1 files changed, 13 insertions, 0 deletions
diff --git a/libgo/go/runtime/export_test.go b/libgo/go/runtime/export_test.go
index fcc1e6199a4..cc4b188b60c 100644
--- a/libgo/go/runtime/export_test.go
+++ b/libgo/go/runtime/export_test.go
@@ -243,3 +243,16 @@ func CountPagesInUse() (pagesInUse, counted uintptr) {
 	return
 }
 */
+
+// BlockOnSystemStack switches to the system stack, prints "x\n" to
+// stderr, and blocks in a stack containing
+// "runtime.blockOnSystemStackInternal".
+func BlockOnSystemStack() {
+	systemstack(blockOnSystemStackInternal)
+}
+
+func blockOnSystemStackInternal() {
+	print("x\n")
+	lock(&deadlock)
+	lock(&deadlock)
+}