GT-2723 Finish configuration for min/max address changes for constant

reference propagation.
This commit is contained in:
emteere 2019-04-02 11:51:32 -04:00
parent 3a27a22fed
commit a57a7a3533
5 changed files with 256 additions and 60 deletions

View File

@ -39,37 +39,59 @@
//@category Analysis
import java.math.BigInteger;
import java.util.Arrays;
import java.util.List;
import ghidra.app.script.GhidraScript;
import ghidra.program.model.address.*;
import ghidra.program.model.address.Address;
import ghidra.program.model.address.AddressRange;
import ghidra.program.model.address.AddressRangeImpl;
import ghidra.program.model.address.AddressRangeIterator;
import ghidra.program.model.address.AddressSet;
import ghidra.program.model.address.AddressSetView;
import ghidra.program.model.address.AddressSpace;
import ghidra.program.model.block.CodeBlock;
import ghidra.program.model.block.PartitionCodeSubModel;
import ghidra.program.model.lang.*;
import ghidra.program.model.lang.OperandType;
import ghidra.program.model.lang.Register;
import ghidra.program.model.lang.RegisterValue;
import ghidra.program.model.listing.Function;
import ghidra.program.model.listing.Instruction;
import ghidra.program.model.pcode.Varnode;
import ghidra.program.model.symbol.RefType;
import ghidra.program.model.symbol.Reference;
import ghidra.program.model.symbol.SourceType;
import ghidra.program.util.*;
import ghidra.program.util.ContextEvaluator;
import ghidra.program.util.ContextEvaluatorAdapter;
import ghidra.program.util.OperandFieldLocation;
import ghidra.program.util.SymbolicPropogator;
import ghidra.program.util.VarnodeContext;
import ghidra.util.exception.CancelledException;
import ghidra.util.task.TaskMonitor;
public class MultiInstructionMemReference extends GhidraScript {
Address memReferenceLocation = null;
private Address curInstrloc;
private Object[] inputObjects;
private Object[] resultObjects;
private Register singleRegister;
private boolean registerInOut;
@Override
public void run() throws Exception {
long numInstructions = currentProgram.getListing().getNumInstructions();
monitor.initialize((int) (numInstructions));
monitor.setMessage("Multi-Instruction Reference Markup");
int currentOpIndex = 0;
int currentOpIndex = -1;
Address start = currentLocation.getAddress();
if ((currentSelection == null || currentSelection.isEmpty()) &&
currentLocation instanceof OperandFieldLocation) {
currentOpIndex = ((OperandFieldLocation) currentLocation).getOperandIndex();
OperandFieldLocation operandLocation = (OperandFieldLocation) currentLocation;
currentOpIndex = operandLocation.getOperandIndex();
int subOpIndex = operandLocation.getSubOperandIndex();
singleRegister = getRegister(start, currentOpIndex, subOpIndex);
}
// set up the address set to restrict processing
@ -81,6 +103,34 @@ public class MultiInstructionMemReference extends GhidraScript {
findMemRefAtOperand(currentOpIndex, refLocationsSet);
}
/**
* Get the register at the location
*
* @param opIndex index into operands for instruction
* @param subOpIndex index into operands for an operand location
*
* @return register if there is one at the location
*/
private Register getRegister(Address addr, int opIndex, int subOpIndex) {
if (addr == null) {
return null;
}
Instruction instr = currentProgram.getListing().getInstructionContaining(addr);
if (instr == null) {
return null;
}
List<Object> defOpRep = instr.getDefaultOperandRepresentationList(opIndex);
if (subOpIndex >= 0 && subOpIndex < defOpRep.size()) {
Object obj = defOpRep.get(subOpIndex);
if (obj instanceof Register) {
return (Register) obj;
}
}
return instr.getRegister(opIndex);
}
@SuppressWarnings("unused")
private boolean isSingleInstructions(AddressSet restrictedSet) {
if (restrictedSet.isEmpty()) {
@ -106,53 +156,154 @@ public class MultiInstructionMemReference extends GhidraScript {
// use context to fill out addresses on certain instructions
ContextEvaluator eval = new ContextEvaluatorAdapter() {
@Override
public boolean evaluateContextBefore(VarnodeContext context, Instruction instr) {
// if the requested reference was on an input op-object, get context before exec
return checkContext(true, opIndex, context, instr);
}
@Override
public boolean evaluateContext(VarnodeContext context, Instruction instr) {
// TODO: could look at instructions like LEA, that are an address to create a reference to something.
