Newer
Older
if (this->BasicBlock->IsLocalName(SearchOp)) {
(void) this->BasicBlock->PropagateLocalDefType(SearchOp, HEAPPTR,
this->GetAddr(), SSANum, false);
}
else { // global name
this->BasicBlock->GetFunc()->ResetProcessedBlocks(); // set Processed to false
(void) this->BasicBlock->PropagateGlobalDefType(SearchOp, HEAPPTR,
SSANum, false);
}
} // end if "malloc"
} // end if (TargetFunc)
return changed;
} // end of SMPInstr::MDFindMallocCall()
// Is instruction a branch (conditional or unconditional) to a
// code target that is not in the current chunk?
bool SMPInstr::IsBranchToFarChunk(void) {
if (this->FarBranchComputed) { // answer is cached
return this->BranchesToFarChunk;
}
func_t *CurrChunk = get_fchunk(this->address);
bool FarBranch = false;
if ((JUMP | COND_BRANCH) & this->GetDataFlowType()) {
// Instruction is a direct branch, conditional or unconditional
if (this->NumUses() > 0) {
set<DefOrUse, LessDefUse>::iterator CurrUse;
for (CurrUse = this->GetFirstUse(); CurrUse != this->GetLastUse(); ++CurrUse) {
op_t JumpTarget = CurrUse->GetOp();
if ((o_near == JumpTarget.type) || (o_far == JumpTarget.type)) {
// Branches to a code address
func_t *TargetChunk = get_fchunk(JumpTarget.addr);
// Is target address within the same chunk as the branch?
FarBranch = (NULL == TargetChunk) || (CurrChunk->startEA != TargetChunk->startEA);
}
this->BranchesToFarChunk = FarBranch;
this->FarBranchComputed = true;
return FarBranch;
} // end of SMPInstr::IsBranchToFarChunk()
set<DefOrUse, LessDefUse>::iterator SMPInstr::SetUseSSA(op_t CurrOp, int SSASub) {
return this->Uses.SetSSANum(CurrOp, SSASub);
};
set<DefOrUse, LessDefUse>::iterator SMPInstr::SetDefSSA(op_t CurrOp, int SSASub) {
return this->Defs.SetSSANum(CurrOp, SSASub);
};
set<DefOrUse, LessDefUse>::iterator SMPInstr::SetUseType(op_t CurrOp, SMPOperandType CurrType) {
return this->Uses.SetType(CurrOp, CurrType, this);
};
set<DefOrUse, LessDefUse>::iterator SMPInstr::SetDefType(op_t CurrOp, SMPOperandType CurrType) {
return this->Defs.SetType(CurrOp, CurrType, this);
set<DefOrUse, LessDefUse>::iterator SMPInstr::SetDefMetadata(op_t CurrOp, SMPMetadataType Status) {
return this->Defs.SetMetadata(CurrOp, Status);
};
set<DefOrUse, LessDefUse>::iterator SMPInstr::SetDefIndWrite(op_t CurrOp, bool IndWriteFlag) {
return this->Defs.SetIndWrite(CurrOp, IndWriteFlag);
};
// Analyze the instruction and its operands.
void SMPInstr::Analyze(void) {
if (this->analyzed)
return;
bool DebugFlag = false;
if (0x8049b00 == this->address) {
// Setting up breakpoint line.
DebugFlag = true;
}
// Fill cmd structure with disassembly of instr
#if IDA_SDK_VERSION < 600
int InstrLen = ua_ana0(this->address);
#else
int InstrLen = decode_insn(this->address);
if (0 >= InstrLen) {
msg("ERROR: decode_insn failed at %x \n", this->address);
this->SMPcmd = cmd;
this->SMPcmd.size = 0;
return;
}
// NOTE: Might do this on demand to save time.
// Get the instr disassembly text.
bool IDAsuccess = generate_disasm_line(this->address, this->disasm, sizeof(this->disasm) - 1);
if (IDAsuccess) {
// Remove interactive color-coding tags.
ssize_t StringLen = tag_remove(this->disasm, this->disasm, 0);
if (0 > StringLen)
msg("ERROR: tag_remove failed at %x \n", this->address);
}
else {
msg("ERROR: generate_disasm_line failed at %x \n", this->address);
}
// Copy cmd to member variable SMPcmd.
this->SMPcmd = cmd;
// Get the canonical features into member variables features.
this->features = cmd.get_canon_feature();
// Record what type of instruction this is, simplified for the needs
// of data flow and type analysis.
this->type = DFACategory[cmd.itype];
// Record optimization category.
this->OptType = OptCategory[cmd.itype];
this->Interrupt = ((NN_int == cmd.itype) || (NN_into == cmd.itype) || (NN_int3 == cmd.itype));
// See if instruction is an ASM idiom for clearing a register.
if (NN_xor == this->SMPcmd.itype) {
ushort FirstReg;
if (o_reg == this->SMPcmd.Operands[0].type) {
FirstReg = this->SMPcmd.Operands[0].reg;
if (this->SMPcmd.Operands[1].is_reg(FirstReg))
this->RegClearIdiom = true;
}
}
// See if instruction is simple nop or ASM idiom for nop.
this->Nop = this->MDIsNop();
// Build the DEF and USE lists for the instruction.
