From 7d8e76bf9ac3604897f0ce12e8bf09b68c2a2c89 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Tue, 16 Nov 2010 19:42:53 +0000 Subject: [PATCH] net: zero kobject in rx_queue_release 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 Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/net-sysfs.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index a5ff5a89f37..7f902cad10f 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -712,15 +712,21 @@ 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); + } if (atomic_dec_and_test(&first->count)) kfree(first); + else + memset(kobj, 0, sizeof(*kobj)); } static struct kobj_type rx_queue_ktype = { -- 2.20.1