SMPFunction.cpp

	//    the block with the same stack pointer delta as previously,
	//    and pop it off the work list
	//    otherwise declare the stack pointer to be un-analyzeable;
	//  else
	//     iterate through all instructions in the block, analyzing
	//     the stack pointer delta of each inst and accumulating current delta
	//     At the end of the block, put the successor blocks on the work list.
	// For both cases, maintain and update reaching definitions sets, and the
	//  UpExposed and VarKill sets that are used by LVA as well as reaching defs analysis.
	bool ReprocessingAllocaBlocks = false;
	bool ReachesInChanged;
	bool ReachesOutChanged = false;
	do {
		SMPBasicBlock *CurrBlock = WorkList.front().first;
		sval_t IncomingDelta = WorkList.front().second;

		if (CurrBlock->IsProcessed()) { // already processed
			ReachesOutChanged = false;
#if 0
			ReachesInChanged = CurrBlock->ComputeReachesInSet();
			if (ReachesInChanged) {
				ReachesOutChanged = CurrBlock->ComputeReachesOutSet();
			}
#else
			if (CurrBlock->IsReachesOutStale()) {
				ReachesOutChanged = CurrBlock->ComputeReachesOutSet();
			}
#endif
			if (ReachesOutChanged) {
				// Push the successor blocks onto the work list
				sval_t SuccIncomingDelta = CurrBlock->GetOutgoingStackDelta();
				list<SMPBasicBlock *>::iterator SuccIter;
				for (SuccIter = CurrBlock->GetFirstSucc(); SuccIter != CurrBlock->GetLastSucc(); ++SuccIter) {
					pair<SMPBasicBlock *, sval_t> SuccPair (*SuccIter, SuccIncomingDelta);
					WorkList.push_back(SuccPair);
				}
			}
			InstIter = CurrBlock->GetFirstInstr();
			sval_t PrevIncomingDelta = (*InstIter)->GetStackPtrOffset();
			if (IncomingDelta == PrevIncomingDelta) {
				// No error, already processed.
				WorkList.pop_front(); // discard already processed block.
			}
#if 1
			else if (this->CallsAlloca || this->HasPushAfterFrameAlloc()) {
#else
			else {
#endif
				ConflictingValuesSeen = true;
				// Calls to alloca() become additional stack allocations, which can produce
				//  multiple possible stack deltas for an instruction if different paths
				//  to the instruction do not hit the same alloca() calls, so it is not
				//  an error to have conflicting deltas in the functions that call alloca().
				//  We want to converge to the smallest magnitude deltas, which are the greatest
				//  values because the deltas are negative. This is the opposite of IDA Pro, which
				//  seems to use the largest stack deltas it has seen.
				if (PrevIncomingDelta >= IncomingDelta) {
					// Old incoming delta should be retained.
					WorkList.pop_front(); // discard already processed block.
				}
				else {
					CurrBlock->SetProcessed(false);
					ReprocessingAllocaBlocks = true;
					DeltaIncrement = IncomingDelta - PrevIncomingDelta;
					continue;  // Make the loop come around and process this block again, using
							   //  the new incoming delta. Because we do this only when it decreases
							   //  the stack size as seen by this block, no infinite loop is possible.
				}
			}
#if 1
			else {
				this->AnalyzedSP = false;
				SMP_msg("ERROR: Stack delta: PrevIncoming is %d NewIncoming is %d at %x\n",
					PrevIncomingDelta, IncomingDelta, (*InstIter)->GetAddr());
				WorkList.clear();
			}
#endif
		}
		else { // not already processed
			// ReprocessingAllocaBlocks => Reaching definitions sets have already been computed; just need to do stack delta analysis
			ReachesOutChanged = false;
#if 0
			ReachesInChanged = CurrBlock->ComputeReachesInSet();
			if (ReachesInChanged && ReprocessingAllocaBlocks) {
				// Because block is not truly being processed for the first time, the ReachesOut set can be
				//  recomputed without processing instructions, as the DEDefs set and VarKill set will never
				//  change after the first pass through the block.
				ReachesOutChanged = CurrBlock->ComputeReachesOutSet();
			}

			if (CurrBlock->IsReachesOutStale()) {
				ReachesOutChanged = CurrBlock->ComputeReachesOutSet();
			}
#endif
			CurrBlock->SetProcessed(true);
			WorkList.pop_front();
			for (InstIter = CurrBlock->GetFirstInstr(); InstIter != CurrBlock->GetLastInstr(); ++InstIter) {
				CurrInst = (*InstIter);
				if (CurrInst->IsFloatNop()) {
					continue; // skip marker instruction
				}
				ea_t InstAddr = CurrInst->GetAddr();
				if (InstAddr == this->GetFirstFrameAllocInstAddr()) {
					// Record the reset point for frame deallocations
					this->PreAllocStackDelta = IncomingDelta;
				}

				CurrInst->SetStackPtrOffset(IncomingDelta);

				// Search for tail calls, defined strictly as having an incoming stack delta of zero and
				//  being jumps to far chunks.
				if ((0 == IncomingDelta) && (CurrInst->IsBranchToFarChunk())) {
					CurrInst->SetTailCall();
#if 0
					SMP_msg("Found tail call at %x from %s: %s\n", InstAddr, this->GetFuncName(),
							CurrInst->GetDisasm());
#endif
				}

#if SMP_COMPARE_IDA_STARS_STACK_POINTER_DELTAS
				if (DebugFlag && IDAProSucceeded && !(this->CallsAlloca || this->HasPushAfterFrameAlloc())) {
					sval_t IDAProDelta = get_spd(this->GetFuncInfo(), InstAddr);
					if ((IDAProDelta != IncomingDelta) && (!CurrInst->MDIsHaltInstr())) {
						// IDA Pro special-cases the HALT instruction to make it appear that the
						//  incoming stack delta is zero. We do no such special case delta adjudstment,
						//  so we suppress error messages, as our delta will be non-zero.
						SMP_msg("ERROR: At %x IDA Pro has stack pointer delta of %d and we compute %d\n", InstAddr,
							IDAProDelta, IncomingDelta);
					}
				}
				if (TraceFlag) {
					SMP_msg("INFO: Stack delta trace: %d at %x\n", IncomingDelta, InstAddr);
				}
#endif

