From 4863bd647afe100d35f61aa08db9ed25f0d5bac1 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Mon, 21 May 2018 14:13:55 +0200
Subject: [PATCH] Add stacktrace via SIGUSR2

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 app/tools/libwg-go/api-android.go | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/app/tools/libwg-go/api-android.go b/app/tools/libwg-go/api-android.go
index 5ea57a9d..a609ec44 100644
--- a/app/tools/libwg-go/api-android.go
+++ b/app/tools/libwg-go/api-android.go
@@ -17,7 +17,10 @@ import (
 	"log"
 	"math"
 	"os"
+	"os/signal"
+	"runtime"
 	"strings"
+	"unsafe"
 )
 
 type AndroidLogger struct {
@@ -34,6 +37,19 @@ var tunnelHandles map[int32]*Device
 
 func init() {
 	tunnelHandles = make(map[int32]*Device)
+	signals := make(chan os.Signal)
+	signal.Notify(signals, unix.SIGUSR2)
+	go func() {
+		buf := make([]byte, os.Getpagesize())
+		for {
+			select {
+			case <-signals:
+				n := runtime.Stack(buf, true)
+				buf[n] = 0
+				C.__android_log_write(C.ANDROID_LOG_ERROR, C.CString("WireGuard/GoBackend/Stacktrace"), (*_Ctype_char)(unsafe.Pointer(&buf[0])))
+			}
+		}
+	}()
 }
 
 //export wgTurnOn
@@ -53,7 +69,6 @@ func wgTurnOn(ifnameRef string, tun_fd int32, settings string) int32 {
 		events: make(chan TUNEvent, 5),
 		errors: make(chan error, 5),
 		nopi:   true,
-		statusListenersShutdown: make(chan struct{}),
 	}
 	var err error