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=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 51F53C2D0A3 for ; Mon, 26 Oct 2020 08:28:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0BF42223B0 for ; Mon, 26 Oct 2020 08:28:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603700904; bh=zW23cEGE62zuYxwPApdEgc2f1jEQe4qQoejLAgsMtyI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=qhpBQLLyEY9gmUxvL/qG0S4z1A+xH+de9bU+kxqABXrCTMcZthhESlVUDJmIWoWS3 5SRRVm6/+Bj7ihJi7eI8Ivh56/y1pfmalfbQXmVQwsjlkmUVPpecNLYAaAk9mNEYlI dT2Y/496QV50dZcbLp9pE2pdCqxcufMg2SL6B6sw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1771712AbgJZI2X (ORCPT ); Mon, 26 Oct 2020 04:28:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:46030 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1771693AbgJZI2V (ORCPT ); Mon, 26 Oct 2020 04:28:21 -0400 Received: from localhost (unknown [213.57.247.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 511FA222B9; Mon, 26 Oct 2020 08:28:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603700900; bh=zW23cEGE62zuYxwPApdEgc2f1jEQe4qQoejLAgsMtyI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jv3emd9RUXLW2L75Ao/+Z52h2W1D5DrIhipkpZ53SN2HFozdUHbr1vOaJek6MK2Ma Ggsnmomi6A1aAxslpehqHkorXcBypDoundUjM8kzc6+kQ0IqZ7EFhOybbx4IQjjoSR F0ALHxCGSHv7vcKyQ5qZCSuwgWJTs16ytj/g0fSM= Date: Mon, 26 Oct 2020 10:28:15 +0200 From: Leon Romanovsky To: Vlad Buslov Cc: "David S . Miller" , Jakub Kicinski , Cong Wang , Jamal Hadi Salim , Jiri Pirko , netdev@vger.kernel.org, Pablo Neira Ayuso Subject: Re: [PATCH net] net: use proper block lock instead of RTNL lock Message-ID: <20201026082815.GB4821@unreal> References: <20201026060407.583080-1-leon@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Oct 26, 2020 at 10:10:31AM +0200, Vlad Buslov wrote: > On Mon 26 Oct 2020 at 08:04, Leon Romanovsky wrote: > > From: Leon Romanovsky > > > > The tcf_block_unbind() expects that the caller will take block->cb_lock > > before calling it, however the code took RTNL lock instead. This causes > > to the following kernel panic. > > > > WARNING: CPU: 1 PID: 13524 at net/sched/cls_api.c:1488 tcf_block_unbind+0x2db/0x420 > > Modules linked in: mlx5_ib mlx5_core mlxfw ptp pps_core act_mirred act_tunnel_key cls_flower vxlan ip6_udp_tunnel udp_tunnel dummy sch_ingress openvswitch nsh xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink xt_addrtype iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter rpcrdma rdma_ucm ib_iser libiscsi scsi_transport_iscsi ib_umad ib_ipoib rdma_cm iw_cm ib_cm ib_uverbs ib_core overlay [last unloaded: mlxfw] > > CPU: 1 PID: 13524 Comm: test-ecmp-add-v Tainted: G W 5.9.0+ #1 > > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 > > RIP: 0010:tcf_block_unbind+0x2db/0x420 > > Code: ff 48 83 c4 40 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8d bc 24 30 01 00 00 be ff ff ff ff e8 7d 7f 70 00 85 c0 0f 85 7b fd ff ff <0f> 0b e9 74 fd ff ff 48 c7 c7 dc 6a 24 84 e8 02 ec fe fe