Newer
Older
for (size_t MapIndex = base; MapIndex < limit; ++MapIndex) {
this->StackFrameMap[MapIndex].VarPtr = &(this->LocalVarTable.at(i));
}
}
// Iterate through all instructions and record stack frame accesses in the StackFrameMap.
for (CurrInst = this->Instrs.begin(); CurrInst != this->Instrs.end(); ++CurrInst) {
#if SMP_USE_SSA_FNOP_MARKER
if (this->Instrs.begin() == CurrInst)
continue; // skip marker instruction
#endif
sval_t sp_delta = get_spd(&(this->FuncInfo), CurrInst->GetAddr());
if (0 < sp_delta) {
// Stack underflow; about to assert
msg("Stack underflow at %x %s sp_delta: %d\n", CurrInst->GetAddr(),
CurrInst->GetDisasm(), sp_delta);
}
assert(0 >= sp_delta);
ea_t offset;
size_t DataSize;
bool UsedFramePointer;
if (CurrInst->HasDestMemoryOperand()) {
set<DefOrUse, LessDefUse>::iterator CurrDef;
for (CurrDef = CurrInst->GetFirstDef(); CurrDef != CurrInst->GetLastDef(); ++CurrDef) {
op_t TempOp = CurrDef->GetOp();
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if (TempOp.type != o_phrase && TempOp.type != o_displ)
continue;
if (this->MDGetStackOffsetAndSize(TempOp, sp_delta, offset, DataSize, UsedFramePointer)) {
assert(0 <= offset);
if (offset >= this->FuncInfo.frsize)
continue; // limit processing to outgoing args and locals
if ((offset + DataSize) > this->StackFrameMap.size()) {
msg("ERROR: offset = %d DataSize = %d FrameMapSize = %d\n",
offset, DataSize, this->StackFrameMap.size());
}
assert((offset + DataSize) <= this->StackFrameMap.size());
for (int j = 0; j < (int) DataSize; ++j) {
this->StackFrameMap[offset + j].Written = true;
if (!UsedFramePointer)
this->StackFrameMap[offset + j].ESPRelativeAccess = true;
else
this->StackFrameMap[offset + j].EBPRelativeAccess = true;
}
}
} // end for all DEFs
} // end if DestMemoryOperand
if (CurrInst->HasSourceMemoryOperand()) {
set<DefOrUse, LessDefUse>::iterator CurrUse;
for (CurrUse = CurrInst->GetFirstUse(); CurrUse != CurrInst->GetLastUse(); ++CurrUse) {
op_t TempOp = CurrUse->GetOp();
if (TempOp.type != o_phrase && TempOp.type != o_displ)
continue;
if (this->MDGetStackOffsetAndSize(TempOp, sp_delta, offset, DataSize, UsedFramePointer)) {
assert(0 <= offset);
if (offset >= this->FuncInfo.frsize)
continue; // limit processing to outgoing args and locals
if ((offset + DataSize) > this->StackFrameMap.size()) {
msg("ERROR: offset = %d DataSize = %d FrameMapSize = %d\n",
offset, DataSize, this->StackFrameMap.size());
}
assert((offset + DataSize) <= this->StackFrameMap.size());
for (int j = 0; j < (int) DataSize; ++j) {
this->StackFrameMap[offset + j].Read = true;
if (!UsedFramePointer)
this->StackFrameMap[offset + j].ESPRelativeAccess = true;
else
this->StackFrameMap[offset + j].EBPRelativeAccess = true;
}
}
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} // end if SourceMemoryOperand
// NOTE: Detect taking the address of stack locations. **!!**
} // end for all instructions
// If function is a leaf function, set OutgoingArgsSize to zero and return.
if (this->IsLeaf()) {
this->OutgoingArgsSize = 0;
return;
}
// For non-leaf functions, set the OutgoingArgsSize to the write-only, ESP-relative
// region of the bottom of the StackFrameMap.
for (size_t MapIndex = 0; MapIndex < this->StackFrameMap.size(); ++MapIndex) {
// Some of the bottom of the stack frame might be below the local frame allocation.
// These are pushes that happened after allocation, etc. We skip over these
// locations and define the outgoing args region to start strictly at the bottom
// of the local frame allocation.
struct StackFrameEntry TempEntry = this->StackFrameMap.at(MapIndex);
if (DebugFlag) {
msg("StackFrameMap entry %d: offset: %d Read: %d Written: %d ESP: %d EBP: %d\n",
MapIndex, TempEntry.offset, TempEntry.Read, TempEntry.Written,
TempEntry.ESPRelativeAccess, TempEntry.EBPRelativeAccess);
}
if (TempEntry.offset < this->AllocPointDelta)
continue;
if (TempEntry.Read || TempEntry.EBPRelativeAccess || !TempEntry.Written
|| !TempEntry.ESPRelativeAccess)
break;
this->OutgoingArgsSize++;
}
// Sometimes we encounter unused stack space above the outgoing args. Lump this space
// in with the outgoing args. We detect this by noting when the outgoing args space
// has only partially used the space assigned to a local var.
