[PATCH 5/5] UML - network interface hotplug error handling
From: Jeff Dike
Date: Tue Mar 06 2007 - 13:42:37 EST
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@xxxxxxxxxxxxxxx>
--
arch/um/drivers/daemon_user.c | 5 +
arch/um/drivers/mcast_user.c | 3 -
arch/um/drivers/net_kern.c | 81 +++++++++++++++++--------------
arch/um/drivers/pcap_user.c | 5 +
arch/um/drivers/slip_user.c | 3 -
arch/um/drivers/slirp_user.c | 3 -
arch/um/include/net_user.h | 2
arch/um/os-Linux/drivers/ethertap_user.c | 3 -
arch/um/os-Linux/drivers/tuntap_user.c | 3 -
9 files changed, 64 insertions(+), 44 deletions(-)
Index: test/arch/um/drivers/daemon_user.c
===================================================================
--- test.orig/arch/um/drivers/daemon_user.c 2007-03-06 12:10:12.000000000 -0500
+++ test/arch/um/drivers/daemon_user.c 2007-03-06 12:14:45.000000000 -0500
@@ -123,7 +123,7 @@ static int connect_to_switch(struct daem
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,
if(pri->fd < 0){
kfree(pri->local_addr);
pri->local_addr = NULL;
+ return pri->fd;
}
+
+ return 0;
}
static int daemon_open(void *data)
Index: test/arch/um/drivers/mcast_user.c
===================================================================
--- test.orig/arch/um/drivers/mcast_user.c 2007-03-06 12:09:57.000000000 -0500
+++ test/arch/um/drivers/mcast_user.c 2007-03-06 12:14:45.000000000 -0500
@@ -42,12 +42,13 @@ static struct sockaddr_in *new_addr(char
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)
Index: test/arch/um/drivers/net_kern.c
===================================================================
--- test.orig/arch/um/drivers/net_kern.c 2007-03-06 12:03:02.000000000 -0500
+++ test/arch/um/drivers/net_kern.c 2007-03-06 12:14:45.000000000 -0500
@@ -325,8 +325,8 @@ static struct platform_driver uml_net_dr
};
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 *in
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 *in
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 *in
}
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 *in
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 = ¨_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 *in
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 = ¨_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)
Index: test/arch/um/drivers/pcap_user.c
===================================================================
--- test.orig/arch/um/drivers/pcap_user.c 2007-03-06 12:09:57.000000000 -0500
+++ test/arch/um/drivers/pcap_user.c 2007-03-06 12:14:45.000000000 -0500
@@ -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, v
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)
Index: test/arch/um/drivers/slip_user.c
===================================================================
--- test.orig/arch/um/drivers/slip_user.c 2007-03-06 12:03:02.000000000 -0500
+++ test/arch/um/drivers/slip_user.c 2007-03-06 12:14:45.000000000 -0500
@@ -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)
Index: test/arch/um/drivers/slirp_user.c
===================================================================
--- test.orig/arch/um/drivers/slirp_user.c 2007-03-06 12:03:02.000000000 -0500
+++ test/arch/um/drivers/slirp_user.c 2007-03-06 12:14:45.000000000 -0500
@@ -15,11 +15,12 @@
#include "slip_common.h"
#include "os.h"
-void slirp_user_init(void *data, void *dev)
+static int slirp_user_init(void *data, void *dev)
{
struct slirp_data *pri = data;
pri->dev = dev;
+ return 0;
}
struct slirp_pre_exec_data {
Index: test/arch/um/include/net_user.h
===================================================================
--- test.orig/arch/um/include/net_user.h 2007-03-06 12:03:02.000000000 -0500
+++ test/arch/um/include/net_user.h 2007-03-06 12:14:45.000000000 -0500
@@ -14,7 +14,7 @@
#define UML_NET_VERSION (4)
struct net_user_info {
- void (*init)(void *, void *);
+ int (*init)(void *, void *);
int (*open)(void *);
void (*close)(int, void *);
void (*remove)(void *);
Index: test/arch/um/os-Linux/drivers/ethertap_user.c
===================================================================
--- test.orig/arch/um/os-Linux/drivers/ethertap_user.c 2007-03-06 12:09:57.000000000 -0500
+++ test/arch/um/os-Linux/drivers/ethertap_user.c 2007-03-06 12:14:45.000000000 -0500
@@ -24,11 +24,12 @@
#define MAX_PACKET ETH_MAX_PACKET
-void etap_user_init(void *data, void *dev)
+static int etap_user_init(void *data, void *dev)
{
struct ethertap_data *pri = data;
pri->dev = dev;
+ return 0;
}
struct addr_change {
Index: test/arch/um/os-Linux/drivers/tuntap_user.c
===================================================================
--- test.orig/arch/um/os-Linux/drivers/tuntap_user.c 2007-03-06 12:09:57.000000000 -0500
+++ test/arch/um/os-Linux/drivers/tuntap_user.c 2007-03-06 12:14:45.000000000 -0500
@@ -24,11 +24,12 @@
#define MAX_PACKET ETH_MAX_PACKET
-void tuntap_user_init(void *data, void *dev)
+static int tuntap_user_init(void *data, void *dev)
{
struct tuntap_data *pri = data;
pri->dev = dev;
+ return 0;
}
static void tuntap_add_addr(unsigned char *addr, unsigned char *netmask,
-
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