// if the requested reference was on an output op-object, get context after exec
return checkContext(false, opIndex, context, instr);
}
private boolean checkContext(boolean input, final int opIndex, VarnodeContext context, Instruction instr) {
if (instr.getMinAddress().equals(curInstrloc)) {
if (checkInstructionMatch(opIndex, context, instr)) {
if (checkInstructionMatch(opIndex, input, context, instr)) {
return true;
}
// if instruction is in delayslot, assume reference is good.
if (instr.getDelaySlotDepth() > 0) {
instr = instr.getNext();
return checkInstructionMatch(opIndex, context, instr);
return checkInstructionMatch(opIndex, input, context, instr);
}
}
return false;
}
private boolean checkInstructionMatch(final int opIdx, VarnodeContext context,
@Override
public boolean evaluateReference(VarnodeContext context, Instruction instr, int pcodeop, Address address,
int size, RefType refType) {
return super.evaluateReference(context, instr, pcodeop, address, size, refType);
}
private boolean checkInstructionMatch(final int opIdx, boolean input, VarnodeContext context,
Instruction instr) {
int firstIndex = opIdx;
if (instr.getRegister(firstIndex) == null) {
firstIndex = 0;
}
for (int index = firstIndex; index < instr.getNumOperands(); index++) {
Object[] opObjects = instr.getOpObjects(index);
for (int indexOpObj = 0; indexOpObj < opObjects.length; indexOpObj++) {
if (!(opObjects[indexOpObj] instanceof Register)) {
continue;
List<Object> list = Arrays.asList(input ? inputObjects : resultObjects);
for (int index = opIdx; index < instr.getNumOperands(); index++)
{
if (getRefsForOperand(context, instr, list, index)) {
// register is both an in/out check if symbolic on out
if (registerInOut) {
break;
}
Register reg = (Register) opObjects[indexOpObj];
RegisterValue rval = context.getRegisterValue(reg);
if (rval == null) {
continue;
}
BigInteger uval = rval.getUnsignedValue();
if (uval == null) {
continue;
}
long offset = uval.longValue();
AddressSpace space = instr.getMinAddress().getAddressSpace();
Address addr = space.getTruncatedAddress(offset, true);
// assume that they want the reference, don't worry it isn't in memory
makeReference(instr, index, addr, monitor);
return false;
return true;
}
}
if (addSymbolicRefs(input, context, instr, list)) {
return true;
}
return false;
}
/**
* Check the current operand for references based on input/outputs
*
* @param context - context holding values
* @param instr - instruction under consideration
* @param list - input/output lists
* @param opIndex - index of operand to check
*
* @return true if a reference was found
*/
private boolean getRefsForOperand(VarnodeContext context, Instruction instr, List<Object> list, int opIndex) {
Object[] opObjects = instr.getOpObjects(opIndex);
for (int indexOpObj = 0; indexOpObj < opObjects.length; indexOpObj++) {
if (!(opObjects[indexOpObj] instanceof Register)) {
continue;
}
Register reg = (Register) opObjects[indexOpObj];
// if operand has a single register and this isn't it
if (singleRegister != null && !reg.equals(singleRegister)) {
continue;
}
// check that the register is on the correct input/output list
if (!list.contains(reg)) {
