From patchwork Fri Sep 28 16:16:31 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Jones X-Patchwork-Id: 976383 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=codemonkey.org.uk Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 42MGyV0wGwz9s5c for ; Sat, 29 Sep 2018 02:16:34 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729438AbeI1WlB (ORCPT ); Fri, 28 Sep 2018 18:41:01 -0400 Received: from scorn.kernelslacker.org ([45.56.101.199]:45888 "EHLO scorn.kernelslacker.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729025AbeI1WlB (ORCPT ); Fri, 28 Sep 2018 18:41:01 -0400 Received: from [2601:196:4600:5b90:ae9e:17ff:feb7:72ca] (helo=wopr.kernelslacker.org) by scorn.kernelslacker.org with esmtp (Exim 4.89) (envelope-from ) id 1g5vRQ-0004Ix-6X for netdev@vger.kernel.org; Fri, 28 Sep 2018 12:16:32 -0400 Received: by wopr.kernelslacker.org (Postfix, from userid 1026) id D7D3E560BDA; Fri, 28 Sep 2018 12:16:31 -0400 (EDT) Date: Fri, 28 Sep 2018 12:16:31 -0400 From: Dave Jones To: netdev@vger.kernel.org Subject: bond: take rcu lock in bond_poll_controller Message-ID: <20180928161631.3pab3m2k6zvoemnz@codemonkey.org.uk> References: <20180924192317.wghbs34ld7klqpi6@codemonkey.org.uk> <20180926.201541.2129538853102457012.davem@davemloft.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20180926.201541.2129538853102457012.davem@davemloft.net> User-Agent: NeoMutt/20170113 (1.7.2) X-Spam-Note: SpamAssassin invocation failed Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Callers of bond_for_each_slave_rcu are expected to hold the rcu lock, otherwise a trace like below is shown WARNING: CPU: 2 PID: 179 at net/core/dev.c:6567 netdev_lower_get_next_private_rcu+0x34/0x40 CPU: 2 PID: 179 Comm: kworker/u16:15 Not tainted 4.19.0-rc5-backup+ #1 Workqueue: bond0 bond_mii_monitor RIP: 0010:netdev_lower_get_next_private_rcu+0x34/0x40 Code: 48 89 fb e8 fe 29 63 ff 85 c0 74 1e 48 8b 45 00 48 81 c3 c0 00 00 00 48 8b 00 48 39 d8 74 0f 48 89 45 00 48 8b 40 f8 5b 5d c3 <0f> 0b eb de 31 c0 eb f5 0f 1f 40 00 0f 1f 44 00 00 48 8> RSP: 0018:ffffc9000087fa68 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff880429614560 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 00000000ffffffff RDI: ffffffffa184ada0 RBP: ffffc9000087fa80 R08: 0000000000000001 R09: 0000000000000000 R10: ffffc9000087f9f0 R11: ffff880429798040 R12: ffff8804289d5980 R13: ffffffffa1511f60 R14: 00000000000000c8 R15: 00000000ffffffff FS: 0000000000000000(0000) GS:ffff88042f880000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4b78fce180 CR3: 000000018180f006 CR4: 00000000001606e0 Call Trace: bond_poll_controller+0x52/0x170 netpoll_poll_dev+0x79/0x290 netpoll_send_skb_on_dev+0x158/0x2c0 netpoll_send_udp+0x2d5/0x430 write_ext_msg+0x1e0/0x210 console_unlock+0x3c4/0x630 vprintk_emit+0xfa/0x2f0 printk+0x52/0x6e ? __netdev_printk+0x12b/0x220 netdev_info+0x64/0x80 ? bond_3ad_set_carrier+0xe9/0x180 bond_select_active_slave+0x1fc/0x310 bond_mii_monitor+0x709/0x9b0 process_one_work+0x221/0x5e0 worker_thread+0x4f/0x3b0 kthread+0x100/0x140 ? process_one_work+0x5e0/0x5e0 ? kthread_delayed_work_timer_fn+0x90/0x90 ret_from_fork+0x24/0x30 Signed-off-by: Dave Jones diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index c05c01a00755..77a3607a7099 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -977,6 +977,7 @@ static void bond_poll_controller(struct net_device *bond_dev) if (bond_3ad_get_active_agg_info(bond, &ad_info)) return; + rcu_read_lock(); bond_for_each_slave_rcu(bond, slave, iter) { if (!bond_slave_is_up(slave)) continue; @@ -992,6 +993,7 @@ static void bond_poll_controller(struct net_device *bond_dev) netpoll_poll_dev(slave->dev); } + rcu_read_unlock(); } static void bond_netpoll_cleanup(struct net_device *bond_dev)