this->BuildSMPDefUseLists();
// Determine whether the instruction is a jump target by looking
// at its cross references and seeing if it has "TO" code xrefs.
xrefblk_t xrefs;
for (bool ok = xrefs.first_to(this->address, XREF_FAR); ok; ok = xrefs.next_to()) {
if ((xrefs.from != 0) && (xrefs.iscode)) {
this->JumpTarget = true;
break;
}
}
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
// If instruction is a call or indirect call, see if a call target has been recorded
// by IDA Pro.
if (this->GetDataFlowType() == INDIR_CALL) {
for (bool ok = xrefs.first_from(this->address, XREF_ALL);
ok;
ok = xrefs.next_from()) {
if ((xrefs.to != 0) && (xrefs.iscode)) {
// Found a code target, with its address in CurrXrefs.to
if (xrefs.to == (this->address + this->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.
this->CallTarget = xrefs.to;
msg("Found indirect call target %x at %x\n",
xrefs.to, this->address);
break;
}
} // end for all code xrefs
if (BADADDR == this->CallTarget) {
msg("WARNING: Did not find indirect call target at %x\n",
this->address);
}
} // end if INDIR_CALL
else if (this->GetDataFlowType() == CALL) {
set<DefOrUse, LessDefUse>::iterator CurrUse;
for (CurrUse = this->GetFirstUse(); CurrUse != this->GetLastUse(); ++CurrUse) {
optype_t OpType = CurrUse->GetOp().type;
if ((OpType == o_near) || (OpType == o_far)) {
this->CallTarget = CurrUse->GetOp().addr;
}
}
if (BADADDR == this->CallTarget) {
msg("WARNING: Target not found for direct call at %x\n", this->address);
}
}
this->analyzed = true;
if (DebugFlag) {
msg("Analyzed debug instruction at %x\n", this->address);
}
return;
} // end of SMPInstr::Analyze()
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
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1198
1199
1200
1201
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1206
1207
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1209
1210
// Analyze the floating point NOP marker instruction at the top of the function.
void SMPInstr::AnalyzeMarker(void) {
if (this->analyzed)
return;
// Fill member variable SMPcmd structure with disassembly of instr
(void) memset(&(this->SMPcmd), 0, sizeof(this->SMPcmd));
this->SMPcmd.itype = NN_fnop;
this->SMPcmd.size = 1;
this->SMPcmd.ea = this->address;
// Get the instr disassembly text.
qstrncpy(this->disasm, "\tfnop\t; Top of function SSA marker for SMP",
sizeof(this->disasm) - 1);
// Record what type of instruction this is, simplified for the needs
// of data flow and type analysis.
this->type = DFACategory[this->SMPcmd.itype];
// Record optimization category.
this->OptType = OptCategory[this->SMPcmd.itype];
this->analyzed = true;
return;
} // end of SMPInstr::AnalyzeMarker()
// Detect oddities of call instructions, such as pseudo-calls that are
// actually jumps within a function
void SMPInstr::AnalyzeCallInst(ea_t FirstFuncAddr, ea_t LastFuncAddr) {
if (BADADDR != this->CallTarget) {
this->CallUsedAsJump = ((this->CallTarget > FirstFuncAddr)
&& (this->CallTarget <= LastFuncAddr));
this->DirectRecursiveCall = (this->CallTarget == FirstFuncAddr);
if (this->CallUsedAsJump)
this->type = JUMP;
}
return;
}
// Find USE-not-DEF operand that is not the flags register.
op_t SMPInstr::GetSourceOnlyOperand(void) {
size_t OpNum;
for (OpNum = 0; OpNum < UA_MAXOP; ++OpNum) {
if (this->features & DefMacros[OpNum]) { // DEF
;
}
else if (this->features & UseMacros[OpNum]) { // USE
op_t CurrOp = this->SMPcmd.Operands[OpNum];
if (!(CurrOp.is_reg(X86_FLAGS_REG))) {
return CurrOp;
}
}
}
// It is expected that increment, decrement, and floating point stores
// will not have a USE-only operand. Increment and decrement have an
// operand that is both USEd and DEFed, while the floating point stack
// registers are implicit in most floating point opcodes. Also, exchange
// and exchange-and-add instructions have multiple DEF-and-USE operands.
int TypeGroup = SMPTypeCategory[this->SMPcmd.itype];
if ((TypeGroup != 2) && (TypeGroup != 4) && (TypeGroup != 9) && (TypeGroup != 12)
&& (TypeGroup != 13)) {
msg("ERROR: Could not find source only operand at %x in %s\n",
this->address, this->GetDisasm());
}
return InitOp;
} // end of SMPInstr::GetSourceOnlyOperand()
// Fill the Defs and Uses private data members.
void SMPInstr::BuildSMPDefUseLists(void) {
size_t OpNum;
bool DebugFlag = (0x8049b00 == this->GetAddr());
this->Defs.clear();
this->Uses.clear();
// Start with the Defs.
for (OpNum = 0; OpNum < UA_MAXOP; ++OpNum) {
if (this->features & DefMacros[OpNum]) { // DEF
op_t TempOp = this->SMPcmd.Operands[OpNum];
if (MDKnownOperandType(TempOp)) {
if (DebugFlag) {
msg("DEBUG: Setting DEF for: ");
PrintOperand(TempOp);
msg("\n");
}
if (o_reg == TempOp.type) {
// We want to map AH, AL, and AX to EAX, etc. throughout our data flow
// analysis and type inference systems.
