JumpBasicOverride Class Reference

A basic jump-table model incorporating manual override information. More...

#include <jumptable.hh>

Inheritance diagram for JumpBasicOverride:

Collaboration diagram for JumpBasicOverride:

Public Member Functions
	JumpBasicOverride (JumpTable *jt)
	Constructor. More...
void	setAddresses (const vector< Address > &adtable)
	Manually set the address table for this model. More...
virtual bool	isOverride (void) const
	Return true if this model was manually overridden.
virtual int4	getTableSize (void) const
	Return the number of entries in the address table.
virtual bool	recoverModel (Funcdata *fd, PcodeOp *indop, uint4 matchsize, uint4 maxtablesize)
	Attempt to recover details of the model, given a specific BRANCHIND. More...
virtual void	buildAddresses (Funcdata *fd, PcodeOp *indop, vector< Address > &addresstable, vector< LoadTable > *loadpoints) const
	Construct the explicit list of target addresses (the Address Table) from this model. More...
virtual void	buildLabels (Funcdata *fd, vector< Address > &addresstable, vector< uintb > &label, const JumpModel *orig) const
	Recover case labels associated with the Address table. More...
virtual bool	foldInGuards (Funcdata *fd, JumpTable *jump)
	Eliminate any guard code involved in computing the switch destination. More...
virtual bool	sanityCheck (Funcdata *fd, PcodeOp *indop, vector< Address > &addresstable)
	Perform a sanity check on recovered addresses. More...
virtual JumpModel *	clone (JumpTable *jt) const
	Clone this model.
virtual void	clear (void)
virtual void	saveXml (ostream &s) const
virtual void	restoreXml (const Element *el, Architecture *glb)
Public Member Functions inherited from JumpBasic
virtual void	findUnnormalized (uint4 maxaddsub, uint4 maxleftright, uint4 maxext)
	Recover the unnormalized switch variable. More...
virtual Varnode *	foldInNormalization (Funcdata *fd, PcodeOp *indop)
	Do normalization of the given switch specific to this model. More...

Additional Inherited Members
Protected Member Functions inherited from JumpBasic
void	findDeterminingVarnodes (PcodeOp *op, int4 slot)
	Calculate the initial set of Varnodes that might be switch variables. More...
void	analyzeGuards (BlockBasic *bl, int4 pathout)
	Analyze CBRANCHs leading up to the given basic-block as a potential switch guard. More...
void	calcRange (Varnode *vn, CircleRange &rng) const
	Calculate the range of values in the given Varnode that direct control-flow to the switch. More...
void	findSmallestNormal (uint4 matchsize)
	Find the putative switch variable with the smallest range of values reaching the switch. More...
void	findNormalized (Funcdata *fd, BlockBasic *rootbl, int4 pathout, uint4 matchsize, uint4 maxtablesize)
	Do all the work necessary to recover the normalized switch variable. More...
void	markFoldableGuards ()
	Mark the guard CBRANCHs that are truly part of the model. More...
void	markModel (bool val)
	Mark (or unmark) all PcodeOps involved in the model. More...
bool	flowsOnlyToModel (Varnode *vn, PcodeOp *trailOp)
	Check if the given Varnode flows to anything other than this model. More...
virtual bool	foldInOneGuard (Funcdata *fd, GuardRecord &guard, JumpTable *jump)
	Eliminate the given guard to this switch. More...
Static Protected Member Functions inherited from JumpBasic
static bool	isprune (Varnode *vn)
	Do we prune in here in our depth-first search for the normalized switch variable. More...
static bool	ispoint (Varnode *vn)
	Is it possible for the given Varnode to be a switch variable? More...
static int4	getStride (Varnode *vn)
	Get the step/stride associated with the Varnode. More...
static uintb	backup2Switch (Funcdata *fd, uintb output, Varnode *outvn, Varnode *invn)
	Back up the constant value in the output Varnode to the value in the input Varnode. More...
Protected Attributes inherited from JumpBasic
JumpValuesRange *	jrange
	Range of values for the (normalized) switch variable.
PathMeld	pathMeld
	Set of PcodeOps and Varnodes producing the final target addresses.
vector< GuardRecord >	selectguards
	Any guards associated with model.
int4	varnodeIndex
	Position of the normalized switch Varnode within PathMeld.
Varnode *	normalvn
	Normalized switch Varnode.
Varnode *	switchvn
	Unnormalized switch Varnode.
Protected Attributes inherited from JumpModel
JumpTable *	jumptable
	The jump-table that is building this model.

