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Commit 4be2700f authored by Paul Moore's avatar Paul Moore Committed by David S. Miller
Browse files

[NetLabel]: correct usage of RCU locking 



This fixes some awkward, and perhaps even problematic, RCU lock usage in the
NetLabel code as well as some other related trivial cleanups found when
looking through the RCU locking.  Most of the changes involve removing the
redundant RCU read locks wrapping spinlocks in the case of a RCU writer.

Signed-off-by: default avatarPaul Moore <paul.moore@hp.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 94d3b1e5

net/ipv4/cipso_ipv4.c

+10 −29
Original line number Diff line number Diff line
@@ -504,22 +504,16 @@ int cipso_v4_doi_add(struct cipso_v4_doi *doi_def) 
	INIT_RCU_HEAD(&doi_def->rcu);

	INIT_LIST_HEAD(&doi_def->dom_list);



	rcu_read_lock();

	if (cipso_v4_doi_search(doi_def->doi) != NULL)

		goto doi_add_failure_rlock;

	spin_lock(&cipso_v4_doi_list_lock);

	if (cipso_v4_doi_search(doi_def->doi) != NULL)

		goto doi_add_failure_slock;

		goto doi_add_failure;

	list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list);

	spin_unlock(&cipso_v4_doi_list_lock);

	rcu_read_unlock();



	return 0;



doi_add_failure_slock:

doi_add_failure:

	spin_unlock(&cipso_v4_doi_list_lock);

doi_add_failure_rlock:

	rcu_read_unlock();

	return -EEXIST;

}
@@ -543,29 +537,23 @@ int cipso_v4_doi_remove(u32 doi, 
	struct cipso_v4_doi *doi_def;

	struct cipso_v4_domhsh_entry *dom_iter;



	rcu_read_lock();

	if (cipso_v4_doi_search(doi) != NULL) {

	spin_lock(&cipso_v4_doi_list_lock);

	doi_def = cipso_v4_doi_search(doi);

		if (doi_def == NULL) {

			spin_unlock(&cipso_v4_doi_list_lock);

			rcu_read_unlock();

			return -ENOENT;

		}

	if (doi_def != NULL) {

		doi_def->valid = 0;

		list_del_rcu(&doi_def->list);

		spin_unlock(&cipso_v4_doi_list_lock);

		rcu_read_lock();

		list_for_each_entry_rcu(dom_iter, &doi_def->dom_list, list)

			if (dom_iter->valid)

				netlbl_domhsh_remove(dom_iter->domain,

						     audit_info);

		cipso_v4_cache_invalidate();

		rcu_read_unlock();



		cipso_v4_cache_invalidate();

		call_rcu(&doi_def->rcu, callback);

		return 0;

	}

	rcu_read_unlock();

	spin_unlock(&cipso_v4_doi_list_lock);



	return -ENOENT;

}
@@ -653,22 +641,19 @@ int cipso_v4_doi_domhsh_add(struct cipso_v4_doi *doi_def, const char *domain) 
	new_dom->valid = 1;

	INIT_RCU_HEAD(&new_dom->rcu);



	rcu_read_lock();

	spin_lock(&cipso_v4_doi_list_lock);

	list_for_each_entry_rcu(iter, &doi_def->dom_list, list)

	list_for_each_entry(iter, &doi_def->dom_list, list)

		if (iter->valid &&

		    ((domain != NULL && iter->domain != NULL &&

		      strcmp(iter->domain, domain) == 0) ||

		     (domain == NULL && iter->domain == NULL))) {

			spin_unlock(&cipso_v4_doi_list_lock);

			rcu_read_unlock();

			kfree(new_dom->domain);

			kfree(new_dom);

			return -EEXIST;

		}

	list_add_tail_rcu(&new_dom->list, &doi_def->dom_list);

	spin_unlock(&cipso_v4_doi_list_lock);

	rcu_read_unlock();



	return 0;

}
@@ -689,9 +674,8 @@ int cipso_v4_doi_domhsh_remove(struct cipso_v4_doi *doi_def, 
{

	struct cipso_v4_domhsh_entry *iter;



	rcu_read_lock();

	spin_lock(&cipso_v4_doi_list_lock);

	list_for_each_entry_rcu(iter, &doi_def->dom_list, list)

	list_for_each_entry(iter, &doi_def->dom_list, list)

		if (iter->valid &&

		    ((domain != NULL && iter->domain != NULL &&

		      strcmp(iter->domain, domain) == 0) ||
@@ -699,13 +683,10 @@ int cipso_v4_doi_domhsh_remove(struct cipso_v4_doi *doi_def, 
			iter->valid = 0;

			list_del_rcu(&iter->list);

			spin_unlock(&cipso_v4_doi_list_lock);

			rcu_read_unlock();

			call_rcu(&iter->rcu, cipso_v4_doi_domhsh_free);



			return 0;

		}

	spin_unlock(&cipso_v4_doi_list_lock);

	rcu_read_unlock();



	return -ENOENT;

}

net/netlabel/netlabel_domainhash.c

+11 −26
Original line number Diff line number Diff line
@@ -178,11 +178,9 @@ int netlbl_domhsh_init(u32 size) 
	for (iter = 0; iter < hsh_tbl->size; iter++)

		INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);



	rcu_read_lock();

	spin_lock(&netlbl_domhsh_lock);

	rcu_assign_pointer(netlbl_domhsh, hsh_tbl);

	spin_unlock(&netlbl_domhsh_lock);

	rcu_read_unlock();



	return 0;

