SELinux: more user friendly unknown handling printk

I've gotten complaints and reports about people not understanding the
meaning of the current unknown class/perm handling the kernel emits on
every policy load.  Hopefully this will make make it clear to everyone
the meaning of the message and won't waste a printk the user won't care
about anyway on systems where the kernel and the policy agree on
everything.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 04c0b70..b52f923 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -1171,6 +1171,7 @@
 	const struct selinux_class_perm *kdefs = &selinux_class_perm;
 	const char *def_class, *def_perm, *pol_class;
 	struct symtab *perms;
+	bool print_unknown_handle = 0;
 
 	if (p->allow_unknown) {
 		u32 num_classes = kdefs->cts_len;
@@ -1191,6 +1192,7 @@
 				return -EINVAL;
 			if (p->allow_unknown)
 				p->undefined_perms[i-1] = ~0U;
+			print_unknown_handle = 1;
 			continue;
 		}
 		pol_class = p->p_class_val_to_name[i-1];
@@ -1220,6 +1222,7 @@
 				return -EINVAL;
 			if (p->allow_unknown)
 				p->undefined_perms[class_val-1] |= perm_val;
+			print_unknown_handle = 1;
 			continue;
 		}
 		perdatum = hashtab_search(perms->table, def_perm);
@@ -1267,6 +1270,7 @@
 					return -EINVAL;
 				if (p->allow_unknown)
 					p->undefined_perms[class_val-1] |= (1 << j);
+				print_unknown_handle = 1;
 				continue;
 			}
 			perdatum = hashtab_search(perms->table, def_perm);
@@ -1284,6 +1288,9 @@
 			}
 		}
 	}
+	if (print_unknown_handle)
+		printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
+			(security_get_allow_unknown() ? "allowed" : "denied"));
 	return 0;
 }