1 files changed, 95 insertions, 184 deletions

diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 845bf67d94ca..dd061da3aba9 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -29,6 +29,7 @@
 char hotplug_path[HOTPLUG_PATH_LEN] = "/sbin/hotplug";
 u64 hotplug_seqnum;
 static DEFINE_SPINLOCK(sequence_lock);
+static struct sock *uevent_sock;
 
 static char *action_to_string(enum kobject_action action)
 {
@@ -48,123 +49,6 @@ static char *action_to_string(enum kobject_action action)
         }
 }
 
-static struct sock *uevent_sock;
-
-/**
- * send_uevent - notify userspace by sending event through netlink socket
- *
- * @signal: signal name
- * @obj: object path (kobject)
- * @envp: possible hotplug environment to pass with the message
- * @gfp_mask:
- */
-static int send_uevent(const char *signal, const char *obj,
-                       char **envp, gfp_t gfp_mask)
-{
-        struct sk_buff *skb;
-        char *pos;
-        int len;
-
-        if (!uevent_sock)
-                return -EIO;
-
-        len = strlen(signal) + 1;
-        len += strlen(obj) + 1;
-
-        /* allocate buffer with the maximum possible message size */
-        skb = alloc_skb(len + BUFFER_SIZE, gfp_mask);
-        if (!skb)
-                return -ENOMEM;
-
-        pos = skb_put(skb, len);
-        sprintf(pos, "%s@%s", signal, obj);
-
-        /* copy the environment key by key to our continuous buffer */
-        if (envp) {
-                int i;
-
-                for (i = 2; envp[i]; i++) {
-                        len = strlen(envp[i]) + 1;
-                        pos = skb_put(skb, len);
-                        strcpy(pos, envp[i]);
-                }
-        }
-
-        NETLINK_CB(skb).dst_group = 1;
-        return netlink_broadcast(uevent_sock, skb, 0, 1, gfp_mask);
-}
-
-static int do_kobject_uevent(struct kobject *kobj, enum kobject_action action, 
-                             struct attribute *attr, gfp_t gfp_mask)
-{
-        char *path;
-        char *attrpath;
-        char *signal;
-        int len;
-        int rc = -ENOMEM;
-
-        path = kobject_get_path(kobj, gfp_mask);
-        if (!path)
-                return -ENOMEM;
-
-        signal = action_to_string(action);
-        if (!signal)
-                return -EINVAL;
-
-        if (attr) {
-                len = strlen(path);
-                len += strlen(attr->name) + 2;
-                attrpath = kmalloc(len, gfp_mask);
-                if (!attrpath)
-                        goto exit;
-                sprintf(attrpath, "%s/%s", path, attr->name);
-                rc = send_uevent(signal, attrpath, NULL, gfp_mask);
-                kfree(attrpath);
-        } else
-                rc = send_uevent(signal, path, NULL, gfp_mask);
-
-exit:
-        kfree(path);
-        return rc;
-}
-
-/**
- * kobject_uevent - notify userspace by sending event through netlink socket
- * 
- * @signal: signal name
- * @kobj: struct kobject that the event is happening to
- * @attr: optional struct attribute the event belongs to
- */
-int kobject_uevent(struct kobject *kobj, enum kobject_action action,
-                   struct attribute *attr)
-{
-        return do_kobject_uevent(kobj, action, attr, GFP_KERNEL);
-}
-EXPORT_SYMBOL_GPL(kobject_uevent);
-
-int kobject_uevent_atomic(struct kobject *kobj, enum kobject_action action,
-                          struct attribute *attr)
-{
-        return do_kobject_uevent(kobj, action, attr, GFP_ATOMIC);
-}
-EXPORT_SYMBOL_GPL(kobject_uevent_atomic);
-
-static int __init kobject_uevent_init(void)
-{
-        uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL,
-                                            THIS_MODULE);
-
-        if (!uevent_sock) {
-                printk(KERN_ERR
-                       "kobject_uevent: unable to create netlink socket!\n");
-                return -ENODEV;
-        }
-
-        return 0;
-}
-
-postcore_initcall(kobject_uevent_init);
-
 /**
  * kobject_hotplug - notify userspace by executing /sbin/hotplug
  *
@@ -173,95 +57,84 @@ postcore_initcall(kobject_uevent_init);
  */
 void kobject_hotplug(struct kobject *kobj, enum kobject_action action)
 {
-        char *argv [3];
-        char **envp = NULL;
-        char *buffer = NULL;
-        char *seq_buff;
+        char **envp;
+        char *buffer;
         char *scratch;
+        const char *action_string;
+        const char *devpath = NULL;
+        const char *subsystem;
+        struct kobject *top_kobj;
+        struct kset *kset;
+        struct kset_hotplug_ops *hotplug_ops;
+        u64 seq;
+        char *seq_buff;
         int i = 0;
         int retval;
-        char *kobj_path = NULL;
-        const char *name = NULL;
-        char *action_string;
-        u64 seq;
-        struct kobject *top_kobj = kobj;
-        struct kset *kset;
-        static struct kset_hotplug_ops null_hotplug_ops;
-        struct kset_hotplug_ops *hotplug_ops = &null_hotplug_ops;
 
