Exemplo n.º 1
0
        public void Load(bool UserMode)
        {
            bool OK = true;

            try
            {
                bool DynamicLinkingRequired = false;

                ThreadStartMethod mainMethod = (ThreadStartMethod)Utilities.ObjectUtilities.GetObject(theFile.Header.EntryPoint);
                theProcess = ProcessManager.CreateProcess(
                    mainMethod, theFile.TheFile.Name, UserMode);

                uint threadStackVirtAddr = (uint)((Thread)theProcess.Threads[0]).State->ThreadStackTop - 4092;
                uint threadStackPhysAddr = (uint)Hardware.VirtMemManager.GetPhysicalAddress(threadStackVirtAddr);
                ProcessManager.CurrentProcess.TheMemoryLayout.AddDataPage(threadStackPhysAddr, threadStackVirtAddr);

                // Load the ELF segments (i.e. the program code and data)
                BaseAddress = theFile.BaseAddress;
                LoadSegments(theFile, ref OK, ref DynamicLinkingRequired, BaseAddress);

                //BasicConsole.WriteLine();

                #region Relocations

                // Useful articles / specifications on Relocations:
                //      - Useful / practical explanation of various relocation types: http://eli.thegreenplace.net/2011/08/25/load-time-relocation-of-shared-libraries/#id20
                //      - Orcale : ELF Specification copy: http://docs.oracle.com/cd/E23824_01/html/819-0690/chapter6-54839.html

                if (DynamicLinkingRequired)
                {
                    Console.Default.WriteLine("Dynamic Linking");
                    BasicConsole.WriteLine("Dynamic Linking");

                    ELFDynamicSection            dynamicSection        = theFile.DynamicSection;
                    ELFDynamicSymbolTableSection dynamicSymbolsSection = theFile.DynamicSymbolsSection;

                    ELFStringTable DynamicsStringTable = new ELFStringTable(
                        dynamicSection.StrTabDynamic.Val_Ptr, dynamicSection.StrTabSizeDynamic.Val_Ptr);

                    for (uint i = 0; i < dynamicSection.Dynamics.Count; i++)
                    {
                        ELFDynamicSection.Dynamic theDyn = dynamicSection[i];

                        //BasicConsole.WriteLine("     - Dynamic : ");
                        //BasicConsole.Write("         - Tag : ");
                        //BasicConsole.WriteLine((int)theDyn.Tag);
                        //BasicConsole.Write("         - Value or Pointer : ");
                        //BasicConsole.WriteLine(theDyn.Val_Ptr);

                        if (theDyn.Tag == ELFDynamicSection.DynamicTag.Needed)
                        {
                            BasicConsole.Write("         - Needed library name : ");

                            FOS_System.String libFullPath = DynamicsStringTable[theDyn.Val_Ptr];
                            Console.Default.WriteLine(libFullPath);
                            BasicConsole.WriteLine(libFullPath);

                            FOS_System.String libFileName = (FOS_System.String)libFullPath.Split('\\').Last();
                            libFileName = (FOS_System.String)libFileName.Split('/').Last();
                            FOS_System.String libTestPath = theFile.TheFile.Parent.GetFullPath() + libFileName;
                            File sharedObjectFile         = File.Open(libTestPath);
                            if (sharedObjectFile == null)
                            {
                                Console.Default.WarningColour();
                                Console.Default.WriteLine("Failed to find needed library file!");
                                BasicConsole.WriteLine("Failed to find needed library file!");
                                Console.Default.DefaultColour();
                                OK = false;
                            }
                            else
                            {
                                Console.Default.WriteLine("Found library file. Loading library...");
                                BasicConsole.WriteLine("Found library file. Loading library...");

                                ELFSharedObject sharedObject = DynamicLinkerLoader.LoadLibrary_FromELFSO(sharedObjectFile, this);
                                SharedObjectDependencies.Add(sharedObject);

                                Console.Default.WriteLine("Library loaded.");
                                BasicConsole.WriteLine("Library loaded.");
                            }
                        }
                    }

                    Console.Default.WriteLine("Library Relocations");
                    BasicConsole.WriteLine("Library Relocations");

                    // Perform relocation / dynamic linking of all libraries
                    for (int i = 0; i < SharedObjectDependencies.Count; i++)
                    {
                        ELFSharedObject SO = (ELFSharedObject)SharedObjectDependencies[i];

                        //BasicConsole.WriteLine("Shared Object base address : " + (FOS_System.String)SO.BaseAddress);
                        //BasicConsole.WriteLine("Shared Object file base address : " + (FOS_System.String)SO.TheFile.BaseAddress);

