From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: [net-next-2.6 PATCH v2] net: zero kobject in rx_queue_release Date: Tue, 16 Nov 2010 08:31:39 -0800 Message-ID: <20101116163139.2084.20075.stgit@jf-dev1-dcblab> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: john.r.fastabend@intel.com, netdev@vger.kernel.org, eric.dumazet@gmail.com, therbert@google.com To: davem@davemloft.net Return-path: Received: from mga11.intel.com ([192.55.52.93]:5380 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753064Ab0KPQeQ (ORCPT ); Tue, 16 Nov 2010 11:34:16 -0500 Sender: netdev-owner@vger.kernel.org List-ID: netif_set_real_num_rx_queues() can decrement and increment the number of rx queues. For example ixgbe does this as features and offloads are toggled. Presumably this could also happen across down/up on most devices if the available resources changed (cpu offlined). The kobject needs to be zero'd in this case so that the state is not preserved across kobject_put()/kobject_init_and_add(). This resolves the following error report. ixgbe 0000:03:00.0: eth2: NIC Link is Up 10 Gbps, Flow Control: RX/TX kobject (ffff880324b83210): tried to init an initialized object, something is seriously wrong. Pid: 1972, comm: lldpad Not tainted 2.6.37-rc18021qaz+ #169 Call Trace: [] kobject_init+0x3a/0x83 [] kobject_init_and_add+0x23/0x57 [] ? mark_lock+0x21/0x267 [] net_rx_queue_update_kobjects+0x63/0xc6 [] netif_set_real_num_rx_queues+0x5f/0x78 [] ixgbe_set_num_queues+0x1c6/0x1ca [ixgbe] [] ixgbe_init_interrupt_scheme+0x1e/0x79c [ixgbe] [] ixgbe_dcbnl_set_state+0x167/0x189 [ixgbe] Signed-off-by: John Fastabend --- net/core/net-sysfs.c | 9 +++++++-- 1 files changed, 7 insertions(+), 2 deletions(-) diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 3ba526b..7abeb7c 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -711,13 +711,18 @@ static void rx_queue_release(struct kobject *kobj) map = rcu_dereference_raw(queue->rps_map); - if (map) + if (map) { + RCU_INIT_POINTER(queue->rps_map, NULL); call_rcu(&map->rcu, rps_map_release); + } flow_table = rcu_dereference_raw(queue->rps_flow_table); - if (flow_table) + if (flow_table) { + RCU_INIT_POINTER(queue->rps_flow_table, NULL); call_rcu(&flow_table->rcu, rps_dev_flow_table_release); + } + memset(kobj, 0, sizeof(*kobj)); dev_put(queue->dev); }