-        /* If this kobj does not belong to a kset,
-           try to find a parent that does. */
+        pr_debug("%s\n", __FUNCTION__);
+
+        action_string = action_to_string(action);
+        if (!action_string)
+                return;
+
+        /* search the kset we belong to */
+        top_kobj = kobj;
         if (!top_kobj->kset && top_kobj->parent) {
                 do {
                         top_kobj = top_kobj->parent;
                 } while (!top_kobj->kset && top_kobj->parent);
         }
-
-        if (top_kobj->kset)
-                kset = top_kobj->kset;
-        else
+        if (!top_kobj->kset)
                 return;
 
-        if (kset->hotplug_ops)
-                hotplug_ops = kset->hotplug_ops;
+        kset = top_kobj->kset;
+        hotplug_ops = kset->hotplug_ops;
 
-        /* If the kset has a filter operation, call it.
-           Skip the event, if the filter returns zero. */
-        if (hotplug_ops->filter) {
+        /*  skip the event, if the filter returns zero. */
+        if (hotplug_ops && hotplug_ops->filter)
                 if (!hotplug_ops->filter(kset, kobj))
                         return;
-        }
-
-        pr_debug ("%s\n", __FUNCTION__);
-
-        action_string = action_to_string(action);
-        if (!action_string)
-                return;
 
-        envp = kmalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL);
+        /* environment index */
+        envp = kzalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL);
         if (!envp)
                 return;
-        memset (envp, 0x00, NUM_ENVP * sizeof (char *));
 
+        /* environment values */
         buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
         if (!buffer)
                 goto exit;
 
-        if (hotplug_ops->name)
-                name = hotplug_ops->name(kset, kobj);
-        if (name == NULL)
-                name = kobject_name(&kset->kobj);
+        /* complete object path */
+        devpath = kobject_get_path(kobj, GFP_KERNEL);
+        if (!devpath)
+                goto exit;
 
-        argv [0] = hotplug_path;
-        argv [1] = (char *)name; /* won't be changed but 'const' has to go */
-        argv [2] = NULL;
+        /* originating subsystem */
+        if (hotplug_ops && hotplug_ops->name)
+                subsystem = hotplug_ops->name(kset, kobj);
+        else
+                subsystem = kobject_name(&kset->kobj);
 
-        /* minimal command environment */
-        envp [i++] = "HOME=/";
-        envp [i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
+        /* event environemnt for helper process only */
+        envp[i++] = "HOME=/";
+        envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
 
+        /* default keys */
         scratch = buffer;
-
         envp [i++] = scratch;
         scratch += sprintf(scratch, "ACTION=%s", action_string) + 1;
-
-        kobj_path = kobject_get_path(kobj, GFP_KERNEL);
-        if (!kobj_path)
-                goto exit;
-
         envp [i++] = scratch;
-        scratch += sprintf (scratch, "DEVPATH=%s", kobj_path) + 1;
-
+        scratch += sprintf (scratch, "DEVPATH=%s", devpath) + 1;
         envp [i++] = scratch;
-        scratch += sprintf(scratch, "SUBSYSTEM=%s", name) + 1;
+        scratch += sprintf(scratch, "SUBSYSTEM=%s", subsystem) + 1;
 
