C++ put_fs_long函数代码示例

static int file_ioctl(struct file *filp,unsigned int cmd,unsigned long arg)
{
	int block;

	switch (cmd) {
		case FIBMAP:
			if (filp->f_inode->i_op == NULL)
				return -EBADF;
		    	if (filp->f_inode->i_op->bmap == NULL)
				return -EINVAL;
			verify_area((void *) arg,4);
			block = get_fs_long((long *) arg);
			block = filp->f_inode->i_op->bmap(filp->f_inode,block);
			put_fs_long(block,(long *) arg);
			return 0;
		case FIGETBSZ:
			if (filp->f_inode->i_sb == NULL)
				return -EBADF;
			verify_area((void *) arg,4);
			put_fs_long(filp->f_inode->i_sb->s_blocksize,
			    (long *) arg);
			return 0;
		case FIONREAD:
			verify_area((void *) arg,4);
			put_fs_long(filp->f_inode->i_size - filp->f_pos,
			    (long *) arg);
			return 0;
		default:
			return -EINVAL;
	}
}

static int do_get_ps_info(int arg)
{
	struct tstruct {
		int flag;
		int present[NR_TASKS];
		struct task_struct tasks[NR_TASKS];
	};
	struct tstruct *ts = (struct tstruct *)arg;
	struct task_struct **p;
	char *c, *d;
	int i, n = 0;
	
	verify_area((void *)arg, sizeof(struct tstruct));
		
	for (p = &FIRST_TASK ; p <= &LAST_TASK ; p++, n++)
		if (*p)
		{
			c = (char *)(*p);
			d = (char *)(ts->tasks+n);
			for (i=0 ; i<sizeof(struct task_struct) ; i++)
				put_fs_byte(*c++, d++);
			put_fs_long(1, (unsigned long *)(ts->present+n));
		}
		else	
			put_fs_long(0, (unsigned long *)(ts->present+n));
	return(0);			
}

static int
unix_proto_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
	struct unix_proto_data *upd, *peerupd;

	upd = UN_DATA(sock);
	peerupd = (sock->state == SS_CONNECTED) ? UN_DATA(sock->conn) : NULL;

	switch (cmd) {
	case TIOCINQ:
		verify_area((void *)arg, sizeof(unsigned long));
		if (UN_BUF_AVAIL(upd) || peerupd)
			put_fs_long(UN_BUF_AVAIL(upd), (unsigned long *)arg);
		else
			put_fs_long(1, (unsigned long *)arg); /* read EOF */
		break;

	case TIOCOUTQ:
		verify_area((void *)arg, sizeof(unsigned long));
		if (peerupd)
			put_fs_long(UN_BUF_SPACE(peerupd),
				    (unsigned long *)arg);
		else
			put_fs_long(0, (unsigned long *)arg);
		break;

	default:
		return -EINVAL;
	}
	return 0;
}

/* 向文件发送一个命令，如获取文件信息的命令，
 * 将文件的信息拷贝到arg所指向的内存，如关于文件的flag和版本等信息
 */
int ext2_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
		unsigned long arg)
{

	ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);

	switch (cmd) {
	case EXT2_IOC_GETFLAGS:
		put_fs_long (inode->u.ext2_i.i_flags, (long *) arg);
		return 0;
	case EXT2_IOC_SETFLAGS:
		if ((current->euid != inode->i_uid) && !suser())
			return -EPERM;
		if (IS_RDONLY(inode))
			return -EROFS;
		inode->u.ext2_i.i_flags = get_fs_long ((long *) arg);
		inode->i_ctime = CURRENT_TIME;
		inode->i_dirt = 1;
		return 0;
	case EXT2_IOC_GETVERSION:
		put_fs_long (inode->u.ext2_i.i_version, (long *) arg);
		return 0;
	case EXT2_IOC_SETVERSION:
		if ((current->euid != inode->i_uid) && !suser())
			return -EPERM;
		if (IS_RDONLY(inode))
			return -EROFS;
		inode->u.ext2_i.i_version = get_fs_long ((long *) arg);
		inode->i_ctime = CURRENT_TIME;
		inode->i_dirt = 1;
		return 0;
	default:
		return -EINVAL;
	}
}

