From: John Fastabend <john.fastabend@gmail.com>
Date: Thu, 5 Jul 2018 08:06:01 -0700
Subject: bpf: sockmap, hash table is RCU so readers do not need locks
Patch-mainline: v4.18-rc6
Git-commit: 1d1ef005dbc6de673c62cbd2562290ada3090463
References: bsc#1109837

This removes locking from readers of RCU hash table. Its not
necessary.

Fixes: 81110384441a ("bpf: sockmap, add hash map support")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 kernel/bpf/sockmap.c |    2 --
 1 file changed, 2 deletions(-)

--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -2449,10 +2449,8 @@ struct sock  *__sock_hash_lookup_elem(st
 	b = __select_bucket(htab, hash);
 	head = &b->head;
 
-	raw_spin_lock_bh(&b->lock);
 	l = lookup_elem_raw(head, hash, key, key_size);
 	sk = l ? l->sk : NULL;
-	raw_spin_unlock_bh(&b->lock);
 	return sk;
 }