From 2429f7ac2ef429378536d87fcbbf6f424aa5b47f Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Mon, 9 Jan 2012 06:36:54 +0000 Subject: [PATCH] net: introduce netif_addr_lock_nested() and call if when appropriate dev_uc_sync() and dev_mc_sync() are acquiring netif_addr_lock for destination device of synchronization. Since netif_addr_lock is already held at the time for source device, this triggers lockdep deadlock warning. There's no way this deadlock can happen so use spin_lock_nested() to silence the warning. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- include/linux/netdevice.h | 5 +++++ net/core/dev_addr_lists.c | 12 ++++++------ 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index a1d109590da..d0522bb2d4a 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2450,6 +2450,11 @@ static inline void netif_addr_lock(struct net_device *dev) spin_lock(&dev->addr_list_lock); } +static inline void netif_addr_lock_nested(struct net_device *dev) +{ + spin_lock_nested(&dev->addr_list_lock, SINGLE_DEPTH_NESTING); +} + static inline void netif_addr_lock_bh(struct net_device *dev) { spin_lock_bh(&dev->addr_list_lock); diff --git a/net/core/dev_addr_lists.c b/net/core/dev_addr_lists.c index c34ce9f9c97..29c07fef922 100644 --- a/net/core/dev_addr_lists.c +++ b/net/core/dev_addr_lists.c @@ -439,11 +439,11 @@ int dev_uc_sync(struct net_device *to, struct net_device *from) if (to->addr_len != from->addr_len) return -EINVAL; - netif_addr_lock_bh(to); + netif_addr_lock_nested(to); err = __hw_addr_sync(&to->uc, &from->uc, to->addr_len); if (!err) __dev_set_rx_mode(to); - netif_addr_unlock_bh(to); + netif_addr_unlock(to); return err; } EXPORT_SYMBOL(dev_uc_sync); @@ -463,7 +463,7 @@ void dev_uc_unsync(struct net_device *to, struct net_device *from) return; netif_addr_lock_bh(from); - netif_addr_lock(to); + netif_addr_lock_nested(to); __hw_addr_unsync(&to->uc, &from->uc, to->addr_len); __dev_set_rx_mode(to); netif_addr_unlock(to); @@ -602,11 +602,11 @@ int dev_mc_sync(struct net_device *to, struct net_device *from) if (to->addr_len != from->addr_len) return -EINVAL; - netif_addr_lock_bh(to); + netif_addr_lock_nested(to); err = __hw_addr_sync(&to->mc, &from->mc, to->addr_len); if (!err) __dev_set_rx_mode(to); - netif_addr_unlock_bh(to); + netif_addr_unlock(to); return err; } EXPORT_SYMBOL(dev_mc_sync); @@ -626,7 +626,7 @@ void dev_mc_unsync(struct net_device *to, struct net_device *from) return; netif_addr_lock_bh(from); - netif_addr_lock(to); + netif_addr_lock_nested(to); __hw_addr_unsync(&to->mc, &from->mc, to->addr_len); __dev_set_rx_mode(to); netif_addr_unlock(to);