                        List SOSections = SO.TheFile.Sections;
                        for (int j = 0; j < SOSections.Count; j++)
                        {
                            ELFSection SOSection = (ELFSection)SOSections[j];
                            if (SOSection is ELFRelocationTableSection)
                            {
                                //BasicConsole.WriteLine(" - Normal Relocation");

                                ELFRelocationTableSection relocTableSection = (ELFRelocationTableSection)SOSection;
                                ELFSymbolTableSection     symbolTable       = (ELFSymbolTableSection)SO.TheFile.Sections[relocTableSection.SymbolTableSectionIndex];
                                ELFStringTableSection     symbolNamesTable  = (ELFStringTableSection)SO.TheFile.Sections[symbolTable.StringsSectionIndex];

                                List Relocations = relocTableSection.Relocations;
                                for (int k = 0; k < Relocations.Count; k++)
                                {
                                    // Reference: http://docs.oracle.com/cd/E19683-01/817-3677/chapter6-26/index.html

                                    ELFRelocationTableSection.Relocation relocation = (ELFRelocationTableSection.Relocation)Relocations[k];
                                    if (relocation.Type == ELFRelocationTableSection.RelocationType.R_386_NONE)
                                    {
                                        continue;
                                    }

                                    uint *resolvedRelLocation               = (uint *)(SO.BaseAddress + (relocation.Offset - SO.TheFile.BaseAddress));
                                    ELFSymbolTableSection.Symbol symbol     = (ELFSymbolTableSection.Symbol)symbolTable[relocation.Symbol];
                                    FOS_System.String            symbolName = symbolNamesTable[symbol.NameIdx];

                                    //BasicConsole.WriteLine("Relocation:");
                                    ////BasicConsole.WriteLine("    > Symbol index : " + (FOS_System.String)relocation.Symbol);
                                    //BasicConsole.WriteLine("    > Type : " + (FOS_System.String)(uint)relocation.Type);
                                    //BasicConsole.WriteLine("    > Offset : " + (FOS_System.String)(uint)relocation.Offset);
                                    //BasicConsole.WriteLine(((FOS_System.String)"    > Resolved location address: ") + (uint)resolvedRelLocation);
                                    ////BasicConsole.WriteLine(((FOS_System.String)"    > Resolved location start value: ") + *resolvedRelLocation);
                                    //BasicConsole.Write("    > Symbol name : ");
                                    //BasicConsole.WriteLine(symbolName);

                                    uint newValue = 0;
                                    switch (relocation.Type)
                                    {
                                    case ELFRelocationTableSection.RelocationType.R_386_32:
                                        newValue = GetSymbolAddress(symbol, symbolName) + *resolvedRelLocation;
                                        break;

                                    case ELFRelocationTableSection.RelocationType.R_386_PC32:
                                        newValue = GetSymbolAddress(symbol, symbolName) + *resolvedRelLocation - (uint)resolvedRelLocation;
                                        break;

                                    case ELFRelocationTableSection.RelocationType.R_386_RELATIVE:
                                        newValue = SO.BaseAddress + *resolvedRelLocation;
                                        break;

                                    //TODO: Support more relocation types
                                    default:
                                        Console.Default.WarningColour();
                                        Console.Default.Write("WARNING: Unrecognised relocation type! (");
                                        Console.Default.Write_AsDecimal((uint)relocation.Type);
                                        Console.Default.WriteLine(")");
                                        Console.Default.DefaultColour();

                                        BasicConsole.Write("WARNING: Unrecognised relocation type! (");
                                        BasicConsole.Write((uint)relocation.Type);
                                        BasicConsole.WriteLine(")");
                                        break;
                                    }

                                    *resolvedRelLocation = newValue;

                                    //BasicConsole.WriteLine("    > New value: " + (FOS_System.String)(newValue));
                                    //BasicConsole.WriteLine("    > Resolved location end value: " + (FOS_System.String)(*resolvedRelLocation));
                                }
                            }
                            else if (SOSection is ELFRelocationAddendTableSection)
                            {
                                //BasicConsole.WriteLine(" - Addend Relocation");

                                ELFRelocationAddendTableSection relocTableSection = (ELFRelocationAddendTableSection)SOSection;
                                ELFSymbolTableSection           symbolTable       = (ELFSymbolTableSection)SO.TheFile.Sections[relocTableSection.SymbolTableSectionIndex];
                                ELFStringTableSection           symbolNamesTable  = (ELFStringTableSection)SO.TheFile.Sections[symbolTable.StringsSectionIndex];