				// As soon as the stack ptr offset has been set for the current instruction, we can normalize
				//  all of its stack DEFs and USEs.
				bool StackOpsChanged = CurrInst->MDNormalizeStackOps(UseFP, this->GetFramePtrStackDelta(), ReprocessingAllocaBlocks, DeltaIncrement);

				// Dataflow equation for upward exposed variables: If a variable has not been
				//  killed yet in this block, starting from the top of the block, and it is used
				//  in the current instruction, then it is upwardly exposed.
				set<DefOrUse, LessDefUse>::iterator CurrUse;
				if (!ReprocessingAllocaBlocks) { // Only compute on first pass through block
					for (CurrUse = CurrInst->GetFirstUse(); CurrUse != CurrInst->GetLastUse(); ++CurrUse) {
						op_t UseOp = CurrUse->GetOp();
						CanonicalizeOpnd(UseOp);
						if (MDIsDataFlowOpnd(UseOp, this->UsesFramePointer())) {
							// We have a register or stack operand. If stack operand, it is normalized, i.e. EBP-4 might be ESP-8,
							//  where the ESP-8 refers to the value of ESP upon entry to the function, not its current value.
							//  This normalization makes each stack location uniquely named (no aliases at different code locations due
							//  to different values of ESP at different code locations).
							// We only track certain kinds of operands in our data flow analyses.
							// Only add non-immediate operands that are not already killed in this block.
							//  o_near and o_far operands are code addresses in immediate form, e.g.
							//  call _printf might be call 0x8048040, with o_near = 0x8048040.
							if (!(CurrBlock->MDAlreadyKilled(UseOp))) {
								CurrBlock->AddUpExposed(UseOp);
							}
						}
					}
				}

				// Find stack pointer saves and restores.
				bool StackPtrSaved;
				sval_t SavedDelta;
				op_t CopyOperand;
				bool SavedDeltaHasNewValue = false;
				bool ErrorFlag = false;
				if (CurrInst->MDIsStackPtrSaveOrRestore(this->UsesFramePointer(), this->GetFramePtrStackDelta(), StackPtrSaved, SavedDelta, CopyOperand, ErrorFlag)) {
					// NOTE: If CopyOperand is a stack location, it is normalized.
					if (StackPtrSaved) {
						// Insert new entry into the StackPtrCopySet. For the ReprocessingAllocaBlocks case, this might be
						//  just a tricky update of the delta for an existing item in the set.
						bool DeltaInserted = this->AddToStackPtrCopySet(CopyOperand, InstAddr, SavedDelta);
						if (TraceFlag) {
							SMP_msg("INFO: Stack delta saved: %d at %x\n", SavedDelta, InstAddr);
						}
					}
					else { // stack pointer was restored from saved value
						StackPointerRestoreSeen = true;
						SavedDeltaHasNewValue = true; // no need to compute effect of restore instruction later
						if (ReprocessingAllocaBlocks) {
							// Now that the stack pointer has been restored, the effect of the alloca() should
							//  be undone. We no longer need to adjust delta values for the rest of the block.
							DeltaIncrement = 0;
						}
					}
				} // end if (CurrInst->MDIsStackPtrSaveOrRestore())
				else if (ErrorFlag) {
					this->AnalyzedSP = false;
					WorkList.clear();
					SMP_msg("ERROR: ErrorFlag=true from MDIsStackPtrSaveOrRestore() at %x\n", InstAddr);
					break;
				}

				// Update VarKill and DownExposedDefs sets for DEFs in current instruction.
				// Dataflow equation for killed variables: If a variable is defined in any
				//  instruction in the block, it is killed by this block (i.e. prior definitions
				//  of that variable will not make it through the block).
				if (!ReprocessingAllocaBlocks) { // Only compute on first pass through block
					set<DefOrUse, LessDefUse>::iterator CurrDef;
					for (CurrDef = CurrInst->GetFirstDef(); CurrDef != CurrInst->GetLastDef(); ++CurrDef) {
						op_t DefOp = CurrDef->GetOp();
						if (MDIsDataFlowOpnd(DefOp, this->UsesFramePointer())) {
							// We have a register or stack operand. If stack operand, it is normalized, i.e. EBP-4 might be ESP-8,
							//  where the ESP-8 refers to the value of ESP upon entry to the function, not its current value.
							//  This normalization makes each stack location uniquely named (no aliases at different code locations due
							//  to different values of ESP at different code locations).
							CurrBlock->AddVarKill(DefOp);
							CurrBlock->UpdateDownExposedDefs(DefOp, InstAddr);
						}
					}
				}