if ((0 < this->OutgoingArgsSize) && (this->OutgoingArgsSize < this->FuncInfo.frsize)) {
long MapIndex = (this->AllocPointDelta - this->MinStackDelta);
assert(0 <= MapIndex);
MapIndex += (((long) this->OutgoingArgsSize) - 1);
struct StackFrameEntry TempEntry = this->StackFrameMap.at((size_t) MapIndex);
if (this->OutgoingArgsSize < (TempEntry.VarPtr->offset + TempEntry.VarPtr->size)) {
clc5q
committed
#if SMP_DEBUG_FRAMEFIXUP
msg("OutGoingArgsSize = %d", this->OutgoingArgsSize);
clc5q
committed
#endif
this->OutgoingArgsSize = TempEntry.VarPtr->offset + TempEntry.VarPtr->size;
clc5q
committed
#if SMP_DEBUG_FRAMEFIXUP
msg(" adjusted to %d\n", this->OutgoingArgsSize);
clc5q
committed
#endif
}
}
return;
} // end of SMPFunction::FindOutgoingArgsSize()
// If TempOp reads or writes to a stack location, return the offset (relative to the initial
// stack pointer value) and the size in bytes of the data access.
// NOTE: TempOp must be of type o_displ or o_phrase, as no other operand type could be a
// stack memory access.
// sp_delta is the stack pointer delta of the current instruction, relative to the initial
// stack pointer value for the function.
// Return true if a stack memory access was found in TempOp, false otherwise.
bool SMPFunction::MDGetStackOffsetAndSize(op_t TempOp, sval_t sp_delta, ea_t &offset, size_t &DataSize, bool &FP) {
clc5q
committed
int BaseReg;
int IndexReg;
ushort ScaleFactor;
assert((o_displ == TempOp.type) || (o_phrase == TempOp.type));
clc5q
committed
MDExtractAddressFields(TempOp, BaseReg, IndexReg, ScaleFactor, offset);
clc5q
committed
if (TempOp.type == o_phrase) {
assert(offset == 0); // implicit zero, as in [esp] ==> [esp+0]
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}
if ((BaseReg == R_sp) || (IndexReg == R_sp)) {
// ESP-relative constant offset
offset += sp_delta; // base offsets from entry ESP value
offset -= this->MinStackDelta; // convert to StackFrameMap index
// Get size of data written
DataSize = GetOpDataSize(TempOp);
FP = false;
return true;
}
else if (this->UseFP && ((BaseReg == R_bp) || (IndexReg == R_bp))) {
offset -= this->FuncInfo.frregs; // base offsets from entry ESP value
offset -= this->MinStackDelta; // convert to StackFrameMap index
DataSize = GetOpDataSize(TempOp);
FP = true;
return true;
}
else {
return false;
}
} // end of SMPFunction::MDGetStackOffsetAndSize()
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// Is DestOp within the outgoing args area? Assume it must be an ESP-relative
// DEF operand in order to be a write to the outgoing args area.
bool SMPFunction::WritesToOutgoingArgs(op_t DestOp) {
bool OutArgWrite = false;
int BaseReg, IndexReg;
ushort ScaleFactor;
ea_t offset;
if (this->IsLeaf())
return false;
MDExtractAddressFields(DestOp, BaseReg, IndexReg, ScaleFactor, offset);
if ((BaseReg != R_sp) && (IndexReg != R_sp))
return false;
if (((BaseReg == R_sp) && (IndexReg != R_none))
|| ((IndexReg == R_sp) && (BaseReg != R_none))
|| (0 < ScaleFactor)) {
msg("WARNING: WritesToOutgoingArgs called with indexed write.");
PrintOperand(DestOp);
return false;
}
if (!this->OutgoingArgsComputed) {
OutArgWrite = true; // be conservative
}
else {
OutArgWrite = (offset < this->OutgoingArgsSize);
}
return OutArgWrite;
} // end of SMPFunction::WritesToOutgoingArgs()
// Is DestOp a direct memory access above the local vars frame?
bool SMPFunction::WritesAboveLocalFrame(op_t DestOp) {
bool InArgWrite = false;
int BaseReg, IndexReg;
ushort ScaleFactor;
ea_t offset;
MDExtractAddressFields(DestOp, BaseReg, IndexReg, ScaleFactor, offset);
bool ESPrelative = (BaseReg == R_sp) || (IndexReg == R_sp);
bool EBPrelative = this->UseFP && ((BaseReg == R_bp) || (IndexReg == R_bp));
if (!(ESPrelative || EBPrelative))
return false;
if (((IndexReg != R_none) && (BaseReg != R_none))
|| (0 < ScaleFactor)) {
msg("WARNING: WritesToOutgoingArgs called with indexed write.");
PrintOperand(DestOp);
return false;
}
InArgWrite = (ESPrelative && (SignedOffset > ((long) this->LocalVarsSize)))
|| (EBPrelative && (SignedOffset > 0));
return InArgWrite;
}// end of SMPFunction::WritesAboveLocalFrame()
bool SMPFunction::IndexedWritesAboveLocalFrame(op_t DestOp)
{
bool InArgWrite = false;
int BaseReg, IndexReg;
ushort ScaleFactor;
ea_t offset;
MDExtractAddressFields(DestOp, BaseReg, IndexReg, ScaleFactor, offset);
bool ESPrelative = (BaseReg == R_sp) || (IndexReg == R_sp);
bool EBPrelative = this->UseFP && ((BaseReg == R_bp) || (IndexReg == R_bp));
if (!(ESPrelative || EBPrelative))
return false;
InArgWrite = (ESPrelative && (offset > this->LocalVarsSize))
|| (EBPrelative && (offset > 0));
return InArgWrite;
} // end of SMPFunction::WritesAboveLocalFrame
// Find evidence of calls to alloca(), which appear as stack space allocations (i.e.
