[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 <tilman@imap.cc> 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]  [<c02015b9>] debug_smp_processor_id+0x99/0xb0
[   48.180297]  [<fac643a7>] __nf_conntrack_find+0x9b/0xeb [nf_conntrack]

Tested-by: Tilman Schmidt <tilman@imap.cc>
Tested-by: Christian Casteyde <casteyde.christian@free.fr> [Bugzilla #10097]

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2008-02-27 12:07:47 -08:00 committed by David S. Miller
parent 3bdfe7ec08
commit 4e29e9ec7e
1 changed files with 12 additions and 3 deletions

View File

@ -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;
}