From 77151ccf10659d4066074f278402032f3265f0cc Mon Sep 17 00:00:00 2001 From: Toke Høiland-Jørgensen Date: Thu, 24 Jun 2021 18:05:56 +0200 Subject: bpf, sched: Remove unneeded rcu_read_lock() around BPF program invocation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The rcu_read_lock() call in cls_bpf and act_bpf are redundant: on the TX side, there's already a call to rcu_read_lock_bh() in __dev_queue_xmit(), and on RX there's a covering rcu_read_lock() in netif_receive_skb{,_list}_internal(). With the previous patches we also amended the lockdep checks in the map code to not require any particular RCU flavour, so we can just get rid of the rcu_read_lock()s. Suggested-by: Daniel Borkmann Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20210624160609.292325-7-toke@redhat.com --- net/sched/act_bpf.c | 2 -- net/sched/cls_bpf.c | 3 --- 2 files changed, 5 deletions(-) (limited to 'net/sched') diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c index e48e980c3b93..e409a0005717 100644 --- a/net/sched/act_bpf.c +++ b/net/sched/act_bpf.c @@ -43,7 +43,6 @@ static int tcf_bpf_act(struct sk_buff *skb, const struct tc_action *act, tcf_lastuse_update(&prog->tcf_tm); bstats_cpu_update(this_cpu_ptr(prog->common.cpu_bstats), skb); - rcu_read_lock(); filter = rcu_dereference(prog->filter); if (at_ingress) { __skb_push(skb, skb->mac_len); @@ -56,7 +55,6 @@ static int tcf_bpf_act(struct sk_buff *skb, const struct tc_action *act, } if (skb_sk_is_prefetched(skb) && filter_res != TC_ACT_OK) skb_orphan(skb); - rcu_read_unlock(); /* A BPF program may overwrite the default action opcode. * Similarly as in cls_bpf, if filter_res == -1 we use the diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c index 6e3e63db0e01..fa739efa59f4 100644 --- a/net/sched/cls_bpf.c +++ b/net/sched/cls_bpf.c @@ -85,8 +85,6 @@ static int cls_bpf_classify(struct sk_buff *skb, const struct tcf_proto *tp, struct cls_bpf_prog *prog; int ret = -1; - /* Needed here for accessing maps. */ - rcu_read_lock(); list_for_each_entry_rcu(prog, &head->plist, link) { int filter_res; @@ -131,7 +129,6 @@ static int cls_bpf_classify(struct sk_buff *skb, const struct tcf_proto *tp, break; } - rcu_read_unlock(); return ret; } -- cgit v1.2.3