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//
// SMPInstr.cpp
//
// This module performs the instruction level analyses needed for the
// SMP project (Software Memory Protection).
//
#include <cstring>
#include <pro.h>
#include <assert.h>
#include <ida.hpp>
#include <idp.hpp>
#include <allins.hpp>
#include <auto.hpp>
#include <bytes.hpp>
#include <funcs.hpp>
#include <intel.hpp>
#include <loader.hpp>
#include <lines.hpp>
#include <name.hpp>
#include "SMPStaticAnalyzer.h"
#include "SMPDataFlowAnalysis.h"
#include "SMPInstr.h"
// Set to 1 for debugging output
#define SMP_DEBUG 1
#define SMP_DEBUG2 0 // verbose
#define SMP_DEBUG_XOR 0
static char *RegNames[R_of + 1] =
{ "EAX", "ECX", "EDX", "EBX", "ESP", "EBP", "ESI", "EDI",
"R8", "R9", "R10", "R11", "R12", "R13", "R14", "R15",
"AL", "CL", "DL", "BL", "AH", "CH", "DH", "BH",
"SPL", "BPL", "SIL", "DIL", "EIP", "ES", "CS", "SS",
"DS", "FS", "GS", "CF", "ZF", "SF", "OF"
};
// Make the CF_CHG1 .. CF_CHG6 and CF_USE1..CF_USE6 macros more usable
// by allowing us to pick them up with an array index.
static ulong DefMacros[UA_MAXOP] = {CF_CHG1, CF_CHG2, CF_CHG3, CF_CHG4, CF_CHG5, CF_CHG6};
static ulong UseMacros[UA_MAXOP] = {CF_USE1, CF_USE2, CF_USE3, CF_USE4, CF_USE5, CF_USE6};
// Text to be printed in each optimizing annotation explaining why
// the annotation was emitted.
static char *OptExplanation[LAST_OPT_CATEGORY + 1] =
{ "NoOpt", "NoMetaUpdate", "AlwaysNUM", "NUMVia2ndSrcIMMEDNUM",
"Always1stSrc", "1stSrcVia2ndSrcIMMEDNUM", "AlwaysPtr",
"AlwaysNUM", "AlwaysNUM", "NUMViaFPRegDest"
};
// *****************************************************************
// Class SMPInstr
// *****************************************************************
// Constructor for instruction.
SMPInstr::SMPInstr(ea_t addr) {
this->address = addr;
this->analyzed = false;
this->JumpTarget = false;
return;
}
// Is the instruction the type that terminates a basic block?
bool SMPInstr::IsBasicBlockTerminator() const {
return ((type == JUMP) || (type == COND_BRANCH)
|| (type == INDIR_JUMP) || (type == RETURN));
}
// Is the destination operand a memory reference?
bool SMPInstr::HasDestMemoryOperand(void) const {
bool MemDest = false;
for (size_t index = 0; index < Defs.GetSize(); ++index) {
optype_t CurrType = Defs.GetRef(index).GetOp().type;
MemDest = ((CurrType == o_mem) || (CurrType == o_phrase) || (CurrType == o_displ));
if (MemDest)
break;
}
return MemDest;
} // end of SMPInstr::HasDestMemoryOperand()
// Is a source operand a memory reference?
bool SMPInstr::HasSourceMemoryOperand(void) const {
bool MemSrc = false;
for (size_t index = 0; index < Uses.GetSize(); ++index) {
optype_t CurrType = Uses.GetRef(index).GetOp().type;
MemSrc = ((CurrType == o_mem) || (CurrType == o_phrase) || (CurrType == o_displ));
if (MemSrc)
break;
}
return MemSrc;
} // end of SMPInstr::HasSourceMemoryOperand()
// Does the instruction whose flags are in F have a numeric type
// as the second source operand?
// NOTE: We can only analyze immediate values now, using a heuristic
// that values in the range +/- 8K are numeric and others are
// probably addresses. When data flow analyses are implemented,
// we will be able to analyze many non-immediate operands.