TempOp.reg = MDCanonicalizeSubReg(TempOp.reg);
}
this->Defs.SetRef(TempOp);
}
} // end for (OpNum = 0; ...)
if (this->RegClearIdiom) {
// Something like xor eax,eax clears eax but does not really
// use eax. It is the same as mov eax,0 and we don't want to
// extend the prior def-use chain for eax to this instruction
// by treating the instruction as xor eax,eax. Instead, we
// build the DEF and USE lists and RTL as if it were mov eax,0.
op_t ImmOp = InitOp;
ImmOp.type = o_imm;
this->Uses.SetRef(ImmOp, NUMERIC);
return;
}
// Now, do the Uses. Uses have special case operations, because
// any memory operand could have register uses in the addressing
// expression, and we must create Uses for those registers. For
// example: mov eax,[ebx + esi*2 + 044Ch]
// This is a two-operand instruction with one def: eax. But
// there are three uses: [ebx + esi*2 + 044Ch], ebx, and esi.
// The first use is an op_t of type o_phrase (memory phrase),
// which can be copied from cmd.Operands[1]. Likewise, we just
// copy cmd.Operands[0] into the defs list. However, we must create
// op_t types for register ebx and register esi and append them
// to the Uses list. This is handled by the machine dependent
// method MDFixupDefUseLists().
for (OpNum = 0; OpNum < UA_MAXOP; ++OpNum) {
if (this->features & UseMacros[OpNum]) { // USE
op_t TempOp = this->SMPcmd.Operands[OpNum];
if (MDKnownOperandType(TempOp)) {
if (DebugFlag) {
msg("DEBUG: Setting USE for: ");
PrintOperand(TempOp);
msg("\n");
}
if (o_reg == TempOp.type) {
// We want to map AH, AL, and AX to EAX, etc. throughout our data flow
// analysis and type inference systems.
TempOp.reg = MDCanonicalizeSubReg(TempOp.reg);
}
this->Uses.SetRef(TempOp);
}
} // end for (OpNum = 0; ...)
return;
} // end of SMPInstr::BuildSMPDefUseLists()
// If DefReg is not already in the DEF list, add a DEF for it.
void SMPInstr::MDAddRegDef(ushort DefReg, bool Shown, SMPOperandType Type) {
op_t TempDef = InitOp;
TempDef.type = o_reg;
TempDef.reg = DefReg;
if (Shown)
TempDef.set_showed();
else
TempDef.clr_showed();
return;
} // end of SMPInstr::MDAddRegDef()
// If UseReg is not already in the USE list, add a USE for it.
void SMPInstr::MDAddRegUse(ushort UseReg, bool Shown, SMPOperandType Type) {
op_t TempUse = InitOp;
TempUse.type = o_reg;
TempUse.reg = UseReg;
if (Shown)
TempUse.set_showed();
else
TempUse.clr_showed();
return;
} // end of SMPInstr::MDAddRegUse()
// Perform machine dependent ad hoc fixes to the def and use lists.
// For example, some multiply and divide instructions in x86 implicitly
// use and/or define register EDX. For memory phrase examples, see comment
// in BuildSMPDefUseLists().
void SMPInstr::MDFixupDefUseLists(void) {
// First, handle the uses hidden in memory addressing modes. Note that we do not
// care whether we are dealing with a memory destination operand or source
// operand, because register USEs, not DEFs, happen within the addressing expressions.
size_t OpNum;
SMPOperandType RefType;
int BaseReg;
int IndexReg;
ushort ScaleFactor;
ea_t displacement;
bool UseFP = true;
bool HasIndexReg = false;
bool leaInst = (NN_lea == this->SMPcmd.itype);
bool DebugFlag = (this->GetAddr() == 0x8086177);
if (DebugFlag) {
msg("DEBUG: Fixing up DEF-USE lists for debug location\n");
this->Dump();
}
#if SMP_BASEREG_POINTER_TYPE
// Some instructions are analyzed outside of any function or block when fixing up
// the IDB, so we have to assume the block and func pointers might be NULL.
if ((NULL != this->BasicBlock) && (NULL != this->BasicBlock->GetFunc()))
UseFP = this->BasicBlock->GetFunc()->UsesFramePointer();
#endif
if (DebugFlag) {
msg("DEBUG: UseFP = %d\n", UseFP);
}
for (OpNum = 0; OpNum < UA_MAXOP; ++OpNum) {
op_t Opnd = SMPcmd.Operands[OpNum];
if ((Opnd.type == o_phrase) || (Opnd.type == o_displ) || (Opnd.type == o_mem)) {
MDExtractAddressFields(Opnd, BaseReg, IndexReg, ScaleFactor, displacement);
SingleAddressReg = ((0 == displacement)
&& ((R_none == BaseReg) || (R_none == IndexReg)));
if (R_none != IndexReg) {
op_t IndexOpnd = Opnd; // Init to current operand field values
IndexOpnd.type = o_reg; // Change type and reg fields
IndexOpnd.reg = (ushort) IndexReg;
IndexOpnd.hasSIB = 0;
IndexOpnd.set_showed();
// We want to map AH, AL, and AX to EAX, etc. throughout our data flow
// analysis and type inference systems.
