From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from SN4PR2101CU001.outbound.protection.outlook.com (mail-southcentralusazon11012037.outbound.protection.outlook.com [40.93.195.37]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CD99B3D2FF7; Mon, 13 Jul 2026 08:53:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.93.195.37 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783932822; cv=fail; b=r0wVA1g0el244bM1SnC5jbYDDmvckQ0PbiCWiAxvG7cHAq8XgUAzp4n5O/jU+b86tnEZGb1B01KQD/FvKDa8ST2kP2A20HncYKJNG+GBh1bm7mpYZneMqR7L3ZYOtxwfjNL2rL2qMyQs4ssq5ZvLzsnKoGJ7WHSG9ZjuPtIleBI= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783932822; c=relaxed/simple; bh=PdV0FoPtcmAxCo35ijpumQ51RuwCWfk3XCoHIx+bpRs=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=WuNIVh7L3NTvk6raHa5FdF6sHBc3K2jbrCykaH1zDTALLMCxVZCywfonqg/ccfp2KIw94XUo01dfEAaDs72zWo2BJkYE+KKuzQu5xjQqIsAhw/FgRgm6y6ALg+hXP0jzSM7ceIypLvfQb+4KsJOLOCNSe0CgFNNS0vGy/jOU7dY= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=IZFI83lv; arc=fail smtp.client-ip=40.93.195.37 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="IZFI83lv" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=h+7ccXDXkm08FWr6hDWEt3jErtsSqOF8/i3JIuLgtHCYuP2SovYuLduJMf+L88v5BFJZycidp0W+11Ykhv9qgDnYvlySagBzNYneP07N8AEmtVDRkFVxRQ6igoV7vtRxSFCXYtvwTcmF3Lo/B9JI/4UV/AgR+LXeHcOKaE7yzpneH784+ckn2zAFgLKePwvyAjk1dCTejsAqAV11xclM1Vf/KzumcGz6vB7s3MZVEIwe2O5vdv3IqlhUEhqR45oRnfZU+v9sVjijCyJEV6X0d7X/rChQQmkUKD/0k8bIqbZEly6nmfsKyKEcmt/bOhsqXfgkb/wzj1UXkaBfKrrq/A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=U6OUI6Rs4jLqJf7P1SrdiXm4Mj5pO/bdm79Js8wEBpw=; b=lAMHGnbKg0M8ZU+Gp4hzeYnOQwulpJp6ivclTYgOGfVjzRvgdJJDAtEFizco8BQcAxCLZquJPZwu/ZynPfGRCrbB6ZBkTHk8q98BkCgKp0Qva9JXSsvcYQB0Fh5N7IGklVzT3NKsFbIyQOfq5B/9+7QyUbO4m977MO4dzKB2X+wcEqrNIleUOcu1ryoMCpm4G0w6dT6FQXELBqT0H5JRzbb3KDYsoAU8KrmyaUgFVT18yCA2pQRqhoEWYU4d5wod1iAc1OixgGPlr+KAYaUnGctnDF5wNjBtiI9BhKW4ox8dpweFeuLukxgDGgj7lCue6BeYivXoU3gZUzjewa7fMw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=U6OUI6Rs4jLqJf7P1SrdiXm4Mj5pO/bdm79Js8wEBpw=; b=IZFI83lvRbppEUowwH5D30W7e3nbTArGJaWqs9eZTKzKl3hoAWXd2NUtQNO1WJzWEztj1+OLF9LyxTYB+6Wdr8ILB/JwAT1e0wQBp0bHYpbGXWeVdLZM3W4Xxug4dSykhhaZenh+UYIiFghI3kCd+5H4K5svC6L2MbZjoIH97FfvOKBhLuFoA44HlSOJFdiClf4sKEzajN7l53glNYVz4hVXYvHmT3txuztnxaXzrQqeQeU0Fl7zwCXULyXe5qdh7BB8+YhGoloOS5koVGVU6mIn4V7S/BYEP0tQQhCe8d9ErhXVk6q5wrZtV0gvz7TrwK1EJ9EzJ+KcwyI+7kH/Vg== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from SA3PR12MB7901.namprd12.prod.outlook.com (2603:10b6:806:306::12) by MW4PR12MB6684.namprd12.prod.outlook.com (2603:10b6:303:1ee::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.181.19; Mon, 13 Jul 2026 08:53:36 +0000 Received: from SA3PR12MB7901.namprd12.prod.outlook.com ([fe80::6f7f:5844:f0f7:acc2]) by SA3PR12MB7901.namprd12.prod.outlook.com ([fe80::6f7f:5844:f0f7:acc2%5]) with mapi id 15.21.0202.014; Mon, 13 Jul 2026 08:53:35 +0000 Date: Mon, 13 Jul 2026 11:53:25 +0300 From: Ido Schimmel To: Yun Zhou Cc: dsahern@kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] net: gre: fix lltx regression for GRE tunnels with SEQ/CSUM Message-ID: <20260713085325.GA472073@shredder> References: <20260709105243.864835-1-yun.zhou@windriver.