Remove PTRSUB operations with mismatched data-type information. More...

Inheritance diagram for ghidra::RulePtrsubUndo:

Collaboration diagram for ghidra::RulePtrsubUndo:

Public Member Functions
	RulePtrsubUndo (const string &g)
	Constructor.

virtual Rule *	clone (const ActionGroupList &grouplist) const
	Clone the Rule.

virtual void	getOpList (vector< uint4 > &oplist) const
	List of op codes this rule operates on.

virtual int4	applyOp (PcodeOp *op, Funcdata &data)
	Attempt to apply this Rule.

Public Member Functions inherited from ghidra::Rule
	Rule (const string &g, uint4 fl, const string &nm)
	Construct given group, properties name.

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.

uint4	getBreakPoint (void) const
	Return breakpoint toggles.

virtual void	reset (Funcdata &data)
	Reset this Rule.

virtual void	resetStats (void)
	Reset Rule statistics.

virtual void	printStatistics (ostream &s) const
	Print statistics for this Rule.

Static Private Member Functions
static int8	getConstOffsetBack (Varnode *vn, int8 &multiplier, int4 maxLevel)
	Recursively search for additive constants and multiplicative constants.

static int8	getExtraOffset (PcodeOp *op, int8 &multiplier)
	Collect constants and the biggest multiplier in the given PTRSUB expression.

static int8	removeLocalAdds (Varnode *vn, Funcdata &data)
	Remove constants in the additive expression involving the given Varnode.

static int8	removeLocalAddRecurse (PcodeOp *op, int4 slot, int4 maxLevel, Funcdata &data)
	Remove any constants in the additive expression rooted at the given PcodeOp.

Static Private Attributes
static const int4	DEPTH_LIMIT = 8
	The maximum depth of the additive expression to check.

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

Detailed Description

Remove PTRSUB operations with mismatched data-type information.

Incorrect data-types may be assigned to Varnodes in the middle of simplification. This causes incorrect PTRSUBs, which are discovered later. This rule converts the PTRSUB back to an INT_ADD when the mistake is discovered.

Member Function Documentation

◆ applyOp()

int4 ghidra::RulePtrsubUndo::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

op	is the given PcodeOp where the Rule may apply
data	is the function to which to apply

Reimplemented from ghidra::Rule.

References ghidra::calc_mask(), ghidra::PcodeOp::clearStopTypePropagation(), ghidra::CPUI_INT_ADD, getExtraOffset(), ghidra::PcodeOp::getIn(), ghidra::Varnode::getOffset(), ghidra::PcodeOp::getOut(), ghidra::Varnode::getSize(), ghidra::Varnode::getTypeReadFacing(), ghidra::Funcdata::hasTypeRecoveryStarted(), ghidra::Datatype::isPtrsubMatching(), ghidra::Funcdata::newConstant(), ghidra::Funcdata::opSetInput(), ghidra::Funcdata::opSetOpcode(), and removeLocalAdds().

◆ clone()

virtual Rule * ghidra::RulePtrsubUndo::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

grouplist is the list of groups being cloned

Returns: the cloned Rule or NULL

Implements ghidra::Rule.

References ghidra::ActionGroupList::contains(), and ghidra::Rule::getGroup().

◆ getConstOffsetBack()

int8 ghidra::RulePtrsubUndo::getConstOffsetBack	(	Varnode *	vn,
		int8 &	multiplier,
		int4	maxLevel
	)

staticprivate

Recursively search for additive constants and multiplicative constants.

Walking backward from the given Varnode, search for constants being added in and return the sum of all the constants. Additionally pass back the biggest constant coefficient, for any term formed with INT_MULT.

Parameters

vn	is the given root Varnode of the additive tree
multiplier	will hold the biggest constant multiplier or 0, if no multiplier is present
maxLevel	is the maximum depth to search in the tree

Returns: the sum of all constants in the additive expression

References ghidra::PcodeOp::code(), ghidra::CPUI_INT_ADD, ghidra::CPUI_INT_MULT, getConstOffsetBack(), ghidra::Varnode::getDef(), ghidra::PcodeOp::getIn(), ghidra::Varnode::getOffset(), ghidra::Varnode::isConstant(), and ghidra::Varnode::isWritten().

Referenced by getConstOffsetBack(), and getExtraOffset().

