Initialize policydb.process_class eariler.

Initialize policydb.process_class once all symtabs read from policy image,
so that it could be used to setup the role_trans.tclass field when a lower
version policy.X is loaded.
Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

security/selinux/ss/policydb.c

@@ -2275,6 +2275,11 @@ int policydb_read(struct policydb *p, void *fp)
 		p->symtab[i].nprim = nprim;
 	}
 
+	rc = -EINVAL;
+	p->process_class = string_to_security_class(p, "process");
+	if (!p->process_class)
+		goto bad;
+
 	rc = avtab_read(&p->te_avtab, fp, p);
 	if (rc)
 		goto bad;
@@ -2358,11 +2363,6 @@ int policydb_read(struct policydb *p, void *fp)
 	if (rc)
 		goto bad;
 
-	rc = -EINVAL;
-	p->process_class = string_to_security_class(p, "process");
-	if (!p->process_class)
-		goto bad;
-
 	rc = -EINVAL;
 	p->process_trans_perms = string_to_av_perm(p, p->process_class, "transition");
 	p->process_trans_perms |= string_to_av_perm(p, p->process_class, "dyntransition");