-        /* reserve space for the sequence,
-         * put the real one in after the hotplug call */
+        /* just reserve the space, overwrite it after kset call has returned */
         envp[i++] = seq_buff = scratch;
         scratch += strlen("SEQNUM=18446744073709551616") + 1;
 
-        if (hotplug_ops->hotplug) {
-                /* have the kset specific function add its stuff */
+        /* let the kset specific function add its stuff */
+        if (hotplug_ops && hotplug_ops->hotplug) {
                 retval = hotplug_ops->hotplug (kset, kobj,
                                   &envp[i], NUM_ENVP - i, scratch,
                                   BUFFER_SIZE - (scratch - buffer));
@@ -272,27 +145,49 @@ void kobject_hotplug(struct kobject *kobj, enum kobject_action action)
                 }
         }
 
+        /* we will send an event, request a new sequence number */
         spin_lock(&sequence_lock);
         seq = ++hotplug_seqnum;
         spin_unlock(&sequence_lock);
         sprintf(seq_buff, "SEQNUM=%llu", (unsigned long long)seq);
 
-        pr_debug ("%s: %s %s seq=%llu %s %s %s %s %s\n",
-                  __FUNCTION__, argv[0], argv[1], (unsigned long long)seq,
-                  envp[0], envp[1], envp[2], envp[3], envp[4]);
-
-        send_uevent(action_string, kobj_path, envp, GFP_KERNEL);
+        /* send netlink message */
+        if (uevent_sock) {
+                struct sk_buff *skb;
+                size_t len;
+
+                /* allocate message with the maximum possible size */
+                len = strlen(action_string) + strlen(devpath) + 2;
+                skb = alloc_skb(len + BUFFER_SIZE, GFP_KERNEL);
+                if (skb) {
+                        /* add header */
+                        scratch = skb_put(skb, len);
+                        sprintf(scratch, "%s@%s", action_string, devpath);
+
+                        /* copy keys to our continuous event payload buffer */
+                        for (i = 2; envp[i]; i++) {
+                                len = strlen(envp[i]) + 1;
+                                scratch = skb_put(skb, len);
+                                strcpy(scratch, envp[i]);
+                        }
+
+                        NETLINK_CB(skb).dst_group = 1;
+                        netlink_broadcast(uevent_sock, skb, 0, 1, GFP_KERNEL);
+                }
+        }
 
-        if (!hotplug_path[0])
-                goto exit;
+        /* call uevent_helper, usually only enabled during early boot */
+        if (hotplug_path[0]) {
+                char *argv [3];
 
-        retval = call_usermodehelper (argv[0], argv, envp, 0);
-        if (retval)
-                pr_debug ("%s - call_usermodehelper returned %d\n",
-                          __FUNCTION__, retval);
+                argv [0] = hotplug_path;
+                argv [1] = (char *)subsystem;
+                argv [2] = NULL;
+                call_usermodehelper (argv[0], argv, envp, 0);
+        }
 
 exit:
-        kfree(kobj_path);
+        kfree(devpath);
         kfree(buffer);
         kfree(envp);
         return;
@@ -350,4 +245,20 @@ int add_hotplug_env_var(char **envp, int num_envp, int *cur_index,
 }
 EXPORT_SYMBOL(add_hotplug_env_var);
 
+static int __init kobject_uevent_init(void)
+{
+        uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL,
+                                            THIS_MODULE);
+
+        if (!uevent_sock) {
+                printk(KERN_ERR
+                       "kobject_uevent: unable to create netlink socket!\n");
+                return -ENODEV;
+        }
+
+        return 0;
+}
+
+postcore_initcall(kobject_uevent_init);
+
 #endif /* CONFIG_HOTPLUG */