Delete ThreadAbort support from native AOT (#119173)

dotnet/runtimelab#893 (comment) better 4 years late than never I guess.

Author: MichalStrehovsky

src/coreclr/nativeaot/Runtime.Base/src/System/Runtime/ExceptionHandling.cs

@@ -446,7 +446,6 @@ private enum HwExceptionCode : uint
         {
             STATUS_NATIVEAOT_NULL_REFERENCE = 0x00000000u,
             STATUS_NATIVEAOT_UNMANAGED_HELPER_NULL_REFERENCE = 0x00000042u,
-            STATUS_NATIVEAOT_THREAD_ABORT = 0x00000043u,
 
             STATUS_DATATYPE_MISALIGNMENT = 0x80000002u,
             STATUS_ACCESS_VIOLATION = 0xC0000005u,
@@ -586,12 +585,6 @@ public static void RhThrowHwEx(uint exceptionCode, ref ExInfo exInfo)
                     exceptionId = ExceptionIDs.NullReference;
                     break;
 
-#if NATIVEAOT
-                case (uint)HwExceptionCode.STATUS_NATIVEAOT_THREAD_ABORT:
-                    exceptionToThrow = InternalCalls.RhpGetThreadAbortException();
-                    break;
-#endif
-
                 case (uint)HwExceptionCode.STATUS_DATATYPE_MISALIGNMENT:
                     exceptionId = ExceptionIDs.DataMisaligned;
                     break;

src/coreclr/nativeaot/Runtime.Base/src/System/Runtime/InternalCalls.cs

@@ -232,10 +232,6 @@ internal static extern unsafe IntPtr RhpCallPropagateExceptionCallback(
         internal static extern unsafe void RhpCopyContextFromExInfo(void* pOSContext, int cbOSContext, EH.PAL_LIMITED_CONTEXT* pPalContext);
 #endif
 
-        [RuntimeImport(RuntimeLibrary, "RhpGetThreadAbortException")]
-        [MethodImpl(MethodImplOptions.InternalCall)]
-        internal static extern Exception RhpGetThreadAbortException();
-
         [RuntimeImport(RuntimeLibrary, "RhCurrentNativeThreadId")]
         [MethodImpl(MethodImplOptions.InternalCall)]
         internal static extern unsafe IntPtr RhCurrentNativeThreadId();

src/coreclr/nativeaot/Runtime/AsmOffsets.h

@@ -55,9 +55,8 @@ ASM_OFFSET(   34,    50, Thread, m_pDeferredTransitionFrame)
 ASM_OFFSET(   40,    68, Thread, m_ppvHijackedReturnAddressLocation)
 ASM_OFFSET(   44,    70, Thread, m_pvHijackedReturnAddress)
 ASM_OFFSET(   48,    78, Thread, m_pExInfoStackHead)
-ASM_OFFSET(   4c,    80, Thread, m_threadAbortException)
 #ifdef TARGET_X86
-ASM_OFFSET(   50,    FF, Thread, m_uHijackedReturnValueFlags)
+ASM_OFFSET(   4c,    FF, Thread, m_uHijackedReturnValueFlags)
 #endif
 
 ASM_SIZEOF(   14,    20, EHEnum)

src/coreclr/nativeaot/Runtime/StackFrameIterator.cpp

@@ -1107,7 +1107,7 @@ void StackFrameIterator::UnwindFuncletInvokeThunk()
 
         if (EQUALS_RETURN_ADDRESS(m_ControlPC, RhpCallCatchFunclet2))
         {
-            SP += 3; // 3 locals
+            SP += 2 + 1; // 2 locals and stack alignment
         }
         else
         {
@@ -1143,14 +1143,7 @@ void StackFrameIterator::UnwindFuncletInvokeThunk()
         m_funcletPtrs.pRbx = m_RegDisplay.pRbx;
     }
 
-    if (EQUALS_RETURN_ADDRESS(m_ControlPC, RhpCallCatchFunclet2))
-    {
-        SP += 2; // 2 locals
-    }
-    else
-    {
-        SP++; // 1 local
-    }
+    SP++; // local / stack alignment
     m_RegDisplay.pRdi = SP++;
     m_RegDisplay.pRsi = SP++;
     m_RegDisplay.pRbx = SP++;

src/coreclr/nativeaot/Runtime/amd64/AsmMacros.inc

@@ -359,16 +359,11 @@ PTFF_SAVE_ALL_PRESERVED equ 000000F7h   ;; NOTE: RBP is not included in this set
 PTFF_SAVE_RSP           equ 00008000h
 PTFF_SAVE_RAX           equ 00000100h   ;; RAX is saved in hijack handler - in case it contains a GC ref
 PTFF_SAVE_ALL_SCRATCH   equ 00007F00h
-PTFF_THREAD_ABORT       equ 00100000h   ;; indicates that ThreadAbortException should be thrown when returning from the transition
-PTFF_THREAD_HIJACK      equ 00200000h   ;; indicates that this is a frame for a hijacked call
+PTFF_THREAD_HIJACK      equ 00100000h   ;; indicates that this is a frame for a hijacked call
 
