &PROT_EXEC) tempprot |=1;
-	if(prot &PROT_WRITE) tempprot |=2;
-
-	//特殊量len>0 off%4096==0 prot至少有read权限
-	if(len<=0 ||  off<0 || (off%PAGE_SIZE)) 
-	{
-		if(len<=0) 
-			printk("the len of the wanting bytes must be positive");
-		else
-			printk("offset must be the mul of 4096");
-		return MAP_FAILED;
-	}	
-	if(!(prot& PROT_READ)) return MAP_FAILED;
-
-	//permissions of the file ,搬运函数namei.c::permissions
-	printk("fd: %d\n",fd);
-	struct m_inode *inode=current->filp[fd]->f_inode;
-	printk("end of permissions\n");
-	int mode = inode->i_mode;
-	if (inode->i_dev && !inode->i_nlinks)
-		{printk("end of permissions1\n");return MAP_FAILED;}
-	else if (current->euid==inode->i_uid)
-		mode >>= 6;
-	else if (current->egid==inode->i_gid)
-		mode >>= 3;
-	if (!(((mode & tempprot & 0007) == tempprot) || suser()))
-	{
-		printk("error permission.");
-		return MAP_FAILED;
-	}
-	//end of permission check
-	printk("end of permissions\n");
-	
-	//设置用户空间的虚拟地址，初始为32MB处，这样写在brk增长至32MB时会有bug,我们忽略
-	//同时，当栈向下增长到一定程度时，也会和当前地址冲突，我们忽略
-	if(start<=current->brk || start>=current->start_stack-0x8000 || start==NULL) 
-	{
-		if(!current->mmap_tail)
-			buf=0x2000000;
-		else
-			buf=current->mmap_tail->endaddr;
-	}
-	//申请mmap
-	struct mmap_struct *mmap=(struct mmap_struct *)malloc(sizeof(struct mmap_struct));
-	mmap->address=buf;
-	mmap->size=len;
-	mmap->endaddr=(unsigned long)buf+(len + 0xfff)&0xfffff000;
-	mmap->rw=prot;
-	mmap->ps=flags;
-	mmap->next=NULL;
-	//加入current->mmap
-	if(!current->mmap) 
-		{current->mmap=current->mmap_tail=mmap;}
-	else 
-		current->mmap_tail->next=mmap;
-	printk("buf: %x\n",(unsigned long )buf);
-	
-	//分配物理页
-
-	unsigned long from;
-	unsigned long to;
-	unsigned long from_page;
-	unsigned long to_page;
-	unsigned long phys_addr;
-	unsigned long tpage;
-	unsigned long address=mmap->address;
-	while(address<mmap->endaddr)
-	{
-		from_page =  ((mmap->address>>20) & 0xffc);
-		from_page += ((current->start_code>>20) & 0xffc);//页目录
-		if(!(*(unsigned long *)from_page&1))  //页表项不存在，申请页面
-			if(!(tpage=get_free_page()))
-			{
-				printk("out of memory.\n");
-				return MAP_FAILED;
-			}
-			else
-				*(unsigned long *)from_page= tpage | 7;
-		from=*(unsigned long *)from_page;	//页表项
-		from &= 0xfffff000;
-		from_page = from + ((address>>10) & 0xffc);
-		if(!(*(unsigned long *)from_page & 1))	//物理页不存在
-			if(!(tpage=get_free_page()))
-			{
-				printk("out of memory.\n");
-				return MAP_FAILED;
-			}
-			else
-				*(unsigned long *)from_page= tpage | 7; 
-		*(unsigned long *)from_page &= (prot&PROT_WRITE); //分配读写权限
-		if(flags & MAP_SHARED)
-		{
-			struct task_struct ** p;
-
-			for (p = &LAST_TASK ; p > &FIRST_TASK ; --p) {
-				if (!*p)
-					continue;
-				if (current == *p)
-					continue;
-				if(!my_share(address,*p))
-					printk("share failed at task:pid=%d",(*p)->pid);
-			}
-		}
-		address+=PAGE_SIZE;
-	}
-		
-	//read and put in 
-	if (!(block = inode->i_zone[0]))
-		return NULL;
-	if (!(bh = bread(inode->i_dev,block)))
-		return NULL;
-	temp = (char *) bh->b_data;
-	p1=temp;p2=buf;
-	while(l--)
-		put_fs_byte(*(p1++),p2++);
-	printk("%s\n",temp);
-	return buf;
-}
-int sys_munmap()
-{
 
-	return -1;
-}