From 7a47281439ba00b11fc098f36695522184ce5a82 Mon Sep 17 00:00:00 2001 From: Vlad Buslov Date: Mon, 17 Feb 2020 12:12:09 +0200 Subject: net: sched: lock action when translating it to flow_action infra 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 Acked-by: Jiri Pirko Signed-off-by: David S. Miller --- net/sched/act_sample.c | 2 -- net/sched/cls_api.c | 17 +++++++++++------ 2 files changed, 11 insertions(+), 8 deletions(-) (limited to 'net') diff --git a/net/sched/act_sample.c b/net/sched/act_sample.c index ce948c1e24dc..5e2df590bb58 100644 --- a/net/sched/act_sample.c +++ b/net/sched/act_sample.c @@ -267,14 +267,12 @@ 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 c2cdd0fc2e70..610505117780 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -3435,7 +3435,7 @@ 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) @@ -3449,6 +3449,7 @@ 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)) { @@ -3489,13 +3490,13 @@ 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)) { @@ -3509,7 +3510,7 @@ 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); @@ -3560,15 +3561,16 @@ 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++; @@ -3582,6 +3584,9 @@ err_out: 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); -- cgit 1.4.1