continue;
}
RegisterValue rval = context.getRegisterValue(reg);
if (rval == null) {
continue;
}
BigInteger uval = rval.getUnsignedValue();
if (uval == null) {
continue;
}
long offset = uval.longValue();
AddressSpace space = instr.getMinAddress().getAddressSpace();
Address addr = space.getTruncatedAddress(offset, true);
// assume that they want the reference, don't worry it isn't in memory
makeReference(instr, opIndex, addr);
return true;
}
return false;
}
private boolean addSymbolicRefs(boolean input, VarnodeContext context, Instruction instr, List<Object> list) {
// get the value of the single register to see if this is the value desired
if (singleRegister == null) {
return false;
}
// check that the register is on the correct input/output list
if (!list.contains(singleRegister)) {
return false;
}
Varnode registerVarnodeValue = context.getRegisterVarnodeValue(singleRegister);
if (!context.isSymbol(registerVarnodeValue) && !registerVarnodeValue.isRegister()) {
return false;
}
Address symAddr = registerVarnodeValue.getAddress();
if (symAddr == context.BAD_ADDRESS) {
return false;
}
String valStr = "";
if (registerVarnodeValue.isRegister()) {
valStr = context.getRegister(registerVarnodeValue).toString();
} else {
// is an offset from a space
String name = symAddr.getAddressSpace().getName();
BigInteger offset = symAddr.getOffsetAsBigInteger();
valStr = name + " + 0x" + offset.toString(16);
}
Address lastSetLocation = context.getLastSetLocation(singleRegister, null);
String comment = instr.getComment(Instruction.EOL_COMMENT);
if (comment == null) {
comment = "";
}
String inoutChar = (input ? " " : "\'");
String lastStr = (lastSetLocation != null ? " @" + lastSetLocation : "");
String markup = singleRegister+inoutChar+"= "+ valStr + lastStr;
if (comment.replace('\'',' ').contains(markup.replace('\'',' '))) {
return false;
}
comment = (comment.trim().length()==0 ? markup : comment + "\n" + markup);
instr.setComment(Instruction.EOL_COMMENT, comment);
return false;
}
@ -188,8 +339,14 @@ public class MultiInstructionMemReference extends GhidraScript {
}
}
// if the instruction attempting to markup is in the delayslot, backup an instruction
Instruction instr = currentProgram.getListing().getInstructionAt(curInstrloc);
if (instr != null) {
inputObjects = instr.getInputObjects();
resultObjects = instr.getResultObjects();
registerInOut = checkRegisterInOut(singleRegister, inputObjects, resultObjects);
}
// if the instruction attempting to markup is in the delayslot, backup an instruction
if (instr != null && instr.isInDelaySlot()) {
instr = instr.getPrevious();
if (instr != null) {
@ -209,16 +366,24 @@ public class MultiInstructionMemReference extends GhidraScript {
}
}
/**
* @param instruction
* @param space
* @param scalar
* @param nextInstr
* @param addend
* @param taskMonitor
private boolean checkRegisterInOut(Register reg, Object[] in, Object[] out) {
if (reg == null || in == null || out == null) {
return false;
}
List<Object> inList = Arrays.asList(in);
List<Object> outList = Arrays.asList(out);
return inList.contains(reg) && outList.contains(reg);
}
/** Make the reference on the instruction at the correct location.
