Commit 72603d20 authored by Geliang Tang's avatar Geliang Tang Committed by Jakub Kicinski
Browse files

mptcp: use WRITE_ONCE for the pernet *_max 



This patch uses WRITE_ONCE() for all the pernet add_addr_signal_max,
add_addr_accept_max, local_addr_max and subflows_max fields in struct
pm_nl_pernet to avoid concurrency issues.

Signed-off-by: default avatarGeliang Tang <geliangtang@gmail.com>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent e6d6ca6e

net/mptcp/pm_netlink.c

+21 −11
Original line number Diff line number Diff line
@@ -572,6 +572,7 @@ static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet, 
					     struct mptcp_pm_addr_entry *entry)

{

	struct mptcp_pm_addr_entry *cur;

	unsigned int addr_max;

	int ret = -EINVAL;



	spin_lock_bh(&pernet->lock);
@@ -614,10 +615,14 @@ static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet, 
	if (entry->addr.id > pernet->next_id)

		pernet->next_id = entry->addr.id;



	if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)

		pernet->add_addr_signal_max++;

	if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)

		pernet->local_addr_max++;

	if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {

		addr_max = pernet->add_addr_signal_max;

		WRITE_ONCE(pernet->add_addr_signal_max, addr_max + 1);

	}

	if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {

		addr_max = pernet->local_addr_max;

		WRITE_ONCE(pernet->local_addr_max, addr_max + 1);

	}



	pernet->addrs++;

	list_add_tail_rcu(&entry->list, &pernet->local_addr_list);
@@ -912,6 +917,7 @@ static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info) 
	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];

	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);

	struct mptcp_pm_addr_entry addr, *entry;

	unsigned int addr_max;

	int ret;



	ret = mptcp_pm_parse_addr(attr, info, false, &addr);
@@ -925,10 +931,14 @@ static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info) 
		spin_unlock_bh(&pernet->lock);

		return -EINVAL;

	}

	if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)

		pernet->add_addr_signal_max--;

	if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)

		pernet->local_addr_max--;

	if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {

		addr_max = pernet->add_addr_signal_max;

		WRITE_ONCE(pernet->add_addr_signal_max, addr_max - 1);

	}

	if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {

		addr_max = pernet->local_addr_max;

		WRITE_ONCE(pernet->local_addr_max, addr_max - 1);

	}



	pernet->addrs--;

	list_del_rcu(&entry->list);
@@ -956,9 +966,9 @@ static void __flush_addrs(struct net *net, struct list_head *list) 


static void __reset_counters(struct pm_nl_pernet *pernet)

{

	pernet->add_addr_signal_max = 0;

	pernet->add_addr_accept_max = 0;

	pernet->local_addr_max = 0;

	WRITE_ONCE(pernet->add_addr_signal_max, 0);

	WRITE_ONCE(pernet->add_addr_accept_max, 0);

	WRITE_ONCE(pernet->local_addr_max, 0);

	pernet->addrs = 0;

}