From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 67BFBA04F2 for ; Sun, 7 Jun 2020 11:59:19 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 99FB31BE9B; Sun, 7 Jun 2020 11:59:18 +0200 (CEST) Received: from wh10.alp1.flow.ch (wh10.alp1.flow.ch [185.119.84.194]) by dpdk.org (Postfix) with ESMTP id 6CD721BE99 for ; Sun, 7 Jun 2020 11:59:17 +0200 (CEST) Received: from [::1] (port=40264 helo=wh10.alp1.flow.ch) by wh10.alp1.flow.ch with esmtpa (Exim 4.92) (envelope-from ) id 1jhs5E-00F2xa-QR; Sun, 07 Jun 2020 11:59:16 +0200 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Sun, 07 Jun 2020 11:59:16 +0200 From: Alex Kiselev To: Cliff Burdick Cc: Stephen Hemminger , users In-Reply-To: References: <504fcb6e5a12a03035e7b55507e7c279@therouter.net> <20200601091729.03ea9e50@hermes.lan> <7DA537F2-9887-4B0A-9249-064736E8A9AD@therouter.net> Message-ID: X-Sender: alex@therouter.net User-Agent: Roundcube Webmail/1.3.8 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - wh10.alp1.flow.ch X-AntiAbuse: Original Domain - dpdk.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - therouter.net X-Get-Message-Sender-Via: wh10.alp1.flow.ch: authenticated_id: alex@therouter.net X-Authenticated-Sender: wh10.alp1.flow.ch: alex@therouter.net X-Source: X-Source-Args: X-Source-Dir: Subject: Re: [dpdk-users] segmention fault while accessing mbuf X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: users-bounces@dpdk.org Sender: "users" On 2020-06-07 04:41, Cliff Burdick wrote: > I can't tell from your code, but you assigned nb_rx to the number of > packets received, but then used vec_size, which might be larger. Does > this happen if you use nb_rx in your loops? No, this doesn't happen. I just skip the part of the code that translates nb_rx to vec_size, since that code is double checked. My actual question now is about possible impact of using incorrect values of mbuf's pkt_len and data_len fields. > > On Sat, Jun 6, 2020 at 5:59 AM Alex Kiselev > wrote: > >>> 1 июня 2020 г., в 19:17, Stephen Hemminger >> написал(а): >>> >>> On Mon, 01 Jun 2020 15:24:25 +0200 >>> Alex Kiselev wrote: >>> >>>> Hello, >>>> >>>> I've got a segmentation fault error in my data plane path. >>>> I am pretty sure the code where the segfault happened is ok, >>>> so my guess is that I somehow received a corrupted mbuf. >>>> How could I troubleshoot this? Is there any way? >>>> Is it possible that other threads of the application >>>> corrupted that mbuf? >>>> >>>> I would really appriciate any advice. >>>> Thanks. >>>> >>>> DPDK 18.11.3 >>>> NIC: 82599ES >>>> >>>> Code: >>>> >>>> nb_rx = rte_eth_rx_burst(port_id, queue_id, pkts_burst, >>>> MAX_PKT_BURST); >>>> >>>> ... >>>> >>>> for (i=0; i < vec_size; i++) { >>>> rte_prefetch0(rte_pktmbuf_mtod(m_v[i], void *)); >>>> >>>> for (i=0; i < vec_size; i++) { >>>> m = m_v[i]; >>>> eth_hdr = rte_pktmbuf_mtod(m, struct ether_hdr *); >>>> eth_type = rte_be_to_cpu_16(eth_hdr->ether_type); >> <--- >>>> Segmentation fault >>>> ... >>>> >>>> #0 rte_arch_bswap16 (_x=> memory >>>> at address 0x4d80000000053010>) >>> >>> Build with as many of the debug options turned on in the DPDK >> config, >>> and build with EXTRA_CFLAGS of -g. >> >> Could using an incorrect (a very big one) value of mbuf pkt_len and >> data_len while transmitting cause mbuf corruption and following >> segmentation fault on rx?