*
* @param instruction to receive reference
* @param space reference created in this space
* @param scalar used as offset into address space
*/
private void makeReference(Instruction instruction, int opIndex, Address addr,
TaskMonitor taskMonitor) {
private void makeReference(Instruction instruction, int opIndex, Address addr) {
if (instruction.getPrototype().hasDelaySlots()) {
instruction = instruction.getNext();
if (instruction == null) {
@ -238,6 +403,13 @@ public class MultiInstructionMemReference extends GhidraScript {
if (opIndex == -1) {
opIndex = instruction.getNumOperands() - 1;
}
// check if it already has the reference
Reference[] referencesFrom = instruction.getReferencesFrom();
boolean hasRef = Arrays.stream(referencesFrom).anyMatch(p -> p.getToAddress().equals(addr));
if (hasRef) {
return;
}
if (opIndex == -1) {
instruction.addMnemonicReference(addr, RefType.DATA, SourceType.ANALYSIS);

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@ -67,10 +67,16 @@ public class ConstantPropagationAnalyzer extends AbstractAnalyzer {
protected static final int MINKNOWNREFADDRESS_OPTION_DEFAULT_VALUE = 4;
protected static final String MINSPECULATIVEREFADDRESS_OPTION_NAME =
"Min speculative reference";
"Speculative reference min";
protected static final String MINSPECULATIVEREFADDRESS_OPTION_DESCRIPTION =
"Minimum speculative reference address for offsets and parameters";
protected static final int MINSPECULATIVEREFADDRESS_OPTION_DEFAULT_VALUE = 1024;
protected static final String MAXSPECULATIVEREFADDRESS_OPTION_NAME =
"Speculative reference max";
protected static final String MAXSPECULATIVEREFADDRESS_OPTION_DESCRIPTION =
"Maxmimum speculative reference address offset from the end of memory for offsets and parameters";
protected static final int MAXSPECULATIVEREFADDRESS_OPTION_DEFAULT_VALUE = 256;
protected final static int NOTIFICATION_INTERVAL = 100;
@ -80,6 +86,7 @@ public class ConstantPropagationAnalyzer extends AbstractAnalyzer {
protected int maxThreadCount = MAXTHREADCOUNT_OPTION_DEFAULT_VALUE;
protected long minStoreLoadRefAddress = MINKNOWNREFADDRESS_OPTION_DEFAULT_VALUE;
protected long minSpeculativeRefAddress = MINSPECULATIVEREFADDRESS_OPTION_DEFAULT_VALUE;
protected long maxSpeculativeRefAddress = MAXSPECULATIVEREFADDRESS_OPTION_DEFAULT_VALUE;
protected boolean followConditional = false;
@ -391,7 +398,7 @@ public class ConstantPropagationAnalyzer extends AbstractAnalyzer {
throws CancelledException {
ContextEvaluator eval = new ConstantPropagationContextEvaluator(trustWriteMemOption,
minStoreLoadRefAddress, minSpeculativeRefAddress);
minStoreLoadRefAddress, minSpeculativeRefAddress, maxSpeculativeRefAddress);
return symEval.flowConstants(flowStart, flowSet, eval, true, monitor);
}
@ -461,9 +468,13 @@ public class ConstantPropagationAnalyzer extends AbstractAnalyzer {
MINKNOWNREFADDRESS_OPTION_DESCRIPTION);
long size = program.getAddressFactory().getDefaultAddressSpace().getSize();
minSpeculativeRefAddress = size * 8;
minSpeculativeRefAddress = size * 16;
options.registerOption(MINSPECULATIVEREFADDRESS_OPTION_NAME, minSpeculativeRefAddress, null,
MINSPECULATIVEREFADDRESS_OPTION_DESCRIPTION);
maxSpeculativeRefAddress = size * 8;
options.registerOption(MAXSPECULATIVEREFADDRESS_OPTION_NAME, maxSpeculativeRefAddress, null,
MAXSPECULATIVEREFADDRESS_OPTION_DESCRIPTION);
}
@Override
@ -479,6 +490,8 @@ public class ConstantPropagationAnalyzer extends AbstractAnalyzer {
options.getLong(MINKNOWNREFADDRESS_OPTION_NAME, minStoreLoadRefAddress);
minSpeculativeRefAddress =
options.getLong(MINSPECULATIVEREFADDRESS_OPTION_NAME, minSpeculativeRefAddress);
maxSpeculativeRefAddress =
options.getLong(MAXSPECULATIVEREFADDRESS_OPTION_NAME, maxSpeculativeRefAddress);
}
}

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@ -42,7 +42,9 @@ public class ConstantPropagationContextEvaluator extends ContextEvaluatorAdapter
protected AddressSet destSet = new AddressSet();
private boolean trustMemoryWrite = false;
private long minStoreLoadOffset = 4;
private long minSpeculativeOffset = 1024;
private long minSpeculativeOffset = 1024; // from the beginning of memory
private long maxSpeculativeOffset = 256; // from the end of memory
public ConstantPropagationContextEvaluator() {
}
@ -55,10 +57,10 @@ public class ConstantPropagationContextEvaluator extends ContextEvaluatorAdapter
}
public ConstantPropagationContextEvaluator(boolean trustWriteMemOption,
long minStoreLoadRefAddress, long minSpeculativeRefAddress) {
long minStoreLoadRefAddress, long minSpeculativeRefAddress, long maxSpeculativeRefAddress) {
this(trustWriteMemOption);
this.minStoreLoadOffset = minStoreLoadRefAddress;
this.minSpeculativeOffset = minSpeculativeRefAddress;
this.maxSpeculativeOffset = maxSpeculativeRefAddress;
}
/**
@ -85,7 +87,7 @@ public class ConstantPropagationContextEvaluator extends ContextEvaluatorAdapter
long wordOffset = constant.getOffset();
if (((wordOffset >= 0 && wordOffset < minSpeculativeOffset) ||
(Math.abs(maxAddrOffset - wordOffset) < minSpeculativeOffset)) &&
(Math.abs(maxAddrOffset - wordOffset) < maxSpeculativeOffset)) &&
!space.isExternalSpace()) {
return null;
}

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@ -43,7 +43,7 @@ public class SymbolicPropogator {
// 1. How are "register-relative" varnodes distinguished based upon target space ? Not sure how we handle wrapping/truncation concerns.