				if (SavedDeltaHasNewValue) {
					IncomingDelta = SavedDelta; // from restore instruction
				}
				else {
					CurrentDelta = CurrInst->AnalyzeStackPointerDelta(IncomingDelta, this->GetFramePtrStackDelta());
					if (SMP_STACK_POINTER_BITWISE_AND_CODE == CurrentDelta) {
						// For now, we ignore instructions that AND a constant into the stack pointer.
						CurrentDelta = 0;
						SMP_msg("WARNING: Stack pointer bitwise AND ignored at %x\n", CurrInst->GetAddr());
					}
					else if (SMP_STACK_DELTA_ERROR_CODE == CurrentDelta) {
						this->AnalyzedSP = false;
						SMP_msg("ERROR: Stack delta unanalyzeable at %x\n", InstAddr);
						WorkList.clear();
						break;
					}
					SMPitype FlowType = CurrInst->GetDataFlowType();
					IncomingDelta += CurrentDelta;
					if ((RETURN == FlowType) && (!CurrInst->IsCondTailCall())) {
						// We hope to see a consistent outgoing delta from all RETURN points.
						//  We special-case the conditional jump used as tail call, because it must be followed
						//  by a real return instruction later. If the jump is taken, it acts as a return, but
						//  it has not yet popped the stack.
						if (ReturnSeen) { // This is not the first RETURN seen.
							if (IncomingDelta != this->NetStackDelta) { // Inconsistent
								SMP_msg("ERROR: Inconsistent stack deltas at return instruction at %x\n", CurrInst->GetAddr());
								ConsistentNetDelta = false;
								this->AnalyzedSP = false;
								WorkList.clear();
								break;
							}
						}
						else { // First RETURN statement seen.
							ReturnSeen = true;
							this->NetStackDelta = IncomingDelta;
#if SMP_AUDIT_STACK_POINTER_DELTAS
							if (CALLING_CONVENTION_DEFAULT_FUNCTION_STACK_DELTA != IncomingDelta) {
								SMP_msg("WARNING: Stack delta not %d after return instruction at %x\n", 
									CALLING_CONVENTION_DEFAULT_FUNCTION_STACK_DELTA, CurrInst->GetAddr());
							}
#endif
						}
						// If we permitted inconsistent stack deltas previously, then the stack pointer has to
						//  have been restored, e.g. if we allocate a frame with sub esp,32 and then we later
						//  have paths that pass through an alloca() call, a push, etc., then the alloca() or
						//  push will not be undone by add esp,32. It must be undone by something like mov esp,ebp.
						if (ConflictingValuesSeen && !StackPointerRestoreSeen) {
							SMP_msg("ERROR: Inconsistent stack deltas seen, no stack pointer restore before return instruction at %x\n", CurrInst->GetAddr());
							this->AnalyzedSP = false;
							WorkList.clear();
							break;
						}
					}
				} // end if (SavedDeltaHasNewValue) ... else ...
			} // end for each instruction in WorkList block
			if (CurrBlock->IsReachesOutStale()) {
				ReachesOutChanged = CurrBlock->ComputeReachesOutSet();
			}
			// Push the successor blocks onto the work list if anything changed
			if (this->AnalyzedSP) { // if we do not have an error already
				CurrBlock->SetOutgoingStackDelta(IncomingDelta); // record incoming delta for all successors
				if (ReachesOutChanged || (!ReprocessingAllocaBlocks)) { // if anything changed (deltas or reaching defs ReachOut set)
					list<SMPBasicBlock *>::iterator SuccIter;
					if (DebugFlag && (0 == IncomingDelta)) {
						SMP_msg("ERROR: Pushing WorkList items with IncomingDelta of zero. Dumping Block:\n");
						CurrBlock->Dump();
					}
					for (SuccIter = CurrBlock->GetFirstSucc(); SuccIter != CurrBlock->GetLastSucc(); ++SuccIter) {
						pair<SMPBasicBlock *, sval_t> SuccPair (*SuccIter, IncomingDelta);
						WorkList.push_back(SuccPair);
					}
				}
			}
		} // end if block already processed ... else ...
		ReprocessingAllocaBlocks = false; // reset to default before processing next worklist element
	} while (!WorkList.empty());

	this->STARSStackPtrAnalysisPerformed = true;
	if (this->AnalyzedSP) {
		if (CALLING_CONVENTION_DEFAULT_FUNCTION_STACK_DELTA != this->NetStackDelta) {
			SMP_msg("WARNING: Non-default stack ptr delta %d for function: %s\n", this->NetStackDelta, this->GetFuncName());
		}
		if (this->StackAdjustmentComputed 
			&& (this->GlobalStackAdjustment != (CALLING_CONVENTION_DEFAULT_FUNCTION_STACK_DELTA - this->NetStackDelta))) {
			// Oops. When program graph cycles caused us to try to compute the GlobalStackAdjustment as our best guess
			//  for this function's effect on the stack delta, we told our callers that these three values would cancel out.
			//  They do not. Our callers have now been using a bad stack delta for their call instructions. Too late for
			//  anything but a diagnostic message.
				SMP_msg("ERROR: Earlier GlobalStackAdjustment computation %d does not agree with current NetStackDelta result for function: %s\n",
					this->GlobalStackAdjustment, this->GetFuncName());
		}
	}


	if (IDAProSucceeded) {
		if (!this->AnalyzedSP) {
			SMP_msg("ERROR: Stack Ptr Delta Analysis succeeded in IDA, failed in STARS for %x : %s\n", this->FirstEA,
				this->GetFuncName());
		}
	}
	else {
		if (this->AnalyzedSP) {
			SMP_msg("SUCCESS: Stack Ptr Delta Analysis failed in IDA, succeeded in STARS for %x : %s\n", this->FirstEA,
				this->GetFuncName());
		}
	}
	if (!this->AnalyzedSP) {
		(void) this->UseIDAStackPointerDeltas();
	}

	// Cannot keep the reaching defs around on huge benchmarks, or we run out of memory.
	//  Once we have SSA form, we can obtain reaching defs info on the fly if we want it.
	list<SMPBasicBlock *>::iterator BlockIter;
	for (BlockIter = this->Blocks.begin(); BlockIter != this->Blocks.end(); ++BlockIter) {
		(*BlockIter)->FreeReachingDefsMemory();
	}

	return this->AnalyzedSP;
} // end of SMPFunction::AnalyzeStackPointerDeltas()

// Insert the arguments into the StackPtrCopySet; or, if a matching entry already exists
//  with a StackDelta of greater magnitude than StackDelta, update just the StackDelta.
// Return true if StackDelta was inserted, false if it was used to update an old entry.
bool SMPFunction::AddToStackPtrCopySet(op_t CopyOp, ea_t InstAddr, sval_t StackDelta) {
	bool NewInsertion;
	pair<ea_t, sval_t> InsertStackDefn(InstAddr, StackDelta);
	pair<op_t, pair<ea_t, sval_t> > InsertStackDefnOp(CopyOp, InsertStackDefn);
	set<pair<op_t, pair<ea_t, sval_t> >, LessStackDeltaCopy>::iterator FindIter;
	pair<set<pair<op_t, pair<ea_t, sval_t> >, LessStackDeltaCopy>::iterator, bool> InsertResult;

