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| author | WANG Cong <xiyou.wangcong@gmail.com> | 2017-06-13 13:36:24 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-06-14 14:39:19 -0400 |
| commit | 74030603dfd9f76c0f279f19f1dd1ee3028fee7a (patch) | |
| tree | 27b6e967e99232169cadc0420099717f241a38f3 /net | |
| parent | 20a3d5bf5e5b13c02450ab6178ec374abd830686 (diff) | |
| download | linux-74030603dfd9f76c0f279f19f1dd1ee3028fee7a.tar.gz | |
net_sched: move tcf_lock down after gen_replace_estimator()
Laura reported a sleep-in-atomic kernel warning inside tcf_act_police_init() which calls gen_replace_estimator() with spinlock protection. It is not necessary in this case, we already have RTNL lock here so it is enough to protect concurrent writers. For the reader, i.e. tcf_act_police(), it needs to make decision based on this rate estimator, in the worst case we drop more/less packets than necessary while changing the rate in parallel, it is still acceptable. Reported-by: Laura Abbott <labbott@redhat.com> Reported-by: Nick Huber <nicholashuber@gmail.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sched/act_police.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/net/sched/act_police.c b/net/sched/act_police.c index f42008b29311..b062bc80c7cb 100644 --- a/net/sched/act_police.c +++ b/net/sched/act_police.c @@ -132,21 +132,21 @@ static int tcf_act_police_init(struct net *net, struct nlattr *nla, } } - spin_lock_bh(&police->tcf_lock); if (est) { err = gen_replace_estimator(&police->tcf_bstats, NULL, &police->tcf_rate_est, &police->tcf_lock, NULL, est); if (err) - goto failure_unlock; + goto failure; } else if (tb[TCA_POLICE_AVRATE] && (ret == ACT_P_CREATED || !gen_estimator_active(&police->tcf_rate_est))) { err = -EINVAL; - goto failure_unlock; + goto failure; } + spin_lock_bh(&police->tcf_lock); /* No failure allowed after this point */ police->tcfp_mtu = parm->mtu; if (police->tcfp_mtu == 0) { @@ -192,8 +192,6 @@ static int tcf_act_police_init(struct net *net, struct nlattr *nla, return ret; -failure_unlock: - spin_unlock_bh(&police->tcf_lock); failure: qdisc_put_rtab(P_tab); qdisc_put_rtab(R_tab); |