From b9d451406decb5cab037cc3a473547e0eb940370 Mon Sep 17 00:00:00 2001
From: georlav <georlav@gmail.com>
Date: Mon, 4 Mar 2019 20:38:10 +0200
Subject: [PATCH 1/2] fix ReportCaller race condition

---
 entry.go       |  2 ++
 logrus_test.go | 17 +++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/entry.go b/entry.go
index fd377286c..4ca6081d3 100644
--- a/entry.go
+++ b/entry.go
@@ -206,7 +206,9 @@ func (entry Entry) log(level Level, msg string) {
 	entry.Level = level
 	entry.Message = msg
 	if entry.Logger.ReportCaller {
+		entry.Logger.mu.Lock()
 		entry.Caller = getCaller()
+		entry.Logger.mu.Unlock()
 	}
 
 	entry.fireHooks()
diff --git a/logrus_test.go b/logrus_test.go
index dfa053bbd..72b6ea254 100644
--- a/logrus_test.go
+++ b/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()
+}

From cf1b9fd15e80ce9ce658546d333f031de2d08331 Mon Sep 17 00:00:00 2001
From: David Bariod <davidriod@googlemail.com>
Date: Wed, 6 Mar 2019 14:08:02 +0100
Subject: [PATCH 2/2] fix sync.Once usage instead of adding a mutex lock

---
 entry.go | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/entry.go b/entry.go
index 4ca6081d3..191621487 100644
--- a/entry.go
+++ b/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)
 
@@ -206,9 +209,7 @@ func (entry Entry) log(level Level, msg string) {
 	entry.Level = level
 	entry.Message = msg
 	if entry.Logger.ReportCaller {
-		entry.Logger.mu.Lock()
 		entry.Caller = getCaller()
-		entry.Logger.mu.Unlock()
 	}
 
 	entry.fireHooks()