NET: Meth: Fix unsafe mix of irq and non-irq spinlocks.
Subsystems (3)
PATCH 1/1 NET: Meth: Fix unsafe mix of irq and non-irq spinlocks.
Mixing of normal and irq spinlocks results in the following lockdep messages on bootup on IP32:
[...]
Sending DHCP requests .
======================================================
[ INFO: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected ] 2.6.30-rc5-00164-g41baeef #30
------------------------------------------------------
swapper/1 [HC0[0]:SC0[1]:HE0:SE0] is trying to acquire:
(&priv->meth_lock){+.+...}, at: [<ffffffff8026388c>] meth_tx+0x48/0x43c
and this task is already holding:
(_xmit_ETHER#2){+.-...}, at: [<ffffffff802d3a00>] __qdisc_run+0x118/0x30c
which would create a new lock dependency:
(_xmit_ETHER#2){+.-...} -> (&priv->meth_lock){+.+...}
but this new dependency connects a SOFTIRQ-irq-safe lock:
(_xmit_ETHER#2){+.-...}
... which became SOFTIRQ-irq-safe at:
[<ffffffff80061458>] __lock_acquire+0x784/0x1a14 [<ffffffff800627e0>] lock_acquire+0xf8/0x150 [<ffffffff800128d0>] _spin_lock+0x30/0x44 [<ffffffff802d2b88>] dev_watchdog+0x70/0x398 [<ffffffff800433b8>] run_timer_softirq+0x1a8/0x248 [<ffffffff8003da5c>] __do_softirq+0xec/0x208 [<ffffffff8003dbd8>] do_softirq+0x60/0xe4 [<ffffffff8003dda0>] irq_exit+0x54/0x9c [<ffffffff80004420>] ret_from_irq+0x0/0x4 [<ffffffff80004720>] r4k_wait+0x20/0x40 [<ffffffff80015418>] cpu_idle+0x30/0x60 [<ffffffff804cd934>] start_kernel+0x3ec/0x404
to a SOFTIRQ-irq-unsafe lock:
(&priv->meth_lock){+.+...}
... which became SOFTIRQ-irq-unsafe at:
... [<ffffffff800614f8>] __lock_acquire+0x824/0x1a14
[<ffffffff800627e0>] lock_acquire+0xf8/0x150 [<ffffffff800128d0>] _spin_lock+0x30/0x44 [<ffffffff80263f20>] meth_reset+0x118/0x2d8 [<ffffffff8026424c>] meth_open+0x28/0x140 [<ffffffff802c1ae8>] dev_open+0xe0/0x18c [<ffffffff802c1268>] dev_change_flags+0xd8/0x1d4 [<ffffffff804e7770>] ip_auto_config+0x1d4/0xf28 [<ffffffff80012e68>] do_one_initcall+0x58/0x170 [<ffffffff804cd190>] kernel_init+0x98/0x104 [<ffffffff8001520c>] kernel_thread_helper+0x10/0x18
other info that might help us debug this:
2 locks held by swapper/1:
#0: (rcu_read_lock){.+.+..}, at: [<ffffffff802c0954>] dev_queue_xmit+0x1e0/0x4b0 #1: (_xmit_ETHER#2){+.-...}, at: [<ffffffff802d3a00>] __qdisc_run+0x118/0x30c
the SOFTIRQ-irq-safe lock's dependencies:
-> (_xmit_ETHER#2){+.-...} ops: 0 {
HARDIRQ-ON-W at:
[<ffffffff800614d0>] __lock_acquire+0x7fc/0x1a14
[<ffffffff800627e0>] lock_acquire+0xf8/0x150
[<ffffffff800128d0>] _spin_lock+0x30/0x44
[<ffffffff802d2b88>] dev_watchdog+0x70/0x398
[<ffffffff800433b8>] run_timer_softirq+0x1a8/0x248
[<ffffffff8003da5c>] __do_softirq+0xec/0x208
[<ffffffff8003dbd8>] do_softirq+0x60/0xe4
