Hi Jeremy, I love your patch! Perhaps something to improve: [auto build test WARNING on net-next/master] url: https://github.com/0day-ci/linux/commits/Jeremy-Kerr/MCTP-tag-control-interface/20220208-195325 base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git c3e676b98326a419f30dd5d956c68fc33323f4fd config: nios2-randconfig-r021-20220208 (https://download.01.org/0day-ci/archive/20220209/202202090043.BhR7muS4-lkp@xxxxxxxxx/config) compiler: nios2-linux-gcc (GCC) 11.2.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/0day-ci/linux/commit/a1d553f399d7457bd3e455cd3f5e10dddb4bc2bf git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Jeremy-Kerr/MCTP-tag-control-interface/20220208-195325 git checkout a1d553f399d7457bd3e455cd3f5e10dddb4bc2bf # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=nios2 SHELL=/bin/bash kernel/ net/mctp/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> net/mctp/route.c:660:21: warning: no previous prototype for 'mctp_lookup_prealloc_tag' [-Wmissing-prototypes] 660 | struct mctp_sk_key *mctp_lookup_prealloc_tag(struct mctp_sock *msk, | ^~~~~~~~~~~~~~~~~~~~~~~~ vim +/mctp_lookup_prealloc_tag +660 net/mctp/route.c 659 > 660 struct mctp_sk_key *mctp_lookup_prealloc_tag(struct mctp_sock *msk, 661 mctp_eid_t daddr, u8 req_tag, 662 u8 *tagp) 663 { 664 struct net *net = sock_net(&msk->sk); 665 struct netns_mctp *mns = &net->mctp; 666 struct mctp_sk_key *key, *tmp; 667 unsigned long flags; 668 669 req_tag &= ~(MCTP_TAG_PREALLOC | MCTP_TAG_OWNER); 670 key = NULL; 671 672 spin_lock_irqsave(&mns->keys_lock, flags); 673 674 hlist_for_each_entry(tmp, &mns->keys, hlist) { 675 if (tmp->tag != req_tag) 676 continue; 677 678 if (!(tmp->peer_addr == daddr || tmp->peer_addr == MCTP_ADDR_ANY)) 679 continue; 680 681 if (!tmp->manual_alloc) 682 continue; 683 684 spin_lock(&tmp->lock); 685 if (tmp->valid) { 686 key = tmp; 687 refcount_inc(&key->refs); 688 spin_unlock(&tmp->lock); 689 break; 690 } 691 spin_unlock(&tmp->lock); 692 } 693 spin_unlock_irqrestore(&mns->keys_lock, flags); 694 695 if (!key) 696 return ERR_PTR(-ENOENT); 697 698 if (tagp) 699 *tagp = key->tag; 700 701 return key; 702 } 703 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx