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Arithmetic overflow checks

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This commit is contained in:
Brian Fiete 2022-01-11 08:17:09 -05:00
parent 1f0d2dcc82
commit eb375362a1
29 changed files with 503 additions and 87 deletions
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52
IDEHelper/X86.cpp
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@ -575,26 +575,39 @@ String X86CPU::InstructionToString(X86Instr* inst, uint32 addr)
return result;
}
bool X86CPU::IsObjectAccessBreak(uint32 address, DbgModuleMemoryCache* memoryCache, int32* regs, int32* outObjectPtr)
DbgBreakKind X86CPU::GetDbgBreakKind(uint32 address, DbgModuleMemoryCache* memoryCache, int32* regs, int32* outObjectPtr)
{
// We've looking for a CMP BYTE PTR [<reg>], -0x80
// if <reg> is R12 then encoding takes an extra 2 bytes
X86Instr inst;
X86Instr inst;
for (int checkLen = 5; checkLen >= 3; checkLen--)
{
{
int offset = -3 - checkLen;
if (!Decode(address + offset, memoryCache, &inst))
continue;
continue;
if (inst.GetLength() != checkLen)
continue;
const MCInstrDesc &instDesc = mInstrInfo->get(inst.mMCInst.getOpcode());
const MCInstrDesc& instDesc = mInstrInfo->get(inst.mMCInst.getOpcode());
if (!instDesc.isCompare())
continue;
auto immediateType = (instDesc.TSFlags & llvm::X86II::ImmMask);
if ((immediateType == llvm::X86II::Imm8) && (inst.mMCInst.getNumOperands() == 2))
{
// We're checking for a TEST [<reg>], 1
if (inst.mMCInst.getOpcode() != llvm::X86::TEST8ri)
continue;
auto immOp = inst.mMCInst.getOperand(1);
if (!immOp.isImm())
continue;
if (immOp.getImm() != 1)
continue;
return DbgBreakKind_ArithmeticOverflow;
}
if ((immediateType == 0) || (inst.mMCInst.getNumOperands() < 6))
continue;
@ -617,10 +630,35 @@ bool X86CPU::IsObjectAccessBreak(uint32 address, DbgModuleMemoryCache* memoryCac
*outObjectPtr = (uint64)regs[regNum];
return true;
return DbgBreakKind_ObjectAccess;
}
return false;
// check jno/jnb
for (int offset = 3; offset <= 3; offset++)
{
if (!Decode(address - offset, memoryCache, &inst))
continue;
if (inst.GetLength() != 2)
continue;
const MCInstrDesc& instDesc = mInstrInfo->get(inst.mMCInst.getOpcode());
if (!instDesc.isBranch())
continue;
auto immediateType = (instDesc.TSFlags & llvm::X86II::ImmMask);
if ((immediateType == llvm::X86II::Imm8PCRel) && (inst.mMCInst.getNumOperands() == 2))
{
auto immOp = inst.mMCInst.getOperand(1);
if (!immOp.isImm())
continue;
if ((immOp.getImm() != 1) && (immOp.getImm() != 3))
continue;
return DbgBreakKind_ArithmeticOverflow;
}
}
return DbgBreakKind_None;
}
int X86CPU::GetOpcodesForMnemonic(const StringImpl& mnemonic, Array<int>& outOpcodes)