[PATCH] Add adm8211 802.11b wireless driver
[pandora-kernel.git] / drivers / net / netconsole.c
index 69233f6..69ef1eb 100644 (file)
  ****************************************************************/
 
 #include <linux/mm.h>
-#include <linux/tty.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/console.h>
-#include <linux/tty_driver.h>
 #include <linux/moduleparam.h>
 #include <linux/string.h>
-#include <linux/sysrq.h>
-#include <linux/smp.h>
 #include <linux/netpoll.h>
+#include <linux/inet.h>
+#include <linux/configfs.h>
 
 MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@selenic.com>");
 MODULE_DESCRIPTION("Console driver for network interfaces");
 MODULE_LICENSE("GPL");
 
-static char config[256];
-module_param_string(netconsole, config, 256, 0);
+#define MAX_PARAM_LENGTH       256
+#define MAX_PRINT_CHUNK                1000
+
+static char config[MAX_PARAM_LENGTH];
+module_param_string(netconsole, config, MAX_PARAM_LENGTH, 0);
 MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]\n");
 
-static struct netpoll np = {
-       .name = "netconsole",
-       .dev_name = "eth0",
-       .local_port = 6665,
-       .remote_port = 6666,
-       .remote_mac = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
+#ifndef        MODULE
+static int __init option_setup(char *opt)
+{
+       strlcpy(config, opt, MAX_PARAM_LENGTH);
+       return 1;
+}
+__setup("netconsole=", option_setup);
+#endif /* MODULE */
+
+/* Linked list of all configured targets */
+static LIST_HEAD(target_list);
+
+/* This needs to be a spinlock because write_msg() cannot sleep */
+static DEFINE_SPINLOCK(target_list_lock);
+
+/**
+ * struct netconsole_target - Represents a configured netconsole target.
+ * @list:      Links this target into the target_list.
+ * @item:      Links us into the configfs subsystem hierarchy.
+ * @enabled:   On / off knob to enable / disable target.
+ *             Visible from userspace (read-write).
+ *             We maintain a strict 1:1 correspondence between this and
+ *             whether the corresponding netpoll is active or inactive.
+ *             Also, other parameters of a target may be modified at
+ *             runtime only when it is disabled (enabled == 0).
+ * @np:                The netpoll structure for this target.
+ *             Contains the other userspace visible parameters:
+ *             dev_name        (read-write)
+ *             local_port      (read-write)
+ *             remote_port     (read-write)
+ *             local_ip        (read-write)
+ *             remote_ip       (read-write)
+ *             local_mac       (read-only)
+ *             remote_mac      (read-write)
+ */
+struct netconsole_target {
+       struct list_head        list;
+#ifdef CONFIG_NETCONSOLE_DYNAMIC
+       struct config_item      item;
+#endif
+       int                     enabled;
+       struct netpoll          np;
 };
-static int configured = 0;
 
-#define MAX_PRINT_CHUNK 1000
+#ifdef CONFIG_NETCONSOLE_DYNAMIC
 
-static void write_msg(struct console *con, const char *msg, unsigned int len)
+static struct configfs_subsystem netconsole_subsys;
+
+static int __init dynamic_netconsole_init(void)
 {
-       int frag, left;
-       unsigned long flags;
+       config_group_init(&netconsole_subsys.su_group);
+       mutex_init(&netconsole_subsys.su_mutex);
+       return configfs_register_subsystem(&netconsole_subsys);
+}
 
-       if (!np.dev)
-               return;
+static void __exit dynamic_netconsole_exit(void)
+{
+       configfs_unregister_subsystem(&netconsole_subsys);
+}
+
+/*
+ * Targets that were created by parsing the boot/module option string
+ * do not exist in the configfs hierarchy (and have NULL names) and will
+ * never go away, so make these a no-op for them.
+ */
+static void netconsole_target_get(struct netconsole_target *nt)
+{
+       if (config_item_name(&nt->item))
+               config_item_get(&nt->item);
+}
+
+static void netconsole_target_put(struct netconsole_target *nt)
+{
+       if (config_item_name(&nt->item))
+               config_item_put(&nt->item);
+}
+
+#else  /* !CONFIG_NETCONSOLE_DYNAMIC */
+
+static int __init dynamic_netconsole_init(void)
+{
+       return 0;
+}
 
