apparmor: Add a wildcard secid

Reserve a secid value that we can use as a wildcard, allowing us to
define policy that's expected to match against all secids.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>

security/apparmor/include/secid.h

@@ -22,6 +22,9 @@ struct aa_label;
 /* secid value that will not be allocated */
 #define AA_SECID_INVALID 0
 
+/* secid value that matches any other secid */
+#define AA_SECID_WILDCARD 1
+
 struct aa_label *aa_secid_to_label(u32 secid);
 int apparmor_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
 int apparmor_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid);

security/apparmor/secid.c

@@ -32,8 +32,7 @@
  * secids - do not pin labels with a refcount. They rely on the label
  * properly updating/freeing them
  */
-
-#define AA_FIRST_SECID 1
+#define AA_FIRST_SECID 2
 
 static DEFINE_IDR(aa_secids);
 static DEFINE_SPINLOCK(secid_lock);