	FindIter = this->StackPtrCopySet.find(InsertStackDefnOp);
	if (FindIter == this->StackPtrCopySet.end()) {
		// Not already present; insert new triple.
		NewInsertion = true;
		InsertResult = this->StackPtrCopySet.insert(InsertStackDefnOp);
		assert(InsertResult.second);
	}
	else {
		// Already there; see if delta needs to be updated.
		NewInsertion = false;
		pair<op_t, pair<ea_t, sval_t> > OldStackDefnOp(*FindIter);
		// Favor a smaller stack frame for the alloca-calling functions, e.g. favor -24 over -32 as a delta.
		if (StackDelta > OldStackDefnOp.second.second) {
			// Replace the old entry with a new one.
			this->StackPtrCopySet.erase(FindIter);
			InsertResult = this->StackPtrCopySet.insert(InsertStackDefnOp);
			assert(InsertResult.second);
		}
	}

	return NewInsertion;
} // end of SMPFunction::AddToStackPtrCopySet()

void SMPFunction::FindAllAllocsAndDeallocs(void) {
	bool FoundAllocInstr = false;
	bool FoundDeallocInstr = false;
	bool DebugFlag = false;
#if SMP_DEBUG_FRAMEFIXUP
	DebugFlag |= (0 == strcmp("frame_dummy", this->GetFuncName()));
#endif

	// Now, if LocalVarsSize is not zero, we need to find the instruction
	//  in the function prologue that allocates space on the stack for
	//  local vars. This code could be made more robust in the future
	//  by matching LocalVarsSize to the immediate value in the allocation
	//  instruction. However, IDA Pro is sometimes a little off on this
	//  number. **!!**
	if (0 < this->LocalVarsSize) {
		if (DebugFlag) SMP_msg("Searching for alloc and dealloc\n");
		list<SMPInstr *>::iterator InstIter = this->Instrs.begin();
#if SMP_USE_SSA_FNOP_MARKER
		++InstIter;  // skip marker instruction
#endif
		for ( ; InstIter != this->Instrs.end(); ++InstIter) {
			SMPInstr *CurrInst = (*InstIter);
			ea_t addr = CurrInst->GetAddr();

			// Keep the most recent instruction in the DeallocInstr
			//  in case we reach the return without seeing a dealloc.
			if (!FoundDeallocInstr) {
				this->LocalVarsDeallocInstr = addr;
			}

			if (!FoundAllocInstr
				&& CurrInst->MDIsFrameAllocInstr()) {
#if SMP_DEBUG_CONTROLFLOW
				SMP_msg("Returned from MDIsFrameAllocInstr()\n");
#endif
				this->LocalVarsAllocInstr = addr;
				FoundAllocInstr = true;
				if (DebugFlag) SMP_msg("Found alloc: %s\n", CurrInst->GetDisasm());
				// As soon as we have found the local vars allocation,
				//  we can try to fix incorrect sets of UseFP by IDA.
				// NOTE: We might want to extend this in the future to
				//  handle functions that have no locals.  **!!**
				bool FixedUseFP = MDFixUseFP();
#if SMP_DEBUG_FRAMEFIXUP
				if (FixedUseFP) {
					SMP_msg("Fixed UseFP in %s\n", this->GetFuncName());
				}
#endif
				if (this->UsesFramePointer()) { // now that MDFixUseFP() has validated this flag ...
					this->FindFramePointerDelta(); // find stack delta that is saved in frame pointer in function prologue
				}
			}
			else if (FoundAllocInstr) {
				// We can now start searching for the DeallocInstr.
				if (CurrInst->MDIsFrameDeallocInstr(UseFP, this->LocalVarsSize)) {
					// Keep saving the most recent addr that looks
					//  like the DeallocInstr until we reach the
					//  end of the function. Last one to look like
					//  it is used as the DeallocInstr.
#if SMP_DEBUG_CONTROLFLOW
					SMP_msg("Returned from MDIsFrameDeallocInstr()\n");
#endif
					this->LocalVarsDeallocInstr = addr;
					FoundDeallocInstr = true;
				}
				else {
					if (DebugFlag) SMP_msg("Not dealloc: %s\n", CurrInst->GetDisasm());
				}
			}
		} // end for (list<SMPInstr *>::iterator InstIter ... )
		if (!FoundAllocInstr) {
			// Could not find the frame allocating instruction.  Bad.
			// See if we can find the point at which the stack allocation reaches
			//  a total of FuncInfo.frsize+frregs, regardless of whether it happened by push
			//  instructions or some other means.
			this->LocalVarsAllocInstr = this->FindAllocPoint(this->FuncInfo.frsize + this->FuncInfo.frregs);
#if SMP_DEBUG_CONTROLFLOW
			SMP_msg("Returned from FindAllocPoint()\n");
#endif
#if SMP_DEBUG_FRAMEFIXUP
			if (BADADDR == this->LocalVarsAllocInstr) {
				SMP_msg("WARNING: Could not find stack frame allocation in %s\n",
					this->GetFuncName());
				SMP_msg("LocalVarsSize: %d  SavedRegsSize: %d ArgsSize: %d\n",
					LocalVarsSize, CalleeSavedRegsSize, IncomingArgsSize);
			}
			else {
				SMP_msg("FindAllocPoint found %x for function %s\n",
					this->LocalVarsAllocInstr, this->GetFuncName());
			}
#endif
		}
#if SMP_DEBUG_FRAMEFIXUP
		if (!FoundDeallocInstr) {
			// Could not find the frame deallocating instruction.  Bad.
			// Emit diagnostic and use the last instruction in the
			// function.
			SMP_msg("WARNING: Could not find stack frame deallocation in %s\n",
				this->GetFuncName());
		}
#endif
	}
	// else LocalVarsSize was zero, meaning that we need to search 
	//  for the end of the function prologue code and emit stack frame
	//  annotations from that address (i.e. this method returns that
	//  address). We will approximate this by finding the end of the
	//  sequence of PUSH instructions at the beginning of the function.
	//  The last PUSH instruction should be the last callee-save-reg
	//  instruction. We can make this more robust in the future by
	//  making sure that we do not count a PUSH of anything other than
	//  a register. **!!**
	// NOTE: 2nd prologue instr is usually mov ebp,esp
	// THE ASSUMPTION THAT WE HAVE ONLY PUSH INSTRUCTIONS BEFORE
	// THE ALLOCATING INSTR IS ONLY TRUE WHEN LOCALVARSSIZE == 0;
	else {
		ea_t SaveAddr = this->FuncInfo.startEA;
		list<SMPInstr *>::iterator InstIter = this->Instrs.begin();
#if SMP_USE_SSA_FNOP_MARKER
		++InstIter;  // skip marker instruction
#endif
		for ( ;	InstIter != this->Instrs.end(); ++InstIter) {
			SMPInstr *CurrInst = (*InstIter);
			insn_t CurrCmd = CurrInst->GetCmd();
			ea_t addr = CurrInst->GetAddr();
			if (CurrCmd.itype == NN_push)
				SaveAddr = addr;
			else
				break;
		}
		this->LocalVarsAllocInstr = SaveAddr;
		this->LocalVarsDeallocInstr = 0;
		// As soon as we have found the local vars allocation,
		//  we can try to fix incorrect sets of UseFP by IDA.
		// NOTE: We might want to extend this in the future to
		//  handle functions that have no locals.  **!!**
		bool FixedUseFP = this->MDFixUseFP();
#if SMP_DEBUG_FRAMEFIXUP
		if (FixedUseFP) {
			SMP_msg("Fixed UseFP in %s\n", this->GetFuncName());
		}
#endif
		if (this->UsesFramePointer()) { // now that MDFixUseFP() has validated this flag ...
			this->FindFramePointerDelta(); // find stack delta that is saved in frame pointer in function prologue
		}
	} // end if (LocalVarsSize > 0) ... else ...