-       local_irq_save(flags);
+static void __exit dynamic_netconsole_exit(void)
+{
+}
 
-       for(left = len; left; ) {
-               frag = min(left, MAX_PRINT_CHUNK);
-               netpoll_send_udp(&np, msg, frag);
-               msg += frag;
-               left -= frag;
+/*
+ * No danger of targets going away from under us when dynamic
+ * reconfigurability is off.
+ */
+static void netconsole_target_get(struct netconsole_target *nt)
+{
+}
+
+static void netconsole_target_put(struct netconsole_target *nt)
+{
+}
+
+#endif /* CONFIG_NETCONSOLE_DYNAMIC */
+
+/* Allocate new target (from boot/module param) and setup netpoll for it */
+static struct netconsole_target *alloc_param_target(char *target_config)
+{
+       int err = -ENOMEM;
+       struct netconsole_target *nt;
+
+       /*
+        * Allocate and initialize with defaults.
+        * Note that these targets get their config_item fields zeroed-out.
+        */
+       nt = kzalloc(sizeof(*nt), GFP_KERNEL);
+       if (!nt) {
+               printk(KERN_ERR "netconsole: failed to allocate memory\n");
+               goto fail;
        }
 
-       local_irq_restore(flags);
+       nt->np.name = "netconsole";
+       strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
+       nt->np.local_port = 6665;
+       nt->np.remote_port = 6666;
+       memset(nt->np.remote_mac, 0xff, ETH_ALEN);
+
+       /* Parse parameters and setup netpoll */
+       err = netpoll_parse_options(&nt->np, target_config);
+       if (err)
+               goto fail;
+
+       err = netpoll_setup(&nt->np);
+       if (err)
+               goto fail;
+
+       nt->enabled = 1;
+
+       return nt;
+
+fail:
+       kfree(nt);
+       return ERR_PTR(err);
 }
 
-static struct console netconsole = {
-       .name = "netcon",
-       .flags = CON_ENABLED | CON_PRINTBUFFER,
-       .write = write_msg
+/* Cleanup netpoll for given target (from boot/module param) and free it */
+static void free_param_target(struct netconsole_target *nt)
+{
+       netpoll_cleanup(&nt->np);
+       kfree(nt);
+}
+
+#ifdef CONFIG_NETCONSOLE_DYNAMIC
+
+/*
+ * Our subsystem hierarchy is:
+ *
+ * /sys/kernel/config/netconsole/
+ *                             |
+ *                             <target>/
+ *                             |       enabled
+ *                             |       dev_name
+ *                             |       local_port
+ *                             |       remote_port
+ *                             |       local_ip
+ *                             |       remote_ip
+ *                             |       local_mac
+ *                             |       remote_mac
+ *                             |
+ *                             <target>/...
+ */
+
+struct netconsole_target_attr {
+       struct configfs_attribute       attr;
+       ssize_t                         (*show)(struct netconsole_target *nt,
+                                               char *buf);
+       ssize_t                         (*store)(struct netconsole_target *nt,
+                                                const char *buf,
+                                                size_t count);
 };
 
-static int option_setup(char *opt)
+static struct netconsole_target *to_target(struct config_item *item)
 {
-       configured = !netpoll_parse_options(&np, opt);
-       return 1;
+       return item ?
+               container_of(item, struct netconsole_target, item) :
+               NULL;
 }
 
