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authorJeff Dike <jdike@addtoit.com>2007-05-06 14:51:04 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-07 12:13:00 -0700
commitf34d9d2dcb7f17b64124841345b23adc0843e7a5 (patch)
tree0bb200273bcc37da8dd32945ae25c213c9efe2c2 /arch/um/drivers/net_kern.c
parentb16895b63c504698b0c3ab26ca3c41a4fa162a42 (diff)
uml: network interface hotplug error handling
This fixes a number of problems associated with network interface hotplug. The userspace initialization function can fail in some cases, but the failure was never passed back to eth_configure, which proceeded with the configuration. This results in a zombie device that is present, but can't work. This is fixed by allowing the initialization routines to return an error, which is checked, and the configuration aborted on failure. eth_configure failed to check for many failures. Even when it did check, it didn't undo whatever initializations has already happened, so a present, but partially initialized and non-working device could result. It now checks everything that can fail, and bails out, undoing whatever had been done. The return value of eth_configure was always ignored, so it is now just void. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/um/drivers/net_kern.c')
-rw-r--r--arch/um/drivers/net_kern.c81
1 files changed, 46 insertions, 35 deletions
diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index 859303730b2..ac746fb5d10 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -325,8 +325,8 @@ static struct platform_driver uml_net_driver = {
};
static int driver_registered;
-static int eth_configure(int n, void *init, char *mac,
- struct transport *transport)
+static void eth_configure(int n, void *init, char *mac,
+ struct transport *transport)
{
struct uml_net *device;
struct net_device *dev;
@@ -339,16 +339,12 @@ static int eth_configure(int n, void *init, char *mac,
device = kzalloc(sizeof(*device), GFP_KERNEL);
if (device == NULL) {
printk(KERN_ERR "eth_configure failed to allocate uml_net\n");
- return(1);
+ return;
}
INIT_LIST_HEAD(&device->list);
device->index = n;
- spin_lock(&devices_lock);
- list_add(&device->list, &devices);
- spin_unlock(&devices_lock);
-
setup_etheraddr(mac, device->mac);
printk(KERN_INFO "Netdevice %d ", n);
@@ -360,7 +356,7 @@ static int eth_configure(int n, void *init, char *mac,
dev = alloc_etherdev(size);
if (dev == NULL) {
printk(KERN_ERR "eth_configure: failed to allocate device\n");
- return 1;
+ goto out_free_device;
}
lp = dev->priv;
@@ -376,7 +372,8 @@ static int eth_configure(int n, void *init, char *mac,
}
device->pdev.id = n;
device->pdev.name = DRIVER_NAME;
- platform_device_register(&device->pdev);
+ if(platform_device_register(&device->pdev))
+ goto out_free_netdev;
SET_NETDEV_DEV(dev,&device->pdev.dev);
/* If this name ends up conflicting with an existing registered
@@ -386,31 +383,12 @@ static int eth_configure(int n, void *init, char *mac,
snprintf(dev->name, sizeof(dev->name), "eth%d", n);
device->dev = dev;
+ /*
+ * These just fill in a data structure, so there's no failure
+ * to be worried about.
+ */
(*transport->kern->init)(dev, init);
- dev->mtu = transport->user->max_packet;
- dev->open = uml_net_open;
- dev->hard_start_xmit = uml_net_start_xmit;
- dev->stop = uml_net_close;
- dev->get_stats = uml_net_get_stats;
- dev->set_multicast_list = uml_net_set_multicast_list;
- dev->tx_timeout = uml_net_tx_timeout;
- dev->set_mac_address = uml_net_set_mac;
- dev->change_mtu = uml_net_change_mtu;
- dev->ethtool_ops = &uml_net_ethtool_ops;
- dev->watchdog_timeo = (HZ >> 1);
- dev->irq = UM_ETH_IRQ;
-
- rtnl_lock();
- err = register_netdevice(dev);
- rtnl_unlock();
- if (err) {
- device->dev = NULL;
- /* XXX: should we call ->remove() here? */
- free_netdev(dev);
- return 1;
- }
-
/* lp.user is the first four bytes of the transport data, which
* has already been initialized. This structure assignment will
* overwrite that, so we make sure that .user gets overwritten with
@@ -438,12 +416,45 @@ static int eth_configure(int n, void *init, char *mac,
lp->tl.function = uml_net_user_timer_expire;
memcpy(lp->mac, device->mac, sizeof(lp->mac));
- if (transport->user->init)
- (*transport->user->init)(&lp->user, dev);
+ if ((transport->user->init != NULL) &&
+ ((*transport->user->init)(&lp->user, dev) != 0))
+ goto out_unregister;
set_ether_mac(dev, device->mac);
+ dev->mtu = transport->user->max_packet;
+ dev->open = uml_net_open;
+ dev->hard_start_xmit = uml_net_start_xmit;
+ dev->stop = uml_net_close;
+ dev->get_stats = uml_net_get_stats;
+ dev->set_multicast_list = uml_net_set_multicast_list;
+ dev->tx_timeout = uml_net_tx_timeout;
+ dev->set_mac_address = uml_net_set_mac;
+ dev->change_mtu = uml_net_change_mtu;
+ dev->ethtool_ops = &uml_net_ethtool_ops;
+ dev->watchdog_timeo = (HZ >> 1);
+ dev->irq = UM_ETH_IRQ;
- return 0;
+ rtnl_lock();
+ err = register_netdevice(dev);
+ rtnl_unlock();
+ if (err)
+ goto out_undo_user_init;
+
+ spin_lock(&devices_lock);
+ list_add(&device->list, &devices);
+ spin_unlock(&devices_lock);
+
+ return;
+
+out_undo_user_init:
+ if (transport->user->init != NULL)
+ (*transport->user->remove)(&lp->user);
+out_unregister:
+ platform_device_unregister(&device->pdev);
+out_free_netdev:
+ free_netdev(dev);
+out_free_device: ;
+ kfree(device);
}
static struct uml_net *find_device(int n)