Hi Yonglong, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on mptcp/export] [also build test WARNING on linus/master v5.13-rc6 next-20210617] [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/Yonglong-Li/mptcp-fix-conflicts-... base: https://github.com/multipath-tcp/mptcp_net-next.git export config: x86_64-randconfig-a015-20210617 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 64720f57bea6a6bf033feef4a5751ab9c0c3b401) 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 # install x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://github.com/0day-ci/linux/commit/dcb008513c667a57c48dd885599f2d760... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Yonglong-Li/mptcp-fix-conflicts-when-using-pm-add_signal-in-ADD_ADDR-echo-and-RM_ADDR-process/20210617-171559 git checkout dcb008513c667a57c48dd885599f2d760c8cf7eb # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): net/mptcp/options.c:567:21: warning: parameter 'remaining' set but not used [-Wunused-but-set-parameter] unsigned int remaining, ^ } else if (mptcp_pm_should_add_signal_addr(msk)) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:56:28: note: expanded from macro 'if' #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) ) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:58:30: note: expanded from macro '__trace_if_var' #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ net/mptcp/options.c:726:34: note: uninitialized use occurs here WRITE_ONCE(msk->pm.addr_signal, flags | msk->pm.addr_signal); ^~~~~ include/asm-generic/rwonce.h:61:18: note: expanded from macro 'WRITE_ONCE' __WRITE_ONCE(x, val); \ ^~~ include/asm-generic/rwonce.h:55:33: note: expanded from macro '__WRITE_ONCE' *(volatile typeof(x) *)&(x) = (val); \ ^~~ net/mptcp/options.c:698:9: note: remove the 'if' if its condition is always true } else if (mptcp_pm_should_add_signal_addr(msk)) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:56:23: note: expanded from macro 'if' #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) ) ^ net/mptcp/options.c:669:20: note: initialize the variable 'flags' to silence this warning u8 add_addr, flags; ^ = '\0' 2 warnings generated. vim +698 net/mptcp/options.c 563 564 static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb, 565 bool snd_data_fin_enable, 566 unsigned int *size, 568 struct mptcp_out_options *opts) 569 { 570 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); 571 struct mptcp_sock *msk = mptcp_sk(subflow->conn); 572 unsigned int dss_size = 0; 573 struct mptcp_ext *mpext; 574 unsigned int ack_size; 575 bool ret = false; 576 u64 ack_seq; 577 578 opts->csum_reqd = READ_ONCE(msk->csum_enabled); 579 mpext = skb ? mptcp_get_ext(skb) : NULL; 580 581 if (!skb || (mpext && mpext->use_map) || snd_data_fin_enable) { 582 unsigned int map_size = TCPOLEN_MPTCP_DSS_BASE + TCPOLEN_MPTCP_DSS_MAP64; 583 584 if (mpext) { 585 if (opts->csum_reqd) 586 map_size += TCPOLEN_MPTCP_DSS_CHECKSUM; 587 588 opts->ext_copy = *mpext; 589 } 590 591 remaining -= map_size; 592 dss_size = map_size; 593 if (skb && snd_data_fin_enable) 594 mptcp_write_data_fin(subflow, skb, &opts->ext_copy); 595 ret = true; 596 } 597 598 /* passive sockets msk will set the 'can_ack' after accept(), even 599 * if the first subflow may have the already the remote key handy 600 */ 601 opts->ext_copy.use_ack = 0; 602 if (!READ_ONCE(msk->can_ack)) { 603 *size = ALIGN(dss_size, 4); 604 return ret; 605 } 606 607 ack_seq = READ_ONCE(msk->ack_seq); 608 if (READ_ONCE(msk->use_64bit_ack)) { 609 ack_size = TCPOLEN_MPTCP_DSS_ACK64; 610 opts->ext_copy.data_ack = ack_seq; 611 opts->ext_copy.ack64 = 1; 612 } else { 613 ack_size = TCPOLEN_MPTCP_DSS_ACK32; 614 opts->ext_copy.data_ack32 = (uint32_t)ack_seq; 615 opts->ext_copy.ack64 = 0; 616 } 617 opts->ext_copy.use_ack = 1; 618 WRITE_ONCE(msk->old_wspace, __mptcp_space((struct sock *)msk)); 619 620 /* Add kind/length/subtype/flag overhead if mapping is not populated */ 621 if (dss_size == 0) 622 ack_size += TCPOLEN_MPTCP_DSS_BASE; 623 624 dss_size += ack_size; 625 626 *size = ALIGN(dss_size, 4); 627 return true; 628 } 629 630 static u64 add_addr_generate_hmac(u64 key1, u64 key2, 631 struct mptcp_addr_info *addr) 632 { 633 u16 port = ntohs(addr->port); 634 u8 hmac[SHA256_DIGEST_SIZE]; 635 u8 msg[19]; 636 int i = 0; 637 638 msg[i++] = addr->id; 639 if (addr->family == AF_INET) { 640 memcpy(&msg[i], &addr->addr.s_addr, 4); 641 i += 4; 642 } 643 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 644 else if (addr->family == AF_INET6) { 645 memcpy(&msg[i], &addr->addr6.s6_addr, 16); 646 i += 16; 647 } 648 #endif 649 msg[i++] = port >> 8; 650 msg[i++] = port & 0xFF; 651 652 mptcp_crypto_hmac_sha(key1, key2, msg, i, hmac); 653 654 return get_unaligned_be64(&hmac[SHA256_DIGEST_SIZE - sizeof(u64)]); 655 } 656 657 static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff *skb, 658 unsigned int *size, 659 unsigned int remaining, 660 struct mptcp_out_options *opts) 661 { 662 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); 663 struct mptcp_sock *msk = mptcp_sk(subflow->conn); 664 bool drop_other_suboptions = false; 665 unsigned int opt_size = *size; 666 struct mptcp_addr_info remote; 667 struct mptcp_addr_info local; 668 int ret = false; 669 u8 add_addr, flags; 670 int len; 671 672 if (!mptcp_pm_should_add_signal(msk)) 673 goto out; 674 675 *size = 0; 676 mptcp_pm_add_addr_signal(msk, &local, &remote, &add_addr); 677 if (mptcp_pm_should_add_signal_echo(msk)) { 678 if (skb && skb_is_tcp_pure_ack(skb)) { 679 pr_debug("drop other suboptions"); 680 opts->suboptions = 0; 681 opts->ext_copy.use_ack = 0; 682 opts->ext_copy.use_map = 0; 683 remaining += opt_size; 684 drop_other_suboptions = true; 685 } 686 len = mptcp_add_addr_len(remote.family, true, !!remote.port); 687 if (remaining < len && mptcp_pm_should_add_signal_addr(msk)) 688 goto add_addr; 689 else if (remaining < len) 690 goto out; 691 remaining -= len; 692 *size += len; 693 opts->remote = remote; 694 flags = (u8)~BIT(MPTCP_ADD_ADDR_ECHO); 695 opts->suboptions |= OPTION_MPTCP_ADD_ECHO; 696 pr_debug("addr_id=%d, echo=1, port=%d addr_signal:%x", 697 opts->remote.id, ntohs(opts->remote.port), add_addr); 699 add_addr: 700 if ((local.family == AF_INET6 || local.port) && skb && 701 skb_is_tcp_pure_ack(skb)) { 702 pr_debug("drop other suboptions"); 703 opts->suboptions = 0; 704 opts->ext_copy.use_ack = 0; 705 opts->ext_copy.use_map = 0; 706 remaining += opt_size; 707 drop_other_suboptions = true; 708 } 709 len = mptcp_add_addr_len(local.family, false, !!local.port); 710 if (remaining < len) 711 goto out; 712 *size += len; 713 opts->addr = local; 714 opts->ahmac = add_addr_generate_hmac(msk->local_key, 715 msk->remote_key, 716 &opts->addr); 717 opts->suboptions |= OPTION_MPTCP_ADD_ADDR; 718 flags = (u8)~BIT(MPTCP_ADD_ADDR_SIGNAL); 719 pr_debug("addr_id=%d, ahmac=%llu, echo=0, port=%d, addr_signal:%x", 720 opts->addr.id, opts->ahmac, ntohs(opts->addr.port), add_addr); 721 } 722 723 if (drop_other_suboptions) 724 *size -= opt_size; 725 spin_lock_bh(&msk->pm.lock); 726 WRITE_ONCE(msk->pm.addr_signal, flags | msk->pm.addr_signal); 727 spin_unlock_bh(&msk->pm.lock); 728 ret = true; 729 730 out: 731 return ret; 732 } 733 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org