ghidra::LoadGuard Class Reference

Description of a LOAD operation that needs to be guarded. More...

#include <heritage.hh>

Public Member Functions
PcodeOp *	getOp (void) const
	Get the PcodeOp being guarded.
uintb	getMinimum (void) const
	Get minimum offset of the guarded range.
uintb	getMaximum (void) const
	Get maximum offset of the guarded range.
int4	getStep (void) const
	Get the calculated step associated with the range (or 0)
bool	isGuarded (const Address &addr) const
	Does this guard apply to the given address. More...
bool	isRangeLocked (void) const
	Return true if the range is fully determined.
bool	isValid (OpCode opc) const
	Return true if the record still describes an active LOAD.

Private Member Functions
void	establishRange (const ValueSetRead &valueSet)
	Convert partial value set analysis into guard range. More...
void	finalizeRange (const ValueSetRead &valueSet)
	Convert value set analysis to final guard range.
void	set (PcodeOp *o, AddrSpace *s, uintb off)
	Set a new unanalyzed LOAD guard that initially guards everything. More...

Private Attributes
PcodeOp *	op
	The LOAD op.
AddrSpace *	spc
	The stack space being loaded from.
uintb	pointerBase
	Base offset of the pointer.
uintb	minimumOffset
	Minimum offset of the LOAD.
uintb	maximumOffset
	Maximum offset of the LOAD.
int4	step
	Step of any access into this range (0=unknown)
int4	analysisState
	0=unanalyzed, 1=analyzed(partial result), 2=analyzed(full result)

Friends
class	Heritage

Detailed Description

Description of a LOAD operation that needs to be guarded.

Heritage maintains a list of CPUI_LOAD ops that reference the stack dynamically. These can potentially alias stack Varnodes, so we maintain what (possibly limited) information we known about the range of stack addresses that can be referenced.

Member Function Documentation

establishRange()

void ghidra::LoadGuard::establishRange ( const ValueSetRead &  valueSet )

private

Convert partial value set analysis into guard range.

Make some determination of the range of possible values for a LOAD based an partial value set analysis. This can sometimes get

• minimumOffset - otherwise the original constant pulled with the LOAD is used
• step - the partial analysis shows step and direction
• maximumOffset - in rare cases

isAnalyzed is set to true, if full range analysis is not needed

Parameters

valueSet

is the calculated value set as seen by the LOAD operation

References ghidra::ValueSetRead::getRange(), ghidra::CircleRange::getSize(), ghidra::ValueSetRead::isLeftStable(), and ghidra::ValueSetRead::isRightStable().

Referenced by ghidra::Heritage::analyzeNewLoadGuards().

isGuarded()

bool ghidra::LoadGuard::isGuarded

(

const Address &

addr

)

const

Does this guard apply to the given address.

Check if the address falls within the range defined by this

Parameters

addr	is the given address

Returns

true if the address is contained

References ghidra::Address::getOffset(), and ghidra::Address::getSpace().

Referenced by ghidra::RuleIndirectCollapse::applyOp().

set()

void ghidra::LoadGuard::set ( PcodeOp *  o, AddrSpace *  s, uintb  off  )

inlineprivate

Set a new unanalyzed LOAD guard that initially guards everything.

Parameters

o	is the LOAD op
s	is the (stack) space it is loading from
off	is the base offset that is indexed from

References ghidra::AddrSpace::getHighest().

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

• heritage.hh
• heritage.cc