-__setup("netconsole=", option_setup);
+/*
+ * Wrapper over simple_strtol (base 10) with sanity and range checking.
+ * We return (signed) long only because we may want to return errors.
+ * Do not use this to convert numbers that are allowed to be negative.
+ */
+static long strtol10_check_range(const char *cp, long min, long max)
+{
+       long ret;
+       char *p = (char *) cp;
+
+       WARN_ON(min < 0);
+       WARN_ON(max < min);
+
+       ret = simple_strtol(p, &p, 10);
+
+       if (*p && (*p != '\n')) {
+               printk(KERN_ERR "netconsole: invalid input\n");
+               return -EINVAL;
+       }
+       if ((ret < min) || (ret > max)) {
+               printk(KERN_ERR "netconsole: input %ld must be between "
+                               "%ld and %ld\n", ret, min, max);
+               return -EINVAL;
+       }
+
+       return ret;
+}
+
+/*
+ * Attribute operations for netconsole_target.
+ */
+
+static ssize_t show_enabled(struct netconsole_target *nt, char *buf)
+{
+       return snprintf(buf, PAGE_SIZE, "%d\n", nt->enabled);
+}
+
+static ssize_t show_dev_name(struct netconsole_target *nt, char *buf)
+{
+       return snprintf(buf, PAGE_SIZE, "%s\n", nt->np.dev_name);
+}
+
+static ssize_t show_local_port(struct netconsole_target *nt, char *buf)
+{
+       return snprintf(buf, PAGE_SIZE, "%d\n", nt->np.local_port);
+}
+
+static ssize_t show_remote_port(struct netconsole_target *nt, char *buf)
+{
+       return snprintf(buf, PAGE_SIZE, "%d\n", nt->np.remote_port);
+}
+
+static ssize_t show_local_ip(struct netconsole_target *nt, char *buf)
+{
+       return snprintf(buf, PAGE_SIZE, "%d.%d.%d.%d\n",
+                       HIPQUAD(nt->np.local_ip));
+}
+
+static ssize_t show_remote_ip(struct netconsole_target *nt, char *buf)
+{
+       return snprintf(buf, PAGE_SIZE, "%d.%d.%d.%d\n",
+                       HIPQUAD(nt->np.remote_ip));
+}
+
+static ssize_t show_local_mac(struct netconsole_target *nt, char *buf)
+{
+       return snprintf(buf, PAGE_SIZE, "%02x:%02x:%02x:%02x:%02x:%02x\n",
+                       nt->np.local_mac[0], nt->np.local_mac[1],
+                       nt->np.local_mac[2], nt->np.local_mac[3],
+                       nt->np.local_mac[4], nt->np.local_mac[5]);
+}
+
+static ssize_t show_remote_mac(struct netconsole_target *nt, char *buf)
+{
+       return snprintf(buf, PAGE_SIZE, "%02x:%02x:%02x:%02x:%02x:%02x\n",
+                       nt->np.remote_mac[0], nt->np.remote_mac[1],
+                       nt->np.remote_mac[2], nt->np.remote_mac[3],
+                       nt->np.remote_mac[4], nt->np.remote_mac[5]);
+}
 