// subtractions from the stack pointer) AFTER the local frame allocation instruction
// for this function.
// Return true if such an allocation is found and false otherwise.
bool SMPFunction::FindAlloca(void) {
list<SMPInstr>::iterator CurrInst;
for (CurrInst = this->Instrs.begin(); CurrInst != this->Instrs.end(); ++CurrInst) {
#if SMP_USE_SSA_FNOP_MARKER
if (this->Instrs.begin() == CurrInst)
continue; // skip marker instruction
#endif
if ((CurrInst->GetAddr() > this->LocalVarsAllocInstr) && CurrInst->MDIsFrameAllocInstr()) {
return true;
}
}
return false;
} // end of SMPFunction::FindAlloca()
// Emit the annotations describing the regions of the stack frame.
void SMPFunction::EmitStackFrameAnnotations(FILE *AnnotFile, list<SMPInstr>::iterator Instr) {
ea_t addr = Instr->GetAddr();
#if 0
if (0 < IncomingArgsSize) {
qfprintf(AnnotFile, "%10x %6d INARGS STACK esp + %d %s \n",
addr, IncomingArgsSize,
(LocalVarsSize + CalleeSavedRegsSize + RetAddrSize),
Instr->GetDisasm());
}
#endif
if (0 < RetAddrSize) {
qfprintf(AnnotFile, "%10x %6d MEMORYHOLE STACK esp + %d ReturnAddress \n",
addr, RetAddrSize, (LocalVarsSize + CalleeSavedRegsSize));
}
if (0 < CalleeSavedRegsSize) {
qfprintf(AnnotFile, "%10x %6d MEMORYHOLE STACK esp + %d CalleeSavedRegs \n",
addr, CalleeSavedRegsSize, LocalVarsSize);
if (0 < LocalVarsSize) {
unsigned long ParentReferentID = DataReferentID++;
qfprintf(AnnotFile, "%10x %6d DATAREF STACK %d esp + %d PARENT LocalFrame LOCALFRAME\n",
addr, LocalVarsSize, ParentReferentID, 0);
#if SMP_COMPUTE_STACK_GRANULARITY
if (this->AnalyzedSP && !this->CallsAlloca && (BADADDR != this->LocalVarsAllocInstr)) {
// We can only fine-grain the stack frame if we were able to analyze the stack
if (this->OutgoingArgsSize > 0) {
qfprintf(AnnotFile, "%10x %6d DATAREF STACK %d esp + %d CHILDOF %d OFFSET %d OutArgsRegion OUTARGS\n",
addr, this->OutgoingArgsSize, DataReferentID, 0, ParentReferentID, 0);
++DataReferentID;
#if SMP_DEBUG_STACK_GRANULARITY
msg("LocalVarTable of size %d for function %s\n", this->LocalVarTable.size(),
this->GetFuncName());
for (size_t i = 0; i < this->LocalVarTable.size(); ++i) {
#if SMP_DEBUG_STACK_GRANULARITY
msg("Entry %d offset %d size %d name %s\n", i, this->LocalVarTable[i].offset,
this->LocalVarTable[i].size, this->LocalVarTable[i].VarName);
// Don't emit annotations for incoming or outgoing args or anything else
// above or below the current local frame.
if ((this->LocalVarTable[i].offset >= (long) this->FuncInfo.frsize)
|| (this->LocalVarTable[i].offset < (long) this->OutgoingArgsSize))
continue;
qfprintf(AnnotFile, "%10x %6d DATAREF STACK %d esp + %d CHILDOF %d OFFSET %d LOCALVAR %s \n",
addr, this->LocalVarTable[i].size, DataReferentID,
this->LocalVarTable[i].offset, ParentReferentID,
this->LocalVarTable[i].offset, this->LocalVarTable[i].VarName);
++DataReferentID;
} // end if (this->AnalyzedSP and not Alloca .... )
} // end if (0 < LocalVarsSize)
return;
} // end of SMPFunction::EmitStackFrameAnnotations()
// Main data flow analysis driver. Goes through the function and
// fills all objects for instructions, basic blocks, and the function
// itself.
void SMPFunction::Analyze(void) {
clc5q
committed
bool FoundAllCallers = false;
list<SMPInstr>::iterator FirstInBlock = this->Instrs.end();
// For starting a basic block
list<SMPInstr>::iterator LastInBlock = this->Instrs.end();
// Terminating a basic block
#if SMP_DEBUG_CONTROLFLOW
msg("Entering SMPFunction::Analyze.\n");
#endif
// Get some basic info from the FuncInfo structure.
this->Size = this->FuncInfo.endEA - this->FuncInfo.startEA;
this->UseFP = (0 != (this->FuncInfo.flags & (FUNC_FRAME | FUNC_BOTTOMBP)));
this->StaticFunc = (0 != (this->FuncInfo.flags & FUNC_STATIC));
get_func_name(this->FuncInfo.startEA, this->FuncName,
sizeof(this->FuncName) - 1);
this->BlockCount = 0;
this->AnalyzedSP = this->FuncInfo.analyzed_sp();
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#if SMP_DEBUG_CONTROLFLOW
msg("SMPFunction::Analyze: got basic info.\n");
#endif
// Cycle through all chunks that belong to the function.
func_tail_iterator_t FuncTail(&(this->FuncInfo));
size_t ChunkCounter = 0;
for (bool ChunkOK = FuncTail.main(); ChunkOK; ChunkOK = FuncTail.next()) {
const area_t &CurrChunk = FuncTail.chunk();
++ChunkCounter;
if (1 < ChunkCounter) {
this->SharedChunks = true;
#if SMP_DEBUG_CHUNKS
msg("Found tail chunk for %s at %x\n", this->FuncName, CurrChunk.startEA);
#endif
}
// Build the instruction and block lists for the function.
for (ea_t addr = CurrChunk.startEA; addr < CurrChunk.endEA;
addr = get_item_end(addr)) {
flags_t InstrFlags = getFlags(addr);
if (isHead(InstrFlags) && isCode(InstrFlags)) {
SMPInstr CurrInst = SMPInstr(addr);
// Fill in the instruction data members.
