测试

asmlinkage long sys_accept(int fd, struct sockaddr __user *upeer_sockaddr,               int __user *upeer_addrlen){    struct socket *sock, *newsock;    struct file *newfile;    int err, len, newfd, fput_needed;    char address[MAX_SOCK_ADDR];    sock = sockfd_lookup_light(fd, &err, &fput_needed);    if (!sock)        goto out;    err = -ENFILE;    if (!(newsock = sock_alloc()))        goto out_put;    newsock->type = sock->type;    newsock->ops = sock->ops;    /*     * We don't need try_module_get here, as the listening socket (sock)     * has the PRotocol module (sock->ops->owner) held.     */    __module_get(newsock->ops->owner);    newfd = sock_alloc_fd(&newfile);    if (unlikely(newfd < 0)) {        err = newfd;        sock_release(newsock);        goto out_put;    }    err = sock_attach_fd(newsock, newfile);    if (err < 0)        goto out_fd_simple;    err = security_socket_accept(sock, newsock);    if (err)        goto out_fd;    err = sock->ops->accept(sock, newsock, sock->file->f_flags);    if (err < 0)        goto out_fd;    if (upeer_sockaddr) {        if (newsock->ops->getname(newsock, (struct sockaddr *)address,                      &len, 2) < 0) {            err = -ECONNABORTED;            goto out_fd;        }        err = move_addr_to_user(address, len, upeer_sockaddr,                    upeer_addrlen);        if (err < 0)            goto out_fd;    }    /* File flags are not inherited via accept() unlike another OSes. */    fd_install(newfd, newfile);    err = newfd;    security_socket_post_accept(sock, newsock);out_put:    fput_light(sock->file, fput_needed);out:    return err;out_fd_simple:    sock_release(newsock);    put_filp(newfile);    put_unused_fd(newfd);    goto out_put;out_fd:    fput(newfile);    put_unused_fd(newfd);    goto out_put;}