[ Upstream commit
90b3b339364c76baa2436445401ea9ade040c216 ]
When doing stress test, we get the following trace:
kernel BUG at lib/dynamic_queue_limits.c:26!
Internal error: Oops - BUG: 0 [#1] SMP ARM
Modules linked in: hip04_eth
CPU: 0 PID: 2003 Comm: tDblStackPcap0 Tainted: G O L 4.4.197 #1
Hardware name: Hisilicon A15
task:
c3637668 task.stack:
de3bc000
PC is at dql_completed+0x18/0x154
LR is at hip04_tx_reclaim+0x110/0x174 [hip04_eth]
pc : [<
c041abfc>] lr : [<
bf0003a8>] psr:
800f0313
sp :
de3bdc2c ip :
00000000 fp :
c020fb10
r10:
00000000 r9 :
c39b4224 r8 :
00000001
r7 :
00000046 r6 :
c39b4000 r5 :
0078f392 r4 :
0078f392
r3 :
00000047 r2 :
00000000 r1 :
00000046 r0 :
df5d5c80
Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
Control:
32c5387d Table:
1e189b80 DAC:
55555555
Process tDblStackPcap0 (pid: 2003, stack limit = 0xde3bc190)
Stack: (0xde3bdc2c to 0xde3be000)
[<
c041abfc>] (dql_completed) from [<
bf0003a8>] (hip04_tx_reclaim+0x110/0x174 [hip04_eth])
[<
bf0003a8>] (hip04_tx_reclaim [hip04_eth]) from [<
bf0012c0>] (hip04_rx_poll+0x20/0x388 [hip04_eth])
[<
bf0012c0>] (hip04_rx_poll [hip04_eth]) from [<
c04c8d9c>] (net_rx_action+0x120/0x374)
[<
c04c8d9c>] (net_rx_action) from [<
c021eaf4>] (__do_softirq+0x218/0x318)
[<
c021eaf4>] (__do_softirq) from [<
c021eea0>] (irq_exit+0x88/0xac)
[<
c021eea0>] (irq_exit) from [<
c0240130>] (msa_irq_exit+0x11c/0x1d4)
[<
c0240130>] (msa_irq_exit) from [<
c0267ba8>] (__handle_domain_irq+0x110/0x148)
[<
c0267ba8>] (__handle_domain_irq) from [<
c0201588>] (gic_handle_irq+0xd4/0x118)
[<
c0201588>] (gic_handle_irq) from [<
c0558360>] (__irq_svc+0x40/0x58)
Exception stack(0xde3bdde0 to 0xde3bde28)
dde0:
00000000 00008001 c3637668 00000000 00000000 a00f0213 dd3627a0 c0af6380
de00:
c086d380 a00f0213 c0a22a50 de3bde6c 00000002 de3bde30 c0558138 c055813c
de20:
600f0213 ffffffff
[<
c0558360>] (__irq_svc) from [<
c055813c>] (_raw_spin_unlock_irqrestore+0x44/0x54)
Kernel panic - not syncing: Fatal exception in interrupt
Pre-modification code:
int hip04_mac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
[...]
[1] priv->tx_head = TX_NEXT(tx_head);
[2] count++;
[3] netdev_sent_queue(ndev, skb->len);
[...]
}
An rx interrupt occurs if hip04_mac_start_xmit just executes to the line 2,
tx_head has been updated, but corresponding 'skb->len' has not been
added to dql_queue.
And then
hip04_mac_interrupt->__napi_schedule->hip04_rx_poll->hip04_tx_reclaim
In hip04_tx_reclaim, because tx_head has been updated,
bytes_compl will plus an additional "skb-> len"
which has not been added to dql_queue. And then
trigger the BUG_ON(bytes_compl > num_queued - dql->num_completed).
To solve the problem described above, we put
"netdev_sent_queue(ndev, skb->len);"
before
"priv->tx_head = TX_NEXT(tx_head);"
Fixes:
a41ea46a9a12 ("net: hisilicon: new hip04 ethernet driver")
Signed-off-by: Jiangfeng Xiao <xiaojiangfeng@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>