#if SMP_DEBUG_CONTROLFLOW
msg("SMPFunction::Analyze: calling CurrInst::Analyze.\n");
#endif
CurrInst.Analyze();
if (SMPBinaryDebug) {
msg("Disasm: %s \n", CurrInst.GetDisasm());
}
#if SMP_USE_SSA_FNOP_MARKER
if (this->Instrs.empty()) {
// First instruction in function. We want to create a pseudo-instruction
// at the top of the function that can hold SSA DEFs for LiveIn names
// to the function. We use a floating point no-op as the pseudo-inst.
// The code address is one less than the start address of the function.
SMPInstr MarkerInst = SMPInstr(addr - 1);
MarkerInst.AnalyzeMarker();
assert(FirstInBlock == this->Instrs.end());
this->Instrs.push_back(MarkerInst);
}
#endif
if (this->AnalyzedSP) {
// Audit the IDA SP analysis.
sval_t sp_delta = get_spd(&(this->FuncInfo), addr);
// sp_delta is difference between current value of stack pointer
// and value of the stack pointer coming into the function. It
// is updated AFTER each instruction. Thus, it should not get back
// above zero (e.g. to +4) until after a return instruction.
if (sp_delta > 0) {
// Stack pointer has underflowed, according to IDA's analysis,
// which is probably incorrect.
this->AnalyzedSP = false;
msg("Resetting AnalyzedSP to false for %s\n", this->GetFuncName());
msg("Underflowing instruction: %s sp_delta: %d\n", CurrInst.GetDisasm(),
sp_delta);
}
else if (sp_delta == 0) {
// Search for tail calls.
if (CurrInst.IsBranchToFarChunk()) {
// After the stack has been restored to the point at which
// we are ready to return, we instead find a jump to a
// far chunk. This is the classic tail call optimization:
// the return statement has been replaced with a jump to
// another function, which will return not to this function,
// but to the caller of this function.
CurrInst.SetTailCall();
msg("Found tail call at %x from %s: %s\n", addr, this->GetFuncName(),
CurrInst.GetDisasm());
// Just like a return instruction, we must make
// DEF-USE chains reach the tail call.
CurrInst.MDAddRegUse(R_ax, false);
CurrInst.MDAddRegUse(R_bx, false);
CurrInst.MDAddRegUse(R_cx, false);
CurrInst.MDAddRegUse(R_dx, false);
CurrInst.MDAddRegUse(R_bp, false);
CurrInst.MDAddRegUse(R_si, false);
CurrInst.MDAddRegUse(R_di, false);
clc5q
committed
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// Find all functions that call the current function.
xrefblk_t CurrXrefs;
if (!FoundAllCallers) {
for (bool ok = CurrXrefs.first_to(CurrInst.GetAddr(), XREF_ALL);
ok;
ok = CurrXrefs.next_to()) {
if ((CurrXrefs.from != 0) && (CurrXrefs.iscode)) {
// Make sure it is not a fall-through. Must be a
// control-flow instruction of some sort, including
// direct or indirect calls or tail calls.
SMPInstr CallInst(CurrXrefs.from);
CallInst.Analyze();
SMPitype CallType = CallInst.GetDataFlowType();
if ((COND_BRANCH <= CallType) && (RETURN >= CallType)) {
// Found a caller, with its call address in CurrXrefs.from
this->AddCallSource(CurrXrefs.from);
}
}
}
FoundAllCallers = true; // only do this for first inst
}
if (CurrInst.GetDataFlowType() == INDIR_CALL) {
this->IndirectCalls = true;
// See if IDA has determined all possible targets
// of the indirect call.
bool LinkedToTarget = false;
for (bool ok = CurrXrefs.first_from(CurrInst.GetAddr(), XREF_ALL);
ok;
ok = CurrXrefs.next_from()) {
if ((CurrXrefs.to != 0) && (CurrXrefs.iscode)) {
// Found a code target, with its address in CurrXrefs.to
if (CurrXrefs.to == (CurrInst.GetAddr() + CurrInst.GetCmd().size)) {
// A call instruction will have two targets: the fall through to the
// next instruction, and the called function. We want to find
// the called function.
continue;
}
// We found a target, not the fall-through.
