5 files changed, 147 insertions, 5 deletions
diff --git a/src/runtime/signal_windows_test.go b/src/runtime/signal_windows_test.go
index 8b32ad8974..fe74ad56bf 100644
--- a/src/runtime/signal_windows_test.go
+++ b/src/runtime/signal_windows_test.go
@@ -17,6 +17,61 @@ import (
 	"testing"
 )
 
+func TestVectoredHandlerExceptionInNonGoThread(t *testing.T) {
+	if *flagQuick {
+		t.Skip("-quick")
+	}
+	testenv.MustHaveGoBuild(t)
+	testenv.MustHaveCGO(t)
+	testenv.MustHaveExecPath(t, "g++")
+	testprog.Lock()
+	defer testprog.Unlock()
+	dir := t.TempDir()
+
+	// build c program
+	dll := filepath.Join(dir, "veh.dll")
+	cmd := exec.Command("g++", "-shared", "-o", dll, "testdata/testwinlibthrow/veh.cpp", "-static", "-lstdc++")
+	out, err := testenv.CleanCmdEnv(cmd).CombinedOutput()
+	if err != nil {
+		t.Fatalf("failed to build c exe: %s\n%s", err, out)
+	}
+
+	// build go exe
+	exe := filepath.Join(dir, "test.exe")
+	cmd = exec.Command(testenv.GoToolPath(t), "build", "-o", exe, "testdata/testwinlibthrow/main.go")
+	out, err = testenv.CleanCmdEnv(cmd).CombinedOutput()
+	if err != nil {
+		t.Fatalf("failed to build go library: %s\n%s", err, out)
+	}
+
+	// run test program in same thread
+	cmd = exec.Command(exe)
+	out, err = testenv.CleanCmdEnv(cmd).CombinedOutput()
+	if err == nil {
+		t.Fatal("error expected")
+	}
+	if _, ok := err.(*exec.ExitError); ok && len(out) > 0 {
+		if !bytes.Contains(out, []byte("Exception 0x2a")) {
+			t.Fatalf("unexpected failure while running executable: %s\n%s", err, out)
+		}
+	} else {
+		t.Fatalf("unexpected error while running executable: %s\n%s", err, out)
+	}
+	// run test program in a new thread
+	cmd = exec.Command(exe, "thread")
+	out, err = testenv.CleanCmdEnv(cmd).CombinedOutput()
+	if err == nil {
+		t.Fatal("error expected")
+	}
+	if err, ok := err.(*exec.ExitError); ok {
+		if err.ExitCode() != 42 {
+			t.Fatalf("unexpected failure while running executable: %s\n%s", err, out)
+		}
+	} else {
+		t.Fatalf("unexpected error while running executable: %s\n%s", err, out)
+	}
+}
+
 func TestVectoredHandlerDontCrashOnLibrary(t *testing.T) {
 	if *flagQuick {
 		t.Skip("-quick")
diff --git a/src/runtime/sys_windows_arm.s b/src/runtime/sys_windows_arm.s
index 5dc576a260..db6d8f1a08 100644
--- a/src/runtime/sys_windows_arm.s
+++ b/src/runtime/sys_windows_arm.s
@@ -123,8 +123,14 @@ TEXT sigtramp<>(SB),NOSPLIT|NOFRAME,$0
 	MOVW	R1, R7			// Save param1
 
 	BL      runtime·load_g(SB)
-	CMP	$0, g			// is there a current g?
-	BL.EQ	runtime·badsignal2(SB)
+	CMP	$0,	g		// is there a current g?
+	BNE	g_ok
+	ADD	$(8+20), R13	// free locals
+	MOVM.IA.W (R13), [R3, R4-R11, R14]	// pop {r3, r4-r11, lr}
+	MOVW	$0, R0		// continue 
+	BEQ	return
+
+g_ok:
 
