static int smk_ptrace_rule_check(struct task_struct *tracer,
				 struct smack_known *tracee_known,
				 unsigned int mode, const char *func)
{
	int rc;
	struct smk_audit_info ad, *saip = NULL;
	struct task_smack *tsp;
	struct smack_known *tracer_known;
	const struct cred *tracercred;

	if ((mode & PTRACE_MODE_NOAUDIT) == 0) {
		smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK);
		smk_ad_setfield_u_tsk(&ad, tracer);
		saip = &ad;
	}

	rcu_read_lock();
	tracercred = __task_cred(tracer);
	tsp = smack_cred(tracercred);
	tracer_known = smk_of_task(tsp);

	if ((mode & PTRACE_MODE_ATTACH) &&
	    (smack_ptrace_rule == SMACK_PTRACE_EXACT ||
	     smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) {
		if (tracer_known->smk_known == tracee_known->smk_known)
			rc = 0;
		else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)
			rc = -EACCES;
		else if (smack_privileged_cred(CAP_SYS_PTRACE, tracercred))
			rc = 0;
		else
			rc = -EACCES;

		if (saip)
			smack_log(tracer_known->smk_known,
				  tracee_known->smk_known,
				  0, rc, saip);

		rcu_read_unlock();
		return rc;
	}

	/* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */
	rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip);

	rcu_read_unlock();
	return rc;
}