#define IMMEDNUM_LOWER -8191
#define IMMEDNUM_UPPER 8191
bool SMPInstr::IsSecondSrcOperandNumeric(flags_t F) const {
bool SecondOpImm = (SMPcmd.Operands[1].type == o_imm);
signed long TempImm;
if (SecondOpImm) {
TempImm = (signed long) SMPcmd.Operands[1].value;
}
#if SMP_DEBUG
if (SecondOpImm && (0 > TempImm)) {
#if 0
msg("Negative immediate: %d Hex: %x ASM: %s\n", TempImm,
SMPcmd.Operands[1].value, disasm);
#endif
}
else if ((!SecondOpImm) && (SMPcmd.Operands[1].type == o_imm)) {
msg("Problem with flags on immediate src operand: %s\n", disasm);
}
#endif
return (SecondOpImm && (TempImm > IMMEDNUM_LOWER)
&& (TempImm < IMMEDNUM_UPPER));
} // end of SMPInstr::IsSecondSrcOperandNumeric()
// DEBUG Print DEF and/or USE for an operand.
void PrintDefUse(ulong feature, int OpNum) {
// CF_ macros number the operands from 1 to 6, while OpNum
// is a 0 to 5 index into the insn_t.Operands[] array.
// OpNum == -1 is a signal that this is a DEF or USE or VarKillSet etc.
// operand and not an instruction operand.
if (-1 == OpNum)
return;
switch (OpNum) {
case 0:
if (feature & CF_CHG1)
msg(" DEF");
if (feature & CF_USE1)
msg(" USE");
break;
case 1:
if (feature & CF_CHG2)
msg(" DEF");
if (feature & CF_USE2)
msg(" USE");
break;
case 2:
if (feature & CF_CHG3)
msg(" DEF");
if (feature & CF_USE3)
msg(" USE");
break;
case 3:
if (feature & CF_CHG4)
msg(" DEF");
if (feature & CF_USE4)
msg(" USE");
break;
case 4:
if (feature & CF_CHG5)
msg(" DEF");
if (feature & CF_USE5)
msg(" USE");
break;
case 5:
if (feature & CF_CHG6)
msg(" DEF");
if (feature & CF_USE6)
msg(" USE");
break;
}
return;
} // end PrintDefUse()
// DEBUG print SIB info for an operand.
void PrintSIB(op_t Opnd) {
int BaseReg = sib_base(Opnd);
short IndexReg = sib_index(Opnd);
int ScaleFactor = sib_scale(Opnd);
#define NAME_LEN 5
char BaseName[NAME_LEN] = {'N', 'o', 'n', 'e', '\0'};
char IndexName[NAME_LEN] = {'N', 'o', 'n', 'e', '\0'};
#if 0
if (BaseReg != R_bp) // SIB code for NO BASE REG
#endif
qstrncpy(BaseName, RegNames[BaseReg], NAME_LEN - 1);
if (IndexReg != R_sp) { // SIB code for NO INDEX REG
qstrncpy(IndexName, RegNames[IndexReg], NAME_LEN -1);
}
msg(" Base %s Index %s Scale %d", BaseName, IndexName, ScaleFactor);
} // end PrintSIB()
// Debug: print one operand from an instruction or DEF or USE list.
void PrintOneOperand(op_t Opnd, ulong features, int OpNum) {
if (Opnd.type == o_void)
return;
else if (Opnd.type == o_mem) {
msg(" Operand %d : memory : addr: %x", OpNum, Opnd.addr);
PrintDefUse(features, OpNum);
if (Opnd.hasSIB) { // has SIB info -- is this possible for o_mem?
msg(" Found SIB byte for o_mem operand ");
PrintSIB(Opnd);
}
}
else if (Opnd.type == o_phrase) {
msg(" Operand %d : memory phrase :", OpNum);
PrintDefUse(features, OpNum);
if (Opnd.hasSIB) { // has SIB info
PrintSIB(Opnd);
}
else { // no SIB info
ushort BaseReg = Opnd.phrase;
msg(" reg %s", RegNames[BaseReg]);
}
if (Opnd.addr != 0) {
msg(" \n WARNING: addr for o_phrase type: %d\n", Opnd.addr);
}
}
else if (Opnd.type == o_displ) {
msg(" Operand %d : memory displ :", OpNum);
ea_t offset = Opnd.addr;
PrintDefUse(features, OpNum);
if (Opnd.hasSIB) {
PrintSIB(Opnd);
msg(" displ %d", offset);
}
else {
ushort BaseReg = Opnd.reg;
msg(" reg %s displ %d", RegNames[BaseReg], offset);
}
}
else if (Opnd.type == o_reg) {
msg(" Operand %d : register", OpNum);
msg(" regno: %d", Opnd.reg);
PrintDefUse(features, OpNum);
}
else if (Opnd.type == o_imm) {
msg(" Operand %d : immed", OpNum);
PrintDefUse(features, OpNum);
}
else if (Opnd.type == o_far) {
msg(" Operand %d : FarPtrImmed", OpNum);
msg(" addr: %x", Opnd.addr);
PrintDefUse(features, OpNum);
}
else if (Opnd.type == o_near) {
msg(" Operand %d : NearPtrImmed", OpNum);
msg(" addr: %x", Opnd.addr);
PrintDefUse(features, OpNum);
}
else {
msg(" Operand %d : unknown", OpNum);
PrintDefUse(features, OpNum);
}
if (!(Opnd.showed()))
msg(" HIDDEN ");
return;
} // end of PrintOneOperand()
// DEBUG print operands for Inst.
void SMPInstr::PrintOperands(void) const {
op_t Opnd;
for (int i = 0; i < UA_MAXOP; ++i) {
Opnd = SMPcmd.Operands[i];
PrintOneOperand(Opnd, this->features, i);
}
msg(" \n");
return;
} // end of SMPInstr::PrintOperands()
// Print out the destination operand list for the instruction, given
// the OptCategory for the instruction as a hint.
char * SMPInstr::DestString(int OptType) {
static char DestList[MAXSTR] = { '\0', '\0' };
int RegDestCount = 0;
for (size_t DefIndex = 0; DefIndex < this->NumDefs(); ++DefIndex) {
op_t DefOpnd = this->GetDef(DefIndex).GetOp();
if (o_reg == DefOpnd.type) {
ushort DestReg = DefOpnd.reg;
if (0 == RegDestCount) {
qstrncpy(DestList, RegNames[DestReg], 1 + strlen(RegNames[DestReg]));
}
else {
qstrncat(DestList, " ", MAXSTR);
qstrncat(DestList, RegNames[DestReg], MAXSTR);
}
++RegDestCount;
}
}
if (0 >= RegDestCount) {
msg("WARNING: No destination registers: %s\n", this->GetDisasm());
}
else {
qstrncat(DestList, " ZZ ", MAXSTR);
}
return DestList;
} // end of SMPInstr::DestString()
// Equality operator for SMPInstr. Key field is address.
int SMPInstr::operator==(const SMPInstr &rhs) const {
if (this->address != rhs.GetAddr())
return 0;
else
return 1;
}
// Inequality operator for SMPInstr. Key field is address.
int SMPInstr::operator!=(const SMPInstr &rhs) const {
return (this->address != rhs.GetAddr());
}
// Less than operator for sorting SMPInstr lists. Key field is address.
int SMPInstr::operator<(const SMPInstr &rhs) const {
return (this->address < rhs.GetAddr());
}
// Less than or equal operator for sorting SMPInstr lists. Key field is address.
int SMPInstr::operator<=(const SMPInstr &rhs) const {
return (this->address <= rhs.GetAddr());
}
#define MD_FIRST_ENTER_INSTR NN_enterw
#define MD_LAST_ENTER_INSTR NN_enterq
// Is this instruction the one that allocates space on the
// stack for the local variables?
bool SMPInstr::MDIsFrameAllocInstr(void) const {
// The frame allocating instruction should look like:
// sub esp,48 or add esp,-64 etc.
if ((SMPcmd.itype == NN_sub) || (SMPcmd.itype == NN_add)) {
if (Defs.GetRef(0).GetOp().is_reg(R_sp)) {
// We know that an addition or subtraction is being
// performed on the stack pointer. This should not be
// possible within the prologue except at the stack
// frame allocation instruction, so return true. We
// could be more robust in this analysis in the future. **!!**
// CAUTION: If a compiler allocates 64 bytes for locals
// and 16 bytes for outgoing arguments in a single
// instruction: sub esp,80
// you cannot insist on finding sub esp,LocSize
// To make this more robust, we are going to insist that
// an allocation of stack space is either performed by
// adding a negative immediate value, or by subtracting
// a positive immediate value. We will throw in, free of
// charge, a subtraction of a register, which is how alloca()
// usually allocates stack space.