◆ getExtraOffset()

int8 ghidra::RulePtrsubUndo::getExtraOffset	(	PcodeOp *	op,
		int8 &	multiplier
	)

staticprivate

Collect constants and the biggest multiplier in the given PTRSUB expression.

Walking the additive expression (INT_ADD, PTRADD, and other PTRSUBs) and calculate any additional constant value being added to the PTRSUB. Additionally pass back the biggest constant coefficient of any multiplicative term in the expression.

Parameters

op	is the given PTRSUB
multiplier	will hold the biggest multiplicative coefficient or 0, if no INT_MULT or PTRADD is present.

References ghidra::PcodeOp::code(), ghidra::CPUI_INT_ADD, ghidra::CPUI_PTRADD, ghidra::CPUI_PTRSUB, DEPTH_LIMIT, getConstOffsetBack(), ghidra::PcodeOp::getIn(), ghidra::Varnode::getOffset(), ghidra::PcodeOp::getOut(), ghidra::Varnode::getSize(), ghidra::PcodeOp::getSlot(), ghidra::Varnode::isConstant(), and ghidra::Varnode::loneDescend().

Referenced by applyOp().

◆ getOpList()

void ghidra::RulePtrsubUndo::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

oplist is the array to populate

Reimplemented from ghidra::Rule.

References ghidra::CPUI_PTRSUB.

◆ removeLocalAddRecurse()

int8 ghidra::RulePtrsubUndo::removeLocalAddRecurse	(	PcodeOp *	op,
		int4	slot,
		int4	maxLevel,
		Funcdata &	data
	)

staticprivate

Remove any constants in the additive expression rooted at the given PcodeOp.

Walking recursively through the expression, any INT_ADD with a constant input is converted to a COPY. The INT_ADD must only contribute to the root expression.

Parameters

op	is the given root PcodeOp
slot	is the input slot to walk back from
maxLevel	is the maximum depth to recurse
data	is the function containing the expression

Returns: the sum of all constants that are removed

References ghidra::PcodeOp::code(), ghidra::CPUI_COPY, ghidra::CPUI_INT_ADD, ghidra::Varnode::getDef(), ghidra::PcodeOp::getIn(), ghidra::Varnode::getOffset(), ghidra::Varnode::isConstant(), ghidra::Varnode::isWritten(), ghidra::Varnode::loneDescend(), ghidra::Funcdata::opRemoveInput(), ghidra::Funcdata::opSetOpcode(), and removeLocalAddRecurse().

Referenced by removeLocalAddRecurse(), and removeLocalAdds().

◆ removeLocalAdds()

int8 ghidra::RulePtrsubUndo::removeLocalAdds	(	Varnode *	vn,
		Funcdata &	data
	)

staticprivate

Remove constants in the additive expression involving the given Varnode.

Any additional PTRADD, PTRSUB, or INT_ADD that uses the Varnode and adds a constant is converted to a COPY. Additionally any other INT_ADD involved in the expression that adds a constant is also converted to COPY.

Parameters

vn	is the given Varnode
data	is the function containing the expression

Returns: the sum of all constants that are removed

References ghidra::PcodeOp::clearStopTypePropagation(), ghidra::PcodeOp::code(), ghidra::CPUI_COPY, ghidra::CPUI_INT_ADD, ghidra::CPUI_PTRADD, ghidra::CPUI_PTRSUB, DEPTH_LIMIT, ghidra::PcodeOp::getIn(), ghidra::Varnode::getOffset(), ghidra::PcodeOp::getOut(), ghidra::PcodeOp::getSlot(), ghidra::Varnode::isConstant(), ghidra::Varnode::loneDescend(), ghidra::Funcdata::opRemoveInput(), ghidra::Funcdata::opSetOpcode(), ghidra::Funcdata::opUndoPtradd(), and removeLocalAddRecurse().

Referenced by applyOp().

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

/builds/appsec/reveng-binrw/ghidraplusplus/src/dec/ruleaction.hh
/builds/appsec/reveng-binrw/ghidraplusplus/src/dec/ruleaction.cc

Public Member Functions

Static Private Member Functions

Static Private Attributes

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ applyOp()

◆ clone()

◆ getConstOffsetBack()

◆ getExtraOffset()

◆ getOpList()

◆ removeLocalAddRecurse()

◆ removeLocalAdds()