Detailed Description

A basic jump-table model incorporating manual override information.

The list of potential target addresses produced by the BRANCHIND is not recovered by this model, but must provided explicitly via setAddresses(). The model tries to repurpose some of the analysis that JumpBasic does to recover the switch variable. But it will revert to the trivial model if it can't find a suitable switch variable.

Constructor & Destructor Documentation

JumpBasicOverride()

JumpBasicOverride::JumpBasicOverride

(

JumpTable *

jt

)

Constructor.

Parameters

jt	is the parent JumpTable

Member Function Documentation

buildAddresses()

void JumpBasicOverride::buildAddresses ( Funcdata *  fd, PcodeOp *  indop, vector< Address > &  addresstable, vector< LoadTable > *  loadpoints  ) const

virtual

Construct the explicit list of target addresses (the Address Table) from this model.

The addresses produced all come from the BRANCHIND and may not be deduped. Alternate guard destinations are not yet included.

Parameters

fd	is the function containing the switch
indop	is the root BRANCHIND of the switch
addresstable	will hold the list of Addresses
loadpoints	if non-null will hold LOAD table information used by the model

Reimplemented from JumpBasic.

buildLabels()

void JumpBasicOverride::buildLabels ( Funcdata *  fd, vector< Address > &  addresstable, vector< uintb > &  label, const JumpModel *  orig  ) const

virtual

Recover case labels associated with the Address table.

The unnormalized switch variable must already be recovered. Values that the normalized switch value can hold or walked back to obtain the value that the unnormalized switch variable would hold. Labels are returned in the order provided by normalized switch variable iterator JumpValues.

Parameters

fd	is the function containing the switch
addresstable	is the address table (used to label code blocks with bad or missing labels)
label	will hold recovered labels in JumpValues order
orig	is the JumpModel to use for the JumpValues iterator

Reimplemented from JumpBasic.

foldInGuards()

virtual bool JumpBasicOverride::foldInGuards ( Funcdata *  fd, JumpTable *  jump  )

inlinevirtual

Eliminate any guard code involved in computing the switch destination.

We now think of the BRANCHIND as encompassing any guard function.

Parameters

fd	is the function containing the switch
jump	is the JumpTable owning this model.

Reimplemented from JumpBasic.

recoverModel()

bool JumpBasicOverride::recoverModel ( Funcdata *  fd, PcodeOp *  indop, uint4  matchsize, uint4  maxtablesize  )

virtual

Attempt to recover details of the model, given a specific BRANCHIND.

This generally recovers the normalized switch variable and any guards.

Parameters

fd	is the function containing the switch
indop	is the given BRANCHIND
matchsize	is the expected number of address table entries to recover, or 0 for no expectation
maxtablesize	is maximum number of address table entries to allow in the model

Returns

true if details of the model were successfully recovered

Reimplemented from JumpBasic.

sanityCheck()

virtual bool JumpBasicOverride::sanityCheck ( Funcdata *  fd, PcodeOp *  indop, vector< Address > &  addresstable  )

inlinevirtual

Perform a sanity check on recovered addresses.

Individual addresses are checked against the function or its program to determine if they are reasonable. This method can optionally remove addresses from the table. If it does so, the underlying model is changed to reflect the removal.

Parameters

fd	is the function containing the switch
indop	is the root BRANCHIND of the switch
addresstable	is the list of recovered Addresses, which may be modified

Returns

true if there are (at least some) reasonable addresses in the table

Reimplemented from JumpBasic.

setAddresses()

void JumpBasicOverride::setAddresses

(

const vector< Address > &

adtable

)

Manually set the address table for this model.

Parameters

adtable

is the list of externally provided addresses, which will be deduped

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

• jumptable.hh
• jumptable.cc