Commit aa603467 authored by Hangbin Liu's avatar Hangbin Liu Committed by David S. Miller
Browse files

bonding: use rcu_dereference_rtnl when get bonding active slave 



bond_option_active_slave_get_rcu() should not be used in rtnl_mutex as it
use rcu_dereference(). Replace to rcu_dereference_rtnl() so we also can use
this function in rtnl protected context.

With this update, we can rmeove the rcu_read_lock/unlock in
bonding .ndo_eth_ioctl and .get_ts_info.

Reported-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Fixes: 94dd016a ("bond: pass get_ts_info and SIOC[SG]HWTSTAMP ioctl to active device")
Signed-off-by: default avatarHangbin Liu <liuhangbin@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2148927e

drivers/net/bonding/bond_main.c

+0 −4
Original line number Diff line number Diff line
@@ -4133,9 +4133,7 @@ static int bond_eth_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cm 


		fallthrough;

	case SIOCGHWTSTAMP:

		rcu_read_lock();

		real_dev = bond_option_active_slave_get_rcu(bond);

		rcu_read_unlock();

		if (!real_dev)

			return -EOPNOTSUPP;
@@ -5382,9 +5380,7 @@ static int bond_ethtool_get_ts_info(struct net_device *bond_dev, 
	struct net_device *real_dev;

	struct phy_device *phydev;



	rcu_read_lock();

	real_dev = bond_option_active_slave_get_rcu(bond);

	rcu_read_unlock();

	if (real_dev) {

		ops = real_dev->ethtool_ops;

		phydev = real_dev->phydev;

include/net/bonding.h

+1 −1
Original line number Diff line number Diff line
@@ -346,7 +346,7 @@ static inline bool bond_uses_primary(struct bonding *bond) 


static inline struct net_device *bond_option_active_slave_get_rcu(struct bonding *bond)

{

	struct slave *slave = rcu_dereference(bond->curr_active_slave);

	struct slave *slave = rcu_dereference_rtnl(bond->curr_active_slave);



	return bond_uses_primary(bond) && slave ? slave->dev : NULL;

}