Export the symbol 'groups_free' to fix following problem:
WARNING: /lib/modules/2.6.2-rc2-mm2/kernel/net/sunrpc/sunrpc.ko needs unknown symbol groups_free
--- linux-2.6.2-rc2-mm2/kernel/sys.c~	2004-01-30 12:44:00.000000000 +0100
+++ linux-2.6.2-rc2-mm2/kernel/sys.c	2004-01-30 14:12:43.611175872 +0100
@@ -1140,6 +1140,8 @@ void groups_free(struct group_info *grou
 	kfree(group_info);
 }
 
+EXPORT_SYMBOL(groups_free);
+
 /* export the group_info to a user-space array */
 static int groups_to_user(gid_t __user *grouplist,
     struct group_info *group_info)