if (o_imm == Uses.GetRef(0).GetOp().type) {
signed long TempImm = (signed long) Uses.GetRef(0).GetOp().value;
if (((0 > TempImm) && (SMPcmd.itype == NN_add))
|| ((0 < TempImm) && (SMPcmd.itype == NN_sub))) {
return true;
}
}
else if ((o_reg == Uses.GetRef(0).GetOp().type)
&& (SMPcmd.itype == NN_sub)) { // alloca() ?
return true;
}
}
}
else if ((SMPcmd.itype >= MD_FIRST_ENTER_INSTR) && (SMPcmd.itype <= MD_LAST_ENTER_INSTR)) {
return true;
}
return false;
} // end of SMPInstr::MDIsFrameAllocInstr()
// Is this instruction in the epilogue the one that deallocates the local
// vars region of the stack frame?
bool SMPInstr::MDIsFrameDeallocInstr(bool UseFP, asize_t LocalVarsSize) const {
// The usual compiler idiom for the prologue on x86 is to
// deallocate the local var space with: mov esp,ebp
// It could be add esp,constant. We can be tricked by
// add esp,constant when the constant is just the stack
// adjustment after a call. We will have to insist that
// the immediate operand have at least the value of
// LocalVarsSize for this second form, and that UseFP be true
// for the first form.
if (UseFP && (this->SMPcmd.itype == NN_mov)
&& (this->Defs.GetRef(0).GetOp().is_reg(R_sp))
&& (this->Uses.GetRef(0).GetOp().is_reg(R_bp)))
return true;
else if ((this->SMPcmd.itype == NN_add)
&& (this->Defs.GetRef(0).GetOp().is_reg(R_sp))
&& (this->Uses.GetRef(1).GetOp().is_imm((uval_t) LocalVarsSize)))
return true;
else if ((this->SMPcmd.itype == NN_add)
&& (this->Defs.GetRef(0).GetOp().is_reg(R_sp))
&& (this->Uses.GetRef(1).GetOp().type == o_imm)) {
msg("Used imprecise LocalVarsSize to find dealloc instr.\n");
return true;
}
else if (NN_leave == this->SMPcmd.itype)
return true;
else
return false;
} // end of SMPInstr::MDIsFrameDeallocInstr()
// Is instruction a no-op? There are 1-byte, 2-byte, etc versions of no-ops.
bool SMPInstr::MDIsNop(void) const {
bool IsNop = false;
ushort opcode = this->SMPcmd.itype;
if (NN_nop == opcode)
IsNop = true;
else if (NN_mov == opcode) {
if ((o_reg == this->SMPcmd.Operands[0].type)
&& this->SMPcmd.Operands[1].is_reg(this->SMPcmd.Operands[0].reg)) {
// We have a register to register move with source == destination.
IsNop = true;
}
}
else if (NN_lea == opcode) {
if ((o_reg == this->SMPcmd.Operands[0].type)
&& (o_displ == this->SMPcmd.Operands[1].type)) {
// We are looking for 6-byte no-ops like lea esi,[esi+0]
ushort destreg = this->SMPcmd.Operands[0].reg;
if ((this->SMPcmd.Operands[1].hasSIB)
&& (destreg == (ushort) sib_base(this->SMPcmd.Operands[1]))) {
IsNop = true;
}
else if (destreg == this->SMPcmd.Operands[1].reg) {
IsNop = true;
}
}
}
return IsNop;
} // end of SMPInstr::MDIsNop()
// MACHINE DEPENDENT: Is instruction a return instruction?
bool SMPInstr::MDIsReturnInstr(void) const {
return ((SMPcmd.itype == NN_retn) || (SMPcmd.itype == NN_retf));
}
// MACHINE DEPENDENT: Is instruction a POP instruction?
#define FIRST_POP_INST NN_pop
#define LAST_POP_INST NN_popfq
bool SMPInstr::MDIsPopInstr(void) const {
return ((SMPcmd.itype >= FIRST_POP_INST)
&& (SMPcmd.itype <= LAST_POP_INST));
}
// MACHINE DEPENDENT: Is instruction a PUSH instruction?