[<ffffffff8003dda0>] irq_exit+0x54/0x9c
[<ffffffff80004420>] ret_from_irq+0x0/0x4
[<ffffffff80004720>] r4k_wait+0x20/0x40
[<ffffffff80015418>] cpu_idle+0x30/0x60
[<ffffffff804cd934>] start_kernel+0x3ec/0x404
IN-SOFTIRQ-W at:
[<ffffffff80061458>] __lock_acquire+0x784/0x1a14
[<ffffffff800627e0>] lock_acquire+0xf8/0x150
[<ffffffff800128d0>] _spin_lock+0x30/0x44
[<ffffffff802d2b88>] dev_watchdog+0x70/0x398
[<ffffffff800433b8>] run_timer_softirq+0x1a8/0x248
[<ffffffff8003da5c>] __do_softirq+0xec/0x208
[<ffffffff8003dbd8>] do_softirq+0x60/0xe4
[<ffffffff8003dda0>] irq_exit+0x54/0x9c
[<ffffffff80004420>] ret_from_irq+0x0/0x4
[<ffffffff80004720>] r4k_wait+0x20/0x40
[<ffffffff80015418>] cpu_idle+0x30/0x60
[<ffffffff804cd934>] start_kernel+0x3ec/0x404
INITIAL USE at:
[<ffffffff80061570>] __lock_acquire+0x89c/0x1a14
[<ffffffff800627e0>] lock_acquire+0xf8/0x150
[<ffffffff800128d0>] _spin_lock+0x30/0x44
[<ffffffff802d2b88>] dev_watchdog+0x70/0x398
[<ffffffff800433b8>] run_timer_softirq+0x1a8/0x248
[<ffffffff8003da5c>] __do_softirq+0xec/0x208
[<ffffffff8003dbd8>] do_softirq+0x60/0xe4
[<ffffffff8003dda0>] irq_exit+0x54/0x9c
[<ffffffff80004420>] ret_from_irq+0x0/0x4
[<ffffffff80004720>] r4k_wait+0x20/0x40
[<ffffffff80015418>] cpu_idle+0x30/0x60
[<ffffffff804cd934>] start_kernel+0x3ec/0x404
}
... key at: [<ffffffff80cf93f0>] netdev_xmit_lock_key+0x8/0x1c8the SOFTIRQ-irq-unsafe lock's dependencies:
-> (&priv->meth_lock){+.+...} ops: 0 {
HARDIRQ-ON-W at:
[<ffffffff800614d0>] __lock_acquire+0x7fc/0x1a14
[<ffffffff800627e0>] lock_acquire+0xf8/0x150
[<ffffffff800128d0>] _spin_lock+0x30/0x44
[<ffffffff80263f20>] meth_reset+0x118/0x2d8
[<ffffffff8026424c>] meth_open+0x28/0x140
[<ffffffff802c1ae8>] dev_open+0xe0/0x18c
[<ffffffff802c1268>] dev_change_flags+0xd8/0x1d4
[<ffffffff804e7770>] ip_auto_config+0x1d4/0xf28
[<ffffffff80012e68>] do_one_initcall+0x58/0x170
[<ffffffff804cd190>] kernel_init+0x98/0x104
[<ffffffff8001520c>] kernel_thread_helper+0x10/0x18
SOFTIRQ-ON-W at:
[<ffffffff800614f8>] __lock_acquire+0x824/0x1a14
[<ffffffff800627e0>] lock_acquire+0xf8/0x150
[<ffffffff800128d0>] _spin_lock+0x30/0x44
[<ffffffff80263f20>] meth_reset+0x118/0x2d8
[<ffffffff8026424c>] meth_open+0x28/0x140
[<ffffffff802c1ae8>] dev_open+0xe0/0x18c
[<ffffffff802c1268>] dev_change_flags+0xd8/0x1d4
[<ffffffff804e7770>] ip_auto_config+0x1d4/0xf28
[<ffffffff80012e68>] do_one_initcall+0x58/0x170
[<ffffffff804cd190>] kernel_init+0x98/0x104
[<ffffffff8001520c>] kernel_thread_helper+0x10/0x18
INITIAL USE at:
[<ffffffff80061570>] __lock_acquire+0x89c/0x1a14
[<ffffffff800627e0>] lock_acquire+0xf8/0x150
[<ffffffff800128d0>] _spin_lock+0x30/0x44
[<ffffffff80263f20>] meth_reset+0x118/0x2d8
