From: Vlad Buslov <vladbu@xxxxxxxxxxxx>
[ Upstream commit 7a47281439ba00b11fc098f36695522184ce5a82 ]
In order to remove dependency on rtnl lock, take action's tcfa_lock when
constructing its representation as flow_action_entry structure.
Refactor tcf_sample_get_group() to assume that caller holds tcf_lock and
don't take it manually. This callback is only called from flow_action infra
representation translator which now calls it with tcf_lock held, so this
refactoring is necessary to prevent deadlock.
Allocate memory with GFP_ATOMIC flag for ip_tunnel_info copy because
tcf_tunnel_info_copy() is only called from flow_action representation infra
code with tcf_lock spinlock taken.
Signed-off-by: Vlad Buslov <vladbu@xxxxxxxxxxxx>
Acked-by: Jiri Pirko <jiri@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
include/net/tc_act/tc_tunnel_key.h | 2 +-
net/sched/act_sample.c | 2 --
net/sched/cls_api.c | 17 +++++++++++------
3 files changed, 12 insertions(+), 9 deletions(-)
diff --git a/include/net/tc_act/tc_tunnel_key.h b/include/net/tc_act/tc_tunnel_key.h
index 0689d9bcdf841..2b3df076e5b62 100644
--- a/include/net/tc_act/tc_tunnel_key.h
+++ b/include/net/tc_act/tc_tunnel_key.h
@@ -69,7 +69,7 @@ tcf_tunnel_info_copy(const struct tc_action *a)
if (tun) {
size_t tun_size = sizeof(*tun) + tun->options_len;
struct ip_tunnel_info *tun_copy = kmemdup(tun, tun_size,
- GFP_KERNEL);
+ GFP_ATOMIC);
return tun_copy;
}
diff --git a/net/sched/act_sample.c b/net/sched/act_sample.c
index 74450b0f69fc5..214f4efdd9920 100644
--- a/net/sched/act_sample.c
+++ b/net/sched/act_sample.c
@@ -265,14 +265,12 @@ tcf_sample_get_group(const struct tc_action *a,
struct tcf_sample *s = to_sample(a);
struct psample_group *group;
- spin_lock_bh(&s->tcf_lock);
group = rcu_dereference_protected(s->psample_group,
lockdep_is_held(&s->tcf_lock));
if (group) {
psample_group_take(group);
*destructor = tcf_psample_group_put;
}
- spin_unlock_bh(&s->tcf_lock);
return group;
}
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 7f20fd37e01e0..61aa63cc170b4 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -3436,7 +3436,7 @@ static void tcf_sample_get_group(struct flow_action_entry *entry,
int tc_setup_flow_action(struct flow_action *flow_action,
const struct tcf_exts *exts, bool rtnl_held)
{
- const struct tc_action *act;
+ struct tc_action *act;
int i, j, k, err = 0;
if (!exts)
@@ -3450,6 +3450,7 @@ int tc_setup_flow_action(struct flow_action *flow_action,
struct flow_action_entry *entry;
entry = &flow_action->entries[j];
+ spin_lock_bh(&act->tcfa_lock);
if (is_tcf_gact_ok(act)) {
entry->id = FLOW_ACTION_ACCEPT;
} else if (is_tcf_gact_shot(act)) {
@@ -3490,13 +3491,13 @@ int tc_setup_flow_action(struct flow_action *flow_action,
break;
default:
err = -EOPNOTSUPP;
- goto err_out;
+ goto err_out_locked;
}
} else if (is_tcf_tunnel_set(act)) {
entry->id = FLOW_ACTION_TUNNEL_ENCAP;
err = tcf_tunnel_encap_get_tunnel(entry, act);
if (err)
- goto err_out;
+ goto err_out_locked;
} else if (is_tcf_tunnel_release(act)) {
entry->id = FLOW_ACTION_TUNNEL_DECAP;
} else if (is_tcf_pedit(act)) {
@@ -3510,7 +3511,7 @@ int tc_setup_flow_action(struct flow_action *flow_action,
break;
default:
err = -EOPNOTSUPP;
- goto err_out;
+ goto err_out_locked;
}
entry->mangle.htype = tcf_pedit_htype(act, k);
entry->mangle.mask = tcf_pedit_mask(act, k);
@@ -3561,15 +3562,16 @@ int tc_setup_flow_action(struct flow_action *flow_action,
entry->mpls_mangle.ttl = tcf_mpls_ttl(act);
break;
default:
- goto err_out;
+ goto err_out_locked;
}
} else if (is_tcf_skbedit_ptype(act)) {
entry->id = FLOW_ACTION_PTYPE;
entry->ptype = tcf_skbedit_ptype(act);
} else {
err = -EOPNOTSUPP;
- goto err_out;
+ goto err_out_locked;
}
+ spin_unlock_bh(&act->tcfa_lock);
if (!is_tcf_pedit(act))
j++;
@@ -3583,6 +3585,9 @@ int tc_setup_flow_action(struct flow_action *flow_action,
tc_cleanup_flow_action(flow_action);
return err;
+err_out_locked:
+ spin_unlock_bh(&act->tcfa_lock);
+ goto err_out;
}
EXPORT_SYMBOL(tc_setup_flow_action);
--
2.33.0