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260709105243.864835-1-yun.zhou@windriver.com> X-ClientProxiedBy: FR0P281CA0047.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:48::18) To SA3PR12MB7901.namprd12.prod.outlook.com (2603:10b6:806:306::12) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SA3PR12MB7901:EE_|MW4PR12MB6684:EE_ X-MS-Office365-Filtering-Correlation-Id: ba224db4-7b66-47d6-9134-08dee0bc3993 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|23010399003|1800799024|366016|56012099006|11063799006|18002099003|22082099003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:SA3PR12MB7901.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(23010399003)(1800799024)(366016)(56012099006)(11063799006)(18002099003)(22082099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?qeQbiC7RJN1JZy4o5Yi0Vtwba0XcjyEZzuS8F4n5qgC1QGAskCDlK12miDj6?= =?us-ascii?Q?s2NeobhAyhfHxUpcZ0PGP5E8Xpq2HqFfSICqjdlvovlYVcJlwy39yc+i/B7H?= =?us-ascii?Q?+xecoFkzeUrIwCfcvj+ahPqj4bjkf+fsMdJNwolwj+HdmqhEE8/iMxY3omZh?= =?us-ascii?Q?n86r7fdLkbni5McrVwbNyHFB/bp4Azmg88OKuAwgiBLstWQQMbiae9B59g75?= =?us-ascii?Q?YdUhpdRx8XG4ixlpLXNhWrAyTzOjM5Mr/D+sdmTiCRPak+k0fElyKQ6Sw68M?= =?us-ascii?Q?1y3jJ5qJ4Fk7hEYW2zJUocCz3zNCeP8DSrBBmMIjW1eb222Cy0dwRv2ibHmX?= =?us-ascii?Q?5Vc7G+uSeqaXVP79VZcKTVfdfCuvXFRyAQUWU0Znep73K/r1Q6eLRphlFN9y?= =?us-ascii?Q?/gayi0aqhjs1ywjqI350WyG17sqURlK3bR3H2G2OAUuLIBWZpAWkN0cQWU9W?= =?us-ascii?Q?Ahc8zAc8c4jdHXnrYI4dLaa8m6AxGCTDB2Q0DIzk673hzzdaXsp9FKVn5N1Y?= =?us-ascii?Q?tgEt30nWyXkVqJsL3CIZS4c/3+xb55gKCtdaGGHdUy5RW6rIzLJUEplh13Zf?= =?us-ascii?Q?g+eKalxLKhDRJvGWa1VcvxR9VUY3owJ1YuYKdgPINm80iWrUgwfjPars37Un?= =?us-ascii?Q?hZWAt5o83Tb/7gvMKkhbV9m/ZGppOkrLCMj1jnosRy1EdxLQG6VPg7E8ZVZS?= =?us-ascii?Q?ozuXC3/CmlsPw3YZHQkFyOZhPvZsXncnRaGqI00Gp9BKVKfGazgFFaFQVapT?= =?us-ascii?Q?MQfrpy8yGEGOno1TmatARu7R3RmRbmeT+2hSk8OmSq1qKhYzG9bDrtLJFzkl?= =?us-ascii?Q?YVi1c4cYrra7nKR3F5aPfbSsPvfiFpZUA80IqTiEtox4pK5NPdpnrYqkqAer?= =?us-ascii?Q?qGrC150eyZle1d9j26JMayoExMwQiKAQuYJDLWtQb82sR3YBzzCD7LsUcuPi?= =?us-ascii?Q?TwGHn5BYGFH5yfjppZ9G3rjLAB1Vzjfv0n066riHRkhy+u1JqcrI6LpBkP1N?= =?us-ascii?Q?lkZjrE6XJbHUSl3c5LfovWotZpZjpZtGUF2JF4E24OSjRdI4OvcVi8SdiQYz?= =?us-ascii?Q?rNbhrpLN3axOG6djJHz8qiLBQCN5PJcaYmGVYikjGZfL0sV9CokIYr3bNnNT?= =?us-ascii?Q?k8p8yfstLICQnzaXhIXUqMELBiJzZfOPi0ZtPy680p9TwfNtN7E6l7UcQELQ?= =?us-ascii?Q?MaWo+bSAPseSuo6nxYpzCv7IpWa4LGXWbvC1fnYyp3D6N/WfmlkbZmTIh8vF?= =?us-ascii?Q?tNMOMW9uu2V6JefURc0zp/o2CT9M/d8xGNYJALewEGe+v0MiyP02nGohiX8+?= =?us-ascii?Q?CtpCMNJQ7rpdLPHGn5SS/gIUEKaRPWjGo5++4GWNTpJRoIBCc6V/r9TGZCo9?= =?us-ascii?Q?YLULYG14rXfXiPjHR27ZkgyNpella1J+WiIuahIufOiLt8P2hU/33mjqZ4Sv?