 	// save g and SP in case of stack switch
 	MOVW	R13, 24(R13)
diff --git a/src/runtime/sys_windows_arm64.s b/src/runtime/sys_windows_arm64.s
index b39df4f124..4702a4d7d2 100644
--- a/src/runtime/sys_windows_arm64.s
+++ b/src/runtime/sys_windows_arm64.s
@@ -147,10 +147,15 @@ TEXT sigtramp<>(SB),NOSPLIT|NOFRAME,$0
 	MOVD	g, R17 			// saved R28 (callee-save from Windows, not really g)
 
 	BL      runtime·load_g(SB)	// smashes R0, R27, R28 (g)
-	CMP	$0, g			// is there a current g?
-	BNE	2(PC)
-	BL	runtime·badsignal2(SB)
+	CMP	$0,	g		// is there a current g?
+	BNE	g_ok
+	MOVD	R7, LR
+	MOVD	R16, R27	// restore R27
+	MOVD	R17, g		// restore R28
+	MOVD	$0, R0		// continue 
+	RET
 
+g_ok:
 	// Do we need to switch to the g0 stack?
 	MOVD	g, R3			// R3 = oldg (for sigtramp_g0)
 	MOVD	g_m(g), R2		// R2 = m
diff --git a/src/runtime/testdata/testwinlibthrow/main.go b/src/runtime/testdata/testwinlibthrow/main.go
new file mode 100644
index 0000000000..50c483f401
--- /dev/null
+++ b/src/runtime/testdata/testwinlibthrow/main.go
@@ -0,0 +1,23 @@
+package main
+
+import (
+	"os"
+	"syscall"
+)
+
+func main() {
+	dll := syscall.MustLoadDLL("veh.dll")
+	RaiseExcept := dll.MustFindProc("RaiseExcept")
+	RaiseNoExcept := dll.MustFindProc("RaiseNoExcept")
+	ThreadRaiseExcept := dll.MustFindProc("ThreadRaiseExcept")
+	ThreadRaiseNoExcept := dll.MustFindProc("ThreadRaiseNoExcept")
+
+	thread := len(os.Args) > 1 && os.Args[1] == "thread"
+	if !thread {
+		RaiseExcept.Call()
+		RaiseNoExcept.Call()
+	} else {
+		ThreadRaiseExcept.Call()
+		ThreadRaiseNoExcept.Call()
+	}
+}
diff --git a/src/runtime/testdata/testwinlibthrow/veh.cpp b/src/runtime/testdata/testwinlibthrow/veh.cpp
new file mode 100644
index 0000000000..ed7015a064
--- /dev/null
+++ b/src/runtime/testdata/testwinlibthrow/veh.cpp
@@ -0,0 +1,53 @@
+//go:build ignore
+
+#include <windows.h>
+
+extern "C" __declspec(dllexport)
+void RaiseExcept(void)
+{
+    try
+    {
+        RaiseException(42, 0, 0, 0);
+    }
+    catch (...)
+    {
+    }
+}
+
+extern "C" __declspec(dllexport)
+void RaiseNoExcept(void)
+{
+    RaiseException(42, 0, 0, 0);
+}
+
+static DWORD WINAPI ThreadRaiser(void* Context)
+{
+    if (Context)
+        RaiseExcept();
+    else
+        RaiseNoExcept();
+    return 0;
+}
+
+static void ThreadRaiseXxx(int except)
+{
+    static int dummy;
+    HANDLE thread = CreateThread(0, 0, ThreadRaiser, except ? &dummy : 0, 0, 0);
+    if (0 != thread)
+    {
+        WaitForSingleObject(thread, INFINITE);
+        CloseHandle(thread);
+    }
+}
+
+extern "C" __declspec(dllexport)
+void ThreadRaiseExcept(void)
+{
+    ThreadRaiseXxx(1);
+}
+
+extern "C" __declspec(dllexport)
+void ThreadRaiseNoExcept(void)
+{
+    ThreadRaiseXxx(0);
+}