From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AEBC7C433C1 for ; Sat, 20 Mar 2021 03:48:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 766D761998 for ; Sat, 20 Mar 2021 03:48:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229770AbhCTDsH (ORCPT ); Fri, 19 Mar 2021 23:48:07 -0400 Received: from mga17.intel.com ([192.55.52.151]:41612 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229646AbhCTDr7 (ORCPT ); Fri, 19 Mar 2021 23:47:59 -0400 IronPort-SDR: Af6bSwsTk4Xbz65FIdnODV2Ya3MAbqdpyfhvHGxUq/7zZ8+6Cu4hVj3Kea0AOVADDSqZesSBnd NmY64xtEkSQQ== X-IronPort-AV: E=McAfee;i="6000,8403,9928"; a="169940323" X-IronPort-AV: E=Sophos;i="5.81,263,1610438400"; d="scan'208";a="169940323" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Mar 2021 20:47:58 -0700 IronPort-SDR: Td8dh0iTmDpxTDtM8kXIomaMtbtW0x8N7mDeNB3WLbplLbYLk/wHZ7+gmJRddNIlhHez2RJ9vY rNPF10XsnVOA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.81,263,1610438400"; d="scan'208";a="512695394" Received: from lkp-server02.sh.intel.com (HELO 1c294c63cb86) ([10.239.97.151]) by fmsmga001.fm.intel.com with ESMTP; 19 Mar 2021 20:47:56 -0700 Received: from kbuild by 1c294c63cb86 with local (Exim 4.92) (envelope-from ) id 1lNSah-0002J6-I0; Sat, 20 Mar 2021 03:47:55 +0000 Date: Sat, 20 Mar 2021 11:47:00 +0800 From: kernel test robot To: Lorenzo Bianconi , bpf@vger.kernel.org, netdev@vger.kernel.org Cc: kbuild-all@lists.01.org, lorenzo.bianconi@redhat.com, davem@davemloft.net, kuba@kernel.org, ast@kernel.org, daniel@iogearbox.net, shayagr@amazon.com, john.fastabend@gmail.com, dsahern@kernel.org Subject: Re: [PATCH v7 bpf-next 09/14] bpd: add multi-buffer support to xdp copy helpers Message-ID: <202103201112.Qq22IgkP-lkp@intel.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi Lorenzo, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on bpf-next/master] url: https://github.com/0day-ci/linux/commits/Lorenzo-Bianconi/mvneta-introduce-XDP-multi-buffer-support/20210320-055103 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master compiler: nios2-linux-gcc (GCC) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot cppcheck warnings: (new ones prefixed by >>) ^ net/core/filter.c:10085:6: note: Variable 'ret' is reassigned a value before the old one has been used. ret = -EACCES; ^ net/core/filter.c:10090:6: note: Variable 'ret' is reassigned a value before the old one has been used. ret = fprog->len; ^ >> net/core/filter.c:4593:30: warning: Uninitialized variable: copy_len [uninitvar] memcpy(dst_buff, src_buff, copy_len); ^ vim +4593 net/core/filter.c 4551 4552 static unsigned long bpf_xdp_copy(void *dst_buff, const void *ctx, 4553 unsigned long off, unsigned long len) 4554 { 4555 struct xdp_buff *xdp = (struct xdp_buff *)ctx; 4556 struct xdp_shared_info *xdp_sinfo; 4557 unsigned long base_len; 4558 const void *src_buff; 4559 4560 if (likely(!xdp->mb)) { 4561 src_buff = xdp->data; 4562 memcpy(dst_buff, src_buff + off, len); 4563 4564 return 0; 4565 } 4566 4567 base_len = xdp->data_end - xdp->data; 4568 xdp_sinfo = xdp_get_shared_info_from_buff(xdp); 4569 do { 4570 unsigned long copy_len; 4571 4572 if (off < base_len) { 4573 src_buff = xdp->data + off; 4574 copy_len = min(len, base_len - off); 4575 } else { 4576 unsigned long frag_off_total = base_len; 4577 int i; 4578 4579 for (i = 0; i < xdp_sinfo->nr_frags; i++) { 4580 skb_frag_t *frag = &xdp_sinfo->frags[i]; 4581 unsigned long frag_len = xdp_get_frag_size(frag); 4582 unsigned long frag_off = off - frag_off_total; 4583 4584 if (frag_off < frag_len) { 4585 src_buff = xdp_get_frag_address(frag) + 4586 frag_off; 4587 copy_len = min(len, frag_len - frag_off); 4588 break; 4589 } 4590 frag_off_total += frag_len; 4591 } 4592 } > 4593 memcpy(dst_buff, src_buff, copy_len); 4594 off += copy_len; 4595 len -= copy_len; 4596 dst_buff += copy_len; 4597 } while (len); 4598 4599 return 0; 4600 } 4601 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org