 ;; These must match the TrapThreadsFlags enum
 TrapThreadsFlags_None            equ 0
-TrapThreadsFlags_AbortInProgress equ 1
-TrapThreadsFlags_TrapThreads     equ 2
-
-;; This must match HwExceptionCode.STATUS_NATIVEAOT_THREAD_ABORT
-STATUS_NATIVEAOT_THREAD_ABORT      equ 43h
+TrapThreadsFlags_TrapThreads     equ 1
 
 ;;
 ;; CONSTANTS -- SYMBOLS

src/coreclr/nativeaot/Runtime/amd64/ExceptionHandling.asm

@@ -371,12 +371,11 @@ endm
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 NESTED_ENTRY RhpCallCatchFunclet, _TEXT
 
-        FUNCLET_CALL_PROLOGUE 3, 0
+        FUNCLET_CALL_PROLOGUE 2, 1
 
         ;; locals
         rsp_offsetof_thread = rsp_offsetof_locals
         rsp_offsetof_resume_ip = rsp_offsetof_locals + 8;
-        rsp_offsetof_is_handling_thread_abort = rsp_offsetof_locals + 16;
 
         mov     [rsp + rsp_offsetof_arguments + 0h], rcx            ;; save arguments for later
         mov     [rsp + rsp_offsetof_arguments + 8h], rdx
@@ -386,9 +385,6 @@ NESTED_ENTRY RhpCallCatchFunclet, _TEXT
         INLINE_GETTHREAD    rax, rbx                                ;; rax <- Thread*, rbx is trashed
         mov     [rsp + rsp_offsetof_thread], rax                    ;; save Thread* for later
 
-        cmp     rcx, [rax + OFFSETOF__Thread__m_threadAbortException]
-        setz    byte ptr [rsp + rsp_offsetof_is_handling_thread_abort]
-
         ;; Clear the DoNotTriggerGc state before calling out to our managed catch funclet.
         lock and            dword ptr [rax + OFFSETOF__Thread__m_ThreadStateFlags], NOT TSF_DoNotTriggerGc
 
@@ -508,20 +504,8 @@ endif
         xor     r9, r9                                              ;; r9 <- 0
    endif
 
-        test    [RhpTrapThreads], TrapThreadsFlags_AbortInProgress
-        jz      @f
-
-        ;; test if the exception handled by the catch was the ThreadAbortException
-        cmp     byte ptr [rsp + rsp_offsetof_is_handling_thread_abort], 0
-        je      @f
-
-        ;; It was the ThreadAbortException, so rethrow it
-        mov     rcx, STATUS_NATIVEAOT_THREAD_ABORT
-        mov     rdx, rax                                            ;; rdx <- continuation address as exception RIP
-        lea     rax, [RhpThrowHwEx]                                 ;; Throw the ThreadAbortException as a special kind of hardware exception
-
         ;; reset RSP and jump to RAX
-   @@:  mov     rsp, r8                                             ;; reset the SP to resume SP value
+        mov     rsp, r8                                             ;; reset the SP to resume SP value
 
         ;; if have shadow stack, then we need to reconcile it with the rsp change we have just made. (r11 must contain target SSP)
         rdsspq  r9                                                  ;; NB, r9 == 0 prior to this

src/coreclr/nativeaot/Runtime/amd64/GcProbe.S

@@ -124,16 +124,8 @@ NESTED_ENTRY RhpWaitForGC, _TEXT, NoHandler
         mov         rdi, [rbx + OFFSETOF__Thread__m_pDeferredTransitionFrame]
         call        C_FUNC(RhpWaitForGC2)
 
