/sys/class/misc has entry net/tun

[0 tv@tao /sys/class/misc]$ uname -a
Linux tao 2.6.2-rc2 #6 Mon Jan 26 10:54:50 EET 2004 i686 GNU/Linux [0 tv@tao /sys/class/misc]$ echo *
intermezzo net/tun psaux rtc uinput
[0 tv@tao /sys/class/misc]$

Seems like that's all because of this:

static struct miscdevice tun_miscdev = {
.minor = TUN_MINOR,
.name = "net/tun",
.fops = &tun_fops
};

Name is apparently meant to be a filename, not a path. Don't know what should be done to it; maybe

static struct miscdevice tun_miscdev = {
        .minor = TUN_MINOR,
        .name = "tun",
        .fops = &tun_fops,
        .devfs_name = "misc/net/tun",
};

But I havent tried that out.

I'd suggest this, to flush out all the problems. Later, it can be changed to return -EINVAL or BUG_ON.

@@ -212,6 +212,9 @@
 int misc_register(struct miscdevice * misc)
 {
        struct miscdevice *c;
+
+       if (misc->name && strchr(misc->name, '/'))
+         printk("%s: name contains slash when registering %s.\n", __func__, misc->name);
 
        down(&misc_sem);
        list_for_each_entry(c, &misc_list, list) {