-static int init_netconsole(void)
+/*
+ * This one is special -- targets created through the configfs interface
+ * are not enabled (and the corresponding netpoll activated) by default.
+ * The user is expected to set the desired parameters first (which
+ * would enable him to dynamically add new netpoll targets for new
+ * network interfaces as and when they come up).
+ */
+static ssize_t store_enabled(struct netconsole_target *nt,
+                            const char *buf,
+                            size_t count)
 {
        int err;
+       long enabled;
+
+       enabled = strtol10_check_range(buf, 0, 1);
+       if (enabled < 0)
+               return enabled;
+
+       if (enabled) {  /* 1 */
+
+               /*
+                * Skip netpoll_parse_options() -- all the attributes are
+                * already configured via configfs. Just print them out.
+                */
+               netpoll_print_options(&nt->np);
+
+               err = netpoll_setup(&nt->np);
+               if (err)
+                       return err;
+
+               printk(KERN_INFO "netconsole: network logging started\n");
+
+       } else {        /* 0 */
+               netpoll_cleanup(&nt->np);
+       }
+
+       nt->enabled = enabled;
+
+       return strnlen(buf, count);
+}
+
+static ssize_t store_dev_name(struct netconsole_target *nt,
+                             const char *buf,
+                             size_t count)
+{
+       size_t len;
+
+       if (nt->enabled) {
+               printk(KERN_ERR "netconsole: target (%s) is enabled, "
+                               "disable to update parameters\n",
+                               config_item_name(&nt->item));
+               return -EINVAL;
+       }
+
+       strlcpy(nt->np.dev_name, buf, IFNAMSIZ);
+
+       /* Get rid of possible trailing newline from echo(1) */
+       len = strnlen(nt->np.dev_name, IFNAMSIZ);
+       if (nt->np.dev_name[len - 1] == '\n')
+               nt->np.dev_name[len - 1] = '\0';
+
+       return strnlen(buf, count);
+}
+
+static ssize_t store_local_port(struct netconsole_target *nt,
+                               const char *buf,
+                               size_t count)
+{
+       long local_port;
+#define __U16_MAX      ((__u16) ~0U)
+
+       if (nt->enabled) {
+               printk(KERN_ERR "netconsole: target (%s) is enabled, "
+                               "disable to update parameters\n",
+                               config_item_name(&nt->item));
+               return -EINVAL;
+       }
+
+       local_port = strtol10_check_range(buf, 0, __U16_MAX);
+       if (local_port < 0)
+               return local_port;
+
+       nt->np.local_port = local_port;
+
+       return strnlen(buf, count);
+}
+
+static ssize_t store_remote_port(struct netconsole_target *nt,
+                                const char *buf,
+                                size_t count)
+{
+       long remote_port;
+#define __U16_MAX      ((__u16) ~0U)
+
+       if (nt->enabled) {
+               printk(KERN_ERR "netconsole: target (%s) is enabled, "
+                               "disable to update parameters\n",
+                               config_item_name(&nt->item));
+               return -EINVAL;
+       }
+
+       remote_port = strtol10_check_range(buf, 0, __U16_MAX);
+       if (remote_port < 0)
+               return remote_port;
+
+       nt->np.remote_port = remote_port;
+
+       return strnlen(buf, count);
+}
+
+static ssize_t store_local_ip(struct netconsole_target *nt,
+                             const char *buf,
+                             size_t count)
+{
+       if (nt->enabled) {
+               printk(KERN_ERR "netconsole: target (%s) is enabled, "
+                               "disable to update parameters\n",
+                               config_item_name(&nt->item));
+               return -EINVAL;
+       }
+
+       nt->np.local_ip = ntohl(in_aton(buf));
+
+       return strnlen(buf, count);
+}
+
+static ssize_t store_remote_ip(struct netconsole_target *nt,
+                              const char *buf,
+                              size_t count)
+{
+       if (nt->enabled) {
+               printk(KERN_ERR "netconsole: target (%s) is enabled, "
+                               "disable to update parameters\n",
+                               config_item_name(&nt->item));
+               return -EINVAL;
+       }
+
+       nt->np.remote_ip = ntohl(in_aton(buf));
+
+       return strnlen(buf, count);
+}
+
+static ssize_t store_remote_mac(struct netconsole_target *nt,
+                               const char *buf,
+                               size_t count)
+{
+       u8 remote_mac[ETH_ALEN];
+       char *p = (char *) buf;
+       int i;
 
-       if(strlen(config))
-               option_setup(config);
+       if (nt->enabled) {
+               printk(KERN_ERR "netconsole: target (%s) is enabled, "
+                               "disable to update parameters\n",
+                               config_item_name(&nt->item));
+               return -EINVAL;
+       }
 