#define FIRST_PUSH_INST NN_push
#define LAST_PUSH_INST NN_pushfq
bool SMPInstr::MDIsPushInstr(void) const {
return ((SMPcmd.itype >= FIRST_PUSH_INST)
&& (SMPcmd.itype <= LAST_PUSH_INST));
}
// MACHINE DEPENDENT: Is instruction an ENTER instruction?
#define FIRST_ENTER_INST NN_enterw
#define LAST_ENTER_INST NN_enterq
bool SMPInstr::MDIsEnterInstr(void) const {
return ((SMPcmd.itype >= FIRST_ENTER_INST)
&& (SMPcmd.itype <= LAST_ENTER_INST));
}
// MACHINE DEPENDENT: Is instruction a LEAVE instruction?
#define FIRST_LEAVE_INST NN_leavew
#define LAST_LEAVE_INST NN_leaveq
bool SMPInstr::MDIsLeaveInstr(void) const {
return ((SMPcmd.itype >= FIRST_LEAVE_INST)
&& (SMPcmd.itype <= LAST_LEAVE_INST));
}
// MACHINE DEPENDENT: Does instruction use a callee-saved register?
bool SMPInstr::MDUsesCalleeSavedReg(void) const {
for (size_t index = 0; index < this->Uses.GetSize(); ++index) {
op_t CurrUse = this->GetUse(index).GetOp();
if (CurrUse.is_reg(R_bp) || CurrUse.is_reg(R_si)
|| CurrUse.is_reg(R_di) || CurrUse.is_reg(R_bx)) {
return true;
}
}
return false;
} // end of SMPInstr::MDUsesCalleeSavedReg()
// Is the instruction a register to register copy of a stack pointer or frame pointer
// into a general purpose register (which mmStrata will now need to track as a stack
// relative pointer)?
bool SMPInstr::MDIsStackPointerCopy(bool UseFP) const {
if ((this->OptType == 3) && (this->GetDef(0).GetOp().type == o_reg)
&& (!(this->GetDef(0).GetOp().is_reg(R_sp)))) {
if (UseFP) {
if (this->GetUse(0).GetOp().is_reg(R_bp))
// Move of base pointer EBP into a general register
return true;
else if ((this->GetUse(0).GetOp().is_reg(R_sp))
&& !(this->GetDef(0).GetOp().is_reg(R_bp)))
// Move of ESP into something besides a base pointer
return true;
}
else if (this->GetUse(0).GetOp().is_reg(R_sp)) {
// Move of ESP into a register; no base pointer used in this function
return true;
}
}
return false;
} // end of SMPInstr::MDIsStackPointerCopy()
// Is instruction a branch (conditional or unconditional) to a
// code target that is not in the current chunk?
bool SMPInstr::IsBranchToFarChunk(void) const {
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) {
op_t JumpTarget = this->GetUse(0).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);
}
}
}
return FarBranch;
} // end of SMPInstr::IsBranchToFarChunk()
// Analyze the instruction and its operands.
void SMPInstr::Analyze(void) {
if (this->analyzed)
return;
// Fill cmd structure with disassembly of instr
ua_ana0(this->address);
// Get the instr disassembly text.
(void) generate_disasm_line(this->address, this->disasm, sizeof(this->disasm) - 1);
// Remove interactive color-coding tags.
tag_remove(this->disasm, this->disasm, 0);
// 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];
// Build the DEF and USE lists for the instruction.
this->BuildSMPDefUseLists();
// Fix up machine dependent quirks in the def and use lists.
this->MDFixupDefUseLists();
// 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;
}
}
this->analyzed = true;
return;
} // end of SMPInstr::Analyze()
// Fill the Defs and Uses private data members.
void SMPInstr::BuildSMPDefUseLists(void) {
size_t OpNum;
// Start with the Defs.
for (OpNum = 0; OpNum < UA_MAXOP; ++OpNum) {
if (this->features & DefMacros[OpNum]) { // DEF
this->Defs.SetRef(this->SMPcmd.Operands[OpNum]);
}
} // end for (OpNum = 0; ...)
