From: Eric Dumazet Date: Thu, 10 Jan 2008 11:55:57 +0000 (-0800) Subject: [IPV4] ROUTE: fix rcu_dereference() uses in /proc/net/rt_cache X-Git-Tag: v2.6.24-rc8~7^2~11 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=0bcceadceb0907094ba4e40bf9a7cd9b080f13fb;p=linux-2.6-omap-h63xx.git [IPV4] ROUTE: fix rcu_dereference() uses in /proc/net/rt_cache In rt_cache_get_next(), no need to guard seq->private by a rcu_dereference() since seq is private to the thread running this function. Reading seq.private once (as guaranted bu rcu_dereference()) or several time if compiler really is dumb enough wont change the result. But we miss real spots where rcu_dereference() are needed, both in rt_cache_get_first() and rt_cache_get_next() Signed-off-by: Eric Dumazet Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- diff --git a/net/ipv4/route.c b/net/ipv4/route.c index d3377069ce0..28484f396b0 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -283,12 +283,12 @@ static struct rtable *rt_cache_get_first(struct seq_file *seq) break; rcu_read_unlock_bh(); } - return r; + return rcu_dereference(r); } static struct rtable *rt_cache_get_next(struct seq_file *seq, struct rtable *r) { - struct rt_cache_iter_state *st = rcu_dereference(seq->private); + struct rt_cache_iter_state *st = seq->private; r = r->u.dst.rt_next; while (!r) { @@ -298,7 +298,7 @@ static struct rtable *rt_cache_get_next(struct seq_file *seq, struct rtable *r) rcu_read_lock_bh(); r = rt_hash_table[st->bucket].chain; } - return r; + return rcu_dereference(r); } static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)