[ARM64/Unix] (#9500)

* [Arm64/Unix] Update arm64 *.S files to match *.asm

* [Arm64/Unix] Fix CONTEXTToNativeContext()

* [Arm64/Unix] ThrowExceptionFromContextInternal

* [Arm64/Unix] Preserve x8 argument register

* [ARM64/Unix] Add CFI directives

Add native unwind info

* [Arm64/Unix] Fix RtlRestoreContext

* [Arm64/Unix] Restore FP from CurrentContextPointers

* [Arm64/Unix] fix pointer math

* [Arm64/Unix] Fix CallDescrWorkerInternal personality

* [Arm64/Unix] More Fp fixups

* [Arm64/Unix] CallEHFunclet machine state

Restore non-volatile machine state in CallEHFunclet

* [Arm64/Unix] CallDescrWorkerInternal

Use empty stack slot to save argument

* [Arm64/Unix] RtlVirtualUnwind update pointers

* [Arm64] LazyMachState fixes

* [Arm64/Unix] disable USE_REDIRECT_FOR_GCSTRESS

When FEATURE_PAL is enableds USE_REDIRECT_FOR_GCSTRESS
is not supported

* [Arm64] ClearRegDisplayArgumentAndScratchRegisters()

* [Arm64] Remove unnecesary copy in TransitionFrame

* [Arm64/Unix] Fix comment per review

* [Arm64/Unix] move constants per review

* [Arm64/Unix] Use ldp per review

Also fix indentation

* [Arm64/Unix] Fix indentation per review

* [Arm64/Unix] Remove m_Unwound per review comments

* [Arm64/Unix] Use PREPARE_EXTERNAL_VAR to access globals

* [Arm64/Unix] Fix more whitespace per earlier review comments

2 files changed, 41 insertions, 16 deletions

diff --git a/src/debug/ee/arm64/dbghelpers.S b/src/debug/ee/arm64/dbghelpers.S
index 07ed04acd5..64932f322b 100644
--- a/src/debug/ee/arm64/dbghelpers.S
+++ b/src/debug/ee/arm64/dbghelpers.S
@@ -1,25 +1,50 @@
-//Licensed to the .NET Foundation under one or more agreements. 
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#include "asmconstants.h"
 #include "unixasmmacros.inc"
 
-NESTED_ENTRY FuncEvalHijack, _TEXT, FuncEvalHijackPersonalityRoutine
+//
+// hijacking stub used to perform a func-eval, see Debugger::FuncEvalSetup() for use.
+//
+// on entry:
+//   x0  : pointer to DebuggerEval object
+//
 
-// NOTE: FuncEvalHijackPersonalityRoutine is dependent on the stack layout so if 
-// you change the prolog you will also need to update the personality routine.
+// @dbgtodo- once we port Funceval, use the ExceptionHijack stub instead of this func-eval stub.
+NESTED_ENTRY FuncEvalHijack, _TEXT, UnhandledExceptionHandlerUnix
 
-// push arg to the stack so our personality routine can find it 
-// push lr to get good stacktrace in debugger    
+    // NOTE: FuncEvalHijackPersonalityRoutine is dependent on the stack layout so if
+    //       you change the prolog you will also need to update the personality routine.
 
-PROLOG_SAVE_REG_PAIR  fp, lr, #-32
+    // push arg to the stack so our personality routine can find it
+    // push lr to get good stacktrace in debugger
+    PROLOG_SAVE_REG_PAIR_INDEXED   fp, lr, -32
+    str x0, [sp, #16]
+    // FuncEvalHijackWorker returns the address we should jump to.
+    bl FuncEvalHijackWorker
+
+    EPILOG_STACK_FREE 32
+    EPILOG_BRANCH_REG x0
+NESTED_END FuncEvalHijack
+
+// This is the general purpose hijacking stub. The DacDbi Hijack primitive will
+// set up the stack and then set the IP here, and so this just makes the call.
+NESTED_ENTRY ExceptionHijack, _TEXT, UnhandledExceptionHandlerUnix
+
+    // make the call
+    bl ExceptionHijackWorker
+
+    // effective NOP to terminate unwind
+    mov x3, x3
+
+    // *** should never get here ***
+    EMIT_BREAKPOINT
+
+// exported label so the debugger knows where the end of this function is
+PATCH_LABEL ExceptionHijackEnd
+
+NESTED_END ExceptionHijack, _TEXT
 
-	str x0, [sp, #16]
-	// FuncEvalHijackWorker returns the address we should jump to.    
-	bl FuncEvalHijackWorker
-	
-	EPILOG_STACK_FREE 32
-	EPILOG_BRANCH_REG x0
-NESTED_END FuncEvalHijack, _TEXT
 
-//NESTED_ENTRY ExceptionHijack,,ExceptionHijackPersonalityRoutine
\ No newline at end of file
diff --git a/src/debug/ee/wks/CMakeLists.txt b/src/debug/ee/wks/CMakeLists.txt
index 1088355f12..4c4c537607 100644
--- a/src/debug/ee/wks/CMakeLists.txt
+++ b/src/debug/ee/wks/CMakeLists.txt
@@ -58,7 +58,7 @@ add_compile_options(-fPIC)
 if(CLR_CMAKE_PLATFORM_ARCH_AMD64 OR CLR_CMAKE_PLATFORM_ARCH_ARM OR CLR_CMAKE_PLATFORM_ARCH_ARM64 OR CLR_CMAKE_PLATFORM_ARCH_I386)
   add_library_clr(cordbee_wks ${CORDBEE_SOURCES_WKS} ../${ARCH_SOURCES_DIR}/dbghelpers.S)
 elseif(CLR_CMAKE_PLATFORM_ARCH_ARM64)
-  add_library_clr(cordbee_wks ${CORDBEE_SOURCES_WKS})
+  add_library_clr(cordbee_wks ${CORDBEE_SOURCES_WKS} ../${ARCH_SOURCES_DIR}/dbghelpers.S)
 else()
   message(FATAL_ERROR "Only ARM and AMD64 is supported")
 endif()