LinkedToTarget = true;
this->IndirectCallTargets.push_back(CurrXrefs.to);
this->AllCallTargets.push_back(CurrXrefs.to);
msg("Found indirect call target %x at %x\n",
CurrXrefs.to, CurrInst.GetAddr());
}
} // end for all code xfrefs
this->UnresolvedIndirectCalls = (!LinkedToTarget);
if (!LinkedToTarget) {
msg("WARNING: Did not find indirect call target at %x\n",
CurrInst.GetAddr());
}
} // end if INDIR_CALL
else if (CurrInst.GetDataFlowType() == INDIR_JUMP)
this->IndirectJumps = true;
else if (CurrInst.GetDataFlowType() == CALL) {
set<DefOrUse, LessDefUse>::iterator CurrUse;
for (CurrUse = CurrInst.GetFirstUse(); CurrUse != CurrInst.GetLastUse(); ++CurrUse) {
optype_t OpType = CurrUse->GetOp().type;
if ((OpType == o_near) || (OpType == o_far)) {
ea_t CallTarget = CurrUse->GetOp().addr;
this->DirectCallTargets.push_back(CallTarget);
this->AllCallTargets.push_back(CallTarget);
// Before we insert the instruction into the instruction
// list, determine if it is a jump target that does not
// follow a basic block terminator. This is the special case
// of a CASE in a SWITCH that falls through into another
// CASE, for example. The first sequence of statements
// was not terminated by a C "break;" statement, so it
// looks like straight line code, but there is an entry
// point at the beginning of the second CASE sequence and
// we have to split basic blocks at the entry point.
if ((FirstInBlock != this->Instrs.end())
&& CurrInst.IsJumpTarget()) {
#if SMP_DEBUG_CONTROLFLOW
msg("SMPFunction::Analyze: hit special jump target case.\n");
#endif
LastInBlock = --(this->Instrs.end());
SMPBasicBlock CurrBlock = SMPBasicBlock(this, FirstInBlock,
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LastInBlock);
CurrBlock.Analyze();
// If not the first chunk in the function, it is a shared
// tail chunk.
if (ChunkCounter > 1) {
CurrBlock.SetShared();
}
FirstInBlock = this->Instrs.end();
LastInBlock = this->Instrs.end();
this->Blocks.push_back(CurrBlock);
this->BlockCount += 1;
}
#if SMP_DEBUG_CONTROLFLOW
msg("SMPFunction::Analyze: putting CurrInst on list.\n");
#endif
// Insert instruction at end of list.
this->Instrs.push_back(CurrInst);
// Find basic block leaders and terminators.
if (FirstInBlock == this->Instrs.end()) {
#if SMP_DEBUG_CONTROLFLOW
msg("SMPFunction::Analyze: setting FirstInBlock.\n");
#if SMP_USE_SSA_FNOP_MARKER
if (2 == this->Instrs.size()) {
// Just pushed first real instruction, after the fnop marker.
FirstInBlock = this->Instrs.begin();
}
else {
FirstInBlock = --(this->Instrs.end());
}
#else
FirstInBlock = --(this->Instrs.end());
}
if (CurrInst.IsBasicBlockTerminator()) {
#if SMP_DEBUG_CONTROLFLOW
msg("SMPFunction::Analyze: found block terminator.\n");
#endif
LastInBlock = --(this->Instrs.end());
SMPBasicBlock CurrBlock = SMPBasicBlock(this, FirstInBlock, LastInBlock);
CurrBlock.Analyze();
// If not the first chunk in the function, it is a shared
// tail chunk.
if (ChunkCounter > 1) {
CurrBlock.SetShared();
}
FirstInBlock = this->Instrs.end();
LastInBlock = this->Instrs.end();
this->Blocks.push_back(CurrBlock);
this->BlockCount += 1;
// Is the instruction a branch to a target outside the function? If
// so, this function has shared tail chunks.
if (CurrInst.IsBranchToFarChunk() && (!CurrInst.IsTailCall())) {
this->SharedChunks = true;
}
}
} // end if (isHead(InstrFlags) && isCode(InstrFlags)
} // end for (ea_t addr = CurrChunk.startEA; ... )
// Handle the special case in which a function does not terminate
// with a return instruction or any other basic block terminator.
// Sometimes IDA Pro sees a call to a NORET function and decides
// to not include the dead code after it in the function. That
// dead code includes the return instruction, so the function no
// longer includes a return instruction and terminates with a CALL.
if (FirstInBlock != this->Instrs.end()) {
LastInBlock = --(this->Instrs.end());
SMPBasicBlock CurrBlock = SMPBasicBlock(this, FirstInBlock, LastInBlock);
CurrBlock.Analyze();
// If not the first chunk in the function, it is a shared
// tail chunk.
if (ChunkCounter > 1) {
CurrBlock.SetShared();
}
FirstInBlock = this->Instrs.end();
LastInBlock = this->Instrs.end();
this->Blocks.push_back(CurrBlock);
this->BlockCount += 1;
}
} // end for (bool ChunkOK = ...)
// Now that we have all instructions and basic blocks, link each instruction
// to its basic block. Note that the instruction has to be linked to the copy
// of the basic block in this->Blocks(), not to the original SMPBasicBlock
// object that was constructed and destructed on the stack above. (Ouch!
