ringlogger: hook into global panic writer

This is a grotesque hack, and hopefully upstream Go will provide a nicer
way of doing this, but already it seems quite adept at catching panics.
See https://github.com/golang/go/issues/42888 for more info.

This requires us to rewrite the ringlogger path to avoid all
allocations.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

5 files changed, 0 insertions, 23 deletions

diff --git a/manager/interfacecleanup.go b/manager/interfacecleanup.go
index b6c8d6ae..58ed6615 100644
--- a/manager/interfacecleanup.go
+++ b/manager/interfacecleanup.go
@@ -18,8 +18,6 @@ import (
 )
 
 func cleanupStaleWintunInterfaces() {
-	defer printPanic()
-
 	m, err := mgr.Connect()
 	if err != nil {
 		return
diff --git a/manager/ipc_server.go b/manager/ipc_server.go
index 94d24e6f..19298016 100644
--- a/manager/ipc_server.go
+++ b/manager/ipc_server.go
@@ -467,7 +467,6 @@ func IPCServerListen(reader *os.File, writer *os.File, events *os.File, elevated
 	}
 
 	go func() {
-		defer printPanic()
 		managerServicesLock.Lock()
 		managerServices[service] = true
 		managerServicesLock.Unlock()
diff --git a/manager/service.go b/manager/service.go
index 2afd796f..f439c186 100644
--- a/manager/service.go
+++ b/manager/service.go
@@ -7,12 +7,9 @@ package manager
 
 import (
 	"errors"
-	"fmt"
 	"log"
 	"os"
 	"runtime"
-	"runtime/debug"
-	"strings"
 	"sync"
 	"syscall"
 	"time"
@@ -30,17 +27,6 @@ import (
 
 type managerService struct{}
 
-func printPanic() {
-	if x := recover(); x != nil {
-		for _, line := range append([]string{fmt.Sprint(x)}, strings.Split(string(debug.Stack()), "\n")...) {
-			if len(strings.TrimSpace(line)) > 0 {
-				log.Println(line)
-			}
-		}
-		panic(x)
-	}
-}
-
 func (service *managerService) Execute(args []string, r <-chan svc.ChangeRequest, changes chan<- svc.Status) (svcSpecificEC bool, exitCode uint32) {
 	changes <- svc.Status{State: svc.StartPending}
 
@@ -61,7 +47,6 @@ func (service *managerService) Execute(args []string, r <-chan svc.ChangeRequest
 		serviceError = services.ErrorRingloggerOpen
 		return
 	}
-	defer printPanic()
 
 	log.Println("Starting", version.UserAgent())
 
@@ -268,7 +253,6 @@ func (service *managerService) Execute(args []string, r <-chan svc.ChangeRequest
 	goStartProcess := func(session uint32) {
 		procsGroup.Add(1)
 		go func() {
-			defer printPanic()
 			startProcess(session)
 			procsGroup.Done()
 		}()
diff --git a/manager/tunneltracker.go b/manager/tunneltracker.go
index 6d376e4a..cfd28693 100644
--- a/manager/tunneltracker.go
+++ b/manager/tunneltracker.go
@@ -196,8 +196,6 @@ func trackService(service *mgr.Service, callback func(status uint32) bool) error
 }
 
 func trackTunnelService(tunnelName string, service *mgr.Service) {
-	defer printPanic()
-
 	defer func() {
 		service.Close()
 		log.Printf("[%s] Tunnel service tracker finished", tunnelName)
diff --git a/manager/updatestate.go b/manager/updatestate.go
index 9686e92f..e926e63d 100644
--- a/manager/updatestate.go
+++ b/manager/updatestate.go
@@ -24,8 +24,6 @@ const (
 var updateState = UpdateStateUnknown
 
 func checkForUpdates() {
-	defer printPanic()
-
 	if !version.IsRunningOfficialVersion() {
 		log.Println("Build is not official, so updates are disabled")
 		updateState = UpdateStateUpdatesDisabledUnofficialBuild