From a8f492c6ac6072d6c5bce4b2f13dc44612991051 Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Sat, 16 May 2009 01:21:58 +0000 Subject: [PATCH] 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: [] meth_tx+0x48/0x43c and this task is already holding: (_xmit_ETHER#2){+.-...}, at: [] __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: [] __lock_acquire+0x784/0x1a14 [] lock_acquire+0xf8/0x150 [] _spin_lock+0x30/0x44 [] dev_watchdog+0x70/0x398 [] run_timer_softirq+0x1a8/0x248 [] __do_softirq+0xec/0x208 [] do_softirq+0x60/0xe4 [] irq_exit+0x54/0x9c [] ret_from_irq+0x0/0x4 [] r4k_wait+0x20/0x40 [] cpu_idle+0x30/0x60 [] start_kernel+0x3ec/0x404 to a SOFTIRQ-irq-unsafe lock: (&priv->meth_lock){+.+...} ... which became SOFTIRQ-irq-unsafe at: ... [] __lock_acquire+0x824/0x1a14 [] lock_acquire+0xf8/0x150 [] _spin_lock+0x30/0x44 [] meth_reset+0x118/0x2d8 [] meth_open+0x28/0x140 [] dev_open+0xe0/0x18c [] dev_change_flags+0xd8/0x1d4 [] ip_auto_config+0x1d4/0xf28 [] do_one_initcall+0x58/0x170 [] kernel_init+0x98/0x104 [] kernel_thread_helper+0x10/0x18 other info that might help us debug this: 2 locks held by swapper/1: #0: (rcu_read_lock){.+.+..}, at: [] dev_queue_xmit+0x1e0/0x4b0 #1: (_xmit_ETHER#2){+.-...}, at: [] __qdisc_run+0x118/0x30c the SOFTIRQ-irq-safe lock's dependencies: -> (_xmit_ETHER#2){+.-...} ops: 0 { HARDIRQ-ON-W at: [] __lock_acquire+0x7fc/0x1a14 [] lock_acquire+0xf8/0x150 [] _spin_lock+0x30/0x44 [] dev_watchdog+0x70/0x398 [] run_timer_softirq+0x1a8/0x248 [] __do_softirq+0xec/0x208 [] do_softirq+0x60/0xe4 [] irq_exit+0x54/0x9c [] ret_from_irq+0x0/0x4 [] r4k_wait+0x20/0x40 [] cpu_idle+0x30/0x60 [] start_kernel+0x3ec/0x404 IN-SOFTIRQ-W at: [] __lock_acquire+0x784/0x1a14 [] lock_acquire+0xf8/0x150 [] _spin_lock+0x30/0x44 [] dev_watchdog+0x70/0x398 [] run_timer_softirq+0x1a8/0x248 [] __do_softirq+0xec/0x208 [] do_softirq+0x60/0xe4 [] irq_exit+0x54/0x9c [] ret_from_irq+0x0/0x4 [] r4k_wait+0x20/0x40 [] cpu_idle+0x30/0x60 [] start_kernel+0x3ec/0x404 INITIAL USE at: [] __lock_acquire+0x89c/0x1a14 [] lock_acquire+0xf8/0x150 [] _spin_lock+0x30/0x44 [] dev_watchdog+0x70/0x398 [] run_timer_softirq+0x1a8/0x248 [] __do_softirq+0xec/0x208 [] do_softirq+0x60/0xe4 [] irq_exit+0x54/0x9c [] ret_from_irq+0x0/0x4 [] r4k_wait+0x20/0x40 [] cpu_idle+0x30/0x60 [] start_kernel+0x3ec/0x404 } ... key at: [] netdev_xmit_lock_key+0x8/0x1c8 the SOFTIRQ-irq-unsafe lock's dependencies: -> (&priv->meth_lock){+.+...} ops: 0 { HARDIRQ-ON-W at: [] __lock_acquire+0x7fc/0x1a14 [] lock_acquire+0xf8/0x150 [] _spin_lock+0x30/0x44 [] meth_reset+0x118/0x2d8 [] meth_open+0x28/0x140 [] dev_open+0xe0/0x18c [] dev_change_flags+0xd8/0x1d4 [] ip_auto_config+0x1d4/0xf28 [] do_one_initcall+0x58/0x170 [] kernel_init+0x98/0x104 [] kernel_thread_helper+0x10/0x18 SOFTIRQ-ON-W at: [] __lock_acquire+0x824/0x1a14 [] lock_acquire+0xf8/0x150 [] _spin_lock+0x30/0x44 [] meth_reset+0x118/0x2d8 [] meth_open+0x28/0x140 [] dev_open+0xe0/0x18c [] dev_change_flags+0xd8/0x1d4 [] ip_auto_config+0x1d4/0xf28 [] do_one_initcall+0x58/0x170 [] kernel_init+0x98/0x104 [] kernel_thread_helper+0x10/0x18 INITIAL USE at: [] __lock_acquire+0x89c/0x1a14 [] lock_acquire+0xf8/0x150 [] _spin_lock+0x30/0x44 [] meth_reset+0x118/0x2d8 [] meth_open+0x28/0x140 [] dev_open+0xe0/0x18c [] dev_change_flags+0xd8/0x1d4 [] ip_auto_config+0x1d4/0xf28 [] do_one_initcall+0x58/0x170 [] kernel_init+0x98/0x104 [] kernel_thread_helper+0x10/0x18 } ... key at: [] __key.32424+0x0/0x8 stack backtrace: Call Trace: [] dump_stack+0x8/0x34 [] check_usage+0x470/0x4a0 [] check_irq_usage+0x90/0x130 [] __lock_acquire+0x12a4/0x1a14 [] lock_acquire+0xf8/0x150 [] _spin_lock_irqsave+0x60/0x84 [] meth_tx+0x48/0x43c [] __qdisc_run+0x150/0x30c [] dev_queue_xmit+0x334/0x4b0 [] ip_auto_config+0x8d0/0xf28 [] do_one_initcall+0x58/0x170 [] kernel_init+0x98/0x104 [] 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 Tested-by: Andrew Randrianasulu Signed-off-by: David S. Miller --- drivers/net/meth.c | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) diff --git a/drivers/net/meth.c b/drivers/net/meth.c index aa08987..dbd3436 100644 --- a/drivers/net/meth.c +++ b/drivers/net/meth.c @@ -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; } -- 2.7.4