Module openj9.dtfj

Package com.ibm.j9ddr.corereaders.elf.unwind

Class Unwind

java.lang.Object

com.ibm.j9ddr.corereaders.elf.unwind.Unwind

public class Unwind
extends Object

Class for parsing the unwind information from a .eh_frame header It creates a list of FDE's (Frame Description Entry) objects and the associated CIE's (Common Information Entry) for the process when created. It can then be used to get the unwind table for a given instruction address. The table can then be applied to the current register state to create the previous register state (or at least the register state that matters for further unwinding.) See: http://refspecs.linuxfoundation.org/LSB_3.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	Unwind.DW_EH_PE

Constructor Summary

Constructors

Constructor	Description
Unwind(LinuxProcessAddressSpace _process)	Create an unwinder for a process. eh_frame information is added later when the program header entries containing it are found.

Method Summary

Modifier and Type	Method	Description
void	addCallFrameInformation(long libraryBaseAddress, ProgramHeaderEntry ph, String libName)
UnwindTable	getUnwindTableForInstructionAddress(long instructionPointer)
static long	readSignedLEB128(ImageInputStream cfiStream)
static long	readUnsignedLEB128(ImageInputStream cfiStream)

Methods declared in class java.lang.Object

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

Constructor Details

Unwind

public Unwind(LinuxProcessAddressSpace _process)

Create an unwinder for a process. eh_frame information is added later when the program header entries containing it are found.

Parameters:

_process - The process the unwinder will work with.

Method Details

addCallFrameInformation

public void addCallFrameInformation(long libraryBaseAddress,
 ProgramHeaderEntry ph,
 String libName)
                             throws CorruptDataException,
IOException

Throws:

CorruptDataException

IOException

readUnsignedLEB128

public static long readUnsignedLEB128(ImageInputStream cfiStream)
                               throws IOException

Throws:

IOException

readSignedLEB128

public static long readSignedLEB128(ImageInputStream cfiStream)
                             throws IOException

Throws:

IOException

getUnwindTableForInstructionAddress

public UnwindTable getUnwindTableForInstructionAddress(long instructionPointer)
                                                throws CorruptDataException,
IOException

Throws:

CorruptDataException

IOException