From patchwork Mon Dec 28 15:21:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Taehee Yoo X-Patchwork-Id: 11991307 X-Patchwork-Delegate: kuba@kernel.org 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 D6D19C4332B for ; Mon, 28 Dec 2020 15:23:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B02EC22AAA for ; Mon, 28 Dec 2020 15:23:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2440856AbgL1PXF (ORCPT ); Mon, 28 Dec 2020 10:23:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42058 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2439699AbgL1PWX (ORCPT ); Mon, 28 Dec 2020 10:22:23 -0500 Received: from mail-pg1-x532.google.com (mail-pg1-x532.google.com [IPv6:2607:f8b0:4864:20::532]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 788CBC061794 for ; Mon, 28 Dec 2020 07:21:43 -0800 (PST) Received: by mail-pg1-x532.google.com with SMTP id n10so7476781pgl.10 for ; Mon, 28 Dec 2020 07:21:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=u/ofVvhOCIG7qFUy4N/rKxov7RxqX9WJvodYbTo5M4Q=; b=lLeByGQuSAo/yAdlTFlDvxFkAnIMz/fPQpUtb/4oHOVRNiRu18kQPNxMkpe10jrzb7 TGXBSRUTnQ4imkmTK6HO4WO0rv5Svy50TW1Rnyw3dbB5sYZUbniKlvyRBIPhhJdCPayM RpDWqho39zG6F+9hYxAB2DQRse8R/U/IYh6LBWMV5vuQaFwPh8bhhKMPux+rbmXBN+hN rXfVcADN+pkJ+pEkJ1VHxU9gZu+1bnrnHrmxT4sj3IhmivY/r7BILFTvsKVObTyss1QQ VNfyHl5jgIblyx2wYcDXREnunofYLDCeA/FhwrmurvmrCchnPOLC2p6S/aeS6Ofuna99 5lbg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=u/ofVvhOCIG7qFUy4N/rKxov7RxqX9WJvodYbTo5M4Q=; b=EvctodOI6pqizWRwpqo+HM7djZvMOnHAGhZ+MYmRMbj8hK+6rnZ4lBHY+pYqbad035 YzAh5GOn49uI82rM7r7uW/CdSq2t2UC++rtN3x6KW231y7cO+hGMHEGvrWpxooiTOgp1 eJ9UnMhQLuSe9CMcwYnMdu4isVdMXbROvIqLSaNBzrxRXC7heu+Vqr6/z+BmuRP6j+me DXtTwQJrNa5/lZ/Fjji1LZbxVvPGb6R6kSKdui6CmASM4dD7bdQy/JnrryIkKYnCO9Dp oD71EDIs9Q3O73Bh1ifQzK+dZ//RZv5KoSP/XcaSE7GFAncVI0sPq66sVvuvszR60uks iXGQ== X-Gm-Message-State: AOAM532kCjevs2FC16HAxfLLQcSxYG2H/Jdl4y0NsvIPBag1zxESBFjG c4hG/2I3tPzDay/OD5pCZa8= X-Google-Smtp-Source: ABdhPJwDM5DQU0Lpv1JoUm4hTJd9/GHfBZV1cDFqD7F5Ndj6KKWR147nprRrstaPvQWL+vAmJYcEyw== X-Received: by 2002:a63:174f:: with SMTP id 15mr37754228pgx.49.1609168903022; Mon, 28 Dec 2020 07:21:43 -0800 (PST) Received: from localhost.localdomain ([49.173.165.50]) by smtp.gmail.com with ESMTPSA id e29sm37948850pfj.174.2020.12.28.07.21.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Dec 2020 07:21:42 -0800 (PST) From: Taehee Yoo To: davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org Cc: ap420073@gmail.com, gnault@redhat.com Subject: [PATCH net v2 1/2] bareudp: set NETIF_F_LLTX flag Date: Mon, 28 Dec 2020 15:21:36 +0000 Message-Id: <20201228152136.24215-1-ap420073@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Like other tunneling interfaces, the bareudp doesn't need TXLOCK. So, It is good to set the NETIF_F_LLTX flag to improve performance and to avoid lockdep's false-positive warning. Test commands: ip netns add A ip netns add B ip link add veth0 netns A type veth peer name veth1 netns B ip netns exec A ip link set veth0 up ip netns exec A ip a a 10.0.0.1/24 dev veth0 ip netns exec B ip link set veth1 up ip netns exec B ip a a 10.0.0.2/24 dev veth1 for i in {2..1} do let A=$i-1 ip netns exec A ip link add bareudp$i type bareudp \ dstport $i ethertype ip ip netns exec A ip link set bareudp$i up ip netns exec A ip a a 10.0.$i.1/24 dev bareudp$i ip netns exec A ip r a 10.0.$i.2 encap ip src 10.0.$A.1 \ dst 10.0.$A.2 via 10.0.$i.2 dev bareudp$i ip netns exec B ip link add bareudp$i type bareudp \ dstport $i ethertype ip ip netns exec B ip link set bareudp$i up ip netns exec B ip a a 10.0.$i.2/24 dev bareudp$i ip netns exec B ip r a 10.0.$i.1 encap ip src 10.0.$A.2 \ dst 10.0.$A.1 via 10.0.