Fix race getcaller

entry.go

@@ -156,20 +156,23 @@ func getPackageName(f string) string {
 
 // getCaller retrieves the name of the first non-logrus calling function
 func getCaller() *runtime.Frame {
-	// Restrict the lookback frames to avoid runaway lookups
-	pcs := make([]uintptr, maximumCallerDepth)
-	depth := runtime.Callers(minimumCallerDepth, pcs)
-	frames := runtime.CallersFrames(pcs[:depth])
 
 	// cache this package's fully-qualified name
 	callerInitOnce.Do(func() {
-		logrusPackage = getPackageName(runtime.FuncForPC(pcs[0]).Name())
+		pcs := make([]uintptr, 2)
+		_ = runtime.Callers(0, pcs)
+		logrusPackage = getPackageName(runtime.FuncForPC(pcs[1]).Name())
 
 		// now that we have the cache, we can skip a minimum count of known-logrus functions
-		// XXX this is dubious, the number of frames may vary store an entry in a logger interface
+		// XXX this is dubious, the number of frames may vary
 		minimumCallerDepth = knownLogrusFrames
 	})
 
+	// Restrict the lookback frames to avoid runaway lookups
+	pcs := make([]uintptr, maximumCallerDepth)
+	depth := runtime.Callers(minimumCallerDepth, pcs)
+	frames := runtime.CallersFrames(pcs[:depth])
+
 	for f, again := frames.Next(); again; f, again = frames.Next() {
 		pkg := getPackageName(f.Function)
 

logrus_test.go

@@ -743,3 +743,20 @@ func TestReportCallerOnTextFormatter(t *testing.T) {
 	l.Formatter.(*TextFormatter).DisableColors = true
 	l.WithFields(Fields{"func": "func", "file": "file"}).Info("test")
 }
+
+func TestSetReportCallerRace(t *testing.T) {
+	l := New()
+	l.Out = ioutil.Discard
+	l.SetReportCaller(true)
+
+	var wg sync.WaitGroup
+	wg.Add(100)
+
+	for i := 0; i < 100; i++ {
+		go func() {
+			l.Error("Some Error")
+			wg.Done()
+		}()
+	}
+	wg.Wait()
+}