ghidra::ExecutablePcode Class Reference

A snippet of p-code that can be executed outside of normal analysis. More...

#include <pcodeinject.hh>

Inheritance diagram for ghidra::ExecutablePcode:

Public Member Functions
	ExecutablePcode (Architecture *g, const string &src, const string &nm)
	Constructor. More...
virtual string	getSource (void) const
	Return a string describing the source of the injection (.cspec, prototype model, etc.)
uintb	evaluate (const vector< uintb > &input)
	Evaluate the snippet on the given inputs. More...
Public Member Functions inherited from ghidra::InjectPayload
	InjectPayload (const string &nm, int4 tp)
	Construct for use with decode.
int4	getParamShift (void) const
	Get the number of parameters shifted.
bool	isDynamic (void) const
	Return true if p-code in the injection is generated dynamically.
bool	isIncidentalCopy (void) const
	Return true if any injected COPY is considered incidental.
int4	sizeInput (void) const
	Return the number of input parameters.
int4	sizeOutput (void) const
	Return the number of output parameters.
InjectParameter &	getInput (int4 i)
	Get the i-th input parameter.
InjectParameter &	getOutput (int4 i)
	Get the i-th output parameter.
virtual	~InjectPayload (void)
	Destructor.
virtual void	inject (InjectContext &context, PcodeEmit &emit) const =0
virtual void	decode (Decoder &decoder)=0
	Decode this payload from a stream.
virtual void	printTemplate (ostream &s) const =0
	Print the p-code ops of the injection to a stream (for debugging)
string	getName (void) const
	Return the name of the injection.
int4	getType (void) const
	Return the type of injection (CALLFIXUP_TYPE, CALLOTHERFIXUP_TYPE, etc.)

Private Member Functions
void	build (void)
	Initialize the Emulate object with the snippet p-code.

Private Attributes
Architecture *	glb
	The Architecture owning this snippet.
string	source
	Description of the source of this snippet.
bool	built
	Whether build() method has run, setting up the emulator.
EmulateSnippet	emulator
	The emulator.
vector< uintb >	inputList
	Temporary ids of input varnodes.
vector< uintb >	outputList
	Temporary ids of output varnodes.
PcodeEmit *	emitter
	Emitter (allocated temporarily) for initializing the emulator.

Additional Inherited Members
Public Types inherited from ghidra::InjectPayload
enum	{ CALLFIXUP_TYPE = 1, CALLOTHERFIXUP_TYPE = 2, CALLMECHANISM_TYPE = 3, EXECUTABLEPCODE_TYPE = 4 }
Protected Member Functions inherited from ghidra::InjectPayload
void	orderParameters (void)
	Assign an index to parameters. More...
void	decodePayloadAttributes (Decoder &decoder)
	Parse the attributes of the current <pcode> tag. More...
void	decodePayloadParams (Decoder &decoder)
	Parse any <input> or <output> children of current <pcode> tag. More...
Static Protected Member Functions inherited from ghidra::InjectPayload
static void	decodeParameter (Decoder &decoder, string &name, uint4 &size)
	Parse an <input> or <output> element describing an injection parameter. More...
Protected Attributes inherited from ghidra::InjectPayload
string	name
	Formal name of the payload.
int4	type
	Type of this payload: CALLFIXUP_TYPE, CALLOTHERFIXUP_TYPE, etc.
bool	dynamic
	True if the injection is generated dynamically.
bool	incidentalCopy
	True if injected COPYs are considered incidental.
int4	paramshift
	Number of parameters shifted in the original call.
vector< InjectParameter >	inputlist
	List of input parameters to this payload.
vector< InjectParameter >	output
	List of output parameters.

Detailed Description

A snippet of p-code that can be executed outside of normal analysis.

Essentially a p-code script. The p-code contained in this snippet needs to be processor agnostic, so any register Varnodes must be temporary (out of the unique space) and any control-flow operations must be contained within the snippet (p-code relative addressing). Input and output to the snippet/script is provided by standard injection parameters. The class contains, as a field, a stripped down emulator to run the script and a convenience method evaluate() to feed in concrete values to the input parameters and return a value from a single output parameter.

Constructor & Destructor Documentation

ExecutablePcode()

ghidra::ExecutablePcode::ExecutablePcode	(	Architecture *	g,
		const string &	src,
		const string &	nm
	)

Constructor.

Parameters

g	is the Architecture owning snippet
src	is a string describing the source of the snippet
nm	is the formal name of the snippet

References built, emitter, glb, and source.

Member Function Documentation

evaluate()

uintb ghidra::ExecutablePcode::evaluate

(

const vector< uintb > &

input

)

Evaluate the snippet on the given inputs.

The caller provides a list of concrete values that are assigned to the input parameters. The number of values and input parameters must match, and values are assigned in order. Input parameter order is determined either by the order of tags in the defining XML. This method assumes there is exactly 1 relevant output parameter. Once the snippet is executed the value of this parameter is read from the emulator state and returned.

Parameters

input

is the ordered list of input values to feed to this script

Returns

the value of the output parameter after script execution

References build(), emulator, ghidra::Emulate::executeCurrentOp(), ghidra::Emulate::getHalt(), ghidra::EmulateSnippet::getTempValue(), inputList, outputList, ghidra::EmulateSnippet::resetMemory(), and ghidra::EmulateSnippet::setVarnodeValue().

Referenced by ghidra::JumpAssisted::buildAddresses(), ghidra::JumpAssisted::buildLabels(), ghidra::SegmentOp::execute(), and ghidra::JumpAssisted::recoverModel().

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

• pcodeinject.hh
• pcodeinject.cc