e9 55 fd > > RSP: 0018:ffff888117d17968 EFLAGS: 00010246 > > RAX: 0000000000000000 RBX: ffff88812f713c00 RCX: 1ffffffff0848d5b > > RDX: 0000000000000001 RSI: ffff88814fbc8130 RDI: ffff888107f2b878 > > RBP: 1ffff11022fa2f3f R08: 0000000000000000 R09: ffffffff84115a87 > > R10: fffffbfff0822b50 R11: ffff888107f2b898 R12: ffff88814fbc8000 > > R13: ffff88812f713c10 R14: ffff888117d17a38 R15: ffff88814fbc80c0 > > FS: 00007f6593d36740(0000) GS:ffff8882a4f00000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 00005607a00758f8 CR3: 0000000131aea006 CR4: 0000000000170ea0 > > Call Trace: > > tc_block_indr_cleanup+0x3e0/0x5a0 > > ? tcf_block_unbind+0x420/0x420 > > ? __mutex_unlock_slowpath+0xe7/0x610 > > flow_indr_dev_unregister+0x5e2/0x930 > > ? mlx5e_restore_tunnel+0xdf0/0xdf0 [mlx5_core] > > ? mlx5e_restore_tunnel+0xdf0/0xdf0 [mlx5_core] > > ? flow_indr_block_cb_alloc+0x3c0/0x3c0 > > ? mlx5_db_free+0x37c/0x4b0 [mlx5_core] > > mlx5e_cleanup_rep_tx+0x8b/0xc0 [mlx5_core] > > mlx5e_detach_netdev+0xe5/0x120 [mlx5_core] > > mlx5e_vport_rep_unload+0x155/0x260 [mlx5_core] > > esw_offloads_disable+0x227/0x2b0 [mlx5_core] > > mlx5_eswitch_disable_locked.cold+0x38e/0x699 [mlx5_core] > > mlx5_eswitch_disable+0x94/0xf0 [mlx5_core] > > mlx5_device_disable_sriov+0x183/0x1f0 [mlx5_core] > > mlx5_core_sriov_configure+0xfd/0x230 [mlx5_core] > > sriov_numvfs_store+0x261/0x2f0 > > ? sriov_drivers_autoprobe_store+0x110/0x110 > > ? sysfs_file_ops+0x170/0x170 > > ? sysfs_file_ops+0x117/0x170 > > ? sysfs_file_ops+0x170/0x170 > > kernfs_fop_write+0x1ff/0x3f0 > > ? rcu_read_lock_any_held+0x6e/0x90 > > vfs_write+0x1f3/0x620 > > ksys_write+0xf9/0x1d0 > > ? __x64_sys_read+0xb0/0xb0 > > ? lockdep_hardirqs_on_prepare+0x273/0x3f0 > > ? syscall_enter_from_user_mode+0x1d/0x50 > > do_syscall_64+0x2d/0x40 > > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > > <...> > > > > ---[ end trace bfdd028ada702879 ]--- > > > > Fixes: 0fdcf78d5973 ("net: use flow_indr_dev_setup_offload()") > > Signed-off-by: Leon Romanovsky > > --- > > net/sched/cls_api.c | 4 +--- > > 1 file changed, 1 insertion(+), 3 deletions(-) > > > > diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c > > index faeabff283a2..fca147386ad2 100644 > > --- a/net/sched/cls_api.c > > +++ b/net/sched/cls_api.c > > @@ -655,10 +655,8 @@ static void tc_block_indr_cleanup(struct flow_block_cb *block_cb) > > down_write(&block->cb_lock); > > list_del(&block_cb->driver_list); > > list_move(&block_cb->list, &bo.cb_list); > > - up_write(&block->cb_lock); > > - rtnl_lock(); > > tcf_block_unbind(block, &bo); > > - rtnl_unlock(); > > + up_write(&block->cb_lock); > > Hi Leon, > > This fix probably breaks all other drivers besides mlx5 that require > rtnl lock on TC filter update path (called from tp->ops->reoffload()). > I suggest both rtnl lock and cb_lock are required here. You are not taking rtnl lock in other bind/unbind paths, why this is different? Are you taking rtnl lock in layers above? Thanks