From: Vlad Buslov vladbu@mellanox.com
[ 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@mellanox.com Acked-by: Jiri Pirko jiri@mellanox.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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);