Apple silicon debugger (#47834)

* Use PAL_JITWriteEnable in debug/ee/controller.cpp

* Fix breakpoint exception handling on macos

* Fix Arm64SingleStepper for osx W^X

* Fix DebuggerHeapExecutableMemoryPage for W^X

* Fix DebuggerEval::DebuggerEval() during W^X

src/coreclr/debug/ee/controller.cpp

@@ -1364,6 +1364,9 @@ bool DebuggerController::ApplyPatch(DebuggerControllerPatch *patch)
 
         LPVOID baseAddress = (LPVOID)(patch->address);
 
+#if defined(HOST_OSX) && defined(HOST_ARM64)
+        auto jitWriteEnableHolder = PAL_JITWriteEnable(true);
+#else // defined(HOST_OSX) && defined(HOST_ARM64)
         DWORD oldProt;
 
         if (!VirtualProtect(baseAddress,
@@ -1373,12 +1376,14 @@ bool DebuggerController::ApplyPatch(DebuggerControllerPatch *patch)
             _ASSERTE(!"VirtualProtect of code page failed");
             return false;
         }
+#endif // defined(HOST_OSX) && defined(HOST_ARM64)
 
         patch->opcode = CORDbgGetInstruction(patch->address);
 
         CORDbgInsertBreakpoint((CORDB_ADDRESS_TYPE *)patch->address);
         LOG((LF_CORDB, LL_EVERYTHING, "Breakpoint was inserted at %p for opcode %x\n", patch->address, patch->opcode));
 
+#if !defined(HOST_OSX) || !defined(HOST_ARM64)
         if (!VirtualProtect(baseAddress,
                             CORDbg_BREAK_INSTRUCTION_SIZE,
                             oldProt, &oldProt))
@@ -1386,6 +1391,7 @@ bool DebuggerController::ApplyPatch(DebuggerControllerPatch *patch)
             _ASSERTE(!"VirtualProtect of code page failed");
             return false;
         }
+#endif // !defined(HOST_OSX) || !defined(HOST_ARM64)
     }
 // TODO: : determine if this is needed for AMD64
 #if defined(TARGET_X86) //REVISIT_TODO what is this?!
@@ -1454,6 +1460,9 @@ bool DebuggerController::UnapplyPatch(DebuggerControllerPatch *patch)
 
         LPVOID baseAddress = (LPVOID)(patch->address);
 
+#if defined(HOST_OSX) && defined(HOST_ARM64)
+        auto jitWriteEnableHolder = PAL_JITWriteEnable(true);
+#else // defined(HOST_OSX) && defined(HOST_ARM64)
         DWORD oldProt;
 
         if (!VirtualProtect(baseAddress,
@@ -1468,6 +1477,7 @@ bool DebuggerController::UnapplyPatch(DebuggerControllerPatch *patch)
             InitializePRD(&(patch->opcode));
             return false;
         }
+#endif // defined(HOST_OSX) && defined(HOST_ARM64)
 
         CORDbgSetInstruction((CORDB_ADDRESS_TYPE *)patch->address, patch->opcode);
 
@@ -1476,6 +1486,7 @@ bool DebuggerController::UnapplyPatch(DebuggerControllerPatch *patch)
         //header file comment)
         InitializePRD(&(patch->opcode));
 
+#if !defined(HOST_OSX) || !defined(HOST_ARM64)
         if (!VirtualProtect(baseAddress,
                             CORDbg_BREAK_INSTRUCTION_SIZE,
                             oldProt, &oldProt))
@@ -1483,6 +1494,7 @@ bool DebuggerController::UnapplyPatch(DebuggerControllerPatch *patch)
             _ASSERTE(!"VirtualProtect of code page failed");
             return false;
         }
+#endif // !defined(HOST_OSX) || !defined(HOST_ARM64)
     }
     else
     {

src/coreclr/debug/ee/debugger.cpp

@@ -1381,6 +1381,10 @@ DebuggerEval::DebuggerEval(CONTEXT * pContext, DebuggerIPCE_FuncEvalInfo * pEval
 {
     WRAPPER_NO_CONTRACT;
 
