Emulation based on (existing) PcodeOps and Varnodes. More...

#include <emulateutil.hh>

Inheritance diagram for ghidra::EmulatePcodeOp:

Public Member Functions
	EmulatePcodeOp (Architecture *g)
	Constructor. More...

void	setCurrentOp (PcodeOp *op)
	Establish the current PcodeOp being emulated. More...

virtual Address	getExecuteAddress (void) const
	Get the address of the current instruction being executed.

virtual void	setVarnodeValue (Varnode *vn, uintb val)=0
	Given a specific Varnode, set the given value for it in the current machine state. More...

virtual uintb	getVarnodeValue (Varnode *vn) const =0
	Given a specific Varnode, retrieve the current value for it from the machine state. More...

Public Member Functions inherited from ghidra::Emulate
	Emulate (void)
	generic emulator constructor

void	setHalt (bool val)
	Set the halt state of the emulator. More...

bool	getHalt (void) const
	Get the halt state of the emulator. More...

virtual void	setExecuteAddress (const Address &addr)=0
	Set the address of the next instruction to emulate.

void	executeCurrentOp (void)
	Do a single pcode op step. More...

Protected Member Functions
virtual uintb	getLoadImageValue (AddrSpace *spc, uintb offset, int4 sz) const
	Pull a value from the load-image given a specific address. More...

virtual void	executeUnary (void)
	Execute a unary arithmetic/logical operation.

virtual void	executeBinary (void)
	Execute a binary arithmetic/logical operation.

virtual void	executeLoad (void)
	Standard behavior for a p-code LOAD.

virtual void	executeStore (void)
	Standard behavior for a p-code STORE.

virtual bool	executeCbranch (void)
	Check if the conditional of a CBRANCH is true. More...

virtual void	executeMultiequal (void)
	Standard behavior for a MULTIEQUAL (phi-node)

virtual void	executeIndirect (void)
	Standard behavior for an INDIRECT op.

virtual void	executeSegmentOp (void)
	Behavior for a SEGMENTOP.

virtual void	executeCpoolRef (void)
	Standard behavior for a CPOOLREF (constant pool reference) op.

virtual void	executeNew (void)
	Standard behavior for (low-level) NEW op.

Protected Member Functions inherited from ghidra::Emulate
virtual void	executeBranch (void)=0
	Standard behavior for a BRANCH. More...

virtual void	executeBranchind (void)=0
	Standard behavior for a BRANCHIND.

virtual void	executeCall (void)=0
	Standard behavior for a p-code CALL.

virtual void	executeCallind (void)=0
	Standard behavior for a CALLIND.

virtual void	executeCallother (void)=0
	Standard behavior for a user-defined p-code op.

virtual void	fallthruOp (void)=0
	Standard p-code fall-thru semantics.

Protected Attributes
Architecture *	glb
	The underlying Architecture for the program being emulated.

PcodeOp *	currentOp
	Current PcodeOp being executed.

PcodeOp *	lastOp
	Last PcodeOp that was executed.

Protected Attributes inherited from ghidra::Emulate
bool	emu_halted
	Set to true if the emulator is halted.

OpBehavior *	currentBehave
	Behavior of the next op to execute.

Detailed Description

Emulation based on (existing) PcodeOps and Varnodes.

This is still an abstract class. It does most of the work of emulating p-code using PcodeOp and Varnode objects (as opposed to PcodeOpRaw and VarnodeData). This class leaves implementation of control-flow to the derived class. This class implements most operations by going through new virtual methods:

The default executeLoad() implementation pulls values from the underlying LoadImage object. The following p-code ops are provided NULL implementations, as some tasks don't need hard emulation of them:

STORE
CPOOLREF
NEW

Constructor & Destructor Documentation

◆ EmulatePcodeOp()

ghidra::EmulatePcodeOp::EmulatePcodeOp ( Architecture * g )

Constructor.

Parameters

g	is the Architecture providing the LoadImage

References currentOp, glb, and lastOp.