-       if(!configured) {
-               printk("netconsole: not configured, aborting\n");
-               return 0;
+       for (i = 0; i < ETH_ALEN - 1; i++) {
+               remote_mac[i] = simple_strtoul(p, &p, 16);
+               if (*p != ':')
+                       goto invalid;
+               p++;
        }
+       remote_mac[ETH_ALEN - 1] = simple_strtoul(p, &p, 16);
+       if (*p && (*p != '\n'))
+               goto invalid;
+
+       memcpy(nt->np.remote_mac, remote_mac, ETH_ALEN);
+
+       return strnlen(buf, count);
+
+invalid:
+       printk(KERN_ERR "netconsole: invalid input\n");
+       return -EINVAL;
+}
+
+/*
+ * Attribute definitions for netconsole_target.
+ */
+
+#define NETCONSOLE_TARGET_ATTR_RO(_name)                               \
+static struct netconsole_target_attr netconsole_target_##_name =       \
+       __CONFIGFS_ATTR(_name, S_IRUGO, show_##_name, NULL)
 
-       err = netpoll_setup(&np);
+#define NETCONSOLE_TARGET_ATTR_RW(_name)                               \
+static struct netconsole_target_attr netconsole_target_##_name =       \
+       __CONFIGFS_ATTR(_name, S_IRUGO | S_IWUSR, show_##_name, store_##_name)
+
+NETCONSOLE_TARGET_ATTR_RW(enabled);
+NETCONSOLE_TARGET_ATTR_RW(dev_name);
+NETCONSOLE_TARGET_ATTR_RW(local_port);
+NETCONSOLE_TARGET_ATTR_RW(remote_port);
+NETCONSOLE_TARGET_ATTR_RW(local_ip);
+NETCONSOLE_TARGET_ATTR_RW(remote_ip);
+NETCONSOLE_TARGET_ATTR_RO(local_mac);
+NETCONSOLE_TARGET_ATTR_RW(remote_mac);
+
+static struct configfs_attribute *netconsole_target_attrs[] = {
+       &netconsole_target_enabled.attr,
+       &netconsole_target_dev_name.attr,
+       &netconsole_target_local_port.attr,
+       &netconsole_target_remote_port.attr,
+       &netconsole_target_local_ip.attr,
+       &netconsole_target_remote_ip.attr,
+       &netconsole_target_local_mac.attr,
+       &netconsole_target_remote_mac.attr,
+       NULL,
+};
+
+/*
+ * Item operations and type for netconsole_target.
+ */
+
+static void netconsole_target_release(struct config_item *item)
+{
+       kfree(to_target(item));
+}
+
+static ssize_t netconsole_target_attr_show(struct config_item *item,
+                                          struct configfs_attribute *attr,
+                                          char *buf)
+{
+       ssize_t ret = -EINVAL;
+       struct netconsole_target *nt = to_target(item);
+       struct netconsole_target_attr *na =
+               container_of(attr, struct netconsole_target_attr, attr);
+
+       if (na->show)
+               ret = na->show(nt, buf);
+
+       return ret;
+}
+
+static ssize_t netconsole_target_attr_store(struct config_item *item,
+                                           struct configfs_attribute *attr,
+                                           const char *buf,
+                                           size_t count)
+{
+       ssize_t ret = -EINVAL;
+       struct netconsole_target *nt = to_target(item);
+       struct netconsole_target_attr *na =
+               container_of(attr, struct netconsole_target_attr, attr);
+
+       if (na->store)
+               ret = na->store(nt, buf, count);
+
+       return ret;
+}
+
+static struct configfs_item_operations netconsole_target_item_ops = {
+       .release                = netconsole_target_release,
+       .show_attribute         = netconsole_target_attr_show,
+       .store_attribute        = netconsole_target_attr_store,
+};
+
+static struct config_item_type netconsole_target_type = {
+       .ct_attrs               = netconsole_target_attrs,
+       .ct_item_ops            = &netconsole_target_item_ops,
+       .ct_owner               = THIS_MODULE,
+};
+
+/*
+ * Group operations and type for netconsole_subsys.
+ */
+
+static struct config_item *make_netconsole_target(struct config_group *group,
+                                                 const char *name)
+{
+       unsigned long flags;
+       struct netconsole_target *nt;
+
+       /*
+        * Allocate and initialize with defaults.
+        * Target is disabled at creation (enabled == 0).
+        */
+       nt = kzalloc(sizeof(*nt), GFP_KERNEL);
+       if (!nt) {
+               printk(KERN_ERR "netconsole: failed to allocate memory\n");
+               return NULL;
+       }
+
+       nt->np.name = "netconsole";
+       strlcpy(nt->np.dev_name, "eth0", IFNAMSIZ);
+       nt->np.local_port = 6665;
+       nt->np.remote_port = 6666;
+       memset(nt->np.remote_mac, 0xff, ETH_ALEN);
+
+       /* Initialize the config_item member */
+       config_item_init_type_name(&nt->item, name, &netconsole_target_type);
+
+       /* Adding, but it is disabled */
+       spin_lock_irqsave(&target_list_lock, flags);
+       list_add(&nt->list, &target_list);
+       spin_unlock_irqrestore(&target_list_lock, flags);
+
+       return &nt->item;
+}
+
+static void drop_netconsole_target(struct config_group *group,
+                                  struct config_item *item)
+{
+       unsigned long flags;
+       struct netconsole_target *nt = to_target(item);