$i.1 dev bareudp$i done ip netns exec A ping 10.0.2.2 Splat looks like: [ 96.992803][ T822] ============================================ [ 96.993954][ T822] WARNING: possible recursive locking detected [ 96.995102][ T822] 5.10.0+ #819 Not tainted [ 96.995927][ T822] -------------------------------------------- [ 96.997091][ T822] ping/822 is trying to acquire lock: [ 96.998083][ T822] ffff88810f753898 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960 [ 96.999813][ T822] [ 96.999813][ T822] but task is already holding lock: [ 97.001192][ T822] ffff88810c385498 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960 [ 97.002908][ T822] [ 97.002908][ T822] other info that might help us debug this: [ 97.004401][ T822] Possible unsafe locking scenario: [ 97.004401][ T822] [ 97.005784][ T822] CPU0 [ 97.006407][ T822] ---- [ 97.007010][ T822] lock(_xmit_NONE#2); [ 97.007779][ T822] lock(_xmit_NONE#2); [ 97.008550][ T822] [ 97.008550][ T822] *** DEADLOCK *** [ 97.008550][ T822] [ 97.010057][ T822] May be due to missing lock nesting notation [ 97.010057][ T822] [ 97.011594][ T822] 7 locks held by ping/822: [ 97.012426][ T822] #0: ffff888109a144f0 (sk_lock-AF_INET){+.+.}-{0:0}, at: raw_sendmsg+0x12f7/0x2b00 [ 97.014191][ T822] #1: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x249/0x2020 [ 97.016045][ T822] #2: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fd/0x2960 [ 97.017897][ T822] #3: ffff88810c385498 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960 [ 97.019684][ T822] #4: ffffffffbce2f600 (rcu_read_lock){....}-{1:2}, at: bareudp_xmit+0x31b/0x3690 [bareudp] [ 97.021573][ T822] #5: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x249/0x2020 [ 97.023424][ T822] #6: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fd/0x2960 [ 97.025259][ T822] [ 97.025259][ T822] stack backtrace: [ 97.026349][ T822] CPU: 3 PID: 822 Comm: ping Not tainted 5.10.0+ #819 [ 97.027609][ T822] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 97.029407][ T822] Call Trace: [ 97.030015][ T822] dump_stack+0x99/0xcb [ 97.030783][ T822] __lock_acquire.cold.77+0x149/0x3a9 [ 97.031773][ T822] ? stack_trace_save+0x81/0xa0 [ 97.032661][ T822] ? register_lock_class+0x1910/0x1910 [ 97.033673][ T822] ? register_lock_class+0x1910/0x1910 [ 97.034679][ T822] ? rcu_read_lock_sched_held+0x91/0xc0 [ 97.035697][ T822] ? rcu_read_lock_bh_held+0xa0/0xa0 [ 97.036690][ T822] lock_acquire+0x1b2/0x730 [ 97.037515][ T822] ? __dev_queue_xmit+0x1f52/0x2960 [ 97.038466][ T822] ? check_flags+0x50/0x50 [ 97.039277][ T822] ? netif_skb_features+0x296/0x9c0 [ 97.040226][ T822] ? validate_xmit_skb+0x29/0xb10 [ 97.041151][ T822] _raw_spin_lock+0x30/0x70 [ 97.041977][ T822] ? __dev_queue_xmit+0x1f52/0x2960 [ 97.042927][ T822] __dev_queue_xmit+0x1f52/0x2960 [ 97.043852][ T822] ? netdev_core_pick_tx+0x290/0x290 [ 97.044824][ T822] ? mark_held_locks+0xb7/0x120 [ 97.045712][ T822] ? lockdep_hardirqs_on_prepare+0x12c/0x3e0 [ 97.046824][ T822] ? __local_bh_enable_ip+0xa5/0xf0 [ 97.047771][ T822] ? ___neigh_create+0x12a8/0x1eb0 [ 97.048710][ T822] ? trace_hardirqs_on+0x41/0x120 [ 97.049626][ T822] ? ___neigh_create+0x12a8/0x1eb0 [ 97.050556][ T822] ? __local_bh_enable_ip+0xa5/0xf0 [ 97.051509][ T822] ? ___neigh_create+0x12a8/0x1eb0 [ 97.052443][ T822] ? check_chain_key+0x244/0x5f0 [ 97.053352][ T822] ? rcu_read_lock_bh_held+0x56/0xa0 [ 97.054317][ T822] ? ip_finish_output2+0x6ea/0x2020 [ 97.055263][ T822] ? pneigh_lookup+0x410/0x410 [ 97.056135][ T822] ip_finish_output2+0x6ea/0x2020 [ ... ] Acked-by: Guillaume Nault Fixes: 571912c69f0e ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.") Signed-off-by: Taehee Yoo --- v1 -> v2: - Change reproducer script drivers/net/bareudp.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/bareudp.c b/drivers/net/bareudp.c index 85ebd2b7e446..aea10196c222 100644 --- a/drivers/net/bareudp.c +++ b/drivers/net/bareudp.c @@ -534,6 +534,7 @@ static void bareudp_setup(struct net_device *dev) SET_NETDEV_DEVTYPE(dev, &bareudp_type); dev->features |= NETIF_F_SG | NETIF_F_HW_CSUM; dev->features |= NETIF_F_RXCSUM; + dev->features |= NETIF_F_LLTX; dev->features |= NETIF_F_GSO_SOFTWARE; dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM; dev->hw_features |= NETIF_F_GSO_SOFTWARE;