IndexOpnd.reg = MDCanonicalizeSubReg(IndexOpnd.reg);
if (0 == ScaleFactor)
this->Uses.SetRef(IndexOpnd);
else { // scaling == shift ==> NUMERIC
HasIndexReg = true;
this->Uses.SetRef(IndexOpnd, NUMERIC);
if (R_none != BaseReg) {
op_t BaseOpnd = Opnd; // Init to current operand field values
BaseOpnd.type = o_reg; // Change type and reg fields
BaseOpnd.reg = (ushort) BaseReg;
BaseOpnd.set_showed();
// We want to map AH, AL, and AX to EAX, etc. throughout our data flow
// analysis and type inference systems.
BaseOpnd.reg = MDCanonicalizeSubReg(BaseOpnd.reg);
RefType = UNINIT;
#if SMP_BASEREG_POINTER_TYPE
// R_sp and R_bp will get type STACKPTR in SMPInstr::SetImmedTypes().
// Other registers used as base registers should get their USEs as
// base registers typed as POINTER, which might get refined later
// to STACKPTR, GLOBALPTR, HEAPPTR, etc.
// NOTE: the NN_lea opcode is often used without a true base register.
// E.g. lea eax,[eax+eax+5] is an x86 idiom for eax:=eax*2+5, which
// could not be done in one instruction without using the addressing
// modes of the machine to do the arithmetic. We don't want to set the
// USE of EAX to POINTER in this case, so we will conservatively skip
// all lea instructions here.
// We cannot be sure that a register is truly a base register unless
// there is also an index register. E.g. with reg+displacement, we
// could have memaddr+indexreg or basereg+offset, depending on what
// the displacement is. The exception is if there is no offset and only
// one addressing register, e.g. mov eax,[ebx].
if (BaseOpnd.is_reg(R_sp) || (UseFP && BaseOpnd.is_reg(R_bp))
|| leaInst || (!HasIndexReg && !SingleAddressReg)) {
#endif
this->Uses.SetRef(BaseOpnd, RefType);
} // end if R_none != BaseReg
} // end if (o_phrase or o_displ operand)
} // end for (all operands)
// The lea (load effective address) instruction looks as if it has
// a memory USE: lea ebx,[edx+esi]
// However, this instruction is really just: ebx := edx+esi
// Now that the above code has inserted the "addressing" registers
// into the USE list, we should remove the "memory USE".
if (leaInst) {
set<DefOrUse, LessDefUse>::iterator CurrUse;
for (CurrUse = this->GetFirstUse(); CurrUse != this->GetLastUse(); ++CurrUse) {
op_t UseOp = CurrUse->GetOp();
if ((o_mem <= UseOp.type) && (o_displ >= UseOp.type)) {
this->EraseUse(CurrUse);
break;
}
}
}
// Next, handle repeat prefices in the instructions. The Intel REPE/REPZ prefix
// is just the text printed for SCAS/CMPS instructions that have a REP prefix.
// Only two distinct prefix codes are actually defined: REP and REPNE/REPNZ, and
// REPNE/REPNZ only applies to SCAS and CMPS instructions.
bool HasRepPrefix = (0 != (this->SMPcmd.auxpref & aux_rep));
bool HasRepnePrefix = (0 != (this->SMPcmd.auxpref & aux_repne));
if (HasRepPrefix && HasRepnePrefix)
msg("REP and REPNE both present at %x %s\n", this->GetAddr(), this->GetDisasm());
if (HasRepPrefix || HasRepnePrefix) {
// All repeating instructions use ECX as the countdown register.
op_t BaseOpnd = InitOp;
BaseOpnd.type = o_reg; // Change type and reg fields
BaseOpnd.reg = R_cx;
BaseOpnd.clr_showed();
this->Defs.SetRef(BaseOpnd, NUMERIC);
this->Uses.SetRef(BaseOpnd, NUMERIC);
if ((this->SMPcmd.itype == NN_cmps) || (this->SMPcmd.itype == NN_scas)
|| (this->SMPcmd.itype == NN_movs) || (this->SMPcmd.itype == NN_stos)) {
// ESI and EDI are USEd and DEFed to point to source and dest strings for CMPS/MOVS.
// Only EDI is involved with SCAS/STOS.
op_t BaseOpnd = InitOp;
BaseOpnd.type = o_reg; // Change type and reg fields
BaseOpnd.clr_showed();
if ((this->SMPcmd.itype == NN_cmps) || (this->SMPcmd.itype == NN_movs)) {
BaseOpnd.reg = R_si;
this->Defs.SetRef(BaseOpnd, POINTER);
this->Uses.SetRef(BaseOpnd, POINTER);
}
BaseOpnd.reg = R_di;
this->Defs.SetRef(BaseOpnd, POINTER);
this->Uses.SetRef(BaseOpnd, POINTER);
// Now, handle special instruction categories that have implicit operands.
if (NN_cmpxchg == this->SMPcmd.itype) {
// x86 Compare and Exchange conditionally sets EAX. We must keep data flow analysis
// sound by declaring that EAX is always a DEF.
this->MDAddRegDef(R_ax, false);
} // end if NN_cmpxchg
else if (this->MDIsPopInstr() || this->MDIsPushInstr() || this->MDIsReturnInstr()) {
// IDA does not include the stack pointer in the DEFs or USEs.
