1 files changed, 105 insertions, 0 deletions
diff --git a/src/runtime/trace_cgo_test.go b/src/runtime/trace_cgo_test.go
new file mode 100644
index 0000000..3f207aa
--- /dev/null
+++ b/src/runtime/trace_cgo_test.go
@@ -0,0 +1,105 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build cgo
+
+package runtime_test
+
+import (
+	"bytes"
+	"fmt"
+	"internal/testenv"
+	"internal/trace"
+	"io"
+	"os"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+// TestTraceUnwindCGO verifies that trace events emitted in cgo callbacks
+// produce the same stack traces and don't cause any crashes regardless of
+// tracefpunwindoff being set to 0 or 1.
+func TestTraceUnwindCGO(t *testing.T) {
+	if *flagQuick {
+		t.Skip("-quick")
+	}
+	testenv.MustHaveGoBuild(t)
+	t.Parallel()
+
+	exe, err := buildTestProg(t, "testprogcgo")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	logs := map[string]*trace.Event{
+		"goCalledFromC":       nil,
+		"goCalledFromCThread": nil,
+	}
+	for _, tracefpunwindoff := range []int{1, 0} {
+		env := fmt.Sprintf("GODEBUG=tracefpunwindoff=%d", tracefpunwindoff)
+		got := runBuiltTestProg(t, exe, "Trace", env)
+		prefix, tracePath, found := strings.Cut(got, ":")
+		if !found || prefix != "trace path" {
+			t.Fatalf("unexpected output:\n%s\n", got)
+		}
+		defer os.Remove(tracePath)
+
+		traceData, err := os.ReadFile(tracePath)
+		if err != nil {
+			t.Fatalf("failed to read trace: %s", err)
+		}
+		events := parseTrace(t, bytes.NewReader(traceData))
+
+		for category := range logs {
+			event := mustFindLog(t, events, category)
+			if wantEvent := logs[category]; wantEvent == nil {
+				logs[category] = event
+			} else if got, want := dumpStack(event), dumpStack(wantEvent); got != want {
+				t.Errorf("%q: got stack:\n%s\nwant stack:\n%s\n", category, got, want)
+			}
+		}
+	}
+}
+
+// mustFindLog returns the EvUserLog event with the given category in events. It
+// fails if no event or multiple events match the category.
+func mustFindLog(t *testing.T, events []*trace.Event, category string) *trace.Event {
+	t.Helper()
+	var candidates []*trace.Event
+	for _, e := range events {
+		if e.Type == trace.EvUserLog && len(e.SArgs) >= 1 && e.SArgs[0] == category {
+			candidates = append(candidates, e)
+		}
+	}
+	if len(candidates) == 0 {
+		t.Errorf("could not find log with category: %q", category)
+	} else if len(candidates) > 1 {
+		t.Errorf("found more than one log with category: %q", category)
+	}
+	return candidates[0]
+}
+
+// dumpStack returns e.Stk as a string.
+func dumpStack(e *trace.Event) string {
+	var buf bytes.Buffer
+	for _, f := range e.Stk {
+		file := strings.TrimPrefix(f.File, runtime.GOROOT())
+		fmt.Fprintf(&buf, "%s\n\t%s:%d\n", f.Fn, file, f.Line)
+	}
+	return buf.String()
+}
+
+// parseTrace parses the given trace or skips the test if the trace is broken
+// due to known issues. Partially copied from runtime/trace/trace_test.go.
+func parseTrace(t *testing.T, r io.Reader) []*trace.Event {
+	res, err := trace.Parse(r, "")
+	if err == trace.ErrTimeOrder {
+		t.Skipf("skipping trace: %v", err)
+	}
+	if err != nil {
+		t.Fatalf("failed to parse trace: %v", err)
+	}
+	return res.Events
+}