// Very painful memory corruption debugging lesson.)
list<SMPBasicBlock>::iterator CurrBlock;
list<list<SMPInstr>::iterator>::iterator InstIter;
for (CurrBlock = this->Blocks.begin(); CurrBlock != this->Blocks.end(); ++CurrBlock) {
for (InstIter = CurrBlock->GetFirstInstr(); InstIter != CurrBlock->GetLastInstr(); ++InstIter) {
(*InstIter)->SetBlock(CurrBlock->GetThisBlock());
}
}
#if KLUDGE_VFPRINTF_FAMILY
if (0 != strstr(this->GetFuncName(), "printf")) {
this->SharedChunks = true;
msg("Kludging function %s\n", this->GetFuncName());
}
#endif
#if SMP_IDAPRO52_WORKAROUND
if (0 == strcmp(this->GetFuncName(), "error_for_asm")) {
this->SharedChunks = true;
msg("Kludging function %s\n", this->GetFuncName());
}
#endif
// Set up basic block links and map of instructions to blocks.
if (!(this->HasSharedChunks())) {
this->SetLinks();
this->RPONumberBlocks();
// Figure out the stack frame and related info.
this->SetStackFrameInfo();
clc5q
committed
list<SMPInstr>::iterator CurrInst;
bool GoodRTL;
this->BuiltRTLs = true;
for (CurrInst = this->Instrs.begin(); CurrInst != this->Instrs.end(); ++CurrInst) {
// Build tree RTLs for the instruction.
GoodRTL = CurrInst->BuildRTL();
this->BuiltRTLs = (this->BuiltRTLs && GoodRTL);
clc5q
committed
if (!GoodRTL) {
msg("ERROR: Cannot build RTL at %x for %s\n", CurrInst->GetAddr(),
CurrInst->GetDisasm());
}
clc5q
committed
if (GoodRTL)
CurrInst->SyncAllRTs();
} // end for all instructions
} // end if not shared chunks
else { // has shared chunks; still want to compute stack frame info
#if SMP_DEBUG_CONTROLFLOW
msg("SMPFunction::Analyze: set stack frame info.\n");
#ifdef SMP_DEBUG_FUNC
msg(" %s has shared chunks \n", this->GetFuncName());
#endif
// Figure out the stack frame and related info.
this->SetStackFrameInfo();
}
} // end of SMPFunction::Analyze()
// For each instruction, mark the non-flags-reg DEFs as having live
// metadata (mmStrata needs to fetch and track this metadata for this
// instruction) or dead metadata (won't be used as addressing reg, won't
// be stored to memory, won't be returned to caller).
void SMPFunction::AnalyzeMetadataLiveness(void) {
bool changed;
int BaseReg;
int IndexReg;
ushort ScaleFactor;
ea_t offset;
op_t BaseOp, IndexOp, ReturnOp, DefOp, UseOp;
BaseOp.type = o_reg;
IndexOp.type = o_reg;
ReturnOp.type = o_reg;
list<SMPInstr>::iterator CurrInst;
set<DefOrUse, LessDefUse>::iterator CurrDef;
set<DefOrUse, LessDefUse>::iterator CurrUse;
set<DefOrUse, LessDefUse>::iterator NextUse;
bool DebugFlag = false;
if (0 == strcmp("gl_transform_vb_part1", this->GetFuncName())) {
DebugFlag = true;
}
bool SafeMemDest;
for (CurrInst = this->Instrs.begin(); CurrInst != this->Instrs.end(); ++CurrInst) {
SafeMemDest = false; // true for some SafeFunc instructions
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// Skip the SSA marker instruction.
if (NN_fnop == CurrInst->GetCmd().itype)
continue;
CurrDef = CurrInst->GetFirstDef();
while (CurrDef != CurrInst->GetLastDef()) {
if (DEF_METADATA_UNANALYZED == CurrDef->GetMetadataStatus()) {
DefOp = CurrDef->GetOp();
// Handle special registers never used as address regs.
if (DefOp.is_reg(X86_FLAGS_REG)
|| ((o_trreg <= DefOp.type) && (o_xmmreg >= DefOp.type))) {
CurrDef = CurrInst->SetDefMetadata(DefOp,
DEF_METADATA_UNUSED);
changed = true;
}
else if (DefOp.is_reg(R_sp)
|| (this->UseFP && DefOp.is_reg(R_bp))) {
// Stack pointer register DEFs always have live
// metadata, but we don't need to propagate back
// through particular DEF-USE chains.
CurrDef = CurrInst->SetDefMetadata(DefOp, DEF_METADATA_USED);
changed = true;
}
else if ((o_mem <= DefOp.type) && (o_displ >= DefOp.type)) {
// DEF is a memory operand. The addressing registers
// therefore have live metadata, and the memory metadata is live.
// EXCEPTION: If the function is Safe, then direct stack writes
// to local variables (above the outgoing args area of the frame)
// are not live metadata, and there will be no indirect local frame
// writes, by definition of "safe." So, for safe funcs, only
// the o_mem (globals) and indirect writes are live metadata.
