From 9f4de71d9e186733dea7c9f9500148bab8982edb Mon Sep 17 00:00:00 2001
From: John Fastabend <john.r.fastabend@intel.com>
Date: Tue, 16 Nov 2010 06:31:39 +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:
[<ffffffff8121c940>] kobject_init+0x3a/0x83
[<ffffffff8121cf77>] kobject_init_and_add+0x23/0x57
[<ffffffff8107b800>] ? mark_lock+0x21/0x267
[<ffffffff813c6d11>] net_rx_queue_update_kobjects+0x63/0xc6
[<ffffffff813b5e0e>] netif_set_real_num_rx_queues+0x5f/0x78
[<ffffffffa0261d49>] ixgbe_set_num_queues+0x1c6/0x1ca [ixgbe]
[<ffffffffa0262509>] ixgbe_init_interrupt_scheme+0x1e/0x79c [ixgbe]
[<ffffffffa0274596>] ixgbe_dcbnl_set_state+0x167/0x189 [ixgbe]
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/core/net-sysfs.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 3ba526b56fe39..7abeb7ceaa4c8 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);
}
--
2.39.5