[x86/Linux] Add UMThunkStub

Add UMThunkStub method with logic from that of AMD64

src/vm/i386/asmconstants.h

@@ -449,6 +449,10 @@ ASMCONSTANTS_C_ASSERT(CallDescrData__fpReturnSize == offsetof(CallDescrD
 ASMCONSTANTS_C_ASSERT(CallDescrData__pTarget == offsetof(CallDescrData, pTarget))
 ASMCONSTANTS_C_ASSERT(CallDescrData__returnValue == offsetof(CallDescrData, returnValue))
 
+#define UMEntryThunk_m_pUMThunkMarshInfo 0x0C
+#define UMThunkMarshInfo_m_pILStub 0x00
+#define UMThunkMarshInfo_m_cbActualArgSize 0x04
+
 #undef ASMCONSTANTS_C_ASSERT
 #undef ASMCONSTANTS_RUNTIME_ASSERT
 

src/vm/i386/umthunkstub.S

@@ -11,22 +11,132 @@
 //
 NESTED_ENTRY TheUMEntryPrestub, _TEXT, UnhandledExceptionHandlerUnix
  // Preserve argument registers
- push ecx
+ push ebx
  push edx
 
- push eax
+ push eax // UMEntryThunk*
  call C_FUNC(TheUMEntryPrestubWorker)
  pop edx
+ // eax = PCODE
 