// 1) The offset is the only thing that could be used as a reference.
private static final int _POINTER_MIN_BOUNDS = 0x7fff;
private static final int _POINTER_MIN_BOUNDS = 0x100;
// mask for sub-piece extraction
private static long[] maskSize = { 0xffL, 0xffL, 0xffffL, 0xffffffL, 0xffffffffL, 0xffffffffffL,
@ -1836,7 +1836,7 @@ public class SymbolicPropogator {
// see if the offset is a large constant offset from the symbolic space
long offset = refLocation.getOffset();
if (checkPossibleOffsetAddr(offset)) {
if (evaluator != null) {
// symbolic spaces will have the name of the symbolic space be the register space
// String spaceName = refLocation.getAddress().getAddressSpace().getName();
// Register register = vContext.getRegister(spaceName);
@ -1850,7 +1850,7 @@ public class SymbolicPropogator {
// }
// } else
if (evaluator == null) {
if (!vContext.isStackSymbolicSpace(refLocation) && evaluator != null) {
Address constant = program.getAddressFactory().getAddress(
(int) targetSpaceID.getOffset(), offset);
Address newTarget = evaluator.evaluateConstant(vContext, instruction,
@ -2051,7 +2051,7 @@ public class SymbolicPropogator {
*/
private int getReferenceSpaceID(Instruction instruction, long offset) {
// TODO: this should be passed to the client callback to make the decision
if (offset <= 4096 && offset >= -1) {
if (offset <= 4 && offset >= -1) {
return -1; // don't make speculative reference to certain offset values
}

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@ -312,7 +312,7 @@ public class VarnodeContext implements ProcessorContext {
/**
* Return true if this varnode is stored in the symbolic stack space
*/
private boolean isStackSymbolicSpace(Varnode varnode) {
public boolean isStackSymbolicSpace(Varnode varnode) {
// symbolic spaces are off of a register, find the space
AddressSpace regSpace = addrFactory.getAddressSpace(varnode.getSpace());
@ -785,7 +785,9 @@ public class VarnodeContext implements ProcessorContext {
* return the location that this register was last set
* This is a transient thing, so it should only be used as a particular flow is being processed...
*
* @param reg
* @param reg register to find last set location
* @param bval value to look for to differentiate set locations, null if don't care
*
* @return address that the register was set.
*/
public Address getLastSetLocation(Register reg, BigInteger bval) {
@ -1256,6 +1258,13 @@ public class VarnodeContext implements ProcessorContext {
// too big anyway,already extended as far as it will go.
vnodeVal = createConstantVarnode(vnodeVal.getOffset(), out.getSize());
}
} else if (vnodeVal.isRegister() && vnodeVal.getSize() < out.getSize()) {
Register reg = getRegister(vnodeVal);
if (reg == null) {
throw notFoundExc;
}
int spaceID = getAddressSpace(reg.getName());
vnodeVal = createVarnode(0,spaceID,out.getSize());
}
return vnodeVal;
}