+#if defined(HOST_OSX) && defined(HOST_ARM64)
+    auto jitWriteEnableHolder = PAL_JITWriteEnable(true);
+#endif // defined(HOST_OSX) && defined(HOST_ARM64)
+
     // Allocate the breakpoint instruction info in executable memory.
     m_bpInfoSegment = new (interopsafeEXEC, nothrow) DebuggerEvalBreakpointInfoSegment(this);
 

src/coreclr/debug/ee/debugger.h

@@ -1114,6 +1114,10 @@ struct DECLSPEC_ALIGN(4096) DebuggerHeapExecutableMemoryPage
 
     inline void SetNextPage(DebuggerHeapExecutableMemoryPage* nextPage)
     {
+#if defined(HOST_OSX) && defined(HOST_ARM64)
+        auto jitWriteEnableHolder = PAL_JITWriteEnable(true);
+#endif // defined(HOST_OSX) && defined(HOST_ARM64)
+
         chunks[0].bookkeeping.nextPage = nextPage;
     }
 
@@ -1124,6 +1128,10 @@ struct DECLSPEC_ALIGN(4096) DebuggerHeapExecutableMemoryPage
 
     inline void SetPageOccupancy(uint64_t newOccupancy)
     {
+#if defined(HOST_OSX) && defined(HOST_ARM64)
+        auto jitWriteEnableHolder = PAL_JITWriteEnable(true);
+#endif // defined(HOST_OSX) && defined(HOST_ARM64)
+
         // Can't unset first bit of occupancy!
         ASSERT((newOccupancy & 0x8000000000000000) != 0);
 
@@ -1137,6 +1145,10 @@ struct DECLSPEC_ALIGN(4096) DebuggerHeapExecutableMemoryPage
 
     DebuggerHeapExecutableMemoryPage()
     {
+#if defined(HOST_OSX) && defined(HOST_ARM64)
+        auto jitWriteEnableHolder = PAL_JITWriteEnable(true);
+#endif // defined(HOST_OSX) && defined(HOST_ARM64)
+
         SetPageOccupancy(0x8000000000000000); // only the first bit is set.
         for (uint8_t i = 1; i < sizeof(chunks)/sizeof(chunks[0]); i++)
         {

src/coreclr/vm/arm64/arm64singlestepper.cpp

@@ -206,6 +206,9 @@ void Arm64SingleStepper::Apply(T_CONTEXT *pCtx)
     //     control in the breakpoint fixup logic we can then reset the PC to its proper location.
 
     unsigned int idxNextInstruction = 0;
+#if defined(HOST_OSX) && defined(HOST_ARM64)
+    auto jitWriteEnableHolder = PAL_JITWriteEnable(true);
+#endif // defined(HOST_OSX) && defined(HOST_ARM64)
 
     if (TryEmulate(pCtx, opcode, false))
     {

src/coreclr/vm/exceptionhandling.cpp

@@ -5191,11 +5191,11 @@ BOOL HandleHardwareException(PAL_SEHException* ex)
         Thread *pThread = GetThread();
         if (pThread != NULL && g_pDebugInterface != NULL)
         {
-            // On ARM and ARM64 Linux exception point to the break instruction.
+#if (defined(TARGET_ARM) || defined(TARGET_ARM64))
+            // On ARM and ARM64 exception point to the break instruction.
             // See https://static.docs.arm.com/ddi0487/db/DDI0487D_b_armv8_arm.pdf#page=6916&zoom=100,0,152
             // at aarch64/exceptions/debug/AArch64.SoftwareBreakpoint
             // However, the rest of the code expects that it points to an instruction after the break.
-#if defined(__linux__) && (defined(TARGET_ARM) || defined(TARGET_ARM64))
             if (ex->GetExceptionRecord()->ExceptionCode == STATUS_BREAKPOINT)
             {
                 SetIP(ex->GetContextRecord(), GetIP(ex->GetContextRecord()) + CORDbg_BREAK_INSTRUCTION_SIZE);