	return;
} // end of SMPFunction::FindAllAllocsAndDeallocs()

// Compute FramePointerStackDelta as soon as possible so that it is available for SyncAllRTs().
void SMPFunction::FindFramePointerDelta(void) {
	bool FirstBlockProcessed = false;
	bool FPSaved = false;  // have seen push of frame pointer reg
	bool SPintoFP = false; // have seen copy of stack pointer into frame pointer
	sval_t IncomingDelta = 0;
	sval_t CurrentDelta;
	list<SMPInstr *>::iterator InstIter = this->Instrs.begin();
#if SMP_USE_SSA_FNOP_MARKER
	++InstIter;  // skip marker instruction
#endif
	while (!FirstBlockProcessed && (InstIter != this->Instrs.end())) {
		SMPInstr *CurrInst = (*InstIter);
		// Accumulate stack delta values.
		CurrentDelta = CurrInst->AnalyzeStackPointerDelta(IncomingDelta, this->GetFramePtrStackDelta());
		if (SMP_STACK_POINTER_BITWISE_AND_CODE == CurrentDelta) {
			// For now, we ignore instructions that AND a constant into the stack pointer.
			CurrentDelta = 0;
		}
		else if (SMP_STACK_DELTA_ERROR_CODE == CurrentDelta) {
			this->AnalyzedSP = false;
			break; // error exit
		}
		// Look for initialization of frame pointer, record its stack delta
		FirstBlockProcessed = CurrInst->IsLastInBlock();
		if (!FPSaved) { // still looking for "push <framepointerreg>"
			if (CurrInst->MDIsPushInstr() && CurrInst->GetCmd().Operands[0].is_reg(MD_FRAME_POINTER_REG)) {
				FPSaved = true;
			}
		}
		else if (!SPintoFP) { // found "push <framepointerreg>", looking for "fp := sp"
			insn_t CurrCmd = CurrInst->GetCmd();
			if ((CurrCmd.itype == MD_MOVE_INSTRUCTION) 
				&& (CurrInst->GetFirstDef()->GetOp().is_reg(MD_FRAME_POINTER_REG))
				&& (CurrInst->GetFirstUse()->GetOp().is_reg(MD_STACK_POINTER_REG))) {
				SPintoFP = true;
				this->FramePointerStackDelta = IncomingDelta;
				FirstBlockProcessed = true; // stop looking
				assert(this->UsesFramePointer());
			}
		}
		IncomingDelta += CurrentDelta;
		++InstIter;
	}

	return;
} // end of SMPFunction::FindFramePointerDelta()

// Figure out the different regions of the stack frame, and find the
//  instructions that allocate and deallocate the local variables space
//  on the stack frame.
// The stack frame info will be used to emit stack
//  annotations when Analyze() reaches the stack allocation
//  instruction that sets aside space for local vars.
// Set the address of the instruction at which these
//  annotations should be emitted. This should normally
//  be an instruction such as:  sub esp,48
//  However, for a function with no local variables at all,
//  we will need to determine which instruction should be
//  considered to be the final instruction of the function
//  prologue and return its address.
// Likewise, we find the stack deallocating instruction in
//  the function epilogue.
void SMPFunction::SetStackFrameInfo(void) {
#if 0
	for (list<SMPInstr *>::iterator InstIter = this->Instrs.begin(); InstIter != this->Instrs.end(); ++InstIter) {
		// We can finally search for stack loads now that UseFP has been fixed by
		//  MDFixUseFP(). Otherwise, we would do this in SMPInstr::Analyze(),
		//  but the UseFP flag is not ready that early.
		(*InstIter)->MDFindLoadFromStack(this->UseFP);

		// Fix up machine dependent quirks in the def and use lists.
		//  This used to be called from within SMPInstr.Analyze(), but info such as UseFP
		//  is not available that early.
		(*InstIter)->MDFixupDefUseLists();
	}
#endif

#if SMP_COMPUTE_STACK_GRANULARITY
	// Now, find the boundaries between local variables.
	this->BuildLocalVarTable();
#endif

	// Get callee-saved regs info for remediation use.
	if (BADADDR != this->GetFirstFrameAllocInstAddr()) {
		this->MDFindSavedRegs();
	}

	return;
} // end of SMPFunction::SetStackFrameInfo()