// 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
this->Uses.SetRef(this->SMPcmd.Operands[OpNum]);
}
} // 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 AlreadySet = false;
for (size_t DefIndex = 0; DefIndex < this->NumDefs(); ++DefIndex) {
if (this->GetDef(DefIndex).GetOp().is_reg(DefReg)) {
AlreadySet = true;
break;
}
}
if (!AlreadySet) {
op_t TempDef;
TempDef.type = o_reg;
TempDef.reg = DefReg;
this->Defs.SetRef(TempDef);
}
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 AlreadyUsed = false;
for (size_t UseIndex = 0; UseIndex < this->NumUses(); ++UseIndex) {
if (this->GetUse(UseIndex).GetOp().is_reg(UseReg)) {
AlreadyUsed = true;
break;
}
}
if (!AlreadyUsed) {
op_t TempUse;
TempUse.type = o_reg;
TempUse.reg = UseReg;
this->Uses.SetRef(TempUse);
}
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;
for (OpNum = 0; OpNum < UA_MAXOP; ++OpNum) {
op_t Opnd = SMPcmd.Operands[OpNum];
if ((Opnd.type == o_phrase) || (Opnd.type == o_displ)) {
if (Opnd.hasSIB) {
int BaseReg = sib_base(Opnd);
short IndexReg = sib_index(Opnd);
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 = BaseReg;
BaseOpnd.hasSIB = 0;
this->Uses.SetRef(BaseOpnd);
}
if (R_none != IndexReg) { // Should we disallow R_sp here? **!!**
op_t IndexOpnd = Opnd; // Init to current operand field values
IndexOpnd.type = o_reg; // Change type and reg fields
IndexOpnd.reg = IndexReg;
IndexOpnd.hasSIB = 0;
this->Uses.SetRef(IndexOpnd);
}
}
else { // no SIB byte; can have base reg but no index reg
ushort BaseReg = Opnd.reg; // cannot be R_none for no SIB case
op_t BaseOpnd = Opnd; // Init to current operand field values
BaseOpnd.type = o_reg; // Change type and reg fields
BaseOpnd.reg = BaseReg;
BaseOpnd.hasSIB = 0;
this->Uses.SetRef(BaseOpnd);
}
} // end if (o_phrase or o_displ operand)
} // end for (all operands)
// Now, handle special instruction categories that have implicit operands.
if (NN_cmpxchg == 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);
} // 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);
this->MDAddRegUse(R_sp);
}
else if (this->MDIsEnterInstr() || this->MDIsLeaveInstr()) {
// Entire function prologue or epilogue microcoded.
this->MDAddRegDef(R_sp);
this->MDAddRegUse(R_sp);
this->MDAddRegDef(R_bp);
this->MDAddRegUse(R_bp);
}
else if (8 == this->GetOptType()) {
// This category implicitly writes to EDX:EAX.
this->MDAddRegDef(R_dx);
this->MDAddRegDef(R_ax);
} // 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).
bool HiddenEAXUse = false;
for (size_t UseIndex = 0; UseIndex < this->NumUses(); ++UseIndex) {
op_t TempUse = this->GetUse(UseIndex).GetOp();
if (!TempUse.showed()) { // hidden operand
if (TempUse.is_reg(R_ax)) { // not R_al, so it is not 8 bits
this->MDAddRegUse(R_dx);
this->MDAddRegDef(R_ax);
this->MDAddRegDef(R_dx);
}
}
}
} // end else if (7 == OptType)
return;
} // end of SMPInstr::MDFixupDefUseLists()
// Handle x86 opcode SIB byte annotations.
void SMPInstr::MDAnnotateSIBStackConstants(FILE *AnnotFile, op_t Opnd, ea_t offset, bool UseFP) {
int BaseReg = sib_base(Opnd);
short IndexReg = sib_index(Opnd);
if (BaseReg == R_none) {
msg("BaseReg of R_none at %x\n", this->address);
}
if (BaseReg == R_sp) { // ESP cannot be IndexReg
// ESP-relative constant offset
qfprintf(AnnotFile,
"%x %d PTRIMMEDESP STACK %d displ %s\n",
this->SMPcmd.ea, this->SMPcmd.size, offset, this->disasm);
}
else if (UseFP && ((IndexReg == R_bp) || (BaseReg == R_bp))) {
// EBP-relative constant offset
qfprintf(AnnotFile,
"%x %d PTRIMMEDEBP STACK %d displ %s\n",
this->SMPcmd.ea, this->SMPcmd.size, offset, this->disasm);
}
return;
} // end of MDAnnotateSIBStackConstants
// Emit annotations for constants used as ptr offsets from EBP or
// ESP into the stack frame. Only pay attention to EBP-relative
// offsets if EBP is being used as a frame pointer (UseFP == true).