if (this->SafeFunc && MDIsStackAccessOpnd(DefOp, this->UseFP)
&& (!this->WritesAboveLocalFrame(DefOp))
&& (!this->WritesToOutgoingArgs(DefOp))) {
++CurrDef;
SafeMemDest = true;
continue;
}
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CurrDef = CurrInst->SetDefMetadata(DefOp, DEF_METADATA_USED);
changed = true;
MDExtractAddressFields(DefOp, BaseReg, IndexReg,
ScaleFactor, offset);
if (R_none != BaseReg) {
BaseOp.reg = MDCanonicalizeSubReg((ushort) BaseReg);
if (BaseOp.is_reg(R_sp)
|| (this->UseFP && BaseOp.is_reg(R_bp))) {
; // do nothing; DEF handled by case above
}
else {
CurrUse = CurrInst->FindUse(BaseOp);
if (CurrUse == CurrInst->GetLastUse()) {
msg("ERROR: BaseReg %d not in USE list at %x for %s\n",
BaseOp.reg, CurrInst->GetAddr(),
CurrInst->GetDisasm());
}
assert(CurrUse != CurrInst->GetLastUse());
if (this->IsGlobalName(BaseOp)) {
changed |= this->PropagateGlobalMetadata(BaseOp,
DEF_METADATA_USED, CurrUse->GetSSANum());
}
else {
changed |= CurrInst->GetBlock()->PropagateLocalMetadata(BaseOp,
DEF_METADATA_USED, CurrUse->GetSSANum());
}
}
} // end if R_none != BaseReg
if (R_none != IndexReg) {
IndexOp.reg = MDCanonicalizeSubReg((ushort) IndexReg);
if (IndexOp.is_reg(R_sp)
|| (this->UseFP && IndexOp.is_reg(R_bp))) {
; // do nothing; DEF handled by case above
}
else {
CurrUse = CurrInst->FindUse(IndexOp);
if (CurrUse == CurrInst->GetLastUse()) {
msg("ERROR: IndexReg %d not in USE list at %x for %s\n",
IndexOp.reg, CurrInst->GetAddr(),
CurrInst->GetDisasm());
}
assert(CurrUse != CurrInst->GetLastUse());
if (0 != ScaleFactor) {
; // mmStrata knows scaled reg is NUMERIC
// ... its metadata is not fetched
}
else if (this->IsGlobalName(IndexOp)) {
changed |= this->PropagateGlobalMetadata(IndexOp,
DEF_METADATA_USED, CurrUse->GetSSANum());
}
else {
changed |= CurrInst->GetBlock()->PropagateLocalMetadata(IndexOp,
DEF_METADATA_USED, CurrUse->GetSSANum());
}
}
} // end if R_none != IndexReg
} // end if X86_FLAGS_REG .. else if stack ptr ...
} // end if unanalyzed metadata usage
++CurrDef;
} // end while processing DEFs
if ((RETURN == CurrInst->GetDataFlowType())
|| (CALL == CurrInst->GetDataFlowType())
|| (INDIR_CALL == CurrInst->GetDataFlowType())) {
// The EAX and EDX registers can be returned to the caller,
// which might use their metadata. They show up as USEs
// of the return instruction. Some library functions
// pass return values in non-standard ways. e.g. through
// EBX or EDI, so we treat all return regs the same.
// For CALL instructions, values can be passed in caller-saved
// registers, unfortunately, so the metadata is live-in.
CurrUse = CurrInst->GetFirstUse();
while (CurrUse != CurrInst->GetLastUse()) {
NextUse = CurrUse;
++NextUse;
ReturnOp = CurrUse->GetOp();
if ((o_reg == ReturnOp.type) &&
(!ReturnOp.is_reg(X86_FLAGS_REG))) {
if (this->IsGlobalName(ReturnOp)) {
changed |= this->PropagateGlobalMetadata(ReturnOp,
DEF_METADATA_USED, CurrUse->GetSSANum());
}
else {
changed |= CurrInst->GetBlock()->PropagateLocalMetadata(ReturnOp,
DEF_METADATA_USED, CurrUse->GetSSANum());
}
}
CurrUse = NextUse;
} // end while all USEs
} // end if return or call
else if (CurrInst->HasDestMemoryOperand()
// Memory writes cause a lot of metadata usage.
// Addressing registers in the memory destination
// have live metadata used in bounds checking. The
// register being stored to memory could end up being
// used in some other bounds checking, unless we
// have precise memory tracking and know that it
// won't.
// We handled the addressing registers above, so we
// handle the register written to memory here.
// The same exception applies as above: If the destination
// memory operand is not a stack write, then safe functions
// do not need to track the metadata.
if (SafeMemDest) {
continue; // go to next instruction
}
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CurrUse = CurrInst->GetFirstUse();
while (CurrUse != CurrInst->GetLastUse()) {
NextUse = CurrUse;
++NextUse;
UseOp = CurrUse->GetOp();
// NOTE: **!!** To be less conservative, we
// should propagate less for exchange category
// instructions.
if ((UseOp.type == o_reg) && (!UseOp.is_reg(R_sp))
&& (!(this->UseFP && UseOp.is_reg(R_bp)))
&& (!UseOp.is_reg(X86_FLAGS_REG))) {
if (this->IsGlobalName(UseOp)) {
changed |= this->PropagateGlobalMetadata(UseOp,
DEF_METADATA_USED, CurrUse->GetSSANum());
}
else {
changed |= CurrInst->GetBlock()->PropagateLocalMetadata(UseOp,
DEF_METADATA_USED, CurrUse->GetSSANum());
}
} // end if register
CurrUse = NextUse;
} // end while all USEs
} // end if call or return else if memdest ...
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} // end for all instructions
} while (changed);
// All DEFs that still have status DEF_METADATA_UNANALYZED can now
// be marked as DEF_METADATA_UNUSED.
for (CurrInst = this->Instrs.begin(); CurrInst != this->Instrs.end(); ++CurrInst) {
if (NN_fnop == CurrInst->GetCmd().itype)
continue;
CurrDef = CurrInst->GetFirstDef();
while (CurrDef != CurrInst->GetLastDef()) {
if (DEF_METADATA_UNANALYZED == CurrDef->GetMetadataStatus()) {
CurrDef = CurrInst->SetDefMetadata(CurrDef->GetOp(),
DEF_METADATA_UNUSED);
assert(CurrDef != CurrInst->GetLastDef());
}
++CurrDef;
}
}
return;
} // end of SMPFunction::AnalyzeMetadataLiveness()
// Propagate the metadata Status for UseOp/SSANum to its global DEF.
