decompiler  1.0.0
Public Member Functions | Static Private Member Functions | List of all members
RulePiecePathology Class Reference

Search for concatenations with unlikely things to inform return/parameter consumption calculation. More...

Inheritance diagram for RulePiecePathology:
Rule

Public Member Functions

 RulePiecePathology (const string &g)
 Constructor.
 
virtual Ruleclone (const ActionGroupList &grouplist) const
 Clone the Rule. More...
 
virtual void getOpList (vector< uint4 > &oplist) const
 List of op codes this rule operates on. More...
 
virtual int4 applyOp (PcodeOp *op, Funcdata &data)
 Attempt to apply this Rule. More...
 
- Public Member Functions inherited from Rule
 Rule (const string &g, uint4 fl, const string &nm)
 Construct given group, properties name. More...
 
virtual ~Rule (void)
 Destructor.
 
const string & getName (void) const
 Return the name of this Rule.
 
const string & getGroup (void) const
 Return the group this Rule belongs to.
 
uint4 getNumTests (void)
 Get number of attempted applications.
 
uint4 getNumApply (void)
 Get number of successful applications.
 
void setBreak (uint4 tp)
 Set a breakpoint on this Rule.
 
void clearBreak (uint4 tp)
 Clear a breakpoint on this Rule.
 
void clearBreakPoints (void)
 Clear all breakpoints on this Rule.
 
void turnOnWarnings (void)
 Enable warnings for this Rule.
 
void turnOffWarnings (void)
 Disable warnings for this Rule.
 
bool isDisabled (void) const
 Return true if this Rule is disabled.
 
void setDisable (void)
 Disable this Rule (within its pool)
 
void clearDisable (void)
 Enable this Rule (within its pool)
 
bool checkActionBreak (void)
 Check if an action breakpoint is turned on. More...
 
uint4 getBreakPoint (void) const
 Return breakpoint toggles.
 
virtual void reset (Funcdata &data)
 Reset this Rule. More...
 
virtual void resetStats (void)
 Reset Rule statistics. More...
 
virtual void printStatistics (ostream &s) const
 Print statistics for this Rule. More...
 

Static Private Member Functions

static bool isPathology (Varnode *vn, Funcdata &data)
 Return true if concatenating with a SUBPIECE of the given Varnode is unusual. More...
 
static int4 tracePathologyForward (PcodeOp *op, Funcdata &data)
 Given a known pathological concatenation, trace it forward to CALLs and RETURNs. More...
 

Additional Inherited Members

- Public Types inherited from Rule
enum  typeflags { type_disable = 1, rule_debug = 2, warnings_on = 4, warnings_given = 8 }
 Properties associated with a Rule. More...
 

Detailed Description

Search for concatenations with unlikely things to inform return/parameter consumption calculation.

For that can read/write part of a general purpose register, a small return value can get concatenated with unrelated data when the function writes directly to part of the return register. This searches for a characteristic pathology:

retreg = CALL();
...
retreg = CONCAT(SUBPIECE(retreg,#4),smallval);

Member Function Documentation

int4 RulePiecePathology::applyOp ( PcodeOp op,
Funcdata data 
)
virtual

Attempt to apply this Rule.

This method contains the main logic for applying the Rule. It must use a given PcodeOp as the point at which the Rule applies. If it does apply, changes are made directly to the function and 1 (non-zero) is returned, otherwise 0 is returned.

Parameters
opis the given PcodeOp where the Rule may apply
datais the function to which to apply

Reimplemented from Rule.

References PcodeOp::code(), CPUI_INDIRECT, CPUI_SUBPIECE, Varnode::getAddr(), Funcdata::getCallSpecs(), Varnode::getDef(), PcodeOp::getIn(), Varnode::getOffset(), Varnode::getSize(), Address::getSpace(), AddrSpace::isBigEndian(), PcodeOp::isCall(), PcodeOp::isIndirectCreation(), FuncProto::isOutputLocked(), and Varnode::isWritten().

virtual Rule* RulePiecePathology::clone ( const ActionGroupList grouplist) const
inlinevirtual

Clone the Rule.

If this Rule is a member of one of the groups in the grouplist, this returns a clone of the Rule, otherwise NULL is returned.

Parameters
grouplistis the list of groups being cloned
Returns
the cloned Rule or NULL

Implements Rule.

References ActionGroupList::contains().

void RulePiecePathology::getOpList ( vector< uint4 > &  oplist) const
virtual

List of op codes this rule operates on.

Populate the given array with all possible OpCodes this Rule might apply to. By default, this method returns all possible OpCodes

Parameters
oplistis the array to populate

Reimplemented from Rule.

References CPUI_PIECE.

bool RulePiecePathology::isPathology ( Varnode vn,
Funcdata data 
)
staticprivate
int4 RulePiecePathology::tracePathologyForward ( PcodeOp op,
Funcdata data 
)
staticprivate

Given a known pathological concatenation, trace it forward to CALLs and RETURNs.

If the pathology reaches a CALL or RETURN, it is noted, through the FuncProto or FuncCallSpecs object, that the parameter or return value is only partially consumed. The subvariable flow rules can then decide whether or not to truncate this part of the data-flow.

Parameters
opis CPUI_PIECE op that is the pathological concatenation
datais the function containing the data-flow
Returns
a non-zero value if new bytes are labeled as unconsumed

References Varnode::beginDescend(), PcodeOp::code(), CPUI_CALL, CPUI_CALLIND, CPUI_COPY, CPUI_INDIRECT, CPUI_MULTIEQUAL, CPUI_RETURN, Varnode::endDescend(), Funcdata::getCallSpecs(), Funcdata::getFuncProto(), PcodeOp::getIn(), PcodeOp::getOut(), Varnode::getSize(), FuncCallSpecs::isInputActive(), FuncProto::isInputLocked(), PcodeOp::isMark(), FuncProto::isOutputLocked(), PcodeOp::numInput(), FuncCallSpecs::setInputBytesConsumed(), PcodeOp::setMark(), and FuncProto::setReturnBytesConsumed().


The documentation for this class was generated from the following files: