Commit 9f6fa3c4 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

inet: annotate data-races around ifa->ifa_preferred_lft 



ifa->ifa_preferred_lft can be read locklessly.

Add appropriate READ_ONCE()/WRITE_ONCE() annotations.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a5fcf74d

net/ipv4/devinet.c

+8 −8
Original line number Diff line number Diff line
@@ -714,11 +714,13 @@ static void check_lifetime(struct work_struct *work) 
		rcu_read_lock();

		hlist_for_each_entry_rcu(ifa, &inet_addr_lst[i], hash) {

			unsigned long age, tstamp;

			u32 preferred_lft;

			u32 valid_lft;



			if (ifa->ifa_flags & IFA_F_PERMANENT)

				continue;



			preferred_lft = READ_ONCE(ifa->ifa_preferred_lft);

			valid_lft = READ_ONCE(ifa->ifa_valid_lft);

			tstamp = READ_ONCE(ifa->ifa_tstamp);

			/* We try to batch several events at once. */
@@ -728,20 +730,18 @@ static void check_lifetime(struct work_struct *work) 
			if (valid_lft != INFINITY_LIFE_TIME &&

			    age >= valid_lft) {

				change_needed = true;

			} else if (ifa->ifa_preferred_lft ==

			} else if (preferred_lft ==

				   INFINITY_LIFE_TIME) {

				continue;

			} else if (age >= ifa->ifa_preferred_lft) {

			} else if (age >= preferred_lft) {

				if (time_before(tstamp + valid_lft * HZ, next))

					next = tstamp + valid_lft * HZ;



				if (!(ifa->ifa_flags & IFA_F_DEPRECATED))

					change_needed = true;

			} else if (time_before(tstamp +

					       ifa->ifa_preferred_lft * HZ,

			} else if (time_before(tstamp + preferred_lft * HZ,

					       next)) {

				next = tstamp +

				       ifa->ifa_preferred_lft * HZ;

				next = tstamp + preferred_lft * HZ;

			}

		}

		rcu_read_unlock();
@@ -818,7 +818,7 @@ static void set_ifa_lifetime(struct in_ifaddr *ifa, __u32 valid_lft, 
	if (addrconf_finite_timeout(timeout)) {

		if (timeout == 0)

			ifa->ifa_flags |= IFA_F_DEPRECATED;

		ifa->ifa_preferred_lft = timeout;

		WRITE_ONCE(ifa->ifa_preferred_lft, timeout);

	}

	WRITE_ONCE(ifa->ifa_tstamp, jiffies);

	if (!ifa->ifa_cstamp)
@@ -1698,7 +1698,7 @@ static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa, 


	tstamp = READ_ONCE(ifa->ifa_tstamp);

	if (!(ifm->ifa_flags & IFA_F_PERMANENT)) {

		preferred = ifa->ifa_preferred_lft;

		preferred = READ_ONCE(ifa->ifa_preferred_lft);

		valid = READ_ONCE(ifa->ifa_valid_lft);

		if (preferred != INFINITY_LIFE_TIME) {

			long tval = (jiffies - tstamp) / HZ;