  // Restore argument registers
  pop edx
- pop ecx
+ pop ebx
 
  jmp eax // Tail Jmp
 NESTED_END TheUMEntryPrestub, _TEXT
 
 
+#define UMThunkStub_FIXEDALLOCSIZE 0x20
+#define UMThunkStub_UMENTRYTHUNK_OFFSET 0x04
+#define UMThunkStub_THREAD_OFFSET 0x08
+#define UMThunkStub_INT_ARG_OFFSET 0x00
+#define UMThunkStub_EBP_OFFSET (UMThunkStub_FIXEDALLOCSIZE)
+
+
 NESTED_ENTRY UMThunkStub, _TEXT, UnhandledExceptionHandlerUnix
- int 3 // implement here
+ PROLOG_BEG
+ PROLOG_END
+ sub esp, UMThunkStub_FIXEDALLOCSIZE + 4
+
+ mov dword ptr [ebp - UMThunkStub_EBP_OFFSET + UMThunkStub_INT_ARG_OFFSET + 0x00], edi
+ mov dword ptr [ebp - UMThunkStub_EBP_OFFSET + UMThunkStub_INT_ARG_OFFSET + 0x04], esi
+ mov dword ptr [ebp - UMThunkStub_EBP_OFFSET + UMThunkStub_INT_ARG_OFFSET + 0x08], ebx
+ mov dword ptr [ebp - UMThunkStub_EBP_OFFSET + UMThunkStub_INT_ARG_OFFSET + 0x0c], ecx
+
+ mov dword ptr [ebp - UMThunkStub_UMENTRYTHUNK_OFFSET], eax // save UMEntryThunk*
+
+ call C_FUNC(GetThread)
+ test eax, eax
+ jz LOCAL_LABEL(DoThreadSetup)
+
+LOCAL_LABEL(HaveThread):
+
+ mov dword ptr [ebp - UMThunkStub_THREAD_OFFSET], eax // save Thread*
+
+ // FailFast if a native callable method invoked via ldftn and calli.
+ cmp dword ptr [eax + Thread_m_fPreemptiveGCDisabled], 1
+ jz LOCAL_LABEL(InvalidTransition)
+
+ // disable preemptive GC
+ mov dword ptr [eax + Thread_m_fPreemptiveGCDisabled], 1
+
+ // catch returning thread here if a GC is in progress
+ PREPARE_EXTERNAL_VAR g_TrapReturningThreads, eax
+ cmp eax, 0
+ jnz LOCAL_LABEL(DoTrapReturningThreadsTHROW)
+
+LOCAL_LABEL(InCooperativeMode):
+
+ mov eax, dword ptr [ebp - UMThunkStub_UMENTRYTHUNK_OFFSET]
+ mov ebx, dword ptr [eax + UMEntryThunk_m_pUMThunkMarshInfo]
+ mov eax, dword ptr [ebx + UMThunkMarshInfo_m_cbActualArgSize]
+ test eax, eax
+ jnz LOCAL_LABEL(UMThunkStub_CopyStackArgs)
+
+LOCAL_LABEL(UMThunkStub_ArgumentsSetup):
+
+ mov eax, dword ptr [ebp - UMThunkStub_UMENTRYTHUNK_OFFSET]
+ mov ebx, dword ptr [eax + UMEntryThunk_m_pUMThunkMarshInfo]
+ mov eax, dword ptr [ebx + UMThunkMarshInfo_m_pILStub] // eax <- Stub*
+
+ mov edi, dword ptr [ebp - UMThunkStub_EBP_OFFSET + UMThunkStub_INT_ARG_OFFSET + 0x00]
+ mov esi, dword ptr [ebp - UMThunkStub_EBP_OFFSET + UMThunkStub_INT_ARG_OFFSET + 0x04]
+ mov ebx, dword ptr [ebp - UMThunkStub_EBP_OFFSET + UMThunkStub_INT_ARG_OFFSET + 0x08]
+ mov ecx, dword ptr [ebp - UMThunkStub_EBP_OFFSET + UMThunkStub_INT_ARG_OFFSET + 0x0c]
+
+ call eax
+
+LOCAL_LABEL(PostCall):
+
+ mov eax, dword ptr [ebp - UMThunkStub_THREAD_OFFSET]
+ mov dword ptr [eax + Thread_m_fPreemptiveGCDisabled], 0
+
+ lea esp, [ebp - 4] // deallocate arguments
+ EPILOG_BEG
+ EPILOG_END
  ret
+
+LOCAL_LABEL(DoThreadSetup):
+
+ call C_FUNC(CreateThreadBlockThrow)
+ jmp LOCAL_LABEL(HaveThread)
+
+LOCAL_LABEL(InvalidTransition):
+
+ //No arguments to setup , ReversePInvokeBadTransition will failfast
+ call C_FUNC(ReversePInvokeBadTransition)
+
+LOCAL_LABEL(DoTrapReturningThreadsTHROW):
+
+ // extern "C" VOID STDCALL UMThunkStubRareDisableWorker(Thread *pThread, UMEntryThunk *pUMEntryThunk)
+ mov eax, dword ptr [ebp - UMThunkStub_UMENTRYTHUNK_OFFSET]
+ push eax
+ mov eax, dword ptr [ebp - UMThunkStub_THREAD_OFFSET]
+ push eax
+ call C_FUNC(UMThunkStubRareDisableWorker)
+
+ jmp LOCAL_LABEL(InCooperativeMode)
+
+LOCAL_LABEL(UMThunkStub_CopyStackArgs):
+
+ // eax = m_cbActualArgSize
+ sub esp, eax
+ lea esi, [ebp + 0x08]
+ lea edi, [esp]
+
+LOCAL_LABEL(CopyLoop):
+
+ // eax = number of bytes
+ // esi = src
+ // edi = dest
+ // edx = sratch
+
+ add eax, -4
+ mov edx, dword ptr [esi + eax]
+ mov dword ptr [edi + eax], edx
+ jnz LOCAL_LABEL(CopyLoop)
+
+ jmp LOCAL_LABEL(UMThunkStub_ArgumentsSetup)
+
 NESTED_END UMThunkStub, _TEXT

src/vm/stackwalk.cpp

@@ -2677,7 +2677,7 @@ StackWalkAction StackFrameIterator::NextRaw(void)
 
  // We are transitioning from unmanaged code to managed code... lets do some validation of our
  // EH mechanism on platforms that we can.
-#if defined(_DEBUG) && !defined(DACCESS_COMPILE) && defined(_TARGET_X86_)
+#if defined(_DEBUG) && !defined(DACCESS_COMPILE) && (defined(_TARGET_X86_) && !defined(FEATURE_STUBS_AS_IL))
  VerifyValidTransitionFromManagedCode(m_crawl.pThread, &m_crawl);
 #endif // _DEBUG && !DACCESS_COMPILE && _TARGET_X86_
  }