this->MDAddRegDef(R_sp, false);
this->MDAddRegUse(R_sp, false);
// We always reference [esp+0] or [esp-4], so add it to the DEF or USE list.
op_t StackOp = InitOp;
StackOp.type = o_displ;
StackOp.reg = R_sp;
if (this->MDIsPopInstr()) {
StackOp.addr = 0; // [ESP+0]
this->Uses.SetRef(StackOp); // USE
}
else {
StackOp.addr = (ea_t) -4; // [ESP-4]
this->Defs.SetRef(StackOp); // DEF
}
#if SMP_CALL_TRASHES_REGS
else if ((this->type == CALL) || (this->type == INDIR_CALL)) {
// We want to add the caller-saved registers to the USEs and DEFs lists
this->MDAddRegDef(R_ax, false);
this->MDAddRegDef(R_cx, false);
this->MDAddRegDef(R_dx, false);
this->MDAddRegUse(R_ax, false);
this->MDAddRegUse(R_cx, false);
this->MDAddRegUse(R_dx, false);
#if 1
if (this->MDIsInterruptCall()) {
#endif
this->MDAddRegDef(R_bx, false);
this->MDAddRegUse(R_bx, false);
this->MDAddRegDef(R_si, false);
this->MDAddRegUse(R_si, false);
}
#endif
else if (this->MDIsEnterInstr() || this->MDIsLeaveInstr()) {
// Entire function prologue or epilogue microcoded.
this->MDAddRegDef(R_sp, false);
this->MDAddRegUse(R_sp, false);
this->MDAddRegDef(R_bp, false);
this->MDAddRegUse(R_bp, false);
else if ((this->SMPcmd.itype == NN_maskmovq)
|| (this->SMPcmd.itype == NN_maskmovdqu)) {
else if (8 == this->GetOptType()) {
// This category implicitly writes to EDX:EAX.
this->MDAddRegDef(R_dx, false);
this->MDAddRegDef(R_ax, false);
} // end else if (8 == GetOptType)
else if (7 == this->GetOptType()) {
// Category 7 instructions sometimes write implicitly to EDX:EAX or DX:AX.
// DX is the same as EDX to IDA Pro (and SMP); ditto for EAX and AX.
// DIV, IDIV, and MUL all have hidden EAX or AX operands (hidden in the IDA Pro
// sense, because they are not displayed in the disassembly text). For example:
// mul ebx means EDX:EAX <-- EAX*EBX, and mul bx means DX:AX <-- AX*BX. If the
// source operand is only 8 bits wide, there is room to hold the result in AX
// without using DX: mul bl means AX <-- AL*BL.
// IMUL has forms with a hidden EAX or AX operand and forms with no implicit
// operands: imul ebx means EDX:EAX <-- EAX*EBX, but imul ebx,edx means that
// EBX*EDX gets truncated and the result placed in EBX (no hidden operands).
for (OpNum = 0; OpNum < UA_MAXOP; ++OpNum) {
op_t TempUse = this->SMPcmd.Operands[OpNum];
if (!TempUse.showed()) { // hidden operand
if (TempUse.is_reg(R_ax)) { // not R_al, so it is not 8 bits
if ((NN_div == this->SMPcmd.itype) || (NN_idiv == this->SMPcmd.itype)) {
this->MDAddRegUse(R_dx, false);
}
this->MDAddRegDef(R_ax, false);
this->MDAddRegDef(R_dx, false);
}
}
}
} // end else if (7 == OptType)
#if 0
// The floating point instructions in type categories 14 and 15 often USE and DEF
// the floating point register stack, e.g. pushing a value onto that stack is a
// massive copy downward of stack locations. We don't really care about the USE of
// the stack if the value being pushed came from elsewhere than the stack. For example,
// an "fld" opcode pushes its source onto the stack. We build RTLs with a simple
// move structure, but the RTL building can be fooled by seeing two "source" operands
// in the USE list.
if ((14 == SMPTypeCategory[this->SMPcmd.itype])
|| (15 == SMPTypeCategory[this->SMPcmd.itype])) {
}
#endif
clc5q
committed
#if 0 // Not true for LOOP instructions that use only the ECX counter register.
if (this->type == COND_BRANCH) {
assert(SMPUsesFlags[this->SMPcmd.itype]);
}
clc5q
committed
#endif
// The return value register EAX is not quite like a caller-save or callee-save
// register (technically, it is caller-save). Within a callee, it might appear
// that EAX has become dead by the time a return instruction is reached, but
// the USE that would make it not dead is in the caller. To prevent type inference
// from mistakenly thinking that all USEs of EAX have been seen in the callee,
// we add EAX to the USE list for all return instructions, as well as for all
// tail calls, which are essentially returns in terms of data flow analysis.
// This USE of EAX will always be of type UNINIT unless its DEF has a known type
// that propagates to it. Thus, it will prevent an invalid back inference of the
// DEF type from "all" USE types that are visible in the callee; even if they
// were all NUMERIC, this return USE will be UNINIT and inhibit the invalid
// type inference. EAX could be loaded with a pointer from memory, for example,
// and USEd only in a comparison instruction, making it falsely appear to be
// a NUMERIC, without this extra USE at the return instruction.
