From 724ad13fe1fa66ef3e7acba8af34b02fbeccb597 Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@tailscale.com>
Date: Tue, 7 Jul 2020 08:16:16 -0700
Subject: [PATCH] wgengine/tstun: fix alignment of 64-bit atomic field

We had a test for it, but no 32-bit builder apparently. :(

Fixes #529
---
 wgengine/tstun/tun.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/wgengine/tstun/tun.go b/wgengine/tstun/tun.go
index b04714107..cdba27c8d 100644
--- a/wgengine/tstun/tun.go
+++ b/wgengine/tstun/tun.go
@@ -58,7 +58,8 @@ type TUN struct {
 	// tdev is the underlying TUN device.
 	tdev tun.Device
 
-	lastActivityAtomic int64 // unix seconds of last send or receive
+	_                  [4]byte // force 64-bit alignment of following field on 32-bit
+	lastActivityAtomic int64   // unix seconds of last send or receive
 
 	// buffer stores the oldest unconsumed packet from tdev.
 	// It is made a static buffer in order to avoid allocations.