-        mov         rax, [rbx + OFFSETOF__Thread__m_pDeferredTransitionFrame]
-        test        dword ptr [rax + OFFSETOF__PInvokeTransitionFrame__m_Flags], PTFF_THREAD_ABORT
-        jnz         LOCAL_LABEL(Abort)
         POP_PROBE_FRAME
         ret
-LOCAL_LABEL(Abort):
-        POP_PROBE_FRAME
-        mov         rcx, STATUS_NATIVEAOT_THREAD_ABORT
-        pop         rdx         // return address as exception RIP
-        jmp         C_FUNC(RhpThrowHwEx) // Throw the ThreadAbortException as a special kind of hardware exception
 
 NESTED_END RhpWaitForGC, _TEXT
 

src/coreclr/nativeaot/Runtime/amd64/GcProbe.asm

@@ -107,8 +107,6 @@ NESTED_ENTRY RhpGcProbeHijack, _TEXT
         jmp         RhpWaitForGC
 NESTED_END RhpGcProbeHijack, _TEXT
 
-EXTERN RhpThrowHwEx : PROC
-
 NESTED_ENTRY RhpWaitForGC, _TEXT
         PUSH_PROBE_FRAME rdx, rax, rcx
         END_PROLOGUE
@@ -117,16 +115,8 @@ NESTED_ENTRY RhpWaitForGC, _TEXT
         mov         rcx, [rbx + OFFSETOF__Thread__m_pDeferredTransitionFrame]
         call        RhpWaitForGC2
 
-        mov         rax, [rbx + OFFSETOF__Thread__m_pDeferredTransitionFrame]
-        test        dword ptr [rax + OFFSETOF__PInvokeTransitionFrame__m_Flags], PTFF_THREAD_ABORT
-        jnz         Abort
         POP_PROBE_FRAME
         ret
-Abort:
-        POP_PROBE_FRAME
-        mov         rcx, STATUS_NATIVEAOT_THREAD_ABORT
-        pop         rdx         ;; return address as exception RIP
-        jmp         RhpThrowHwEx ;; Throw the ThreadAbortException as a special kind of hardware exception
 
 NESTED_END RhpWaitForGC, _TEXT
 

src/coreclr/nativeaot/Runtime/arm/GcProbe.S

@@ -88,18 +88,9 @@ NESTED_ENTRY RhpWaitForGC, _TEXT, NoHandler
     ldr         r0, [r2, #OFFSETOF__Thread__m_pDeferredTransitionFrame]
     bl          RhpWaitForGC2
 
-    ldr         r2, [sp, #OFFSETOF__PInvokeTransitionFrame__m_Flags]
-    tst         r2, #PTFF_THREAD_ABORT
-    bne         LOCAL_LABEL(ThrowThreadAbort)
-
     POP_PROBE_FRAME
     bx          lr
 
-LOCAL_LABEL(ThrowThreadAbort):
-    POP_PROBE_FRAME
-    mov         r0, #STATUS_NATIVEAOT_THREAD_ABORT
-    mov         r1, lr // return address as exception PC
-    b           C_FUNC(RhpThrowHwEx)
 NESTED_END RhpWaitForGC
 
 LEAF_ENTRY RhpGcPoll

src/coreclr/nativeaot/Runtime/arm64/AsmMacros.h

@@ -58,22 +58,14 @@ PTFF_SAVE_ALL_SCRATCH   equ 0x3FFFF800  ;; NOTE: X0-X18
 PTFF_SAVE_FP            equ 0x40000000
 PTFF_SAVE_LR            equ 0x80000000
 
-PTFF_THREAD_HIJACK_HI   equ 0x00000002           // upper 32 bits of the PTFF_THREAD_HIJACK
-
-;; Bit position for the flags above, to be used with tbz / tbnz instructions
-PTFF_THREAD_ABORT_BIT   equ 32
+PTFF_THREAD_HIJACK_HI   equ 0x00000001           // upper 32 bits of the PTFF_THREAD_HIJACK
 
 ;; These must match the TrapThreadsFlags enum
 TrapThreadsFlags_None            equ 0
-TrapThreadsFlags_AbortInProgress equ 1
-TrapThreadsFlags_TrapThreads     equ 2
+TrapThreadsFlags_TrapThreads     equ 1
 
 ;; Bit position for the flags above, to be used with tbz / tbnz instructions
-TrapThreadsFlags_AbortInProgress_Bit equ 0
-TrapThreadsFlags_TrapThreads_Bit     equ 1
-
-;; This must match HwExceptionCode.STATUS_NATIVEAOT_THREAD_ABORT
-STATUS_NATIVEAOT_THREAD_ABORT      equ 0x43
+TrapThreadsFlags_TrapThreads_Bit     equ 0
 
 ;;
 ;; Rename fields of nested structs