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| author | David Howells <dhowells@redhat.com> | 2010-04-20 00:25:58 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-04-21 01:09:44 -0700 |
| commit | 05d17608a69b3ae653ea5c9857283bef3439c733 (patch) | |
| tree | 89f847bb0a1107f621387c64f332b2a25e8829b5 /net | |
| parent | e04997b13a2c2fc93af970fe95fd29a74db113e8 (diff) | |
| download | linux-stable-05d17608a69b3ae653ea5c9857283bef3439c733.tar.gz linux-stable-05d17608a69b3ae653ea5c9857283bef3439c733.tar.bz2 linux-stable-05d17608a69b3ae653ea5c9857283bef3439c733.zip | |
net: Fix an RCU warning in dev_pick_tx()
Fix the following RCU warning in dev_pick_tx():
===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
net/core/dev.c:1993 invoked rcu_dereference_check() without protection!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 0
2 locks held by swapper/0:
#0: (&idev->mc_ifc_timer){+.-...}, at: [<ffffffff81039e65>] run_timer_softirq+0x17b/0x278
#1: (rcu_read_lock_bh){.+....}, at: [<ffffffff812ea3eb>] dev_queue_xmit+0x14e/0x4dc
stack backtrace:
Pid: 0, comm: swapper Not tainted 2.6.34-rc5-cachefs #4
Call Trace:
<IRQ> [<ffffffff810516c4>] lockdep_rcu_dereference+0xaa/0xb2
[<ffffffff812ea4f6>] dev_queue_xmit+0x259/0x4dc
[<ffffffff812ea3eb>] ? dev_queue_xmit+0x14e/0x4dc
[<ffffffff81052324>] ? trace_hardirqs_on+0xd/0xf
[<ffffffff81035362>] ? local_bh_enable_ip+0xbc/0xc1
[<ffffffff812f0954>] neigh_resolve_output+0x24b/0x27c
[<ffffffff8134f673>] ip6_output_finish+0x7c/0xb4
[<ffffffff81350c34>] ip6_output2+0x256/0x261
[<ffffffff81052324>] ? trace_hardirqs_on+0xd/0xf
[<ffffffff813517fb>] ip6_output+0xbbc/0xbcb
[<ffffffff8135bc5d>] ? fib6_force_start_gc+0x2b/0x2d
[<ffffffff81368acb>] mld_sendpack+0x273/0x39d
[<ffffffff81368858>] ? mld_sendpack+0x0/0x39d
[<ffffffff81052099>] ? mark_held_locks+0x52/0x70
[<ffffffff813692fc>] mld_ifc_timer_expire+0x24f/0x288
[<ffffffff81039ed6>] run_timer_softirq+0x1ec/0x278
[<ffffffff81039e65>] ? run_timer_softirq+0x17b/0x278
[<ffffffff813690ad>] ? mld_ifc_timer_expire+0x0/0x288
[<ffffffff81035531>] ? __do_softirq+0x69/0x140
[<ffffffff8103556a>] __do_softirq+0xa2/0x140
[<ffffffff81002e0c>] call_softirq+0x1c/0x28
[<ffffffff81004b54>] do_softirq+0x38/0x80
[<ffffffff81034f06>] irq_exit+0x45/0x47
[<ffffffff810177c3>] smp_apic_timer_interrupt+0x88/0x96
[<ffffffff810028d3>] apic_timer_interrupt+0x13/0x20
<EOI> [<ffffffff810488dd>] ? __atomic_notifier_call_chain+0x0/0x86
[<ffffffff810096bf>] ? mwait_idle+0x6e/0x78
[<ffffffff810096b6>] ? mwait_idle+0x65/0x78
[<ffffffff810011cb>] cpu_idle+0x4d/0x83
[<ffffffff81380b05>] rest_init+0xb9/0xc0
[<ffffffff81380a4c>] ? rest_init+0x0/0xc0
[<ffffffff8168dcf0>] start_kernel+0x392/0x39d
[<ffffffff8168d2a3>] x86_64_start_reservations+0xb3/0xb7
[<ffffffff8168d38b>] x86_64_start_kernel+0xe4/0xeb
An rcu_dereference() should be an rcu_dereference_bh().
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/dev.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 92584bfef09b..f769098774b7 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1990,7 +1990,7 @@ static struct netdev_queue *dev_pick_tx(struct net_device *dev, queue_index = skb_tx_hash(dev, skb); if (sk) { - struct dst_entry *dst = rcu_dereference(sk->sk_dst_cache); + struct dst_entry *dst = rcu_dereference_bh(sk->sk_dst_cache); if (dst && skb_dst(skb) == dst) sk_tx_queue_set(sk, queue_index); |