Package ghidra.app.plugin.exceptionhandlers.gcc.structures.ehFrame

Class FrameDescriptionEntry

java.lang.Object

ghidra.app.plugin.exceptionhandlers.gcc.GccAnalysisClass

ghidra.app.plugin.exceptionhandlers.gcc.structures.ehFrame.FrameDescriptionEntry

public class FrameDescriptionEntry
extends GccAnalysisClass

A Frame Description Entry (FDE) describes the stack call frame, in particular, how to restore registers.

Taken from binutils-2.14.90.0.4/bfd/elf-bfd.h

 struct eh_cie_fde { 
                unsigned int offset; 
                unsigned int size; 
                asection *sec;
                unsigned int new_offset; 
                unsigned char fde_encoding; 
                unsigned char *lsda_encoding; 
                unsigned char lsda_offset; 
                unsigned char cie : 1; 
                unsigned char removed : 1; 
                unsigned char make_relative : 1; 
                unsigned char make_lsda_relative : 1; 
                unsigned char per_encoding_relative : 1; 
 };
 

 ACTUAL: struct eh_cie_fde { 
                dword fde.length 
                dword fde.ciePointer (Offset to this FDEs CIE) 
                dword fde.pcBegin 
                dword fde.pcRange 
                dword fde.augmentationLength 
                dword fde.augmentationData 
                dword Call Frame Instructions dword 
                !!! NO IDEA !!! 
 }
 

Field Summary

Fields inherited from class ghidra.app.plugin.exceptionhandlers.gcc.GccAnalysisClass

dwordDT, monitor, NEWLINE, program, ptrDT, ptrSize

Constructor Summary

Constructors

Constructor	Description
FrameDescriptionEntry(TaskMonitor monitor, Program program, CieSource cieSource)	Constructor for a frame descriptor entry.

Method Summary

Modifier and Type	Method	Description
RegionDescriptor	create(Address fdeBaseAddress)	Creates a Frame Description Entry (FDE) at the address specified.
byte[]	getAugmentationData()	Gets the bytes which specify the FDE field that refers to the augmentation data.
Address	getAugmentationDataAddress()	Get the address of the augmentation data in this FDE record.
byte[]	getAugmentationExData()	Gets the call frame augmentation data that indicates how registers are saved and restored.
Address	getAugmentationExDataAddress()	Gets the start address for the call frame augmentation data.
Address	getNextAddress()	Gets the next address in memory after this FDE record.
AddressRange	getProtectionRange()	Get the address range that contains the program instructions.
boolean	isEndOfFrame()	Determines if this FDE encountered a zero length record, which indicates the end of the frame.
int	setAugmentationDataExLength(int len)	Sets the value this region descriptor maintains to indicate the length of the augmentation data.

Methods inherited from class ghidra.app.plugin.exceptionhandlers.gcc.GccAnalysisClass

createAndCommentData, createData, init

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FrameDescriptionEntry

public FrameDescriptionEntry(TaskMonitor monitor,
                             Program program,
                             CieSource cieSource)

Constructor for a frame descriptor entry.
Note: The create(Address) method must be called after constructing a FrameDescriptionEntry to associate it with an address before any of its "get..." methods are called.

Parameters:

monitor - a status monitor for tracking progress and allowing cancelling when creating an FDE.

program - the program where this will create an FDE.

cieSource - the call frame information entry for this FDE.

Method Detail

create

public RegionDescriptor create(Address fdeBaseAddress)
                        throws MemoryAccessException,
                               ExceptionHandlerFrameException

Creates a Frame Description Entry (FDE) at the address specified.
Note: This method must get called before any of the "get..." methods.

Parameters:

fdeBaseAddress - Address where the FDE should be created.

Returns:

a region descriptor which holds information about this FDE. Otherwise, null.

Throws:

MemoryAccessException - if memory for the FDE or its associated data can't be accessed

ExceptionHandlerFrameException - if there is an error creating the FDE information.

getNextAddress

public Address getNextAddress()

Gets the next address in memory after this FDE record.

Returns:

the next address after this FDE or null if at the end of the section

isEndOfFrame

public boolean isEndOfFrame()

Determines if this FDE encountered a zero length record, which indicates the end of the frame.

Returns:

true if we are at end of frame due to encountering a zero length record.

getProtectionRange

public AddressRange getProtectionRange()

Get the address range that contains the program instructions.

Returns:

the address range

getAugmentationDataAddress

public Address getAugmentationDataAddress()

Get the address of the augmentation data in this FDE record.

Returns:

the augmentation data field's address

getAugmentationData

public byte[] getAugmentationData()

Gets the bytes which specify the FDE field that refers to the augmentation data.

Returns:

the FDE record's augmentation data.

getAugmentationExDataAddress

public Address getAugmentationExDataAddress()

Gets the start address for the call frame augmentation data.

Returns:

the address of the call frame augmentation data

setAugmentationDataExLength

public int setAugmentationDataExLength(int len)

Sets the value this region descriptor maintains to indicate the length of the augmentation data.

Parameters:

len - number of bytes that compose the augmentation data

Returns:

the length of the augmentation data or -1 if it has already been set.

getAugmentationExData

public byte[] getAugmentationExData()

Gets the call frame augmentation data that indicates how registers are saved and restored.

Returns:

the augmentation data