1 files changed, 95 insertions, 184 deletions

diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 845bf67..dd061da 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 */