From a898def29e4119bc01ebe7ca97423181f4c0ea2d Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 22 Feb 2010 17:04:49 -0800 Subject: net: Add checking to rcu_dereference() primitives Update rcu_dereference() primitives to use new lockdep-based checking. The rcu_dereference() in __in6_dev_get() may be protected either by rcu_read_lock() or RTNL, per Eric Dumazet. The rcu_dereference() in __sk_free() is protected by the fact that it is never reached if an update could change it. Check for this by using rcu_dereference_check() to verify that the struct sock's ->sk_wmem_alloc counter is zero. Acked-by: Eric Dumazet Acked-by: David S. Miller Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1266887105-1528-5-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar --- net/ipv4/route.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/route.c b/net/ipv4/route.c index d62b05d33384..4f11faa5c824 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -287,12 +287,12 @@ static struct rtable *rt_cache_get_first(struct seq_file *seq) if (!rt_hash_table[st->bucket].chain) continue; rcu_read_lock_bh(); - r = rcu_dereference(rt_hash_table[st->bucket].chain); + r = rcu_dereference_bh(rt_hash_table[st->bucket].chain); while (r) { if (dev_net(r->u.dst.dev) == seq_file_net(seq) && r->rt_genid == st->genid) return r; - r = rcu_dereference(r->u.dst.rt_next); + r = rcu_dereference_bh(r->u.dst.rt_next); } rcu_read_unlock_bh(); } @@ -314,7 +314,7 @@ static struct rtable *__rt_cache_get_next(struct seq_file *seq, rcu_read_lock_bh(); r = rt_hash_table[st->bucket].chain; } - return rcu_dereference(r); + return rcu_dereference_bh(r); } static struct rtable *rt_cache_get_next(struct seq_file *seq, @@ -2689,8 +2689,8 @@ int __ip_route_output_key(struct net *net, struct rtable **rp, hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif, rt_genid(net)); rcu_read_lock_bh(); - for (rth = rcu_dereference(rt_hash_table[hash].chain); rth; - rth = rcu_dereference(rth->u.dst.rt_next)) { + for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth; + rth = rcu_dereference_bh(rth->u.dst.rt_next)) { if (rth->fl.fl4_dst == flp->fl4_dst && rth->fl.fl4_src == flp->fl4_src && rth->fl.iif == 0 && @@ -3008,8 +3008,8 @@ int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb) if (!rt_hash_table[h].chain) continue; rcu_read_lock_bh(); - for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt; - rt = rcu_dereference(rt->u.dst.rt_next), idx++) { + for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt; + rt = rcu_dereference_bh(rt->u.dst.rt_next), idx++) { if (!net_eq(dev_net(rt->u.dst.dev), net) || idx < s_idx) continue; if (rt_is_expired(rt)) -- cgit v1.2.3