Disable h/w exceptions for coreclr (non-DAC) builds.

Fixes the recursive GC crash. Added FEATURE_ENABLE_HARDWARE_EXCEPTIONS to the PAL sxs exception tests
so the h/w exceptions generated by the test dlls are caught. Also added to SOS/strike project.

Also fixed sos "clrstack -i". The sos data target needed to implement ICorDebugDataTarget4::VirtualUnwind too.

6 files changed, 48 insertions, 5 deletions

diff --git a/src/ToolBox/SOS/Strike/CMakeLists.txt b/src/ToolBox/SOS/Strike/CMakeLists.txt
index edb046e99e..21272082bc 100644
--- a/src/ToolBox/SOS/Strike/CMakeLists.txt
+++ b/src/ToolBox/SOS/Strike/CMakeLists.txt
@@ -84,6 +84,7 @@ if(WIN32)
     ntdll.lib
   )
 else(WIN32)
+  add_definitions(-DFEATURE_ENABLE_HARDWARE_EXCEPTIONS)
   add_definitions(-DPAL_STDCPP_COMPAT=1)
   add_compile_options(-Wno-null-arithmetic)
   add_compile_options(-Wno-format)
diff --git a/src/ToolBox/SOS/Strike/util.cpp b/src/ToolBox/SOS/Strike/util.cpp
index 8066a22ce9..ffc51852dc 100644
--- a/src/ToolBox/SOS/Strike/util.cpp
+++ b/src/ToolBox/SOS/Strike/util.cpp
@@ -4464,6 +4464,9 @@ protected:
 // get an ICorDebugProcess back
 // 
 class SOSDataTarget : public ICorDebugMutableDataTarget
+#ifdef FEATURE_PAL
+, public ICorDebugDataTarget4
+#endif
 {
 public:
     SOSDataTarget() : m_ref(0)
@@ -4478,7 +4481,7 @@ public:
     {
         if (InterfaceId == IID_IUnknown)
         {
-            *pInterface = static_cast<IUnknown *>(this);
+            *pInterface = static_cast<IUnknown *>(static_cast<ICorDebugDataTarget *>(this));
         }
         else if (InterfaceId == IID_ICorDebugDataTarget)
         {
@@ -4488,6 +4491,12 @@ public:
         {
             *pInterface = static_cast<ICorDebugMutableDataTarget *>(this);
         }
+#ifdef FEATURE_PAL
+        else if (InterfaceId == IID_ICorDebugDataTarget4)
+        {
+            *pInterface = static_cast<ICorDebugDataTarget4 *>(this);
+        }
+#endif
         else
         {
             *pInterface = NULL;
@@ -4547,6 +4556,10 @@ public:
         ULONG32 request,
         ULONG32 * pcbRead)
     {
+        if (g_ExtData == NULL)
+        {
+            return E_UNEXPECTED;
+        }
         return g_ExtData->ReadVirtual(address, pBuffer, request, (PULONG) pcbRead);
     }
 
@@ -4557,6 +4570,10 @@ public:
         BYTE * context)
     {
 #ifdef FEATURE_PAL
+        if (g_ExtSystem == NULL)
+        {
+            return E_UNEXPECTED;
+        }
         return g_ExtSystem->GetThreadContextById(dwThreadOSID, contextFlags, contextSize, context);
 #else
         ULONG ulThreadIDOrig;
@@ -4604,6 +4621,10 @@ public:
                                                    const BYTE * pBuffer,
                                                    ULONG32 bytesRequested)
     {
+        if (g_ExtData == NULL)
+        {
+            return E_UNEXPECTED;
+        }
         return g_ExtData->WriteVirtual(address, (PVOID)pBuffer, bytesRequested, NULL);
     }
 
@@ -4620,6 +4641,20 @@ public:
         return E_NOTIMPL;
     }
 
+#ifdef FEATURE_PAL
+    //
+    // ICorDebugDataTarget4
+    //
+    virtual HRESULT STDMETHODCALLTYPE VirtualUnwind(DWORD threadId, ULONG32 contextSize, PBYTE context)
+    {
+        if (g_ExtClient == NULL)
+        {
+            return E_UNEXPECTED;
+        }
+        return g_ExtClient->VirtualUnwind(threadId, contextSize, context);
+
+    }
+#endif // FEATURE_PAL
 
 protected:
     LONG m_ref;
@@ -4629,7 +4664,7 @@ HRESULT InitCorDebugInterfaceFromModule(ULONG64 ulBase, ICLRDebugging * pClrDebu
 {
     HRESULT hr;
 