                                List Relocations = relocTableSection.Relocations;
                                for (int k = 0; k < Relocations.Count; k++)
                                {
                                    ELFRelocationAddendTableSection.RelocationAddend relocation = (ELFRelocationAddendTableSection.RelocationAddend)Relocations[k];
                                    if (relocation.Type == ELFRelocationTableSection.RelocationType.R_386_NONE)
                                    {
                                        continue;
                                    }

                                    ELFSymbolTableSection.Symbol symbol     = (ELFSymbolTableSection.Symbol)symbolTable[relocation.Symbol];
                                    FOS_System.String            symbolName = symbolNamesTable[symbol.NameIdx];
                                    uint *resolvedRelLocation = (uint *)(SO.BaseAddress + (relocation.Offset - SO.TheFile.BaseAddress));

                                    //BasicConsole.WriteLine("Relocation:");
                                    ////BasicConsole.WriteLine("    > Symbol index : " + (FOS_System.String)relocation.Symbol);
                                    //BasicConsole.WriteLine("    > Type : " + (FOS_System.String)(uint)relocation.Type);
                                    //BasicConsole.WriteLine("    > Offset : " + (FOS_System.String)(uint)relocation.Offset);
                                    //BasicConsole.WriteLine(((FOS_System.String)"    > Resolved location address: ") + (uint)resolvedRelLocation);
                                    ////BasicConsole.WriteLine(((FOS_System.String)"    > Resolved location start value: ") + *resolvedRelLocation);
                                    //BasicConsole.Write("    > Symbol name : ");
                                    //BasicConsole.WriteLine(symbolName);

                                    uint newValue = 0;
                                    switch (relocation.Type)
                                    {
                                    //TODO: Support more relocation types
                                    default:
                                        Console.Default.WarningColour();
                                        Console.Default.Write("WARNING: Unrecognised relocation type! (");
                                        Console.Default.Write_AsDecimal((uint)relocation.Type);
                                        Console.Default.WriteLine(")");
                                        Console.Default.DefaultColour();

                                        BasicConsole.Write("WARNING: Unrecognised relocation type! (");
                                        BasicConsole.Write((uint)relocation.Type);
                                        BasicConsole.WriteLine(")");
                                        break;
                                    }

                                    *resolvedRelLocation = newValue;

                                    //BasicConsole.WriteLine("    > New value: " + (FOS_System.String)(newValue));
                                    //BasicConsole.WriteLine("    > Resolved location end value: " + (FOS_System.String)(*resolvedRelLocation));
                                }
                            }
                        }
                    }

                    Console.Default.WriteLine("Executable Relocations");
                    BasicConsole.WriteLine("Executable Relocations");

                    //BasicConsole.WriteLine("Executable base address : " + (FOS_System.String)BaseAddress);
                    //BasicConsole.WriteLine("Executable file base address : " + (FOS_System.String)theFile.BaseAddress);

                    // Perform dynamic linking of executable
                    List ExeSections = theFile.Sections;
                    for (int j = 0; j < ExeSections.Count; j++)
                    {
                        ELFSection ExeSection = (ELFSection)ExeSections[j];
                        if (ExeSection is ELFRelocationTableSection)
                        {
                            //BasicConsole.WriteLine(" - Normal Relocations");

                            ELFRelocationTableSection relocTableSection = (ELFRelocationTableSection)ExeSection;
                            ELFSymbolTableSection     symbolTable       = (ELFSymbolTableSection)theFile.Sections[relocTableSection.SymbolTableSectionIndex];
                            ELFStringTableSection     symbolNamesTable  = (ELFStringTableSection)theFile.Sections[symbolTable.StringsSectionIndex];

                            List Relocations = relocTableSection.Relocations;
                            for (int k = 0; k < Relocations.Count; k++)
                            {
                                ELFRelocationTableSection.Relocation relocation = (ELFRelocationTableSection.Relocation)Relocations[k];
                                if (relocation.Type == ELFRelocationTableSection.RelocationType.R_386_NONE)
                                {
                                    continue;
                                }

                                uint *resolvedRelLocation               = (uint *)(BaseAddress + (relocation.Offset - theFile.BaseAddress));
                                ELFSymbolTableSection.Symbol symbol     = (ELFSymbolTableSection.Symbol)symbolTable[relocation.Symbol];
                                FOS_System.String            symbolName = symbolNamesTable[symbol.NameIdx];

