LSM: Add /sys/kernel/security/lsm

I am still tired of having to find indirect ways to determine
what security modules are active on a system. I have added
/sys/kernel/security/lsm, which contains a comma separated
list of the active security modules. No more groping around
in /proc/filesystems or other clever hacks.

Unchanged from previous versions except for being updated
to the latest security next branch.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 9cf50ad..0f3c309 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1875,6 +1875,7 @@
 	struct list_head		list;
 	struct list_head		*head;
 	union security_list_options	hook;
+	char				*lsm;
 };
 
 /*
@@ -1887,15 +1888,10 @@
 	{ .head = &security_hook_heads.HEAD, .hook = { .HEAD = HOOK } }
 
 extern struct security_hook_heads security_hook_heads;
+extern char *lsm_names;
 
-static inline void security_add_hooks(struct security_hook_list *hooks,
-				      int count)
-{
-	int i;
-
-	for (i = 0; i < count; i++)
-		list_add_tail_rcu(&hooks[i].list, hooks[i].head);
-}
+extern void security_add_hooks(struct security_hook_list *hooks, int count,
+				char *lsm);
 
 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
 /*