-    ToRelease<IUnknown> pSOSDataTarget = new SOSDataTarget;
+    ToRelease<ICorDebugMutableDataTarget> pSOSDataTarget = new SOSDataTarget;
     pSOSDataTarget->AddRef();
 
     ToRelease<ICLRDebuggingLibraryProvider> pSOSLibraryProvider = new SOSLibraryProvider;
diff --git a/src/inc/ex.h b/src/inc/ex.h
index bf135fc6e1..6837fa8519 100644
--- a/src/inc/ex.h
+++ b/src/inc/ex.h
@@ -11,6 +11,7 @@ void RetailAssertIfExpectedClean();             // Defined in src/utilcode/debug
 
 #ifdef FEATURE_PAL
 #define EX_TRY_HOLDER                                   \
+    HardwareExceptionHolder                             \
     NativeExceptionHolderCatchAll __exceptionHolder;    \
     __exceptionHolder.Push();                           \
 
diff --git a/src/pal/inc/pal.h b/src/pal/inc/pal.h
index 0bf1fb6de5..c0c9ba70bc 100644
--- a/src/pal/inc/pal.h
+++ b/src/pal/inc/pal.h
@@ -6744,6 +6744,11 @@ public:
     static bool IsEnabled();
 };
 
+//
+// NOTE: Catching hardware exceptions are only enabled in the DAC and SOS 
+// builds. A hardware exception in coreclr code will fail fast/terminate
+// the process.
+//
 #ifdef FEATURE_ENABLE_HARDWARE_EXCEPTIONS
 #define HardwareExceptionHolder CatchHardwareExceptionHolder __catchHardwareException;
 #else
@@ -6760,7 +6765,7 @@ extern "C++" {
 // filter to be called during the first pass to better emulate SEH
 // the xplat platforms that only have C++ exception support.
 //
-class NativeExceptionHolderBase : CatchHardwareExceptionHolder
+class NativeExceptionHolderBase
 {
     // Save the address of the holder head so the destructor 
     // doesn't have access the slow (on Linux) TLS value again.
@@ -6870,6 +6875,7 @@ public:
     };                                                                          \
     try                                                                         \
     {                                                                           \
+        HardwareExceptionHolder                                                 \
         auto __exceptionHolder = NativeExceptionHolderFactory::CreateHolder(&exceptionFilter); \
         __exceptionHolder.Push();                                               \
         tryBlock(__param);                                                      \
diff --git a/src/pal/src/exception/seh.cpp b/src/pal/src/exception/seh.cpp
index 22f8aef499..87bc677296 100644
--- a/src/pal/src/exception/seh.cpp
+++ b/src/pal/src/exception/seh.cpp
@@ -263,7 +263,6 @@ __declspec(thread)
 static NativeExceptionHolderBase *t_nativeExceptionHolderHead = nullptr;
 
 NativeExceptionHolderBase::NativeExceptionHolderBase()
-    : CatchHardwareExceptionHolder()
 {
     m_head = nullptr;
     m_next = nullptr;
diff --git a/src/pal/tests/palsuite/exception_handling/pal_sxs/test1/CMakeLists.txt b/src/pal/tests/palsuite/exception_handling/pal_sxs/test1/CMakeLists.txt
index 949fe9294a..fd9af67414 100644
--- a/src/pal/tests/palsuite/exception_handling/pal_sxs/test1/CMakeLists.txt
+++ b/src/pal/tests/palsuite/exception_handling/pal_sxs/test1/CMakeLists.txt
@@ -3,7 +3,8 @@ cmake_minimum_required(VERSION 2.8.12.2)
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 if(CLR_CMAKE_PLATFORM_UNIX)
-   add_compile_options(-fPIC)
+    add_compile_options(-fPIC)
+    add_definitions(-DFEATURE_ENABLE_HARDWARE_EXCEPTIONS)
 endif(CLR_CMAKE_PLATFORM_UNIX)
 
 # Test DLL1