[PATCH 4/20][BNX2]: Fix race conditions when calling register_netdev().

[PATCH 4/20][BNX2]: Fix race conditions when calling register_netdev().

[Michael Chan]

[BNX2]: Fix race conditions when calling register_netdev().
    
Hot-plug scripts can call bnx2_open() as soon as register_netdev() is
called in bnx2_init_one().  We need to call pci_set_drvdata() and
setup everything before calling register_netdev(). netif_carrier_off()
also needs to be moved to bnx2_open() to avoid race conditions with
the irq.
    
Signed-off-by: Michael Chan <mchan@broadcom.com>

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index dba4088..971607c 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -4350,6 +4350,8 @@ bnx2_open(struct net_device *dev)
 	struct bnx2 *bp = netdev_priv(dev);
 	int rc;
 
+	netif_carrier_off(dev);
+
 	bnx2_set_power_state(bp, PCI_D0);
 	bnx2_disable_int(bp);
 
@@ -6195,6 +6197,18 @@ bnx2_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	dev->poll_controller = poll_bnx2;
 #endif
 
+	pci_set_drvdata(pdev, dev);
+
+	memcpy(dev->dev_addr, bp->mac_addr, 6);
+	memcpy(dev->perm_addr, bp->mac_addr, 6);
+	bp->name = board_info[ent->driver_data].name;
+
+	dev->features |= NETIF_F_IP_CSUM | NETIF_F_SG;
+#ifdef BCM_VLAN
+	dev->features |= NETIF_F_HW_VLAN_TX | NETIF_F_HW_VLAN_RX;
+#endif
+	dev->features |= NETIF_F_TSO | NETIF_F_TSO_ECN;
+
 	if ((rc = register_netdev(dev))) {
 		dev_err(&pdev->dev, "Cannot register net device\n");
 		if (bp->regview)
@@ -6206,11 +6220,6 @@ bnx2_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 		return rc;
 	}
 
-	pci_set_drvdata(pdev, dev);
-
-	memcpy(dev->dev_addr, bp->mac_addr, 6);
-	memcpy(dev->perm_addr, bp->mac_addr, 6);
-	bp->name = board_info[ent->driver_data].name,
 	printk(KERN_INFO "%s: %s (%c%d) PCI%s %s %dMHz found at mem %lx, "
 		"IRQ %d, ",
 		dev->name,
@@ -6228,15 +6237,6 @@ bnx2_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 		printk("%2.2x", dev->dev_addr[i]);
 	printk("\n");
 
-	dev->features |= NETIF_F_SG;
-	dev->features |= NETIF_F_IP_CSUM;
-#ifdef BCM_VLAN
-	dev->features |= NETIF_F_HW_VLAN_TX | NETIF_F_HW_VLAN_RX;
-#endif
-	dev->features |= NETIF_F_TSO | NETIF_F_TSO_ECN;
-
-	netif_carrier_off(bp->dev);
-
 	return 0;
 }
 

Re: [PATCH 4/20][BNX2]: Fix race conditions when calling register_netdev().

[Jeff Garzik]

Michael Chan wrote:
> [BNX2]: Fix race conditions when calling register_netdev().
>     
> Hot-plug scripts can call bnx2_open() as soon as register_netdev() is
> called in bnx2_init_one().  We need to call pci_set_drvdata() and
> setup everything before calling register_netdev(). netif_carrier_off()
> also needs to be moved to bnx2_open() to avoid race conditions with
> the irq.
>     
> Signed-off-by: Michael Chan <mchan@broadcom.com>
> 
> diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
> index dba4088..971607c 100644
> --- a/drivers/net/bnx2.c
> +++ b/drivers/net/bnx2.c
> @@ -4350,6 +4350,8 @@ bnx2_open(struct net_device *dev)
>  	struct bnx2 *bp = netdev_priv(dev);
>  	int rc;
>  
> +	netif_carrier_off(dev);
> +
>  	bnx2_set_power_state(bp, PCI_D0);
>  	bnx2_disable_int(bp);
>  
> @@ -6195,6 +6197,18 @@ bnx2_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
>  	dev->poll_controller = poll_bnx2;
>  #endif
>  
> +	pci_set_drvdata(pdev, dev);
> +
> +	memcpy(dev->dev_addr, bp->mac_addr, 6);
> +	memcpy(dev->perm_addr, bp->mac_addr, 6);
> +	bp->name = board_info[ent->driver_data].name;
> +
> +	dev->features |= NETIF_F_IP_CSUM | NETIF_F_SG;
> +#ifdef BCM_VLAN
> +	dev->features |= NETIF_F_HW_VLAN_TX | NETIF_F_HW_VLAN_RX;
> +#endif
> +	dev->features |= NETIF_F_TSO | NETIF_F_TSO_ECN;
> +
>  	if ((rc = register_netdev(dev))) {
>  		dev_err(&pdev->dev, "Cannot register net device\n");
>  		if (bp->regview)
> @@ -6206,11 +6220,6 @@ bnx2_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
>  		return rc;
>  	}
>  
> -	pci_set_drvdata(pdev, dev);
> -
> -	memcpy(dev->dev_addr, bp->mac_addr, 6);
> -	memcpy(dev->perm_addr, bp->mac_addr, 6);
> -	bp->name = board_info[ent->driver_data].name,

NAK.  Since you move the pci_set_drvdata() call, you must now add a call 
to pci_set_drvdata(pdev, NULL) on error.

ACK, once fixed.

Re: [PATCH 4/20][BNX2]: Fix race conditions when calling register_netdev().

[Michael Chan]

On Wed, 2007-05-02 at 03:07 -0400, Jeff Garzik wrote:
> Michael Chan wrote:
> >  
> > @@ -6195,6 +6197,18 @@ bnx2_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
> >  	dev->poll_controller = poll_bnx2;
> >  #endif
> >  
> > +	pci_set_drvdata(pdev, dev);
> > +
> > +	memcpy(dev->dev_addr, bp->mac_addr, 6);
> > +	memcpy(dev->perm_addr, bp->mac_addr, 6);
> > +	bp->name = board_info[ent->driver_data].name;
> > +
> > +	dev->features |= NETIF_F_IP_CSUM | NETIF_F_SG;
> > +#ifdef BCM_VLAN
> > +	dev->features |= NETIF_F_HW_VLAN_TX | NETIF_F_HW_VLAN_RX;
> > +#endif
> > +	dev->features |= NETIF_F_TSO | NETIF_F_TSO_ECN;
> > +
> >  	if ((rc = register_netdev(dev))) {
> >  		dev_err(&pdev->dev, "Cannot register net device\n");
> >  		if (bp->regview)
> > @@ -6206,11 +6220,6 @@ bnx2_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
> >  		return rc;
> >  	}
> >  
> > -	pci_set_drvdata(pdev, dev);
> > -
> > -	memcpy(dev->dev_addr, bp->mac_addr, 6);
> > -	memcpy(dev->perm_addr, bp->mac_addr, 6);
> > -	bp->name = board_info[ent->driver_data].name,
> 
> NAK.  Since you move the pci_set_drvdata() call, you must now add a call 
> to pci_set_drvdata(pdev, NULL) on error.

It is not obvious in the patch, but it already (unnecessarily) calls
pci_set_drvdata(pdev, NULL) if register_netdev() fails in the driver
today.