[PATCH] w1: Added w1_check_family().

w1_check_family() checks new family before registering it.
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/w1/w1_family.c

@@ -27,12 +27,23 @@
 spinlock_t w1_flock = SPIN_LOCK_UNLOCKED;
 static LIST_HEAD(w1_families);
 
+static int w1_check_family(struct w1_family *f)
+{
+	if (!f->fops->rname || !f->fops->rbin || !f->fops->rval || !f->fops->rvalname)
+		return -EINVAL;
+
+	return 0;
+}
+
 int w1_register_family(struct w1_family *newf)
 {
 	struct list_head *ent, *n;
 	struct w1_family *f;
 	int ret = 0;
 
+	if (w1_check_family(newf))
+		return -EINVAL;
+
 	spin_lock(&w1_flock);
 	list_for_each_safe(ent, n, &w1_families) {
 		f = list_entry(ent, struct w1_family, family_entry);