void SMPInstr::AnnotateStackConstants(bool UseFP, FILE *AnnotFile) {
op_t Opnd;
#if 0
if (this->address == 0x80925f4) {
msg("PROBLEM INSTRUCTION: \n");
this->PrintOperands();
}
#endif
for (int i = 0; i < UA_MAXOP; ++i) {
Opnd = SMPcmd.Operands[i];
if (Opnd.type == o_displ) {
ea_t offset = Opnd.addr;
if (Opnd.hasSIB) {
MDAnnotateSIBStackConstants(AnnotFile, Opnd, offset, UseFP);
}
else { // no SIB
ushort BaseReg = Opnd.reg;
if (BaseReg == R_sp) {
// ESP-relative constant offset
qfprintf(AnnotFile,
"%x %d PTRIMMEDESP STACK %d displ %s\n",
SMPcmd.ea, SMPcmd.size, offset, disasm);
}
else if (UseFP && (BaseReg == R_bp)) {
// EBP-relative constant offset
qfprintf(AnnotFile,
"%x %d PTRIMMEDEBP STACK %d displ %s\n",
SMPcmd.ea, SMPcmd.size, offset, disasm);
}
} // end if (Opnd.hasSIB) ... else ...
} // end if (Opnd.type == o_displ)
else if (Opnd.type == o_phrase) {
ea_t offset = 0; // mmStrata thinks [esp] is [esp+0]
if (Opnd.hasSIB) {
MDAnnotateSIBStackConstants(AnnotFile, Opnd, offset, UseFP);
}
else { // Something like [ecx]
ushort BaseReg = Opnd.reg;
if (BaseReg == R_sp) {
// ESP-relative constant offset
qfprintf(AnnotFile,
"%x %d PTRIMMEDESP STACK %d displ %s\n",
SMPcmd.ea, SMPcmd.size, offset, disasm);
}
else if (UseFP && (BaseReg == R_bp)) {
// EBP-relative constant offset
qfprintf(AnnotFile,
"%x %d PTRIMMEDEBP STACK %d displ %s\n",
SMPcmd.ea, SMPcmd.size, offset, disasm);
}
} // end if (Opnd.hasSIB) ... else ...
} // end else if (Opnd.type == o_phrase)
} // end for all operands
// If we move a stack pointer or frame pointer into another register, we
// need to annotate the implicit zero offset, e.g. mov edi,esp == mov edi,esp+0
// and edi is becoming a stack pointer that mmStrata needs to track.
if (this->MDIsStackPointerCopy(UseFP)) {
if (UseFP && this->GetUse(0).GetOp().is_reg(R_bp)) {
qfprintf(AnnotFile, "%x %d PTRIMMEDEBP STACK 0 displ %s\n",
SMPcmd.ea, SMPcmd.size, disasm);
}
else {
qfprintf(AnnotFile, "%x %d PTRIMMEDESP STACK 0 displ %s\n",
SMPcmd.ea, SMPcmd.size, disasm);
}
}
return;
} // end of SMPInstr::AnnotateStackConstants()
// Emit all annotations for the instruction.
void SMPInstr::EmitAnnotations(bool UseFP, bool AllocSeen, FILE *AnnotFile) {
ea_t addr = this->address;
flags_t InstrFlags = getFlags(addr);
bool MemDest = this->HasDestMemoryOperand();
bool MemSrc = this->HasSourceMemoryOperand();
bool SecondSrcOperandNum = this->IsSecondSrcOperandNumeric(InstrFlags);
++OptCount[OptType]; // keep count for debugging info
#if SMP_DEBUG_MEM
if (MemDest || MemSrc) {
msg("OptType: %d %s", OptType, disasm);
this->PrintOperands();
}
#endif
// Emit appropriate optimization annotations.