[<ffffffff8026424c>] meth_open+0x28/0x140
[<ffffffff802c1ae8>] dev_open+0xe0/0x18c
[<ffffffff802c1268>] dev_change_flags+0xd8/0x1d4
[<ffffffff804e7770>] ip_auto_config+0x1d4/0xf28
[<ffffffff80012e68>] do_one_initcall+0x58/0x170
[<ffffffff804cd190>] kernel_init+0x98/0x104
[<ffffffff8001520c>] kernel_thread_helper+0x10/0x18
}
... key at: [<ffffffff80cf6ce8>] __key.32424+0x0/0x8
stack backtrace:
Call Trace:
[<ffffffff8000ed0c>] dump_stack+0x8/0x34
[<ffffffff80060b74>] check_usage+0x470/0x4a0
[<ffffffff80060c34>] check_irq_usage+0x90/0x130
[<ffffffff80061f78>] __lock_acquire+0x12a4/0x1a14
[<ffffffff800627e0>] lock_acquire+0xf8/0x150
[<ffffffff80012a0c>] _spin_lock_irqsave+0x60/0x84
[<ffffffff8026388c>] meth_tx+0x48/0x43c
[<ffffffff802d3a38>] __qdisc_run+0x150/0x30c
[<ffffffff802c0aa8>] dev_queue_xmit+0x334/0x4b0
[<ffffffff804e7e6c>] ip_auto_config+0x8d0/0xf28
[<ffffffff80012e68>] do_one_initcall+0x58/0x170
[<ffffffff804cd190>] kernel_init+0x98/0x104
[<ffffffff8001520c>] kernel_thread_helper+0x10/0x18..... timed out!
IP-Config: Retrying forever (NFS root)...
Sending DHCP requests ., OK
[...]
Fixed by converting all locks to irq locks.
Signed-off-by Ralf Baechle <[email protected]>
Tested-by Andrew Randrianasulu <[email protected]>
---
drivers/net/meth.c | 27 ++++++++++++++------------- 1 files changed, 14 insertions(+), 13 deletions(-)
drivers/net/meth.c +14 -13
@@ -127,11 +127,11 @@ static unsigned long mdio_read(struct meth_private *priv, unsigned long phyreg)static int mdio_probe (struct meth_private *priv) {int i; -unsigned long p2, p3; +unsigned long p2, p3, flags;/* check if phy is detected already */ if (priv->phy_addr>=0 &&priv->phy_addr<32 )return 0 ; -spin_lock (&priv->meth_lock); +spin_lock_irqsave (&priv->meth_lock, flags);for (i=0 ;i<32 ;++i){ priv->phy_addr=i; p2=mdio_read (priv,2 );
@@ -157,7 +157,7 @@ static int mdio_probe(struct meth_private *priv)break ; } } -spin_unlock (&priv->meth_lock); +spin_unlock_irqrestore (&priv->meth_lock, flags);if (priv->phy_addr<32 ) {return 0 ; }
@@ -373,14 +373,14 @@ static int meth_release(struct net_device *dev)static void meth_rx (struct net_device * dev,unsigned long int_status) {struct sk_buff *skb; -unsigned long status; +unsigned long status, flags;struct meth_private *priv =netdev_priv (dev);unsigned long fifo_rptr = (int_status &METH_INT_RX_RPTR_MASK ) >>8 ; -spin_lock (&priv->meth_lock); +spin_lock_irqsave (&priv->meth_lock, flags); priv->dma_ctrl &= ~METH_DMA_RX_INT_EN ; mace->eth.dma_ctrl = priv->dma_ctrl; -spin_unlock (&priv->meth_lock); +spin_unlock_irqrestore (&priv->meth_lock, flags);if (int_status &METH_INT_RX_UNDERFLOW ) { fifo_rptr = (fifo_rptr -1 ) &0x0f ;
