Function crfree

freebsd/kern/kern_prot.c:2033–2060

* Free a cred structure. Throws away space when ref count gets to 0. */

 * Free a cred structure.  Throws away space when ref count gets to 0.
 */
void
crfree(struct ucred *cr)
{
	struct thread *td;

	td = curthread;
	if (__predict_true(td->td_realucred == cr)) {
		KASSERT(cr->cr_users > 0, ("%s: users %d not > 0 on cred %p",
		    __func__, cr->cr_users, cr));
		td->td_ucredref--;
		return;
	}
	mtx_lock(&cr->cr_mtx);
	KASSERT(cr->cr_users >= 0, ("%s: users %d not >= 0 on cred %p",
	    __func__, cr->cr_users, cr));
	cr->cr_ref--;
	if (cr->cr_users > 0) {
		mtx_unlock(&cr->cr_mtx);
		return;
	}
	KASSERT(cr->cr_ref >= 0, ("%s: ref %d not >= 0 on cred %p",
	    __func__, cr->cr_ref, cr));
	if (cr->cr_ref > 0) {
		mtx_unlock(&cr->cr_mtx);
		return;
	}
	crfree_final(cr);
}

static void
crfree_final(struct ucred *cr)