int sys_waitpid(pid_t pid,unsigned long * stat_addr, int options)
{
	int flag, code;
	struct task_struct ** p;

	verify_area(stat_addr,4);
repeat:
	flag=0;
	for(p = &LAST_TASK ; p > &FIRST_TASK ; --p) {
		if (!*p || *p == current)
			continue;
		if ((*p)->father != current->pid)
			continue;
		if (pid>0) {
			if ((*p)->pid != pid)
				continue;
		} else if (!pid) {
			if ((*p)->pgrp != current->pgrp)
				continue;
		} else if (pid != -1) {
			if ((*p)->pgrp != -pid)
				continue;
		}
		switch ((*p)->state) {
			case TASK_STOPPED:
				if (!(options & WUNTRACED))
					continue;
				put_fs_long(0x7f,stat_addr);
				return (*p)->pid;
			case TASK_ZOMBIE:
				current->cutime += (*p)->utime;
				current->cstime += (*p)->stime;
				flag = (*p)->pid;
				code = (*p)->exit_code;
				release(*p);
				put_fs_long(code,stat_addr);
				return flag;
			default:
				flag=1;
				continue;
		}
	}
	if (flag) {
		if (options & WNOHANG)
			return 0;
		current->state=TASK_INTERRUPTIBLE;
		/*
		*当前进程 => 等待
		*/
		fprintk(3,"%d\tW\t%d\n",current->pid,jiffies);
		schedule();
		if (!(current->signal &= ~(1<<(SIGCHLD-1))))
			goto repeat;
		else
			return -EINTR;
	}
	return -ECHILD;
}

static int msdos_readdir(struct inode *inode,struct file *filp,
    struct dirent *dirent,int count)
{
	int ino,i,i2,last;
	char c,*walk;
	struct buffer_head *bh;
	struct msdos_dir_entry *de;

	if (!inode || !S_ISDIR(inode->i_mode)) return -EBADF;
	if (inode->i_ino == MSDOS_ROOT_INO) {
/* Fake . and .. for the root directory. */
		if (filp->f_pos == 2) filp->f_pos = 0;
		else if (filp->f_pos < 2) {
				walk = filp->f_pos++ ? ".." : ".";
				for (i = 0; *walk; walk++)
					put_fs_byte(*walk,dirent->d_name+i++);
				put_fs_long(MSDOS_ROOT_INO,&dirent->d_ino);
				put_fs_byte(0,dirent->d_name+i);
				put_fs_word(i,&dirent->d_reclen);
				return i;
			}
	}
	if (filp->f_pos & (sizeof(struct msdos_dir_entry)-1)) return -ENOENT;
	bh = NULL;
	while ((ino = msdos_get_entry(inode,&filp->f_pos,&bh,&de)) > -1) {
		if (!IS_FREE(de->name) && !(de->attr & ATTR_VOLUME)) {
			for (i = last = 0; i < 8; i++) {
				if (!(c = de->name[i])) break;
				if (c >= 'A' && c <= 'Z') c += 32;
				if (c != ' ') last = i+1;
				put_fs_byte(c,i+dirent->d_name);
			}
			i = last;
			put_fs_byte('.',i+dirent->d_name);
			i++;
			for (i2 = 0; i2 < 3; i2++) {
				if (!(c = de->ext[i2])) break;
				if (c >= 'A' && c <= 'Z') c += 32;
				if (c != ' ') last = i+1;
				put_fs_byte(c,i+dirent->d_name);
				i++;
			}
			if ((i = last) != 0) {
				if (!strcmp(de->name,MSDOS_DOT))
					ino = inode->i_ino;
				else if (!strcmp(de->name,MSDOS_DOTDOT))
						ino = msdos_parent_ino(inode,0);
				put_fs_long(ino,&dirent->d_ino);
				put_fs_byte(0,i+dirent->d_name);
				put_fs_word(i,&dirent->d_reclen);
				brelse(bh);
				return i;
			}
		}
	}
	if (bh) brelse(bh);
	return 0;
}