bool SDTInstrumentation = false;
switch (OptType) {
case 0: // SDT will have to handle these
{
#if SMP_DEBUG_TYPE0
msg("OptType 0: %x %s\n", addr, disasm);
#endif
// mmStrata wants to suppress warnings on the PUSH
// instructions that precede the LocalVarsAllocInstr
// (i.e. the PUSHes of callee-saved regs).
if (!AllocSeen && this->MDIsPushInstr()) {
qfprintf(AnnotFile, "%x %d INSTR LOCAL NoWarn %s \n",
addr, -3, disasm);
}
else {
SDTInstrumentation = true;
}
break;
}
case 1: // nothing for SDT to do
{ qfprintf(AnnotFile, "%x %d INSTR LOCAL NoMetaUpdate %s \n",
addr, -1, disasm);
++AnnotationCount[OptType];
break;
}
case 4: // INC, DEC, etc.: no SDT work unless MemDest
{ if (MemDest || MemSrc) {
SDTInstrumentation = true;
break; // treat as category 0
}
qfprintf(AnnotFile, "%x %d INSTR LOCAL Always1stSrc %s \n",
addr, -1, disasm);
++AnnotationCount[OptType];
break;
}
case 5: // ADD, etc.: If numeric 2nd src operand, no SDT work.
{ if (MemDest || MemSrc) {
SDTInstrumentation = true;
break; // treat as category 0
}
if (SecondSrcOperandNum) { // treat as category 1
qfprintf(AnnotFile, "%x %d INSTR LOCAL %s %s \n",
addr, -1, OptExplanation[OptType], disasm);
++AnnotationCount[OptType];
}
break;
}
case 6: // Only OS code should include these; problem for SDT
{ if (MemDest) {
SDTInstrumentation = true;
break; // treat as category 0
}
qfprintf(AnnotFile, "%x %d INSTR LOCAL AlwaysPTR %s \n",
addr, -OptType, disasm);
++AnnotationCount[OptType];
break;
}
case 8: // Implicitly writes to EDX:EAX, always numeric.
{ qfprintf(AnnotFile, "%x %d INSTR LOCAL n EDX EAX ZZ %s %s \n",
addr, -2, OptExplanation[OptType], disasm);
++AnnotationCount[OptType];
SDTInstrumentation = true;
break;
}
case 9: // Either writes to FP reg (cat. 1) or memory (cat. 0)
{ if (MemDest) {
#if SMP_DEBUG
// MemDest seems to happen too much.
msg("Floating point MemDest: %s \n", disasm);
#endif
SDTInstrumentation = true;
break; // treat as category 0
}
qfprintf(AnnotFile, "%x %d INSTR LOCAL %s %s \n",
addr, -1, OptExplanation[OptType], disasm);
++AnnotationCount[OptType];
break;
}
default: // 2,3,7: Optimization possibilities depend on operands
{
#if SMP_DEBUG2
if (OptType == 3) { // MOV instr class
if (MemDest) {
msg("MemDest on MOV: %s\n", disasm);
}
else if (!SecondSrcOperandNum) {
msg("MOV: not 2nd op numeric: %s\n", disasm);
this->PrintOperands();
}
}
#endif
SDTInstrumentation = true;
if (MemDest) {
#if SMP_DEBUG_XOR
if (OptType == 2)
msg("MemDest on OptType 2: %s\n", disasm);
#endif
break; // treat as category 0
}
if ((OptType == 2) || (OptType == 7) || SecondSrcOperandNum) {
qfprintf(AnnotFile, "%x %d INSTR LOCAL n %s %s %s \n",
addr, -2, this->DestString(OptType),
OptExplanation[OptType], disasm);
++AnnotationCount[OptType];
}
break;
}
} // end switch (OptType)
// If mmStrata is going to have to deal with the
// instruction, then we can annotate EBP and ESP
// relative constant offsets. If we have emitted
// an annotation of type -1, there is no point
// in telling mmStrata about these constants.
if (SDTInstrumentation) {
this->AnnotateStackConstants(UseFP, AnnotFile);
}
return;
} // end of SMPInstr::EmitAnnotations()