Hi Jason, kernel test robot noticed the following build warnings: [auto build test WARNING on net-next/main] url: https://github.com/intel-lab-lkp/linux/commits/Jason-Xing/net-timestamp-add-support-for-bpf_setsockopt/20250112-194115 base: net-next/main patch link: https://lore.kernel.org/r/20250112113748.73504-6-kerneljasonxing%40gmail.com patch subject: [PATCH net-next v5 05/15] net-timestamp: add strict check in some BPF calls config: arm-randconfig-r071-20250117 (https://download.01.org/0day-ci/archive/20250117/202501171802.CSquHTL3-lkp@xxxxxxxxx/config) compiler: arm-linux-gnueabi-gcc (GCC) 14.2.0 If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202501171802.CSquHTL3-lkp@xxxxxxxxx/ smatch warnings: net/core/filter.c:7631 ____bpf_sock_ops_load_hdr_opt() warn: always true condition '(bpf_sock->op != 1009) => (0-255 != 1009)' vim +7631 net/core/filter.c 7622 7623 BPF_CALL_4(bpf_sock_ops_load_hdr_opt, struct bpf_sock_ops_kern *, bpf_sock, 7624 void *, search_res, u32, len, u64, flags) 7625 { 7626 bool eol, load_syn = flags & BPF_LOAD_HDR_OPT_TCP_SYN; 7627 const u8 *op, *opend, *magic, *search = search_res; 7628 u8 search_kind, search_len, copy_len, magic_len; 7629 int ret; 7630 > 7631 if (bpf_sock->op != SK_BPF_CB_FLAGS) 7632 return -EINVAL; 7633 7634 /* 2 byte is the minimal option len except TCPOPT_NOP and 7635 * TCPOPT_EOL which are useless for the bpf prog to learn 7636 * and this helper disallow loading them also. 7637 */ 7638 if (len < 2 || flags & ~BPF_LOAD_HDR_OPT_TCP_SYN) 7639 return -EINVAL; 7640 7641 search_kind = search[0]; 7642 search_len = search[1]; 7643 7644 if (search_len > len || search_kind == TCPOPT_NOP || 7645 search_kind == TCPOPT_EOL) 7646 return -EINVAL; 7647 7648 if (search_kind == TCPOPT_EXP || search_kind == 253) { 7649 /* 16 or 32 bit magic. +2 for kind and kind length */ 7650 if (search_len != 4 && search_len != 6) 7651 return -EINVAL; 7652 magic = &search[2]; 7653 magic_len = search_len - 2; 7654 } else { 7655 if (search_len) 7656 return -EINVAL; 7657 magic = NULL; 7658 magic_len = 0; 7659 } 7660 7661 if (load_syn) { 7662 ret = bpf_sock_ops_get_syn(bpf_sock, TCP_BPF_SYN, &op); 7663 if (ret < 0) 7664 return ret; 7665 7666 opend = op + ret; 7667 op += sizeof(struct tcphdr); 7668 } else { 7669 if (!bpf_sock->skb || 7670 bpf_sock->op == BPF_SOCK_OPS_HDR_OPT_LEN_CB) 7671 /* This bpf_sock->op cannot call this helper */ 7672 return -EPERM; 7673 7674 opend = bpf_sock->skb_data_end; 7675 op = bpf_sock->skb->data + sizeof(struct tcphdr); 7676 } 7677 7678 op = bpf_search_tcp_opt(op, opend, search_kind, magic, magic_len, 7679 &eol); 7680 if (IS_ERR(op)) 7681 return PTR_ERR(op); 7682 7683 copy_len = op[1]; 7684 ret = copy_len; 7685 if (copy_len > len) { 7686 ret = -ENOSPC; 7687 copy_len = len; 7688 } 7689 7690 memcpy(search_res, op, copy_len); 7691 return ret; 7692 } 7693 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