// Because some of the library functions pass values around in EBX, EDI, etc.,
// we will add these general purpose registers to the USE list for returns
// in order to prevent erroneous analyses of dead registers or unused
// metadata.
if ((this->type == RETURN) || this->IsTailCall()) {
this->MDAddRegUse(R_ax, false);
this->MDAddRegUse(R_bx, false);
this->MDAddRegUse(R_cx, false);
this->MDAddRegUse(R_dx, false);
if (!UseFP)
this->MDAddRegUse(R_bp, false);
this->MDAddRegUse(R_si, false);
this->MDAddRegUse(R_di, false);
}
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committed
// Next, add the flags register to the DEFs and USEs for those instructions that
// are marked as defining or using flags.
if (!this->DefsFlags && SMPDefsFlags[this->SMPcmd.itype]) {
this->MDAddRegDef(X86_FLAGS_REG, false);
this->DefsFlags = true;
if (!this->UsesFlags && SMPUsesFlags[this->SMPcmd.itype]) {
this->MDAddRegUse(X86_FLAGS_REG, false);
this->UsesFlags = true;
}
if (this->IsNop()) {
// Clear the DEFs and USEs for no-ops.
// These include machine idioms for no-ops, e.g. mov esi,esi
// or xchg ax,ax or lea esi,[esi].
this->Defs.clear();
this->Uses.clear();
this->MoveSource = InitOp;
this->OptType = 1;
}
#endif
msg("DEBUG after MDFixupDefUseLists:\n");
return;
} // end of SMPInstr::MDFixupDefUseLists()
// If we can definitely identify which part of the addressing expression
// used in MemOp is the POINTER type, and it is not a STACKPTR or GLOBALPTR
// immediate, set the USE type for that register to POINTER and return true.
// If we can find definite NUMERIC addressing registers that are not already
// typed as NUMERIC, set their USE types to NUMERIC and return true.
bool SMPInstr::MDFindPointerUse(op_t MemOp, bool UseFP) {
bool changed = false;
int BaseReg;
int IndexReg;
op_t BaseOp = InitOp;
op_t IndexOp = InitOp;
SMPOperandType BaseType = UNKNOWN;
SMPOperandType IndexType = UNKNOWN;
ushort ScaleFactor;
ea_t offset;
set<DefOrUse, LessDefUse>::iterator BaseIter;
set<DefOrUse, LessDefUse>::iterator IndexIter;
if (NN_lea == this->SMPcmd.itype)
return false; // lea instruction really has no memory operands
if (NN_fnop == this->SMPcmd.itype)
return false; // SSA marker instruction
MDExtractAddressFields(MemOp, BaseReg, IndexReg, ScaleFactor, offset);
if (R_none != IndexReg) {
IndexOp.type = o_reg;
IndexOp.reg = MDCanonicalizeSubReg((ushort) IndexReg);
IndexIter = this->FindUse(IndexOp);
assert(IndexIter != this->GetLastUse());
IndexType = IndexIter->GetType();
}
if (R_none != BaseReg) {
BaseOp.type = o_reg;
BaseOp.reg = MDCanonicalizeSubReg((ushort) BaseReg);
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BaseIter = this->FindUse(BaseOp);
assert(BaseIter != this->GetLastUse());
BaseType = BaseIter->GetType();
}
if ((R_sp == BaseReg) || (UseFP && (R_bp == BaseReg))) {
if ((R_none != IndexReg) && (!IsNumeric(IndexType))) {
// We have an indexed access into the stack frame.
// Set IndexReg USE type to NUMERIC.
changed = true;
IndexIter = this->SetUseType(IndexOp, NUMERIC);
assert(IndexIter != this->GetLastUse());
}
return changed; // stack accesses will get STACKPTR type in SetImmedTypes()
}
if ((R_sp == IndexReg) || (UseFP && (R_bp == IndexReg))) {
if ((R_none != BaseReg) && (!IsNumeric(BaseType))) {
// We have an indexed access into the stack frame.
// Set BaseReg USE type to NUMERIC.
// Note that BaseReg is really an IndexReg and vice versa.
changed = true;
BaseIter = this->SetUseType(BaseOp, NUMERIC);
assert(BaseIter != this->GetLastUse());
msg("WARNING: BaseReg is index, IndexReg is base: %s\n",
this->GetDisasm());
}
return changed; // stack accesses will get STACKPTR type in SetImmedTypes()
}
if (IsImmedGlobalAddress(offset)) {
if ((R_none != IndexReg) && (!IsNumeric(IndexType))) {
// We have an indexed access into a global.
// Set IndexReg USE type to NUMERIC.
changed = true;
IndexIter = this->SetUseType(IndexOp, NUMERIC);
assert(IndexIter != this->GetLastUse());
}
if ((R_none != BaseReg) && (!IsNumeric(BaseType))) {
// We have an indexed access into a global.
// Set BaseReg USE type to NUMERIC.
