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[IPV4] ROUTE: fix rcu_dereference() uses in /proc/net/rt_cache
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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 <dada1@cosmosbay.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Eric Dumazet authored and David S. Miller committed Jan 10, 2008
1 parent 9cd4002 commit 0bccead
Showing 1 changed file with 3 additions and 3 deletions.
6 changes: 3 additions & 3 deletions net/ipv4/route.c
Original file line number Diff line number Diff line change
@@ -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)

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