Commit 844e5e7e authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Paolo Abeni
Browse files

rtnetlink: Add assertion helpers for per-netns RTNL. 



Once an RTNL scope is converted with rtnl_net_lock(), we will replace
RTNL helper functions inside the scope with the following per-netns
alternatives:

  ASSERT_RTNL()           -> ASSERT_RTNL_NET(net)
  rcu_dereference_rtnl(p) -> rcu_dereference_rtnl_net(net, p)

Note that the per-netns helpers are equivalent to the conventional
helpers unless CONFIG_DEBUG_NET_SMALL_RTNL is enabled.

Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 76aed953

include/linux/rtnetlink.h

+41 −4
Original line number Diff line number Diff line
@@ -51,6 +51,10 @@ extern atomic_t dev_unreg_count; 
extern struct rw_semaphore pernet_ops_rwsem;

extern struct rw_semaphore net_rwsem;



#define ASSERT_RTNL() \

	WARN_ONCE(!rtnl_is_locked(), \

		  "RTNL: assertion failed at %s (%d)\n", __FILE__,  __LINE__)



#ifdef CONFIG_PROVE_LOCKING

extern bool lockdep_rtnl_is_held(void);

#else
@@ -98,6 +102,22 @@ void __rtnl_net_unlock(struct net *net); 
void rtnl_net_lock(struct net *net);

void rtnl_net_unlock(struct net *net);

int rtnl_net_lock_cmp_fn(const struct lockdep_map *a, const struct lockdep_map *b);



bool rtnl_net_is_locked(struct net *net);



#define ASSERT_RTNL_NET(net)						\

	WARN_ONCE(!rtnl_net_is_locked(net),				\

		  "RTNL_NET: assertion failed at %s (%d)\n",		\

		  __FILE__,  __LINE__)



bool lockdep_rtnl_net_is_held(struct net *net);



#define rcu_dereference_rtnl_net(net, p)				\

	rcu_dereference_check(p, lockdep_rtnl_net_is_held(net))

#define rtnl_net_dereference(net, p)					\

	rcu_dereference_protected(p, lockdep_rtnl_net_is_held(net))

#define rcu_replace_pointer_rtnl_net(net, rp, p)			\

	rcu_replace_pointer(rp, p, lockdep_rtnl_net_is_held(net))

#else

static inline void __rtnl_net_lock(struct net *net) {}

static inline void __rtnl_net_unlock(struct net *net) {}
@@ -111,6 +131,27 @@ static inline void rtnl_net_unlock(struct net *net) 
{

	rtnl_unlock();

}



static inline void ASSERT_RTNL_NET(struct net *net)

{

	ASSERT_RTNL();

}



static inline void *rcu_dereference_rtnl_net(struct net *net, void *p)

{

	return rcu_dereference_rtnl(p);

}



static inline void *rtnl_net_dereference(struct net *net, void *p)

{

	return rtnl_dereference(p);

}



static inline void *rcu_replace_pointer_rtnl_net(struct net *net,

						 void *rp, void *p)

{

	return rcu_replace_pointer_rtnl(rp, p);

}

#endif



static inline struct netdev_queue *dev_ingress_queue(struct net_device *dev)
@@ -140,10 +181,6 @@ void rtnetlink_init(void); 
void __rtnl_unlock(void);

void rtnl_kfree_skbs(struct sk_buff *head, struct sk_buff *tail);



#define ASSERT_RTNL() \

	WARN_ONCE(!rtnl_is_locked(), \

		  "RTNL: assertion failed at %s (%d)\n", __FILE__,  __LINE__)



extern int ndo_dflt_fdb_dump(struct sk_buff *skb,

			     struct netlink_callback *cb,

			     struct net_device *dev,

net/core/rtnetlink.c

+12 −0
Original line number Diff line number Diff line
@@ -235,6 +235,18 @@ int rtnl_net_lock_cmp_fn(const struct lockdep_map *a, const struct lockdep_map * 


	return rtnl_net_cmp_locks(net_a, net_b);

}



bool rtnl_net_is_locked(struct net *net)

{

	return rtnl_is_locked() && mutex_is_locked(&net->rtnl_mutex);

}

EXPORT_SYMBOL(rtnl_net_is_locked);



bool lockdep_rtnl_net_is_held(struct net *net)

{

	return lockdep_rtnl_is_held() && lockdep_is_held(&net->rtnl_mutex);

}

EXPORT_SYMBOL(lockdep_rtnl_net_is_held);

#endif



static struct rtnl_link __rcu *__rcu *rtnl_msg_handlers[RTNL_FAMILY_MAX + 1];