1 files changed, 43 insertions, 0 deletions
diff --git a/src/runtime/testdata/testprogcgo/stackswitch.go b/src/runtime/testdata/testprogcgo/stackswitch.go
new file mode 100644
index 0000000..a2e422f
--- /dev/null
+++ b/src/runtime/testdata/testprogcgo/stackswitch.go
@@ -0,0 +1,43 @@
+// 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 unix && !android && !openbsd
+
+package main
+
+/*
+void callStackSwitchCallbackFromThread(void);
+*/
+import "C"
+
+import (
+	"fmt"
+	"runtime/debug"
+)
+
+func init() {
+	register("StackSwitchCallback", StackSwitchCallback)
+}
+
+//export stackSwitchCallback
+func stackSwitchCallback() {
+	// We want to trigger a bounds check on the g0 stack. To do this, we
+	// need to call a splittable function through systemstack().
+	// SetGCPercent contains such a systemstack call.
+	gogc := debug.SetGCPercent(100)
+	debug.SetGCPercent(gogc)
+}
+
+
+// Regression test for https://go.dev/issue/62440. It should be possible for C
+// threads to call into Go from different stacks without crashing due to g0
+// stack bounds checks.
+//
+// N.B. This is only OK for threads created in C. Threads with Go frames up the
+// stack must not change the stack out from under us.
+func StackSwitchCallback() {
+	C.callStackSwitchCallbackFromThread();
+
+	fmt.Printf("OK\n")
+}