+
+       spin_lock_irqsave(&target_list_lock, flags);
+       list_del(&nt->list);
+       spin_unlock_irqrestore(&target_list_lock, flags);
+
+       /*
+        * The target may have never been enabled, or was manually disabled
+        * before being removed so netpoll may have already been cleaned up.
+        */
+       if (nt->enabled)
+               netpoll_cleanup(&nt->np);
+
+       config_item_put(&nt->item);
+}
+
+static struct configfs_group_operations netconsole_subsys_group_ops = {
+       .make_item      = make_netconsole_target,
+       .drop_item      = drop_netconsole_target,
+};
+
+static struct config_item_type netconsole_subsys_type = {
+       .ct_group_ops   = &netconsole_subsys_group_ops,
+       .ct_owner       = THIS_MODULE,
+};
+
+/* The netconsole configfs subsystem */
+static struct configfs_subsystem netconsole_subsys = {
+       .su_group       = {
+               .cg_item        = {
+                       .ci_namebuf     = "netconsole",
+                       .ci_type        = &netconsole_subsys_type,
+               },
+       },
+};
+
+#endif /* CONFIG_NETCONSOLE_DYNAMIC */
+
+/* Handle network interface device notifications */
+static int netconsole_netdev_event(struct notifier_block *this,
+                                  unsigned long event,
+                                  void *ptr)
+{
+       unsigned long flags;
+       struct netconsole_target *nt;
+       struct net_device *dev = ptr;
+
+       if (!(event == NETDEV_CHANGEADDR || event == NETDEV_CHANGENAME))
+               goto done;
+
+       spin_lock_irqsave(&target_list_lock, flags);
+       list_for_each_entry(nt, &target_list, list) {
+               netconsole_target_get(nt);
+               if (nt->np.dev == dev) {
+                       switch (event) {
+                       case NETDEV_CHANGEADDR:
+                               memcpy(nt->np.local_mac, dev->dev_addr, ETH_ALEN);
+                               break;
+
+                       case NETDEV_CHANGENAME:
+                               strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ);
+                               break;
+                       }
+               }
+               netconsole_target_put(nt);
+       }
+       spin_unlock_irqrestore(&target_list_lock, flags);
+
+done:
+       return NOTIFY_DONE;
+}
+
+static struct notifier_block netconsole_netdev_notifier = {
+       .notifier_call  = netconsole_netdev_event,
+};
+
+static void write_msg(struct console *con, const char *msg, unsigned int len)
+{
+       int frag, left;
+       unsigned long flags;
+       struct netconsole_target *nt;
+       const char *tmp;
+
+       /* Avoid taking lock and disabling interrupts unnecessarily */
+       if (list_empty(&target_list))
+               return;
+
+       spin_lock_irqsave(&target_list_lock, flags);
+       list_for_each_entry(nt, &target_list, list) {
+               netconsole_target_get(nt);
+               if (nt->enabled && netif_running(nt->np.dev)) {
+                       /*
+                        * We nest this inside the for-each-target loop above
+                        * so that we're able to get as much logging out to
+                        * at least one target if we die inside here, instead
+                        * of unnecessarily keeping all targets in lock-step.
+                        */
+                       tmp = msg;
+                       for (left = len; left;) {
+                               frag = min(left, MAX_PRINT_CHUNK);
+                               netpoll_send_udp(&nt->np, tmp, frag);
+                               tmp += frag;
+                               left -= frag;
+                       }
+               }
+               netconsole_target_put(nt);
+       }
+       spin_unlock_irqrestore(&target_list_lock, flags);
+}
+
+static struct console netconsole = {
+       .name   = "netcon",
+       .flags  = CON_ENABLED | CON_PRINTBUFFER,
+       .write  = write_msg,
+};
+
+static int __init init_netconsole(void)
+{
+       int err;
+       struct netconsole_target *nt, *tmp;
+       unsigned long flags;
+       char *target_config;
+       char *input = config;
+
+       if (strnlen(input, MAX_PARAM_LENGTH)) {
+               while ((target_config = strsep(&input, ";"))) {
+                       nt = alloc_param_target(target_config);
+                       if (IS_ERR(nt)) {
+                               err = PTR_ERR(nt);
+                               goto fail;
+                       }
+                       spin_lock_irqsave(&target_list_lock, flags);
+                       list_add(&nt->list, &target_list);
+                       spin_unlock_irqrestore(&target_list_lock, flags);
+               }
+       }
+
+       err = register_netdevice_notifier(&netconsole_netdev_notifier);
+       if (err)
+               goto fail;
+
+       err = dynamic_netconsole_init();
        if (err)
-               return err;
+               goto undonotifier;
 