                                //BasicConsole.WriteLine("Relocation:");
                                ////BasicConsole.WriteLine("    > Symbol index : " + (FOS_System.String)relocation.Symbol);
                                //BasicConsole.WriteLine("    > Type : " + (FOS_System.String)(uint)relocation.Type);
                                //BasicConsole.WriteLine("    > Offset : " + (FOS_System.String)(uint)relocation.Offset);
                                //BasicConsole.WriteLine(((FOS_System.String)"    > Resolved location address: ") + (uint)resolvedRelLocation);
                                ////BasicConsole.WriteLine(((FOS_System.String)"    > Resolved location start value: ") + *resolvedRelLocation);
                                //BasicConsole.Write("    > Symbol name : ");
                                //BasicConsole.WriteLine(symbolName);

                                bool setFromNewValue = true;
                                uint newValue        = 0;
                                switch (relocation.Type)
                                {
                                //TODO: Support more relocation types
                                case ELFRelocationTableSection.RelocationType.R_386_JMP_SLOT:
                                    newValue = GetSymbolAddress(symbol, symbolName);
                                    break;

                                case ELFRelocationTableSection.RelocationType.R_386_COPY:
                                    // Created by the link-editor for dynamic executables to preserve a read-only text segment.
                                    // Its offset member refers to a location in a writable segment. The symbol table index
                                    // specifies a symbol that should exist both in the current object file and in a shared object.
                                    // During execution, the runtime linker copies data associated with the shared object's symbol
                                    // to the location specified by the offset.
                                    // See Copy Relocations:
                                    //      http://docs.oracle.com/cd/E19683-01/817-3677/6mj8mbtbs/index.html#chapter4-84604

                                    setFromNewValue = false;
                                    uint symbolAddress = 0;
                                    uint symbolSize    = 0;

                                    if (GetSymbolAddressAndSize(symbol, symbolName, ref symbolAddress, ref symbolSize))
                                    {
                                        byte *symbolValuePtr = (byte *)symbolAddress;

                                        //BasicConsole.Write("    > Symbol size : ");
                                        //BasicConsole.WriteLine(symbolSize);

                                        for (int i = 0; i < symbolSize; i++)
                                        {
                                            resolvedRelLocation[i] = symbolValuePtr[i];
                                        }
                                    }
                                    else
                                    {
                                        BasicConsole.WriteLine("Failed to get symbol address and size for R_386_COPY relocation!");
                                    }
                                    break;

                                default:
                                    Console.Default.WarningColour();
                                    Console.Default.Write("WARNING: Unrecognised relocation type! (");
                                    Console.Default.Write_AsDecimal((uint)relocation.Type);
                                    Console.Default.WriteLine(")");
                                    Console.Default.DefaultColour();

                                    BasicConsole.Write("WARNING: Unrecognised relocation type! (");
                                    BasicConsole.Write((uint)relocation.Type);
                                    BasicConsole.WriteLine(")");
                                    break;
                                }
                                if (setFromNewValue)
                                {
                                    *resolvedRelLocation = newValue;
                                    //BasicConsole.WriteLine("    > New value: " + (FOS_System.String)(newValue));
                                    //BasicConsole.WriteLine("    > Resolved location end value: " + (FOS_System.String)(*resolvedRelLocation));
                                }
                            }
                        }
                        else if (ExeSection is ELFRelocationAddendTableSection)
                        {
                            //BasicConsole.WriteLine(" - Addend Relocations");

                            ELFRelocationAddendTableSection relocTableSection = (ELFRelocationAddendTableSection)ExeSection;
                            ELFSymbolTableSection           symbolTable       = (ELFSymbolTableSection)theFile.Sections[relocTableSection.SymbolTableSectionIndex];
                            ELFStringTableSection           symbolNamesTable  = (ELFStringTableSection)theFile.Sections[symbolTable.StringsSectionIndex];

                            List Relocations = relocTableSection.Relocations;
                            for (int k = 0; k < Relocations.Count; k++)
                            {
                                ELFRelocationAddendTableSection.RelocationAddend relocation = (ELFRelocationAddendTableSection.RelocationAddend)Relocations[k];
                                if (relocation.Type == ELFRelocationTableSection.RelocationType.R_386_NONE)
                                {
                                    continue;
                                }

                                uint *resolvedRelLocation               = (uint *)(BaseAddress + (relocation.Offset - theFile.BaseAddress));
                                ELFSymbolTableSection.Symbol symbol     = (ELFSymbolTableSection.Symbol)symbolTable[relocation.Symbol];
                                FOS_System.String            symbolName = symbolNamesTable[symbol.NameIdx];