@@ -452,12 +452,12 @@ static void meth_rx(struct net_device* dev, unsigned long int_status) mace->eth.rx_fifo = priv->rx_ring_dmas[priv->rx_write];ADVANCE_RX_PTR (priv->rx_write); } -spin_lock (&priv->meth_lock); +spin_lock_irqsave (&priv->meth_lock, flags);/* In case there was underflow, and Rx DMA was disabled */ priv->dma_ctrl |=METH_DMA_RX_INT_EN |METH_DMA_RX_EN ; mace->eth.dma_ctrl = priv->dma_ctrl; mace->eth.int_stat =METH_INT_RX_THRESHOLD ; -spin_unlock (&priv->meth_lock); +spin_unlock_irqrestore (&priv->meth_lock, flags); }static int meth_tx_full (struct net_device *dev)
@@ -470,11 +470,11 @@ static int meth_tx_full(struct net_device *dev)static void meth_tx_cleanup (struct net_device * dev,unsigned long int_status) {struct meth_private *priv =netdev_priv (dev); -unsigned long status; +unsigned long status, flags;struct sk_buff *skb;unsigned long rptr = (int_status&TX_INFO_RPTR ) >>16 ; -spin_lock (&priv->meth_lock); +spin_lock_irqsave (&priv->meth_lock, flags);/* Stop DMA notification */ priv->dma_ctrl &= ~(METH_DMA_TX_INT_EN );
@@ -527,12 +527,13 @@ static void meth_tx_cleanup(struct net_device* dev, unsigned long int_status) } mace->eth.int_stat =METH_INT_TX_EMPTY |METH_INT_TX_PKT ; -spin_unlock (&priv->meth_lock); +spin_unlock_irqrestore (&priv->meth_lock, flags); }static void meth_error (struct net_device * dev,unsigned status) {struct meth_private *priv =netdev_priv (dev); +unsigned long flags;printk (KERN_WARNING "meth: error status: 0x%08x\n" ,status);/* check for errors too... */
@@ -547,7 +548,7 @@ static void meth_error(struct net_device* dev, unsigned status)printk (KERN_WARNING "meth: Rx overflow\n" );if (status & (METH_INT_RX_UNDERFLOW )) {printk (KERN_WARNING "meth: Rx underflow\n" ); -spin_lock (&priv->meth_lock); +spin_lock_irqsave (&priv->meth_lock, flags); mace->eth.int_stat =METH_INT_RX_UNDERFLOW ;/* more underflow interrupts will be delivered, * effectively throwing us into an infinite loop.
@@ -555,7 +556,7 @@ static void meth_error(struct net_device* dev, unsigned status) priv->dma_ctrl &= ~METH_DMA_RX_EN ; mace->eth.dma_ctrl = priv->dma_ctrl;DPRINTK ("Disabled meth Rx DMA temporarily\n" ); -spin_unlock (&priv->meth_lock); +spin_unlock_irqrestore (&priv->meth_lock, flags); } mace->eth.int_stat =METH_INT_ERROR ; }
----- End forwarded message -----
Ralf
From: Ralf Baechle <[email protected]>
Date: Sat, 16 May 2009 12:21:58 +0100
Quoted 2 lines
Mixing of normal and irq spinlocks results in the following lockdep messages on bootup on IP32:
...
Quoted 4 lines
Fixed by converting all locks to irq locks.
Signed-off-by Ralf Baechle <[email protected]>Tested-by Andrew Randrianasulu <[email protected]>
Applied, thanks!