// Note that BaseReg is really an index register.
changed = true;
BaseIter = this->SetUseType(BaseOp, NUMERIC);
assert(BaseIter != this->GetLastUse());
msg("WARNING: BaseReg used as index: %s\n", this->GetDisasm());
clc5q
committed
return changed; // global immediate is handled in SetImmedTypes()
// At this point, we must have a base address in a register, not used
// to directly address the stack or a global.
if ((0 < ScaleFactor) || (R_none == IndexReg)) {
// IndexReg is scaled, meaning it is NUMERIC, so BaseReg must
// be a POINTER; or IndexReg is not present, so BaseReg is the
// only possible holder of an address.
if (R_none != BaseReg) {
if (UNINIT == BaseIter->GetType()) {
changed = true;
BaseIter = this->SetUseType(BaseOp, POINTER);
assert(BaseIter != this->GetLastUse());
}
}
}
else if (R_none == BaseReg) {
// We have an unscaled IndexReg and no BaseReg and offset was
// not a global offset, so IndexReg must be a POINTER.
if (R_none != IndexReg) {
changed = true;
IndexIter = this->SetUseType(IndexOp, POINTER);
assert(IndexIter != this->GetLastUse());
}
}
}
else { // We have BaseReg and an unscaled IndexReg.
// The only hope for typing something like [ebx+edx] is for
// one register to already be typed NUMERIC, in which case
// the other one must be a POINTER, or if one register is
// already POINTER, then the other one must be NUMERIC.
if (IsNumeric(BaseType)) {
if (UNINIT == IndexType) {
// Set to POINTER or PROF_POINTER
changed = true;
IndexIter = this->SetUseType(IndexOp, POINTER);
assert(IndexIter != this->GetLastUse());
}
else if (IsNumeric(IndexType)) {
msg("ERROR: BaseReg and IndexReg both NUMERIC at %x: %s\n",
this->address, this->GetDisasm());
}
}
else { // BaseReg was not NUMERIC
if (UNINIT == BaseType) { // BaseReg is UNINIT
if (IsNumeric(IndexType)) {
changed = true;
BaseIter = this->SetUseType(BaseOp, POINTER);
assert(BaseIter != this->GetLastUse());
}
else if (IsDataPtr(IndexType)) {
// IndexReg is POINTER, so make BaseReg NUMERIC.
changed = true;
BaseIter = this->SetUseType(BaseOp, NUMERIC);
assert(BaseIter != this->GetLastUse());
}
}
else if (IsDataPtr(BaseType)) {
// BaseReg was a pointer type. IndexReg must be NUMERIC.
if (UNINIT == IndexType) {
changed = true;
IndexIter = this->SetUseType(IndexOp, NUMERIC);
assert(IndexIter != this->GetLastUse());
}
else if (IsDataPtr(IndexType)) {
msg("ERROR: BaseReg and IndexReg both POINTER at %x: %s\n",
this->address, this->GetDisasm());
}
}
}
}
return changed;
} // end of SMPInstr::MDFindPointerUse()
clc5q
committed
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// Are all DEFs typed to something besides UNINIT?
bool SMPInstr::AllDEFsTyped(void) {
bool FoundUNINIT = false;
set<DefOrUse, LessDefUse>::iterator DefIter;
for (DefIter = this->GetFirstDef(); DefIter != this->GetLastDef(); ++DefIter) {
if (IsEqType(UNINIT, DefIter->GetType())) {
FoundUNINIT = true;
break;
}
}
return (!FoundUNINIT);
} // end of SMPInstr::AllDEFsTyped()
// Are all USEs typed to something besides UNINIT?
bool SMPInstr::AllUSEsTyped(void) {
bool FoundUNINIT = false;
set<DefOrUse, LessDefUse>::iterator UseIter;
for (UseIter = this->GetFirstUse(); UseIter != this->GetLastUse(); ++UseIter) {
if (IsEqType(UNINIT, UseIter->GetType())) {
FoundUNINIT = true;
break;
}
}
return (!FoundUNINIT);
} // end of SMPInstr::AllUSEsTyped()
// Set the type of all immediate operands found in the USE set.
// Set all flags and floating point register USEs and DEFs to NUMERIC also.
void SMPInstr::SetImmedTypes(bool UseFP) {
set<DefOrUse, LessDefUse>::iterator CurrUse;
set<DefOrUse, LessDefUse>::iterator CurrDef;
uval_t ImmVal;
#if SMP_VERBOSE_DEBUG_BUILD_RTL
DebugFlag = DebugFlag || (this->address == 0x805cd52) || (this->address == 0x805cd56);
DebugFlag |= (0 == strncmp("__libc_csu_fini", this->BasicBlock->GetFunc()->GetFuncName(), 15));
#endif
CurrUse = this->GetFirstUse();
while (CurrUse != this->GetLastUse()) {
UseOp = CurrUse->GetOp();
if (DebugFlag) {
msg("SetImmedTypes USE: ");
PrintOperand(UseOp);
msg("\n");
}
if (o_imm == UseOp.type) {
ImmVal = UseOp.value;
if (IsImmedGlobalAddress((ea_t) ImmVal)) {
if (DebugFlag) msg("Setting to GLOBALPTR\n");
CurrUse = this->SetUseType(UseOp, GLOBALPTR);
else if (this->Interrupt || IsImmedCodeAddress((ea_t) ImmVal)) {
if (DebugFlag) msg("Setting to CODEPTR\n");
CurrUse = this->SetUseType(UseOp, CODEPTR);
}
else { // NUMERIC
if (DebugFlag) msg("Setting to NUMERIC\n");
CurrUse = this->SetUseType(UseOp, NUMERIC);
else if (o_reg == UseOp.type) {
if (UseOp.is_reg(X86_FLAGS_REG)) {
if (DebugFlag) msg("Setting flags reg to NUMERIC\n");
CurrUse = this->SetUseType(UseOp, NUMERIC);
}
#if 1
else if (UseOp.is_reg(R_sp) || (UseFP && UseOp.is_reg(R_bp))) {
if (DebugFlag) msg("Setting reg to STACKPTR\n");
CurrUse = this->SetUseType(UseOp, STACKPTR);
}
#endif
}
#if 0 // could these registers have pointers in them?
