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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 21951C49ED7 for ; Mon, 16 Sep 2019 13:48:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD46E214DE for ; Mon, 16 Sep 2019 13:48:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="c/pVpbFg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387746AbfIPNs3 (ORCPT ); Mon, 16 Sep 2019 09:48:29 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:41346 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727806AbfIPNs2 (ORCPT ); Mon, 16 Sep 2019 09:48:28 -0400 Received: by mail-pl1-f194.google.com with SMTP id t10so1309193plr.8 for ; Mon, 16 Sep 2019 06:48:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=ynW3rd5xcj3F3em15sYI7a+15sdwKfWkfP33xIZ/VSw=; b=c/pVpbFgUkOh9ygY6duZQ0tgiVOxrMwQAQQLuxPAhRFXSKHfQc6WURsPSo9FzvNPBt A6I5slw/btQDu0kc3fOaOrHJazyu9vyIOMcwSPmjD21bGtSShanv1CUDt6mwHAvVQg+l RBodth8GJcy81/Q/59r9tAwaqxCEpEBZ4df6u/aRcXRRZE6gv2ctpOVvbduaPw+APMKN 5sbjQRscmwoM5nVjKxxaO861d4AWIcRC7DmObktNTlO0qArhVKMTwO9BgexjgpUBhVhj mLuoAVnQsrnH4Fky9RelMJggLYrgNChZrtVVGBSBjwR4w352hYQtmS/+uFET9/+GplU2 l0sg== 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:in-reply-to :references; bh=ynW3rd5xcj3F3em15sYI7a+15sdwKfWkfP33xIZ/VSw=; b=TodyIgxUxbnJrJSu+iH4BQFVcO/5xeSPBU40/YsQR0qfwtcKAvyCcLejmNijDpBxVP UHcebSE+iHqOe4uRwWmInxFPwRiSowzQ3SqHFZGicEihVirHjAR2oOwAQgpiwAUfNg/L bNF4TzAzXLzy1jO6kxNJ7LCMKcRzX0eGqWumLB3iLXAK8FXl5flTJifO8aqja3bLeA70 plzkmpXfsD8PZdQQBY+6nDT11oYLNXjnlfGUxM9YmUwaNl2kCYyoQa3eq0JYsjzQ7iSQ s9OcawRbXzkHAYoi66CrY91bZcZceAW15mzeYRDXe1Z0DtEZC2/v8hyFPmGNgB2AByKV 2t/A== X-Gm-Message-State: APjAAAW24sIJgeDxhrMD1uqUMfQrCFgugJ5eOonJIfY2iRwwh1qcwwyG WR1z2bViJDTNc0BGIaG7vqs= X-Google-Smtp-Source: APXvYqwfgKOcSLN7HflPU/z1jZrYxpnH+Q/4H1iITJgLeTfazEAEPW023WNZXFnk9bma4kXx9KO6kQ== X-Received: by 2002:a17:902:7c13:: with SMTP id x19mr65153129pll.322.1568641707716; Mon, 16 Sep 2019 06:48:27 -0700 (PDT) Received: from ap-To-be-filled-by-O-E-M.1.1.1.1 ([14.33.120.60]) by smtp.gmail.com with ESMTPSA id z20sm2822266pjn.12.2019.09.16.06.48.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 Sep 2019 06:48:26 -0700 (PDT) From: Taehee Yoo To: davem@davemloft.net, netdev@vger.kernel.org, j.vosburgh@gmail.com, vfalico@gmail.com, andy@greyhouse.net, jiri@resnulli.us, sd@queasysnail.net, roopa@cumulusnetworks.com, saeedm@mellanox.com, manishc@marvell.com, rahulv@marvell.com, kys@microsoft.com, haiyangz@microsoft.com, stephen@networkplumber.org, sashal@kernel.org, hare@suse.de, varun@chelsio.com, ubraun@linux.ibm.com, kgraul@linux.ibm.com, jay.vosburgh@canonical.com Cc: ap420073@gmail.com Subject: [PATCH net v3 02/11] vlan: use dynamic lockdep key instead of subclass Date: Mon, 16 Sep 2019 22:47:53 +0900 Message-Id: <20190916134802.8252-3-ap420073@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190916134802.8252-1-ap420073@gmail.com> References: <20190916134802.8252-1-ap420073@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org All VLAN device