Hi Dmytro, Thank you for the patch! Yet something to improve: [auto build test ERROR on v5.16] [cannot apply to net-next/master linus/master next-20220116] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Dmytro-SHYTYI/net-mptcp-Fast-Ope... base: df0cc57e057f18e44dac8e6c18aba47ab53202f9 config: i386-randconfig-a012 (https://download.01.org/0day-ci/archive/20220116/202201162159.uZep2msW-lk...) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/52c7bf82e2e91eb10c89ef6169fe02e0b... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Dmytro-SHYTYI/net-mptcp-Fast-Open-Mechanism/20220116-081430 git checkout 52c7bf82e2e91eb10c89ef6169fe02e0b63a6772 # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): net/mptcp/protocol.c: In function 'mptcp_sendmsg_fastopen': 1650 | skb = sk_stream_alloc_skb(ssk->sk, 0, ssk->sk->sk_allocation, true); | ^~~~~~~~~~~~~~~~~~~ | tcp_stream_alloc_skb net/mptcp/protocol.c:1650:6: warning: assignment to 'struct sk_buff *' from 'int' makes pointer from integer without a cast [-Wint-conversion] 1650 | skb = sk_stream_alloc_skb(ssk->sk, 0, ssk->sk->sk_allocation, true); | ^ cc1: some warnings being treated as errors vim +1650 net/mptcp/protocol.c 1635 1636 static int mptcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, 1637 size_t len, struct mptcp_sock *msk, size_t copied) 1638 { 1639 const struct iphdr *iph; 1640 struct ubuf_info *uarg; 1641 struct sockaddr *uaddr; 1642 struct sk_buff *skb; 1643 struct tcp_sock *tp; 1644 struct socket *ssk; 1645 int ret; 1646 1647 ssk = __mptcp_nmpc_socket(msk); 1648 if (unlikely(!ssk)) 1649 goto out_EFAULT; 1651 if (unlikely(!skb)) 1652 goto out_EFAULT; 1653 iph = ip_hdr(skb); 1654 if (unlikely(!iph)) 1655 goto out_EFAULT; 1656 uarg = msg_zerocopy_realloc(sk, len, skb_zcopy(skb)); 1657 if (unlikely(!uarg)) 1658 goto out_EFAULT; 1659 uaddr = msg->msg_name; 1660 1661 tp = tcp_sk(ssk->sk); 1662 if (unlikely(!tp)) 1663 goto out_EFAULT; 1664 if (!tp->fastopen_req) 1665 tp->fastopen_req = kzalloc(sizeof(*tp->fastopen_req), ssk->sk->sk_allocation); 1666 1667 if (unlikely(!tp->fastopen_req)) 1668 goto out_EFAULT; 1669 tp->fastopen_req->data = msg; 1670 tp->fastopen_req->size = len; 1671 tp->fastopen_req->uarg = uarg; 1672 1673 /* requests a cookie */ 1674 ret = mptcp_stream_connect(sk->sk_socket, uaddr, 1675 msg->msg_namelen, msg->msg_flags); 1676 1677 return ret; 1678 out_EFAULT: 1679 ret = -EFAULT; 1680 return ret; 1681 } 1682 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org