int sys_times(struct tms * tbuf)
{
	if (tbuf) {
		verify_area(tbuf,sizeof *tbuf);
		put_fs_long(current->utime,(unsigned long *)&tbuf->tms_utime);
		put_fs_long(current->stime,(unsigned long *)&tbuf->tms_stime);
		put_fs_long(current->cutime,(unsigned long *)&tbuf->tms_cutime);
		put_fs_long(current->cstime,(unsigned long *)&tbuf->tms_cstime);
	}
	return jiffies;
}

asmlinkage int sys_times(struct tms * tbuf)
{
	if (tbuf) {
		int error = verify_area(VERIFY_WRITE,tbuf,sizeof *tbuf);
		if (error)
			return error;
		put_fs_long(current->utime,(unsigned long *)&tbuf->tms_utime);
		put_fs_long(current->stime,(unsigned long *)&tbuf->tms_stime);
		put_fs_long(current->cutime,(unsigned long *)&tbuf->tms_cutime);
		put_fs_long(current->cstime,(unsigned long *)&tbuf->tms_cstime);
	}
	return jiffies;
}

static void hpfs_statfs(struct super_block *s, struct statfs *buf)
{
	/*
	 * count the bits in the bitmaps, unless we already have
	 */

	if (s->s_hpfs_n_free == -1) {
		s->s_hpfs_n_free = count_bitmap(s);
		s->s_hpfs_n_free_dnodes =
		    count_one_bitmap(s->s_dev, s->s_hpfs_dmap);
	}

	/*
	 * fill in the user statfs struct
	 */

	put_fs_long(s->s_magic, &buf->f_type);
	put_fs_long(512, &buf->f_bsize);
	put_fs_long(s->s_hpfs_fs_size, &buf->f_blocks);
	put_fs_long(s->s_hpfs_n_free, &buf->f_bfree);
	put_fs_long(s->s_hpfs_n_free, &buf->f_bavail);
	put_fs_long(s->s_hpfs_dirband_size, &buf->f_files);
	put_fs_long(s->s_hpfs_n_free_dnodes, &buf->f_ffree);
	put_fs_long(254, &buf->f_namelen);
}

asmlinkage int sys_getrlimit(unsigned int resource, struct rlimit *rlim)
{
	int error;

	if (resource >= RLIM_NLIMITS)
		return -EINVAL;
	error = verify_area(VERIFY_WRITE,rlim,sizeof *rlim);
	if (error)
		return error;
	put_fs_long(current->rlim[resource].rlim_cur, 
		    (unsigned long *) rlim);
	put_fs_long(current->rlim[resource].rlim_max, 
		    ((unsigned long *) rlim)+1);
	return 0;	
}

/*
 * sys_pipe() is the normal C calling standard for creating
 * a pipe. It's not the way unix traditionally does this, though.
 */
asmlinkage int sys_pipe(unsigned long * fildes)
{
	int fd[2];
	int error;

	error = verify_area(VERIFY_WRITE,fildes,8);
	if (error)
		return error;
	error = do_pipe(fd);
	if (error)
		return error;
	put_fs_long(fd[0],0+fildes);
	put_fs_long(fd[1],1+fildes);
	return 0;
}

int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
	int err;
	switch(cmd) 
	{
		case TIOCOUTQ:
		{
			unsigned long amount;

			if (sk->state == TCP_LISTEN) return(-EINVAL);
			amount = sock_wspace(sk);
			err=verify_area(VERIFY_WRITE,(void *)arg,
					sizeof(unsigned long));
			if(err)
				return(err);
			put_fs_long(amount,(unsigned long *)arg);
			return(0);
		}

		case TIOCINQ:
		{
			struct sk_buff *skb;
			unsigned long amount;

			if (sk->state == TCP_LISTEN) return(-EINVAL);
			amount = 0;
			skb = skb_peek(&sk->receive_queue);
			if (skb != NULL) {
				/*
				 * We will only return the amount
				 * of this packet since that is all
				 * that will be read.
				 */
				amount = skb->len-sizeof(struct udphdr);
			}
			err=verify_area(VERIFY_WRITE,(void *)arg,
						sizeof(unsigned long));
			if(err)
				return(err);
			put_fs_long(amount,(unsigned long *)arg);
			return(0);
		}

		default:
			return(-EINVAL);
	}
	return(0);
}

/* 这个和pipe功能有相似之处，pipe是单工的，socketpair是双工的
 * family只能是UNIX域的。
 */
static int
sock_socketpair(int family, int type, int protocol, unsigned long usockvec[2])
{
  int fd1, fd2, i;
  struct socket *sock1, *sock2;
  int er;