// IDA Pro defines the sizes of regions in the stack frame in a way
//  that suits its purposes but not ours. The frsize field of the func_info_t
//  structure measures the distance between the stack pointer and the
//  frame pointer (ESP and EBP in the x86). This region includes some
//  of the callee-saved registers. So, the frregs field only includes
//  the callee-saved registers that are above the frame pointer.
//  x86 standard prologue on gcc/linux:
//    push ebp      ; save old frame pointer
//    mov ebp,esp   ; new frame pointer = current stack pointer
//    push esi      ; callee save reg
//    push edi      ; callee save reg
//    sub esp,34h   ; allocate 52 bytes for local variables
//
//  Notice that EBP acquires its final frame pointer value AFTER the
//  old EBP has been pushed. This means that, of the three callee saved
//  registers, one is above where EBP points and two are below.
//  IDA Pro is concerned with generating readable addressing expressions
//  for items on the stack. None of the callee-saved regs will ever
//  be addressed in the function; they will be dormant until they are popped
//  off the stack in the function epilogue. In order to create readable
//  disassembled code, IDA defines named constant offsets for locals. These
//  offsets are negative values (x86 stack grows downward from EBP toward
//  ESP). When ESP_relative addressing occurs, IDA converts a statement:
//    mov eax,[esp+12]
//  into the statement:
//    mov eax,[esp+3Ch+var_30]
//  Here, 3Ch == 60 decimal is the distance between ESP and EBP, and
//  var_30 is defined to have the value -30h == -48 decimal. So, the
//  "frame size" in IDA Pro is 60 bytes, and a certain local can be
//  addressed in ESP-relative manner as shown, or as [ebp+var_30] for
//  EBP-relative addressing. The interactive IDA user can then edit
//  the name var_30 to something mnemonic, such as "virus_size", and IDA
//  will replace all occurrences with the new name, so that code references
//  automatically become [ebp+virus_size]. As the user proceeds
//  interactively, he eventually produces very understandable code.
// This all makes sense for producing readable assembly text. However,
//  our analyses have a compiler perspective as well as a memory access
//  defense perspective. SMP distinguishes between callee saved regs,
//  which should not be overwritten in the function body, and local
//  variables, which can be written. We view the stack frame in logical
//  pieces: here are the saved regs, here are the locals, here is the
//  return address, etc. We don't care which direction from EBP the
//  callee-saved registers lie; we don't want to lump them in with the
//  local variables. We also don't like the fact that IDA Pro will take
//  the function prologue code shown above and declare frregs=4 and
//  frsize=60, because frsize no longer matches the stack allocation
//  statement sub esp,34h == sub esp,52. We prefer frsize=52 and frregs=12.
// So, the task of this function is to fix these stack sizes in our
//  private data members for the function, while leaving the IDA database
//  alone because IDA needs to maintain its own definitions of these
//  variables.
// Fixing means we will update the data members LocalVarsSize and
//  CalleeSavedRegsSize.
// NOTE: This function is both machine dependent and platform dependent.
//  The prologue and epilogue code generated by gcc-linux is as discussed
//  above, while on Visual Studio and other Windows x86 compilers, the
//  saving of registers other than EBP happens AFTER local stack allocation.
//  A Windows version of the function would expect to see the pushing
//  of ESI and EDI AFTER the sub esp,34h statement.
bool SMPFunction::MDFixFrameInfo(void) {
	int SavedRegsSize = 0;
	int OtherPushesSize = 0;  // besides callee-saved regs
	int NewLocalsSize = 0;
	int OldFrameTotal = this->CalleeSavedRegsSize + this->LocalVarsSize;
	bool Changed = false;
	bool DebugFlag = (0 == strcmp("__libc_csu_init", this->GetFuncName()));

	// Iterate through the first basic block in the function. If we find
	//  a frame allocating Instr in it, then we have local vars. If not,
	//  we don't, and LocalVarsSize should have been zero. Count the callee
	//  register saves leading up to the local allocation. Set data members
	//  according to what we found if the values of the data members would
	//  change.
	SMPBasicBlock *CurrBlock = this->Blocks.front();
	list<SMPInstr *>::iterator CurrIter = CurrBlock->GetFirstInstr();
#if SMP_USE_SSA_FNOP_MARKER
	++CurrIter;  // skip marker instruction
#endif
	for ( ; CurrIter != CurrBlock->GetLastInstr(); ++CurrIter) {
		SMPInstr *CurrInstr = (*CurrIter);
		if (CurrInstr->MDIsPushInstr()) {
			// We will make the gcc-linux assumption that a PUSH in
			//  the first basic block, prior to the stack allocating
			//  instruction, is a callee register save. To make this
			//  more robust, we ensure that the register is from
			//  the callee saved group of registers, and that it has
			//  not been defined thus far in the function (else it might
			//  be a push of an outgoing argument to a call that happens
			//  in the first block when there are no locals). **!!!!**
			if (CurrInstr->MDUsesCalleeSavedReg()
				&& !CurrInstr->HasSourceMemoryOperand()) {
				SavedRegsSize += 4; // **!!** should check the size
				if (DebugFlag) SMP_msg("libc_csu_init SavedRegsSize: %d  %s\n", SavedRegsSize,
					CurrInstr->GetDisasm());
			}
			else {
				// Pushes of outgoing args can be scheduled so that
				//  they are mixed with the pushes of callee saved regs.
				OtherPushesSize += 4;
				if (DebugFlag) SMP_msg("libc_csu_init OtherPushesSize: %d  %s\n", OtherPushesSize,
					CurrInstr->GetDisasm());
			}
		}
		else if (CurrInstr->MDIsFrameAllocInstr()) {
			if (DebugFlag) SMP_msg("libc_csu_init allocinstr: %s\n", CurrInstr->GetDisasm());
			SavedRegsSize += OtherPushesSize;
			// Get the size being allocated.
			set<DefOrUse, LessDefUse>::iterator CurrUse;
			for (CurrUse = CurrInstr->GetFirstUse(); CurrUse != CurrInstr->GetLastUse(); ++CurrUse) {
				// Find the immediate operand.
				if (o_imm == CurrUse->GetOp().type) {
					// Get its value into LocalVarsSize.
					long AllocValue = (signed long) CurrUse->GetOp().value;
					// One compiler might have sub esp,24 and another
					//  might have add esp,-24. Take the absolute value.
					if (0 > AllocValue)
						AllocValue = -AllocValue;
					if (AllocValue != (long) this->LocalVarsSize) {
						Changed = true;
#if SMP_DEBUG_FRAMEFIXUP
						if (AllocValue + SavedRegsSize != OldFrameTotal)
							SMP_msg("Total frame size changed: %s OldTotal: %d NewTotal: %ld\n",
								this->GetFuncName(), OldFrameTotal, (AllocValue + SavedRegsSize));
#endif
						this->LocalVarsSize = (asize_t) AllocValue;
						this->CalleeSavedRegsSize = (ushort) SavedRegsSize;
						NewLocalsSize = this->LocalVarsSize;
					}
					else { // Old value was correct; no change.
						NewLocalsSize = this->LocalVarsSize;
						if (SavedRegsSize != this->CalleeSavedRegsSize) {
							this->CalleeSavedRegsSize = (ushort) SavedRegsSize;
							Changed = true;
#if SMP_DEBUG_FRAMEFIXUP
							SMP_msg("Only callee regs size changed: %s\n", this->GetFuncName());
#endif
						}
					}
				} // end if (o_imm == ...)
			} // end for all uses
			break; // After frame allocation instr, we are done
		} // end if (push) .. elsif frame allocating instr
	} // end for all instructions in the first basic block