else if ((o_trreg == UseOp.type) ||(o_dbreg == UseOp.type) || (o_crreg == UseOp.type)) {
if (DebugFlag) msg("Setting special reg to NUMERIC\n");
CurrUse = this->SetUseType(UseOp, NUMERIC);
}
#endif
else if ((o_fpreg == UseOp.type) || (o_mmxreg == UseOp.type) || (o_xmmreg == UseOp.type)) {
if (DebugFlag) msg("Setting floating point reg to NUMERIC\n");
CurrUse = this->SetUseType(UseOp, NUMERIC);
}
else if ((o_mem == UseOp.type) || (o_phrase == UseOp.type) || (o_displ == UseOp.type)) {
// For memory operands, we need to identify the POINTER value that
// is used in the addressing mode, if possible.
(void) this->MDFindPointerUse(UseOp, UseFP);
}
++CurrUse;
} // end while all USEs via CurrUse
CurrDef = this->GetFirstDef();
while (CurrDef != this->GetLastDef()) {
DefOp = CurrDef->GetOp();
if (DebugFlag) {
msg("SetImmedTypes DEF: ");
PrintOperand(DefOp);
msg("\n");
}
if (DebugFlag) msg("FuncName: %s\n", this->BasicBlock->GetFunc()->GetFuncName());
if (o_reg == DefOp.type) {
if (DefOp.is_reg(X86_FLAGS_REG)) {
if (DebugFlag) msg("Setting flags reg DEF to NUMERIC\n");
CurrDef = this->SetDefType(DefOp, NUMERIC);
// No need to propagate this DEF type, as all flags will become NUMERIC.
}
#if 1
else if (DefOp.is_reg(R_sp) || (DefOp.is_reg(R_bp) && UseFP)) {
if (DebugFlag) msg("Setting reg DEF to STACKPTR\n");
CurrDef = this->SetDefType(DefOp, STACKPTR);
assert(CurrDef != this->Defs.GetLastRef());
// No need to propagate; all stack and frame pointers will become STACKPTR.
else if ((o_fpreg == DefOp.type) || (o_mmxreg == DefOp.type) || (o_xmmreg == DefOp.type)) {
if (DebugFlag) msg("Setting floating point reg DEF to NUMERIC\n");
CurrDef = this->SetDefType(DefOp, NUMERIC);
// No need to propagate; all FP reg uses will become NUMERIC anyway.
}
#if 0 // could these registers have pointers in them?
else if ((o_trreg == DefOp.type) || (o_dbreg == DefOp.type) || (o_crreg == DefOp.type)) {
if (DebugFlag) msg("Setting special reg DEF to NUMERIC\n");
CurrDef = this->SetDefType(DefOp, NUMERIC);
}
#endif
else if ((o_mem == DefOp.type) || (o_phrase == DefOp.type) || (o_displ == DefOp.type)) {
// For memory operands, we need to identify the POINTER value that
// is used in the addressing mode, if possible.
(void) this->MDFindPointerUse(DefOp, UseFP);
}
++CurrDef;
} // end while all DEFs via CurrDef
return;
} // end of SMPInstr::SetImmedTypes()
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// Is the instruction a load from the stack?
void SMPInstr::MDFindLoadFromStack(bool UseFP) {
set<DefOrUse, LessDefUse>::iterator UseIter;
op_t UseOp;
if ((3 == this->OptType) && (this->HasSourceMemoryOperand())) {
// Loads and stores are OptCategory 3. We want only loads from the stack.
for (UseIter = this->GetFirstUse(); UseIter != this->GetLastUse(); ++UseIter) {
UseOp = UseIter->GetOp();
if (MDIsStackAccessOpnd(UseOp, UseFP)) {
this->LoadFromStack = true;
break;
}
}
}
return;
} // end of SMPInstr::MDFindLoadFromStack()
// Determine if instr is inherently signed load instruction.
// True if sign or zero-extended; pass out mask bits if true.
bool SMPInstr::MDIsSignedLoad(unsigned short &SignMask) {
unsigned short opcode = this->SMPcmd.itype;
if (NN_movzx == opcode) {
SignMask = FG_MASK_UNSIGNED;
}
else if (NN_movsx == opcode) {
SignMask = FG_MASK_SIGNED;
}
else {
return false;
}
return true;
}
// Infer sign, bit width, other type info for simple cases where all the info needed is
// within the instruction or can be read from the FineGrainedStackTable in the SMPFunction.
// NOTE: Must be called after SSA analysis is complete.
void SMPInstr::MDSetWidthSignInfo(bool UseFP) {
set<DefOrUse, LessDefUse>::iterator UseIter;
set<DefOrUse, LessDefUse>::iterator DefIter;
op_t UseOp, DefOp;
struct FineGrainedInfo FGEntry;
bool ValueWillChange;
unsigned short SignMask, TempSign, WidthMask;