// Return true if successful.
bool SMPFunction::PropagateGlobalMetadata(op_t UseOp, SMPMetadataType Status, int SSANum) {
bool changed = false;
if ((0 > SSANum) || (o_void == UseOp.type))
return false;
// Find the DEF of UseOp with SSANum.
bool FoundDef = false;
list<SMPInstr>::iterator CurrInst;
for (CurrInst = this->Instrs.begin(); CurrInst != this->Instrs.end(); ++CurrInst) {
set<DefOrUse, LessDefUse>::iterator CurrDef;
set<DefOrUse, LessDefUse>::iterator CurrUse;
CurrDef = CurrInst->FindDef(UseOp);
if (CurrDef != CurrInst->GetLastDef()) {
if (SSANum == CurrDef->GetSSANum()) {
FoundDef = true;
if (Status != CurrDef->GetMetadataStatus()) {
CurrDef = CurrInst->SetDefMetadata(UseOp, Status);
changed = (CurrDef != CurrInst->GetLastDef());
// If source operand was memory, we have two cases.
// (1) The instruction could be a load, in which
// case we should simply terminate the
// propagation, because the prior DEF of a memory
// location is always considered live metadata
// already, and we do not want to propagate liveness
// to the address regs in the USE list.
// EXCEPTION: For safe funcs, we propagate liveness
// for stack locations.
// (2) We could have an arithmetic operation such
// as reg := reg arithop memsrc. In this case, we
// still do not want to propagate through the memsrc,
// (with the same safe func EXCEPTION),
// but the register is both DEF and USE and we need
// to propagate through the register.
if (CurrInst->HasSourceMemoryOperand()) {
if (this->SafeFunc) {
op_t MemSrcOp = CurrInst->MDGetMemUseOp();
assert(o_void != MemSrcOp.type);
if (MDIsStackAccessOpnd(MemSrcOp, this->UseFP)) {
// We have a SafeFunc stack access. This is
// the EXCEPTION case where we want to
// propagate metadata liveness for a memory
// location.
CurrUse = CurrInst->FindUse(MemSrcOp);
assert(CurrUse != CurrInst->GetLastUse());
if (this->IsGlobalName(MemSrcOp)) {
changed |= this->PropagateGlobalMetadata(MemSrcOp,
Status, CurrUse->GetSSANum());
}
else {
changed |= CurrInst->GetBlock()->PropagateLocalMetadata(MemSrcOp,
Status, CurrUse->GetSSANum());
}
} // end if stack access operand
} // end if SafeFunc
if (3 == CurrInst->GetOptType()) { // move inst
clc5q
committed
break; // load address regs are not live metadata
}
else if ((5 == CurrInst->GetOptType())
|| (NN_and == CurrInst->GetCmd().itype)
|| (NN_or == CurrInst->GetCmd().itype)
|| (NN_xor == CurrInst->GetCmd().itype)) {
// add, subtract, and, or with memsrc
// Find the DEF reg in the USE list.
CurrUse = CurrInst->FindUse(UseOp);
assert(CurrUse != CurrInst->GetLastUse());
changed |= this->PropagateGlobalMetadata(UseOp,
Status, CurrUse->GetSSANum());
break;
}
} // end if memory source
// Now, propagate the metadata status to all the
// non-memory, non-flags-reg, non-special-reg
// (i.e. regular registers) USEs.
CurrUse = CurrInst->GetFirstUse();
while (CurrUse != CurrInst->GetLastUse()) {
op_t UseOp = CurrUse->GetOp();
// NOTE: **!!** To be less conservative, we
// should propagate less for exchange category
// instructions.
if ((UseOp.type == o_reg) && (!UseOp.is_reg(R_sp))
&& (!(this->UseFP && UseOp.is_reg(R_bp)))
&& (!UseOp.is_reg(X86_FLAGS_REG))) {
changed |= this->PropagateGlobalMetadata(UseOp,
Status, CurrUse->GetSSANum());
}
else {
changed |= CurrInst->GetBlock()->PropagateLocalMetadata(UseOp,
Status, CurrUse->GetSSANum());
}
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}
break;
}
}
}
if (!FoundDef) {
// Check the Phi functions
list<SMPBasicBlock>::iterator CurrBlock;
for (CurrBlock = this->Blocks.begin(); CurrBlock != this->Blocks.end(); ++CurrBlock) {
set<SMPPhiFunction, LessPhi>::iterator DefPhi;
DefPhi = CurrBlock->FindPhi(UseOp);
if (DefPhi != CurrBlock->GetLastPhi()) {
if (SSANum == DefPhi->GetDefSSANum()) {
if (Status != DefPhi->GetDefMetadata()) {
DefPhi = CurrBlock->SetPhiDefMetadata(UseOp, Status);
changed = true;
// If the Phi DEF has live metadata, then the Phi
// USEs each have live metadata. Propagate.
int UseSSANum;
for (size_t index = 0; index < DefPhi->GetPhiListSize(); ++index) {
UseSSANum = DefPhi->GetUseSSANum(index);
// UseSSANum can be -1 in some cases because
// we conservatively make EAX and EDX be USEs
// of all return instructions, when the function
// might have a void return type, making it
// appear as if an uninitialized EAX or EDX