	// If we did not find an allocating instruction, see if it would keep
	//  the total size the same to set LocalVarsSize to 0 and to set
	//  CalleeSavedRegsSize to SavedRegsSize. If so, do it. If not, we
	//  might be better off to leave the numbers alone.
	if (!Changed && (NewLocalsSize == 0)) {
		if (DebugFlag) SMP_msg("libc_csu_init OldFrameTotal: %d \n", OldFrameTotal);
		if (OldFrameTotal == SavedRegsSize) {
			this->CalleeSavedRegsSize = (ushort) SavedRegsSize;
			this->LocalVarsSize = 0;
			Changed = true;
		}
#if SMP_DEBUG_FRAMEFIXUP
		else {
			SMP_msg("Could not update frame sizes: %s\n", this->GetFuncName());
		}
#endif
	}

#if SMP_DEBUG_FRAMEFIXUP
	if ((0 < OtherPushesSize) && (0 < NewLocalsSize))
		SMP_msg("Extra pushes found of size %d in %s\n", OtherPushesSize,
			this->GetFuncName());
#endif

#if SMP_DEBUG_FRAMEFIXUP
	if (Changed) {
		SMP_msg("Fixed stack frame size info: %s\n", this->GetFuncName());
#if SMP_DEBUG_FRAMEFIXUP_VERBOSE
		SMPBasicBlock *CurrBlock = this->Blocks.front();
		SMP_msg("First basic block:\n");
		list<SMPInstr *>::iterator CurrInstr = CurrBlock->GetFirstInstr();
#if SMP_USE_SSA_FNOP_MARKER
		++CurrInstr;
#endif
		while (CurrInstr != CurrBlock->GetLastInstr()) {
			SMP_msg("%s\n", (*CurrInstr)->GetDisasm());
			++CurrInstr;
		}
#endif
	}
#endif

	return Changed;
} // end of SMPFunction::MDFixFrameInfo()

// Some functions have difficult to find stack allocations. For example, in some
//  version of glibc, strpbrk() zeroes out register ECX and then pushes it more than
//  100 times in order to allocate zero-ed out local vars space for a character translation
//  table. We will use the stack pointer analysis of IDA to find out if there is a point
//  in the first basic block at which the stack pointer reaches the allocation total
//  that IDA is expecting for the local vars region.
// If so, we return the address of the instruction at which ESP reaches its value, else
//  we return BADADDR.
ea_t SMPFunction::FindAllocPoint(asize_t OriginalLocSize) {
	sval_t TargetSize = - ((sval_t) OriginalLocSize);  // negate; stack grows down 

#if SMP_DEBUG_FRAMEFIXUP
	bool DebugFlag = (0 == strcmp("_dl_runtime_resolve", this->GetFuncName()));
	if (DebugFlag)
		SMP_msg("%s OriginalLocSize: %d\n", this->GetFuncName(), OriginalLocSize);
#endif

	if (this->AnalyzedSP) {
		// Limit our analysis to the first basic block in the function.
		list<SMPInstr *>::iterator InstIter = this->Instrs.begin();
#if SMP_USE_SSA_FNOP_MARKER
		++InstIter;  // skip marker instruction
#endif
		for ( ; InstIter != this->Instrs.end(); ++InstIter) {
			SMPInstr *CurrInst = (*InstIter);
			ea_t addr = CurrInst->GetAddr();
			// get_spd() returns a cumulative delta of ESP
			sval_t sp_delta = get_spd(this->GetFuncInfo(), addr);
#if SMP_DEBUG_FRAMEFIXUP
			if (DebugFlag)
				SMP_msg("%s delta: %d at %x\n", this->GetFuncName(), sp_delta, addr);
#endif
			if (sp_delta == TargetSize) { // <= instead of == here?  **!!**
				// Previous instruction hit the frame size.
				if (InstIter == this->Instrs.begin()) {
					return BADADDR;  // cannot back up from first instruction
				}
				else {
					ea_t PrevAddr = (*(--InstIter))->GetAddr();
#if SMP_USE_SSA_FNOP_MARKER
					if ((*(this->Instrs.begin()))->GetAddr() == PrevAddr)
						return BADADDR;  // don't return marker instruction
					else
						return PrevAddr;
#else
					return PrevAddr;
#endif
				}
			}
			if (CurrInst->IsLastInBlock()) {
				// It could be that the current instruction will cause the stack pointer
				//  delta to reach the TargetSize. sp_delta is not updated until after the
				//  current instruction, so we need to look ahead one instruction if the
				//  current block falls through. On the other hand, if the current block
				//  ends with a jump or return, we cannot hit TargetSize.
				if (CurrInst->IsBasicBlockTerminator())
					return BADADDR;
				list<SMPInstr *>::iterator NextInstIter = InstIter;
				++NextInstIter;
				if (NextInstIter == this->Instrs.end())
					return BADADDR;
				sp_delta = get_spd(this->GetFuncInfo(), (*NextInstIter)->GetAddr());
				if (sp_delta == TargetSize) {
					// CurrInst will cause stack pointer delta to hit TargetSize.
					return addr;
				}
				else {
					return BADADDR;
				}
			} // end if LastInBlock
		} // end for all instructions
	} // end if (this->AnalyzedSP)
#if SMP_DEBUG_FRAMEFIXUP
	else {
		SMP_msg("AnalyzedSP is false for %s\n", this->GetFuncName());
	}
#endif
	return BADADDR;
} // end of SMPFunction::FindAllocPoint()

