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authorJohn Fastabend <john.r.fastabend@intel.com>2013-11-26 07:33:52 +0100
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2013-12-18 06:19:08 +0100
commit85328240c625f322af9f69c7b60e619717101d77 (patch)
tree6013facc2361540665ca6c47b73b7cd2e98bf14f
parentMerge branch 'fixes-for-3.13' of git://gitorious.org/linux-can/linux-can (diff)
downloadlinux-85328240c625f322af9f69c7b60e619717101d77.tar.xz
linux-85328240c625f322af9f69c7b60e619717101d77.zip
net: allow netdev_all_upper_get_next_dev_rcu with rtnl lock held
It is useful to be able to walk all upper devices when bringing a device online where the RTNL lock is held. In this case it is safe to walk the all_adj_list because the RTNL lock is used to protect the write side as well. This patch adds a check to see if the rtnl lock is held before throwing a warning in netdev_all_upper_get_next_dev_rcu(). Also because we now have a call site for lockdep_rtnl_is_held() outside COFIG_LOCK_PROVING an inline definition returning 1 is needed. Similar to the rcu_read_lock_is_held(). Fixes: 2a47fa45d4df ("ixgbe: enable l2 forwarding acceleration for macvlans") CC: Veaceslav Falico <vfalico@redhat.com> Reported-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
-rw-r--r--include/linux/rtnetlink.h5
-rw-r--r--net/core/dev.c2
2 files changed, 6 insertions, 1 deletions
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 939428ad25ac..8e3e66ac0a52 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -24,6 +24,11 @@ extern int rtnl_trylock(void);
extern int rtnl_is_locked(void);
#ifdef CONFIG_PROVE_LOCKING
extern int lockdep_rtnl_is_held(void);
+#else
+static inline int lockdep_rtnl_is_held(void)
+{
+ return 1;
+}
#endif /* #ifdef CONFIG_PROVE_LOCKING */
/**
diff --git a/net/core/dev.c b/net/core/dev.c
index ba3b7ea5ebb3..4fc17221545d 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4500,7 +4500,7 @@ struct net_device *netdev_all_upper_get_next_dev_rcu(struct net_device *dev,
{
struct netdev_adjacent *upper;
- WARN_ON_ONCE(!rcu_read_lock_held());
+ WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);