Commit f34d9d2d authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
Browse files

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: default avatarJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b16895b6

arch/um/drivers/daemon_user.c

+4 −1
Original line number Diff line number Diff line
@@ -123,7 +123,7 @@ static int connect_to_switch(struct daemon_data *pri) 
	return err;

}



static void daemon_user_init(void *data, void *dev)

static int daemon_user_init(void *data, void *dev)

{

	struct daemon_data *pri = data;

	struct timeval tv;
@@ -146,7 +146,10 @@ static void daemon_user_init(void *data, void *dev) 
	if(pri->fd < 0){

		kfree(pri->local_addr);

		pri->local_addr = NULL;

		return pri->fd;

	}



	return 0;

}



static int daemon_open(void *data)

arch/um/drivers/mcast_user.c

+2 −1
Original line number Diff line number Diff line
@@ -42,12 +42,13 @@ static struct sockaddr_in *new_addr(char *addr, unsigned short port) 
	return sin;

}



static void mcast_user_init(void *data, void *dev)

static int mcast_user_init(void *data, void *dev)

{

	struct mcast_data *pri = data;



	pri->mcast_addr = new_addr(pri->addr, pri->port);

	pri->dev = dev;

	return 0;

}



static void mcast_remove(void *data)

arch/um/drivers/net_kern.c

+46 −35
Original line number Diff line number Diff line
@@ -325,7 +325,7 @@ static struct platform_driver uml_net_driver = { 
};

static int driver_registered;



static int eth_configure(int n, void *init, char *mac,

static void eth_configure(int n, void *init, char *mac,

			  struct transport *transport)

{

	struct uml_net *device;
@@ -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)

arch/um/drivers/pcap_user.c

+3 −2
Original line number Diff line number Diff line
@@ -18,7 +18,7 @@ 


#define PCAP_FD(p) (*(int *)(p))



static void pcap_user_init(void *data, void *dev)

static int pcap_user_init(void *data, void *dev)

{

	struct pcap_data *pri = data;

	pcap_t *p;
@@ -28,11 +28,12 @@ static void pcap_user_init(void *data, void *dev) 
	if(p == NULL){

		printk("pcap_user_init : pcap_open_live failed - '%s'\n", 

		       errors);

		return;

		return -EINVAL;

	}



	pri->dev = dev;

	pri->pcap = p;

	return 0;

}



static int pcap_open(void *data)

arch/um/drivers/slip_user.c

+2 −1
Original line number Diff line number Diff line
@@ -17,11 +17,12 @@ 
#include "os.h"

#include "um_malloc.h"



void slip_user_init(void *data, void *dev)

static int slip_user_init(void *data, void *dev)

{

	struct slip_data *pri = data;



	pri->dev = dev;

	return 0;

}



static int set_up_tty(int fd)

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