has same lockdep key and subclass is initialized with nest_level. But actual nest_level value can be changed when a lower device is attached. And at this moment, the subclass should be updated but it seems to be unsafe. So this patch makes VLAN use dynamic lockdep key instead of the subclass. Test commands: ip link add dummy0 type dummy ip link set dummy0 up ip link add bond0 type bond ip link add vlan_dummy1 link dummy0 type vlan id 1 ip link add vlan_bond1 link bond0 type vlan id 2 ip link set vlan_dummy1 master bond0 ip link set bond0 up ip link set vlan_dummy1 up ip link set vlan_bond1 up Both vlan_dummy1 and vlan_bond1 have the same subclass and it makes unnecessary deadlock warning message. Splat looks like: [ 66.163164] WARNING: possible recursive locking detected [ 66.163858] 5.3.0-rc8+ #179 Not tainted [ 66.165520] -------------------------------------------- [ 66.166110] ip/983 is trying to acquire lock: [ 66.166603] 000000009b85ba3e (&vlan_netdev_addr_lock_key/1){+...}, at: dev_uc_sync_multiple+0xfa/0x1a0 [ 66.194006] [ 66.194006] but task is already holding lock: [ 66.194636] 00000000cc752363 (&vlan_netdev_addr_lock_key/1){+...}, at: dev_set_rx_mode+0x19/0x30 [ 66.205191] [ 66.205191] other info that might help us debug this: [ 66.205903] Possible unsafe locking scenario: [ 66.205903] [ 66.206504] CPU0 [ 66.206781] ---- [ 66.208737] lock(&vlan_netdev_addr_lock_key/1); [ 66.257676] lock(&vlan_netdev_addr_lock_key/1); [ 66.282069] [ 66.282069] *** DEADLOCK *** [ 66.282069] [ 66.283708] May be due to missing lock nesting notation [ 66.283708] [ 66.284588] 4 locks held by ip/983: [ 66.285035] #0: 000000002989e16e (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x466/0x8a0 [ 66.286051] #1: 00000000cc752363 (&vlan_netdev_addr_lock_key/1){+...}, at: dev_set_rx_mode+0x19/0x30 [ 66.287217] #2: 00000000eddac627 (&dev_addr_list_lock_key/3){+...}, at: dev_mc_sync+0xfa/0x1a0 [ 66.288327] #3: 000000001a459ff7 (rcu_read_lock){....}, at: bond_set_rx_mode+0x5/0x3c0 [bonding] [ 66.289453] [ 66.289453] stack backtrace: [ 66.290019] CPU: 1 PID: 983 Comm: ip Not tainted 5.3.0-rc8+ #179 [ 66.290802] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 66.297639] Call Trace: [ 66.298009] dump_stack+0x7c/0xbb [ 66.298447] __lock_acquire+0x26a9/0x3de0 [ 66.298965] ? register_lock_class+0x14d0/0x14d0 [ 66.299547] ? register_lock_class+0x14d0/0x14d0 [ 66.300151] lock_acquire+0x164/0x3b0 [ 66.300621] ? dev_uc_sync_multiple+0xfa/0x1a0 [ 66.301198] _raw_spin_lock_nested+0x2e/0x60 [ 66.301743] ? dev_uc_sync_multiple+0xfa/0x1a0 [ 66.302311] dev_uc_sync_multiple+0xfa/0x1a0 [ 66.307650] bond_set_rx_mode+0x269/0x3c0 [bonding] [ 66.308175] ? bond_init+0x6f0/0x6f0 [bonding] [ 66.308585] dev_mc_sync+0x15a/0x1a0 [ 66.308927] vlan_dev_set_rx_mode+0x37/0x80 [8021q] [ 66.309375] dev_set_rx_mode+0x21/0x30 [ 66.309727] __dev_open+0x202/0x310 [ 66.310100] ? dev_set_rx_mode+0x30/0x30 [ 66.310513] ? mark_held_locks+0xa5/0xe0 [ 66.310934] ? __local_bh_enable_ip+0xe9/0x1b0 [ 66.311387] __dev_change_flags+0x3c3/0x500 [ 66.311839] ? dev_set_allmulti+0x10/0x10 [ 66.312248] ? kmem_cache_alloc_trace+0x12c/0x320 [ 66.312746] dev_change_flags+0x7a/0x160 [ 66.313161] vlan_device_event+0x846/0x20d0 [8021q] [ ... ] Fixes: 0fe1e567d0b4 ("[VLAN]: nested VLAN: fix lockdep's recursive locking warning") Signed-off-by: Taehee Yoo --- v2 -> v3 : - This patch is not changed v1 -> v2 : - This patch is not changed include/linux/if_vlan.h | 3 +++ net/8021q/vlan_dev.c | 28 +++++++++++++++------------- 2 files changed, 18 insertions(+), 13 deletions(-) diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index 244278d5c222..1aed9f613e90 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -183,6 +183,9 @@ struct vlan_dev_priv { struct netpoll *netpoll; #endif unsigned int nest_level; + + struct lock_class_key xmit_lock_key; + struct lock_class_key addr_lock_key; }; static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev) diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c index 93eadf179123..12bc80650087 100644 --- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -494,24 +494,24 @@ static void vlan_dev_set_rx_mode(struct net_device *vlan_dev) * "super class" of normal network devices; split their locks off into a * separate class since they always nest. */ -static struct lock_class_key vlan_netdev_xmit_lock_key; -static struct lock_class_key vlan_netdev_addr_lock_key; - static void vlan_dev_set_lockdep_one(struct net_device *dev, struct netdev_queue *txq, - void *_subclass) + void *_unused) { - lockdep_set_class_and_subclass(&txq->_xmit_lock, - &vlan_netdev_xmit_lock_key, - *(int *)_subclass); + struct vlan_dev_priv *vlan = vlan_dev_priv(dev); + + lockdep_set_class(&txq->_xmit_lock, &vlan->xmit_lock_key); } -static void vlan_dev_set_lockdep_class(struct net_device *dev, int subclass) +static void vlan_dev_set_lockdep_class(struct net_device *dev) { - lockdep_set_class_and_subclass(&dev->addr_list_lock, - &vlan_netdev_addr_lock_key, - subclass); - netdev_for_each_tx_queue(dev, vlan_dev_set_lockdep_one, &subclass); + struct vlan_dev_priv *vlan = vlan_dev_priv(dev); + + lockdep_register_key(&vlan->addr_lock_key); + lockdep_set_class(&dev->addr_list_lock, &vlan->addr_lock_key); + + lockdep_register_key(&vlan->xmit_lock_key); + netdev_for_each_tx_queue(dev, vlan_dev_set_lockdep_one, NULL); } static int vlan_dev_get_lock_subclass(struct net_device *dev) @@ -609,7 +609,7 @@ static int vlan_dev_init(struct net_device *dev) SET_NETDEV_DEVTYPE(dev, &vlan_type); - vlan_dev_set_lockdep_class(dev, vlan_dev_get_lock_subclass(dev)); + vlan_dev_set_lockdep_class(dev); vlan->vlan_pcpu_stats = netdev_alloc_pcpu_stats(struct vlan_pcpu_stats); if (!vlan->vlan_pcpu_stats) @@ -630,6 +630,8 @@ static void vlan_dev_uninit(struct net_device *dev) kfree(pm); } } + lockdep_unregister_key(&vlan->addr_lock_key); + lockdep_unregister_key(&vlan->xmit_lock_key); } static netdev_features_t vlan_dev_fix_features(struct net_device *dev, -- 2.17.1