From 4e29e9ec7e0707d3925f5dcc29af0d3f04e49833 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Wed, 27 Feb 2008 12:07:47 -0800 Subject: [PATCH] [NETFILTER]: nf_conntrack: fix smp_processor_id() in preemptible code warning Since we're using RCU for the conntrack hash now, we need to avoid getting preempted or interrupted by BHs while changing the stats. Fixes warning reported by Tilman Schmidt when using preemptible RCU: [ 48.180297] BUG: using smp_processor_id() in preemptible [00000000] code: ntpdate/3562 [ 48.180297] caller is __nf_conntrack_find+0x9b/0xeb [nf_conntrack] [ 48.180297] Pid: 3562, comm: ntpdate Not tainted 2.6.25-rc2-mm1-testing #1 [ 48.180297] [] debug_smp_processor_id+0x99/0xb0 [ 48.180297] [] __nf_conntrack_find+0x9b/0xeb [nf_conntrack] Tested-by: Tilman Schmidt Tested-by: Christian Casteyde [Bugzilla #10097] Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/netfilter/nf_conntrack_core.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 327e847d2702..b77eb56a87e3 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -256,13 +256,19 @@ __nf_conntrack_find(const struct nf_conntrack_tuple *tuple) struct hlist_node *n; unsigned int hash = hash_conntrack(tuple); + /* Disable BHs the entire time since we normally need to disable them + * at least once for the stats anyway. + */ + local_bh_disable(); hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash], hnode) { if (nf_ct_tuple_equal(tuple, &h->tuple)) { NF_CT_STAT_INC(found); + local_bh_enable(); return h; } NF_CT_STAT_INC(searched); } + local_bh_enable(); return NULL; } @@ -400,17 +406,20 @@ nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, struct hlist_node *n; unsigned int hash = hash_conntrack(tuple); - rcu_read_lock(); + /* Disable BHs the entire time since we need to disable them at + * least once for the stats anyway. + */ + rcu_read_lock_bh(); hlist_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash], hnode) { if (nf_ct_tuplehash_to_ctrack(h) != ignored_conntrack && nf_ct_tuple_equal(tuple, &h->tuple)) { NF_CT_STAT_INC(found); - rcu_read_unlock(); + rcu_read_unlock_bh(); return 1; } NF_CT_STAT_INC(searched); } - rcu_read_unlock(); + rcu_read_unlock_bh(); return 0; } -- 2.20.1