Member Function Documentation

◆ executeCbranch()

bool ghidra::EmulatePcodeOp::executeCbranch ( void )

protectedvirtual

Check if the conditional of a CBRANCH is true.

This routine only checks if the condition for a p-code CBRANCH is true. It does not perform the actual branch.

Returns: the boolean state indicated by the condition

Implements ghidra::Emulate.

References currentOp, ghidra::PcodeOp::getIn(), getVarnodeValue(), and ghidra::PcodeOp::isBooleanFlip().

◆ getLoadImageValue()

uintb ghidra::EmulatePcodeOp::getLoadImageValue	(	AddrSpace *	spc,
		uintb	offset,
		int4	sz
	)		const

protectedvirtual

Pull a value from the load-image given a specific address.

A contiguous chunk of memory is pulled from the load-image and returned as a constant value, respecting the endianess of the address space. The default implementation of this method pulls the value directly from the LoadImage object.

Parameters

spc	is the address space to pull the value from
offset	is the starting address offset (from within the space) to pull the value from
sz	is the number of bytes to pull from memory

Returns: indicated bytes arranged as a constant value

References ghidra::calc_mask(), glb, ghidra::AddrSpace::isBigEndian(), ghidra::Architecture::loader, and ghidra::LoadImage::loadFill().

Referenced by executeLoad(), ghidra::EmulateSnippet::executeLoad(), ghidra::EmulateFunction::getVarnodeValue(), and ghidra::EmulateSnippet::getVarnodeValue().

◆ getVarnodeValue()

virtual uintb ghidra::EmulatePcodeOp::getVarnodeValue ( Varnode * vn ) const

pure virtual

Given a specific Varnode, retrieve the current value for it from the machine state.

This is the placeholder internal operation for obtaining a Varnode value during emulation. The value is loaded using the Varnode as the address and storage size.

Parameters

vn	is the specific Varnode

Returns: the corresponding value from the machine state

Implemented in ghidra::EmulateFunction.

Referenced by executeBinary(), ghidra::EmulateSnippet::executeBinary(), executeCbranch(), ghidra::EmulateSnippet::executeCbranch(), executeIndirect(), executeLoad(), ghidra::EmulateSnippet::executeLoad(), executeMultiequal(), executeSegmentOp(), executeUnary(), ghidra::EmulateSnippet::executeUnary(), getExecuteAddress(), and ghidra::EmulateSnippet::setVarnodeValue().

◆ setCurrentOp()

void ghidra::EmulatePcodeOp::setCurrentOp ( PcodeOp * op )

inline

Establish the current PcodeOp being emulated.

Parameters

op	is the PcodeOp that will next be executed via executeCurrentOp()

References ghidra::Emulate::currentBehave, ghidra::TypeOp::getBehavior(), and ghidra::PcodeOp::getOpcode().

Referenced by ghidra::EmulateFunction::emulatePath(), ghidra::EmulateSnippet::executeBranch(), ghidra::EmulateSnippet::fallthruOp(), ghidra::EmulateSnippet::resetMemory(), and ghidra::EmulateSnippet::setExecuteAddress().

◆ setVarnodeValue()

virtual void ghidra::EmulatePcodeOp::setVarnodeValue	(	Varnode *	vn,
		uintb	val
	)

pure virtual

Given a specific Varnode, set the given value for it in the current machine state.

This is the placeholder internal operation for setting a Varnode value during emulation. The value is stored using the Varnode as the address and storage size.

Parameters

vn	is the specific Varnode
val	is the constant value to store

Implemented in ghidra::EmulateFunction.

Referenced by executeBinary(), ghidra::EmulateSnippet::executeBinary(), executeIndirect(), executeLoad(), ghidra::EmulateSnippet::executeLoad(), executeMultiequal(), executeSegmentOp(), executeUnary(), ghidra::EmulateSnippet::executeUnary(), and getExecuteAddress().

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

emulateutil.hh
emulateutil.cc

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ EmulatePcodeOp()

Member Function Documentation

◆ executeCbranch()

◆ getLoadImageValue()

◆ getVarnodeValue()

◆ setCurrentOp()

◆ setVarnodeValue()