Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754828AbaDPHI4 (ORCPT ); Wed, 16 Apr 2014 03:08:56 -0400 Received: from g4t3427.houston.hp.com ([15.201.208.55]:20721 "EHLO g4t3427.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752573AbaDPHIy (ORCPT ); Wed, 16 Apr 2014 03:08:54 -0400 From: "Li, Zhen-Hua" To: "David S. Miller" , Eric Dumazet , Veaceslav Falico , Nicolas Dichtel , Jiri Pirko , stephen hemminger , Jerry Chu , Sathya Perla , Subbu Seetharaman , Ajit Khaparde , , Cc: "Li, Zhen-Hua" Subject: [PATCH 1/1] net: Add rtnl_lock for netif_device_attach/detach Date: Wed, 16 Apr 2014 15:08:02 +0800 Message-Id: <1397632082-18453-1-git-send-email-zhen-hual@hp.com> X-Mailer: git-send-email 1.7.10.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Li, Zhen-Hua" As netif_running is called in netif_device_attach/detach. There should be rtnl_lock/unlock called, to avoid dev stat change during netif_device_attach and detach being called. I checked NIC some drivers, some of them have netif_device_attach/detach called between rtnl_lock/unlock, while some drivers do not. This patch is tring to find a generic way to fix this for all NIC drivers. Signed-off-by: Li, Zhen-Hua --- net/core/dev.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/net/core/dev.c b/net/core/dev.c index 5b3042e..795bbc5 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2190,10 +2190,19 @@ EXPORT_SYMBOL(__dev_kfree_skb_any); */ void netif_device_detach(struct net_device *dev) { + /** + * As netif_running is called , rtnl_lock and unlock are needed to + * avoid __LINK_STATE_START bit changes during this function call. + */ + int need_unlock; + + need_unlock = rtnl_trylock(); if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) && netif_running(dev)) { netif_tx_stop_all_queues(dev); } + if (need_unlock) + rtnl_unlock(); } EXPORT_SYMBOL(netif_device_detach); @@ -2205,11 +2214,20 @@ EXPORT_SYMBOL(netif_device_detach); */ void netif_device_attach(struct net_device *dev) { + /** + * As netif_running is called , rtnl_lock and unlock are needed to + * avoid __LINK_STATE_START bit changes during this function call. + */ + int need_unlock; + + need_unlock = rtnl_trylock(); if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) && netif_running(dev)) { netif_tx_wake_all_queues(dev); __netdev_watchdog_up(dev); } + if (need_unlock) + rtnl_unlock(); } EXPORT_SYMBOL(netif_device_attach); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/