}
@@ -222,7 +220,6 @@ int netlbl_domhsh_add(struct netlbl_dom_map *entry, 
	entry->valid = 1;

	INIT_RCU_HEAD(&entry->rcu);



	ret_val = 0;

	rcu_read_lock();

	if (entry->domain != NULL) {

		bkt = netlbl_domhsh_hash(entry->domain);
@@ -233,7 +230,7 @@ int netlbl_domhsh_add(struct netlbl_dom_map *entry, 
		else

			ret_val = -EEXIST;

		spin_unlock(&netlbl_domhsh_lock);

	} else if (entry->domain == NULL) {

	} else {

		INIT_LIST_HEAD(&entry->list);

		spin_lock(&netlbl_domhsh_def_lock);

		if (rcu_dereference(netlbl_domhsh_def) == NULL)
@@ -241,9 +238,7 @@ int netlbl_domhsh_add(struct netlbl_dom_map *entry, 
		else

			ret_val = -EEXIST;

		spin_unlock(&netlbl_domhsh_def_lock);

	} else

		ret_val = -EINVAL;



	}

	audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_ADD, audit_info);

	if (audit_buf != NULL) {

		audit_log_format(audit_buf,
@@ -262,7 +257,6 @@ int netlbl_domhsh_add(struct netlbl_dom_map *entry, 
		audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);

		audit_log_end(audit_buf);

	}



	rcu_read_unlock();



	if (ret_val != 0) {
@@ -313,38 +307,30 @@ int netlbl_domhsh_remove(const char *domain, struct netlbl_audit *audit_info) 
	struct audit_buffer *audit_buf;



	rcu_read_lock();

	if (domain != NULL)

		entry = netlbl_domhsh_search(domain, 0);

	else

		entry = netlbl_domhsh_search(domain, 1);

	entry = netlbl_domhsh_search(domain, (domain != NULL ? 0 : 1));

	if (entry == NULL)

		goto remove_return;

	switch (entry->type) {

	case NETLBL_NLTYPE_UNLABELED:

		break;

	case NETLBL_NLTYPE_CIPSOV4:

		ret_val = cipso_v4_doi_domhsh_remove(entry->type_def.cipsov4,

		cipso_v4_doi_domhsh_remove(entry->type_def.cipsov4,

					   entry->domain);

		if (ret_val != 0)

			goto remove_return;

		break;

	}

	ret_val = 0;

	if (entry != rcu_dereference(netlbl_domhsh_def)) {

		spin_lock(&netlbl_domhsh_lock);

		if (entry->valid) {

			entry->valid = 0;

			list_del_rcu(&entry->list);

		} else

			ret_val = -ENOENT;

			ret_val = 0;

		}

		spin_unlock(&netlbl_domhsh_lock);

	} else {

		spin_lock(&netlbl_domhsh_def_lock);

		if (entry->valid) {

			entry->valid = 0;

			rcu_assign_pointer(netlbl_domhsh_def, NULL);

		} else

			ret_val = -ENOENT;

			ret_val = 0;

		}

		spin_unlock(&netlbl_domhsh_def_lock);

	}
@@ -357,11 +343,10 @@ int netlbl_domhsh_remove(const char *domain, struct netlbl_audit *audit_info) 
		audit_log_end(audit_buf);

	}



	if (ret_val == 0)

		call_rcu(&entry->rcu, netlbl_domhsh_free_entry);



remove_return:

	rcu_read_unlock();

	if (ret_val == 0)

		call_rcu(&entry->rcu, netlbl_domhsh_free_entry);

	return ret_val;

}

net/netlabel/netlabel_mgmt.c

+0 −4
Original line number Diff line number Diff line
@@ -85,11 +85,9 @@ static const struct nla_policy netlbl_mgmt_genl_policy[NLBL_MGMT_A_MAX + 1] = { 
 */

void netlbl_mgmt_protocount_inc(void)

{

	rcu_read_lock();

	spin_lock(&netlabel_mgmt_protocount_lock);

	netlabel_mgmt_protocount++;

	spin_unlock(&netlabel_mgmt_protocount_lock);

	rcu_read_unlock();

}



/**
@@ -103,12 +101,10 @@ void netlbl_mgmt_protocount_inc(void) 
 */

void netlbl_mgmt_protocount_dec(void)

{

	rcu_read_lock();

	spin_lock(&netlabel_mgmt_protocount_lock);

	if (netlabel_mgmt_protocount > 0)

		netlabel_mgmt_protocount--;

	spin_unlock(&netlabel_mgmt_protocount_lock);

	rcu_read_unlock();

}



/**

net/netlabel/netlabel_unlabeled.c

+1 −3
Original line number Diff line number Diff line
@@ -84,12 +84,10 @@ static void netlbl_unlabel_acceptflg_set(u8 value, 
	struct audit_buffer *audit_buf;

	u8 old_val;



	rcu_read_lock();

	old_val = netlabel_unlabel_acceptflg;

	spin_lock(&netlabel_unlabel_acceptflg_lock);

	old_val = netlabel_unlabel_acceptflg;

	netlabel_unlabel_acceptflg = value;

	spin_unlock(&netlabel_unlabel_acceptflg_lock);

	rcu_read_unlock();



	audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW,

					      audit_info);