runtime/pprof: include labels for caller of goroutine profile

The goroutine profile has close to three code paths for adding a
goroutine record to the goroutine profile: one for the goroutine that
requested the profile, one for every other goroutine, plus some special
handling for the finalizer goroutine. The first of those captured the
goroutine stack, but neglected to include that goroutine's labels.

Update the tests to check for the inclusion of labels for all three
types of goroutines, and include labels for the creator of the goroutine
profile.

For #63712

Change-Id: Id5387a5f536d3c37268c240e0b6db3d329a3d632
Reviewed-on: https://go-review.googlesource.com/c/go/+/537515
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Auto-Submit: Rhys Hiltner <rhys@justin.tv>
Reviewed-by: David Chase <drchase@google.com>

src/runtime/mprof.go

@@ -930,6 +930,9 @@ func goroutineProfileWithLabelsConcurrent(p []StackRecord, labels []unsafe.Point
 	systemstack(func() {
 		saveg(pc, sp, ourg, &p[0])
 	})
+	if labels != nil {
+		labels[0] = ourg.labels
+	}
 	ourg.goroutineProfiled.Store(goroutineProfileSatisfied)
 	goroutineProfile.offset.Store(1)
 

src/runtime/pprof/pprof_test.go

@@ -1419,6 +1419,23 @@ func TestGoroutineCounts(t *testing.T) {
 		}
 	})
 
+	SetGoroutineLabels(WithLabels(context.Background(), Labels("self-label", "self-value")))
+	defer SetGoroutineLabels(context.Background())
+
+	garbage := new(*int)
+	fingReady := make(chan struct{})
+	runtime.SetFinalizer(garbage, func(v **int) {
+		Do(context.Background(), Labels("fing-label", "fing-value"), func(ctx context.Context) {
+			close(fingReady)
+			<-c
+		})
+	})
+	garbage = nil
+	for i := 0; i < 2; i++ {
+		runtime.GC()
+	}
+	<-fingReady
+
 	var w bytes.Buffer
 	goroutineProf := Lookup("goroutine")
 
@@ -1428,8 +1445,22 @@ func TestGoroutineCounts(t *testing.T) {
 
 	labels := labelMap{"label": "value"}
 	labelStr := "\n# labels: " + labels.String()
-	if !containsInOrder(prof, "\n50 @ ", "\n44 @", labelStr,
-		"\n40 @", "\n36 @", labelStr, "\n10 @", "\n9 @", labelStr, "\n1 @") {
+	selfLabel := labelMap{"self-label": "self-value"}
+	selfLabelStr := "\n# labels: " + selfLabel.String()
+	fingLabel := labelMap{"fing-label": "fing-value"}
+	fingLabelStr := "\n# labels: " + fingLabel.String()
+	orderedPrefix := []string{
+		"\n50 @ ",
+		"\n44 @", labelStr,
+		"\n40 @",
+		"\n36 @", labelStr,
+		"\n10 @",
+		"\n9 @", labelStr,
+		"\n1 @"}
+	if !containsInOrder(prof, append(orderedPrefix, selfLabelStr)...) {
+		t.Errorf("expected sorted goroutine counts with Labels:\n%s", prof)
+	}
+	if !containsInOrder(prof, append(orderedPrefix, fingLabelStr)...) {
 		t.Errorf("expected sorted goroutine counts with Labels:\n%s", prof)
 	}
 
@@ -1450,7 +1481,7 @@ func TestGoroutineCounts(t *testing.T) {
 		36: {"label": "value"},
 		10: {},
 		9:  {"label": "value"},
-		1:  {},
+		1:  {"self-label": "self-value", "fing-label": "fing-value"},
 	}
 	if !containsCountsLabels(p, expectedLabels) {
 		t.Errorf("expected count profile to contain goroutines with counts and labels %v, got %v",