= =?us-ascii?Q?+gCINnydkMw7Nzvxel2kBaOCdxdrKeo6ZtTZxu8o/gpq+TH5ut9SA6gz9TpE?= =?us-ascii?Q?Jw4R9Y+1yM2DmARbJR0U3g9YbzfnaRj10lMR/kUYaFZO7z7NWGMLTXnHIQjK?= =?us-ascii?Q?ttcFskoCY0gjAym4kl5VvDd9+OjgtjiPZTZefBGTe39scZK1eabeXYJ+ryJA?= =?us-ascii?Q?N0ENYhVsxgARWigknG7z/AboQOD43t4nqPJcOODmq10mBagAzP3zp8CuvslM?= =?us-ascii?Q?+shJVC2k2bLy1FGhdYChDA+VfRGNFY1emsAidk703pgSg/6V?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: ba224db4-7b66-47d6-9134-08dee0bc3993 X-MS-Exchange-CrossTenant-AuthSource: SA3PR12MB7901.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Jul 2026 08:53:35.8981 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: kLF7HsvAVomtmRQJZrmABPg9nnCIKgZCr4YkyRXHHkj2w7uLZPu+NbbFjpAQPbCEEHkZWQJ+4oqXQ/ZQ5ILNFw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW4PR12MB6684 Patch prefix should be [PATCH net]: https://docs.kernel.org/process/maintainer-netdev.html On Thu, Jul 09, 2026 at 06:52:43PM +0800, Yun Zhou wrote: > Before commit 00d066a4d4ed ("netdev_features: convert NETIF_F_LLTX to > dev->lltx"), NETIF_F_LLTX was set unconditionally in __gre_tunnel_init() > alongside GRE_FEATURES: > > dev->features |= GRE_FEATURES | NETIF_F_LLTX; > > When that commit converted NETIF_F_LLTX to the dev->lltx flag, it > placed 'dev->lltx = true' after the SEQ/CSUM early returns instead > of before them. This causes GRE/GRETAP tunnels with SEQ or CSUM+encap > to lose lockless TX, reintroducing _xmit_lock acquisition around their > ndo_start_xmit. Since GRE xmit re-enters the stack via > ip_tunnel_xmit(), holding _xmit_lock risks ABBA deadlock with the > underlay device. > > CPU0 CPU1 > ---- ---- > lock(&qdisc_xmit_lock_key#6); > lock(&qdisc_xmit_lock_key#3); > lock(&qdisc_xmit_lock_key#6); > lock(&qdisc_xmit_lock_key#3); > > Fix by moving dev->lltx = true before the early returns, restoring > the original unconditional behavior. > > Fixes: 00d066a4d4ed ("netdev_features: convert NETIF_F_LLTX to dev->lltx") Both sashiko instances indicate that this commit introduced the same bug in ip6gre_tnl_init_features(). Please perform the same fix there and fold it into v2. > Signed-off-by: Yun Zhou > --- > net/ipv4/ip_gre.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c > index 9fbff16cda1d..8c5ad8ec8d09 100644 > --- a/net/ipv4/ip_gre.c > +++ b/net/ipv4/ip_gre.c > @@ -1018,6 +1018,8 @@ static void __gre_tunnel_init(struct net_device *dev) > dev->features |= GRE_FEATURES; > dev->hw_features |= GRE_FEATURES; > > + dev->lltx = true; > + > /* TCP offload with GRE SEQ is not supported, nor can we support 2 > * levels of outer headers requiring an update. > */ > @@ -1029,8 +1031,6 @@ static void __gre_tunnel_init(struct net_device *dev) > > dev->features |= NETIF_F_GSO_SOFTWARE; > dev->hw_features |= NETIF_F_GSO_SOFTWARE; > - > - dev->lltx = true; > } > > static int ipgre_tunnel_init(struct net_device *dev) > -- > 2.43.0 >