Implement test checking whether CET is active (#71509)

As part of Control Flow Enforcement Technology (CET) testing we need
to make sure that CET is actually active on the execution machines;
otherwise subtle infra changes could easily regress the testing by
inadvertently deactivating CET without anyone noticing. This change
introduces an initial CET availability test for this purpose.

Thanks

Tomas

4 files changed, 49 insertions, 0 deletions

diff --git a/src/tests/baseservices/CET/CETCheck.cpp b/src/tests/baseservices/CET/CETCheck.cpp
new file mode 100644
index 00000000000..0c8d9d2d381
--- /dev/null
+++ b/src/tests/baseservices/CET/CETCheck.cpp
@@ -0,0 +1,11 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+#if defined(TARGET_AMD64) && defined(TARGET_WINDOWS)
+#include <intrin.h>
+
+extern "C" __declspec(dllexport) __int64 ReadShadowStackPointer()
+{
+    return _rdsspq();
+}
+#endif
diff --git a/src/tests/baseservices/CET/CMakeLists.txt b/src/tests/baseservices/CET/CMakeLists.txt
new file mode 100644
index 00000000000..226738c71f8
--- /dev/null
+++ b/src/tests/baseservices/CET/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_library(cet_check SHARED CETCheck.cpp)
+
+# add the install targets
+install (TARGETS cet_check DESTINATION bin)
diff --git a/src/tests/baseservices/CET/CheckCETPresence.cs b/src/tests/baseservices/CET/CheckCETPresence.cs
new file mode 100644
index 00000000000..656fcadfb7c
--- /dev/null
+++ b/src/tests/baseservices/CET/CheckCETPresence.cs
@@ -0,0 +1,20 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Runtime.InteropServices;
+
+static class Program
+{
+    [DllImport("cet_check.dll")]
+    private static extern long ReadShadowStackPointer();
+    
+    public static int Main()
+    {
+        Console.WriteLine("Checking whether codeflow enforcement technology (CET) is active");
+        long ssp = ReadShadowStackPointer();
+        Console.WriteLine("Shadow stack pointer: 0x{0:x16}", ssp);
+        // Non-zero shadow stack pointer value confirms that CET is active on the runtime processor.
+        return ssp != 0 ? 100 : 101;
+    }
+}
diff --git a/src/tests/baseservices/CET/CheckCETPresence.csproj b/src/tests/baseservices/CET/CheckCETPresence.csproj
new file mode 100644
index 00000000000..845ff56e1c7
--- /dev/null
+++ b/src/tests/baseservices/CET/CheckCETPresence.csproj
@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <RequiresCodeFlowEnforcement>true</RequiresCodeFlowEnforcement>
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
+    <CLRTestTargetUnsupported Condition="'$(TargetArchitecture)' != 'x64' or '$(TargetOS)' != 'windows'">true</CLRTestTargetUnsupported>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildProjectName).cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <CMakeProjectReference Include="CMakeLists.txt" />
+  </ItemGroup>
+</Project>