  DPRINTF((net_debug,
	"NET: sock_socketpair: family = %d, type = %d, protocol = %d\n",
							family, type, protocol));

  /*
   * Obtain the first socket and check if the underlying protocol
   * supports the socketpair call.
   */
  /* 如果创建失败，则直接返回 */
  if ((fd1 = sock_socket(family, type, protocol)) < 0) return(fd1);
  sock1 = sockfd_lookup(fd1, NULL);
  if (!sock1->ops->socketpair) {
	sys_close(fd1);
	return(-EINVAL);
  }

  /* Now grab another socket and try to connect the two together. */
  if ((fd2 = sock_socket(family, type, protocol)) < 0) {
	sys_close(fd1);
	return(-EINVAL);
  }
  sock2 = sockfd_lookup(fd2, NULL);
  if ((i = sock1->ops->socketpair(sock1, sock2)) < 0) {
	sys_close(fd1);
	sys_close(fd2);
	return(i);
  }
  sock1->conn = sock2;
  sock2->conn = sock1;
  /* 完成socketpair操作后，则这只套接字的状态为连接状态 */
  sock1->state = SS_CONNECTED;
  sock2->state = SS_CONNECTED;

  er=verify_area(VERIFY_WRITE, usockvec, 2 * sizeof(int));
  if(er)
  	return er;
  put_fs_long(fd1, &usockvec[0]);
  put_fs_long(fd2, &usockvec[1]);

  return(0);
}

static int proc_readbase(struct inode * inode, struct file * filp,
                         struct dirent * dirent, int count)
{
    struct proc_dir_entry * de;
    unsigned int pid, ino;
    int i,j;

    if (!inode || !S_ISDIR(inode->i_mode))
        return -EBADF;
    ino = inode->i_ino;
    pid = ino >> 16;
    for (i = 0 ; i < NR_TASKS ; i++)
        if (task[i] && task[i]->pid == pid)
            break;
    if (!pid || i >= NR_TASKS)
        return 0;
    if (((unsigned) filp->f_pos) < NR_BASE_DIRENTRY) {
        de = base_dir + filp->f_pos;
        filp->f_pos++;
        i = de->namelen;
        ino = de->low_ino;
        if (ino != 1)
            ino |= (pid << 16);
        put_fs_long(ino, &dirent->d_ino);
        put_fs_word(i,&dirent->d_reclen);
        put_fs_byte(0,i+dirent->d_name);
        j = i;
        while (i--)
            put_fs_byte(de->name[i], i+dirent->d_name);
        return j;
    }
    return 0;
}

int sys_waitpid(pid_t pid,int * stat_addr, int options)
{
	int flag=0;
	struct task_struct ** p;

	verify_area(stat_addr,4);
repeat:
	for(p = &LAST_TASK ; p > &FIRST_TASK ; --p)
		if (*p && *p != current &&
		   (pid==-1 || (*p)->pid==pid ||
		   (pid==0 && (*p)->pgrp==current->pgrp) ||
		   (pid<0 && (*p)->pgrp==-pid)))
			if ((*p)->father == current->pid) {
				flag=1;
				if ((*p)->state==TASK_ZOMBIE) {
					put_fs_long((*p)->exit_code,
						(unsigned long *) stat_addr);
					current->cutime += (*p)->utime;
					current->cstime += (*p)->stime;
					flag = (*p)->pid;
					release(*p);
					return flag;
				}
			}
	if (flag) {
		if (options & WNOHANG)
			return 0;
		sys_pause();
		if (!(current->signal &= ~(1<<(SIGCHLD-1))))
			goto repeat;
		else
			return -EINTR;
	}
	return -ECHILD;
}