        register_console(&netconsole);
        printk(KERN_INFO "netconsole: network logging started\n");
-       return 0;
+
+       return err;
+
+undonotifier:
+       unregister_netdevice_notifier(&netconsole_netdev_notifier);
+
+fail:
+       printk(KERN_ERR "netconsole: cleaning up\n");
+
+       /*
+        * Remove all targets and destroy them (only targets created
+        * from the boot/module option exist here). Skipping the list
+        * lock is safe here, and netpoll_cleanup() will sleep.
+        */
+       list_for_each_entry_safe(nt, tmp, &target_list, list) {
+               list_del(&nt->list);
+               free_param_target(nt);
+       }
+
+       return err;
 }
 
-static void cleanup_netconsole(void)
+static void __exit cleanup_netconsole(void)
 {
+       struct netconsole_target *nt, *tmp;
+
        unregister_console(&netconsole);
-       netpoll_cleanup(&np);
+       dynamic_netconsole_exit();
+       unregister_netdevice_notifier(&netconsole_netdev_notifier);
+
+       /*
+        * Targets created via configfs pin references on our module
+        * and would first be rmdir(2)'ed from userspace. We reach
+        * here only when they are already destroyed, and only those
+        * created from the boot/module option are left, so remove and
+        * destroy them. Skipping the list lock is safe here, and
+        * netpoll_cleanup() will sleep.
+        */
+       list_for_each_entry_safe(nt, tmp, &target_list, list) {
+               list_del(&nt->list);
+               free_param_target(nt);
+       }
 }
 
 module_init(init_netconsole);