// IDA Pro is sometimes confused by a function that uses the frame pointer
//  register for other purposes. For the x86, a function that uses EBP
//  as a frame pointer would begin with: push ebp; mov ebp,esp to save
//  the old value of EBP and give it a new value as a frame pointer. The
//  allocation of local variable space would have to come AFTER the move
//  instruction. A function that begins: push ebp; push esi; sub esp,24
//  is obviously not using EBP as a frame pointer. IDA is apparently
//  confused by the push ebp instruction being the first instruction
//  in the function. We will reset UseFP to false in this case.
// The inverse problem happens with a function that begins with instructions
//  other than push ebp; mov ebp,esp; ... etc. but eventually has those
//  instructions in the first basic block. For example, a C compiler generates
//  for the first block of main():
//    lea ecx,[esp+arg0]
//    and esp, 0xfffffff0
//    push dword ptr [ecx-4]
//    push ebp
//    mov ebp,esp
//    push ecx
//    sub esp,<framesize>
//
//  This function is obviously using EBP as a frame pointer, but IDA Pro marks
//  the function as not using a frame pointer. We will reset UseFP to true in
//  this case.
// NOTE: This logic should work for both Linux and Windows x86 prologues.
bool SMPFunction::MDFixUseFP(void) {
	bool OldUseFP = this->UsesFramePointer();
	bool HasLocals = (0 < this->LocalVarsSize);
	list<SMPInstr *>::iterator InstIter = this->Instrs.begin();
	ea_t addr;

#if SMP_USE_SSA_FNOP_MARKER
	++InstIter;  // skip marker instruction
#endif
	SMPInstr *CurrInst;

#if 0
	if (!(this->UseFP)) {
#endif
		// See if we can detect the instruction "push ebp" followed by the instruction
		//  "mov ebp,esp" in the first basic block. The instructions do not have to be
		//  consecutive. If we find them, we will reset UseFP to true.
		bool FirstBlockProcessed = false;
		bool EBPSaved = false;
		bool ESPintoEBP = false;
		do {
			CurrInst = (*InstIter);
			addr = CurrInst->GetAddr();
			FirstBlockProcessed = CurrInst->IsLastInBlock();
			if (!EBPSaved) { // still looking for "push ebp"
				if (CurrInst->MDIsPushInstr() && CurrInst->GetCmd().Operands[0].is_reg(R_bp)) {
					EBPSaved = true;
				}
			}
			else if (!ESPintoEBP) { // found "push ebp", looking for "mov ebp,esp"
				insn_t CurrCmd = CurrInst->GetCmd();
				if ((CurrCmd.itype == NN_mov) 
					&& (CurrInst->GetFirstDef()->GetOp().is_reg(R_bp))
					&& (CurrInst->GetFirstUse()->GetOp().is_reg(R_sp))) {
					ESPintoEBP = true;
					FirstBlockProcessed = true; // exit loop
				}
			}
			// We must get EBP set to its frame pointer value before we reach the
			//  local frame allocation instruction (i.e. the subtraction of locals space
			//   from the stack pointer).
			if (HasLocals) {
				FirstBlockProcessed |= (addr >= this->LocalVarsAllocInstr);
			}
			++InstIter;
		} while (!FirstBlockProcessed);
		// If we found ESPintoEBP, we also found EBPSaved first, and we need to change
		//  this->UseFP to true and return true. Otherwise, return false.
		this->UseFP = ESPintoEBP;
		bool changed = (ESPintoEBP != OldUseFP);
		if (changed)
			SMP_msg("INFO: MDFixUseFP toggled UseFP for %s\n", this->GetFuncName());
		return (changed);
#if 0
	} // end if (!(this->UseFP))

	// At this point, this->UseFP must have been true on entry to this method and we will
	//  check whether it should be reset to false.
	while (addr <= this->LocalVarsAllocInstr) {
		set<DefOrUse, LessDefUse>::iterator CurrDef = CurrInst->GetFirstDef();
		while (CurrDef != CurrInst->GetLastDef()) {
			if (CurrDef->GetOp().is_reg(R_bp))
				return false; // EBP got set before locals were allocated
			++CurrDef;
		}
		++InstIter;
		CurrInst = (*InstIter);
		addr = CurrInst->GetAddr();
	}
	// If we found no defs of the frame pointer before the local vars
	//  allocation, then the frame pointer register is not being used
	//  as a frame pointer, just as a general callee-saved register.
	this->UseFP = false;
	SMP_msg("INFO: MDFixUseFP reset UseFP to false for %s\n", this->GetFuncName());
	return true;
#endif
} // end of SMPFunction::MDFixUseFP()

// Find the callee-saved reg offsets (negative offset from return address)
//  for all registers pushed onto the stack before the stack frame allocation
//  instruction.
void SMPFunction::MDFindSavedRegs(void) {
	list<SMPInstr *>::iterator InstIter;
	int RegIndex;
	func_t *CurrFunc = SMP_get_func(this->GetStartAddr());
	assert(NULL != CurrFunc);

	for (InstIter = this->Instrs.begin(); InstIter != this->Instrs.end(); ++InstIter) {
		SMPInstr *CurrInst = (*InstIter);
		if (CurrInst->GetAddr() > this->LocalVarsAllocInstr)
			break;
		if (!(CurrInst->MDIsPushInstr()))
			continue;

		sval_t CurrOffset = get_spd(CurrFunc, CurrInst->GetAddr());
		if (CurrInst->GetCmd().itype == NN_push) {
			op_t PushedReg = CurrInst->GetPushedOpnd();
			if (o_reg == PushedReg.type) {