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Diffstat (limited to 'src/vm/i386/remotingx86.cpp')
| -rw-r--r-- | src/vm/i386/remotingx86.cpp | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/src/vm/i386/remotingx86.cpp b/src/vm/i386/remotingx86.cpp new file mode 100644 index 0000000000..3a9e891267 --- /dev/null +++ b/src/vm/i386/remotingx86.cpp @@ -0,0 +1,225 @@ +// 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. +// +// +// +// File: remotingx86.cpp +// + +// +// +// Purpose: Defines various remoting related functions for the x86 architecture +// + +// +// + +// + +#include "common.h" + +#ifdef FEATURE_REMOTING + +#include "excep.h" +#include "comdelegate.h" +#include "remoting.h" +#include "field.h" +#include "siginfo.hpp" +#include "stackbuildersink.h" +#include "threads.h" +#include "method.hpp" +#include "asmconstants.h" +#include "interoputil.h" +#include "virtualcallstub.h" + +#ifdef FEATURE_COMINTEROP +#include "comcallablewrapper.h" +#include "comcache.h" +#endif // FEATURE_COMINTEROP + +//+---------------------------------------------------------------------------- +// +// Method: CTPMethodTable::CreateThunkForVirtualMethod private +// +// Synopsis: Creates the thunk that pushes the supplied slot number and jumps +// to TP Stub +// +//+---------------------------------------------------------------------------- +PCODE CTPMethodTable::CreateThunkForVirtualMethod(DWORD dwSlot, BYTE *startaddr) +{ + CONTRACTL + { + NOTHROW; + GC_NOTRIGGER; + MODE_ANY; + PRECONDITION(CheckPointer(startaddr)); + } + CONTRACTL_END; + + BYTE *pCode = startaddr; + + // 0000 B8 67 45 23 01 MOV EAX, dwSlot + // 0005 E9 ?? ?? ?? ?? JMP TransparentProxyStub + *pCode++ = 0xB8; + *((DWORD *) pCode) = dwSlot; + pCode += sizeof(DWORD); + *pCode++ = 0xE9; + // self-relative call, based on the start of the next instruction. + *((LONG *) pCode) = (LONG)((size_t)GetTPStubEntryPoint() - (size_t) (pCode + sizeof(LONG))); + + _ASSERTE(CVirtualThunkMgr::IsThunkByASM((PCODE)startaddr)); + + return (PCODE)startaddr; +} + + +//+---------------------------------------------------------------------------- +// +// Method: CTPMethodTable::ActivatePrecodeRemotingThunk private +// +// Synopsis: Patch the precode remoting thunk to begin interception +// +//+---------------------------------------------------------------------------- +void CTPMethodTable::ActivatePrecodeRemotingThunk() +{ + CONTRACTL + { + THROWS; + GC_TRIGGERS; + MODE_ANY; + } + CONTRACTL_END; + + // Before activation: + // 0000 C3 ret + // 0001 90 nop + + // After activation: + // 0000 85 C9 test ecx,ecx + + // 0002 74 XX je RemotingDone + // 0004 81 39 XX XX XX XX cmp dword ptr [ecx],11111111h + // 000A 74 XX je RemotingCheck + + // Switch offset and size of patch based on the jump opcode used. + BYTE* pCode = (BYTE*)PrecodeRemotingThunk; + + SIZE_T mtOffset = 0x0006; + SIZE_T size = 0x000A; + + // Patch "ret + nop" to "test ecx,ecx" + *(UINT16 *)pCode = 0xC985; + + // Replace placeholder value with the actual address of TP method table + _ASSERTE(*(PVOID*)(pCode+mtOffset) == (PVOID*)0x11111111); + *(PVOID*)(pCode+mtOffset) = GetMethodTable(); + + FlushInstructionCache(GetCurrentProcess(), pCode, size); +} + +//+---------------------------------------------------------------------------- +// +// Method: CVirtualThunkMgr::DoTraceStub public +// +// Synopsis: Traces the stub given the starting address +// +//+---------------------------------------------------------------------------- +BOOL CVirtualThunkMgr::DoTraceStub(PCODE stubStartAddress, TraceDestination *trace) +{ + CONTRACTL + { + NOTHROW; + GC_NOTRIGGER; + MODE_ANY; + PRECONDITION(stubStartAddress != NULL); + PRECONDITION(CheckPointer(trace)); + } + CONTRACTL_END; + + BOOL bIsStub = FALSE; + + // Find a thunk whose code address matching the starting address + LPBYTE pThunk = FindThunk((LPBYTE)stubStartAddress); + if(NULL != pThunk) + { + LPBYTE pbAddr = NULL; + LONG destAddress = 0; + if((LPBYTE)stubStartAddress == pThunk) + { + + // Extract the long which gives the self relative address + // of the destination + pbAddr = pThunk + sizeof(BYTE) + sizeof(DWORD) + sizeof(BYTE); + destAddress = *(LONG *)pbAddr; + + // Calculate the absolute address by adding the offset of the next + // instruction after the call instruction + destAddress += (LONG)(size_t)(pbAddr + sizeof(LONG)); + + } + + // We cannot tell where the stub will end up until OnCall is reached. + // So we tell the debugger to run till OnCall is reached and then + // come back and ask us again for the actual destination address of + // the call + + Stub *stub = Stub::RecoverStub((TADDR)destAddress); + + trace->InitForFramePush(stub->GetPatchAddress()); + bIsStub = TRUE; + } + + return bIsStub; +} + +//+---------------------------------------------------------------------------- +// +// Method: CVirtualThunkMgr::IsThunkByASM public +// +// Synopsis: Check assembly to see if this one of our thunks +// +//+---------------------------------------------------------------------------- +BOOL CVirtualThunkMgr::IsThunkByASM(PCODE startaddr) +{ + CONTRACTL + { + NOTHROW; + GC_NOTRIGGER; + MODE_ANY; + PRECONDITION(startaddr != NULL); + } + CONTRACTL_END; + + PTR_BYTE pbCode = PTR_BYTE(startaddr); + + return ((pbCode[0] == 0xB8) && + (pbCode[5] == 0xe9) && + (rel32Decode((TADDR)(pbCode + 6)) == CTPMethodTable::GetTPStubEntryPoint())); +} + +//+---------------------------------------------------------------------------- +// +// Method: CVirtualThunkMgr::GetMethodDescByASM public +// +// Synopsis: Parses MethodDesc out of assembly code +// +//+---------------------------------------------------------------------------- +MethodDesc *CVirtualThunkMgr::GetMethodDescByASM(PCODE startaddr, MethodTable *pMT) +{ + CONTRACT (MethodDesc*) + { + NOTHROW; + GC_NOTRIGGER; + MODE_ANY; + PRECONDITION(startaddr != NULL); + PRECONDITION(CheckPointer(pMT)); + POSTCONDITION(CheckPointer(RETVAL)); + } + CONTRACT_END; + + RETURN (pMT->GetMethodDescForSlot(*((DWORD *) (startaddr + 1)))); +} + +#endif// FEATURE_REMOTING + |