diff options
Diffstat (limited to 'target/linux/generic/backport-5.4/080-wireguard-0101-wireguard-send-receive-use-explicit-unlikely-branch-.patch')
| -rw-r--r-- | target/linux/generic/backport-5.4/080-wireguard-0101-wireguard-send-receive-use-explicit-unlikely-branch-.patch | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0101-wireguard-send-receive-use-explicit-unlikely-branch-.patch b/target/linux/generic/backport-5.4/080-wireguard-0101-wireguard-send-receive-use-explicit-unlikely-branch-.patch new file mode 100644 index 0000000000..900e2f2350 --- /dev/null +++ b/target/linux/generic/backport-5.4/080-wireguard-0101-wireguard-send-receive-use-explicit-unlikely-branch-.patch @@ -0,0 +1,88 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: "Jason A. Donenfeld" <Jason@zx2c4.com> +Date: Wed, 6 May 2020 15:33:06 -0600 +Subject: [PATCH] wireguard: send/receive: use explicit unlikely branch instead + of implicit coalescing + +commit 243f2148937adc72bcaaa590d482d599c936efde upstream. + +It's very unlikely that send will become true. It's nearly always false +between 0 and 120 seconds of a session, and in most cases becomes true +only between 120 and 121 seconds before becoming false again. So, +unlikely(send) is clearly the right option here. + +What happened before was that we had this complex boolean expression +with multiple likely and unlikely clauses nested. Since this is +evaluated left-to-right anyway, the whole thing got converted to +unlikely. So, we can clean this up to better represent what's going on. + +The generated code is the same. + +Suggested-by: Sultan Alsawaf <sultan@kerneltoast.com> +Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> +Signed-off-by: David S. Miller <davem@davemloft.net> +Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> +--- + drivers/net/wireguard/receive.c | 13 ++++++------- + drivers/net/wireguard/send.c | 15 ++++++--------- + 2 files changed, 12 insertions(+), 16 deletions(-) + +--- a/drivers/net/wireguard/receive.c ++++ b/drivers/net/wireguard/receive.c +@@ -226,21 +226,20 @@ void wg_packet_handshake_receive_worker( + static void keep_key_fresh(struct wg_peer *peer) + { + struct noise_keypair *keypair; +- bool send = false; ++ bool send; + + if (peer->sent_lastminute_handshake) + return; + + rcu_read_lock_bh(); + keypair = rcu_dereference_bh(peer->keypairs.current_keypair); +- if (likely(keypair && READ_ONCE(keypair->sending.is_valid)) && +- keypair->i_am_the_initiator && +- unlikely(wg_birthdate_has_expired(keypair->sending.birthdate, +- REJECT_AFTER_TIME - KEEPALIVE_TIMEOUT - REKEY_TIMEOUT))) +- send = true; ++ send = keypair && READ_ONCE(keypair->sending.is_valid) && ++ keypair->i_am_the_initiator && ++ wg_birthdate_has_expired(keypair->sending.birthdate, ++ REJECT_AFTER_TIME - KEEPALIVE_TIMEOUT - REKEY_TIMEOUT); + rcu_read_unlock_bh(); + +- if (send) { ++ if (unlikely(send)) { + peer->sent_lastminute_handshake = true; + wg_packet_send_queued_handshake_initiation(peer, false); + } +--- a/drivers/net/wireguard/send.c ++++ b/drivers/net/wireguard/send.c +@@ -124,20 +124,17 @@ void wg_packet_send_handshake_cookie(str + static void keep_key_fresh(struct wg_peer *peer) + { + struct noise_keypair *keypair; +- bool send = false; ++ bool send; + + rcu_read_lock_bh(); + keypair = rcu_dereference_bh(peer->keypairs.current_keypair); +- if (likely(keypair && READ_ONCE(keypair->sending.is_valid)) && +- (unlikely(atomic64_read(&keypair->sending.counter.counter) > +- REKEY_AFTER_MESSAGES) || +- (keypair->i_am_the_initiator && +- unlikely(wg_birthdate_has_expired(keypair->sending.birthdate, +- REKEY_AFTER_TIME))))) +- send = true; ++ send = keypair && READ_ONCE(keypair->sending.is_valid) && ++ (atomic64_read(&keypair->sending.counter.counter) > REKEY_AFTER_MESSAGES || ++ (keypair->i_am_the_initiator && ++ wg_birthdate_has_expired(keypair->sending.birthdate, REKEY_AFTER_TIME))); + rcu_read_unlock_bh(); + +- if (send) ++ if (unlikely(send)) + wg_packet_send_queued_handshake_initiation(peer, false); + } + |