                                //BasicConsole.WriteLine("Relocation:");
                                ////BasicConsole.WriteLine("    > Symbol index : " + (FOS_System.String)relocation.Symbol);
                                //BasicConsole.WriteLine("    > Type : " + (FOS_System.String)(uint)relocation.Type);
                                //BasicConsole.WriteLine("    > Offset : " + (FOS_System.String)(uint)relocation.Offset);
                                //BasicConsole.WriteLine(((FOS_System.String)"    > Resolved location address: ") + (uint)resolvedRelLocation);
                                ////BasicConsole.WriteLine(((FOS_System.String)"    > Resolved location start value: ") + *resolvedRelLocation);
                                //BasicConsole.Write("    > Symbol name : ");
                                //BasicConsole.WriteLine(symbolName);

                                uint newValue = 0;
                                switch (relocation.Type)
                                {
                                //TODO: Support more relocation types
                                default:
                                    Console.Default.WarningColour();
                                    Console.Default.Write("WARNING: Unrecognised relocation type! (");
                                    Console.Default.Write_AsDecimal((uint)relocation.Type);
                                    Console.Default.WriteLine(")");
                                    Console.Default.DefaultColour();

                                    BasicConsole.Write("WARNING: Unrecognised relocation type! (");
                                    BasicConsole.Write((uint)relocation.Type);
                                    BasicConsole.WriteLine(")");
                                    break;
                                }
                                *resolvedRelLocation = newValue;
                                //BasicConsole.WriteLine("    > New value: " + (FOS_System.String)(newValue));
                                //BasicConsole.WriteLine("    > Resolved location end value: " + (FOS_System.String)(*resolvedRelLocation));
                            }
                        }
                    }

                    // TODO: Call Init functions of libraries
                }

                // Unmap processes' memory from current processes' memory
                for (int i = 0; i < SharedObjectDependencies.Count; i++)
                {
                    ELFSharedObject SO = (ELFSharedObject)SharedObjectDependencies[i];
                    uint            FileBaseAddress = SO.TheFile.BaseAddress;
                    uint            MemBaseAddress  = SO.BaseAddress;

                    List SOSegments = SO.TheFile.Segments;
                    for (int j = 0; j < SOSegments.Count; j++)
                    {
                        ELFSegment SOSegment = (ELFSegment)SOSegments[j];
                        ProcessManager.CurrentProcess.TheMemoryLayout.RemovePage(
                            (MemBaseAddress + ((uint)SOSegment.Header.VAddr - FileBaseAddress)) & 0xFFFFF000);
                    }
                }
                {
                    uint FileBaseAddress = theFile.BaseAddress;
                    uint MemBaseAddress  = BaseAddress;

                    List ExeSegments = theFile.Segments;
                    for (int j = 0; j < ExeSegments.Count; j++)
                    {
                        ELFSegment ExeSegment = (ELFSegment)ExeSegments[j];
                        ProcessManager.CurrentProcess.TheMemoryLayout.RemovePage(
                            (MemBaseAddress + ((uint)ExeSegment.Header.VAddr - FileBaseAddress)) & 0xFFFFF000);
                    }
                }

                #endregion

                ProcessManager.CurrentProcess.TheMemoryLayout.RemovePage(threadStackVirtAddr);
            }
            finally
            {
                if (!OK)
                {
                    theProcess = null;
                }
            }
        }
Exemplo n.º 2
0
        public bool GetSymbolAddressAndSize(ELFDynamicSymbolTableSection.Symbol theSymbol, FOS_System.String theSymbolName, ref uint address, ref uint size)
        {
            //BasicConsole.WriteLine("Searching for symbol...");
            //BasicConsole.Write("     - Name : ");
            //BasicConsole.WriteLine(theSymbolName);

            //BasicConsole.WriteLine("     Searching executable's symbols...");
            for (int i = 0; i < theFile.Sections.Count; i++)
            {
                ELFSection aSection = (ELFSection)theFile.Sections[i];
                if (aSection is ELFSymbolTableSection)
                {
                    ELFSymbolTableSection symTabSection = (ELFSymbolTableSection)aSection;
                    ELFStringTableSection strTabSection = (ELFStringTableSection)theFile.Sections[symTabSection.StringsSectionIndex];

                    for (int j = 0; j < symTabSection.Symbols.Count; j++)
                    {
                        ELFSymbolTableSection.Symbol aSymbol = (ELFSymbolTableSection.Symbol)symTabSection.Symbols[j];

                        if (aSymbol.Type == theSymbol.Type &&
                            aSymbol.Binding == ELFSymbolTableSection.SymbolBinding.Global &&
                            aSymbol.SectionIndex > 0)
                        {
                            if (strTabSection.IsMatch(aSymbol.NameIdx, theSymbolName))
                            {
                                //BasicConsole.WriteLine("     Found symbol.");
                                //BasicConsole.Write("     aSymbol Address : ");
                                uint result = ((uint)aSymbol.Value - theFile.BaseAddress) + BaseAddress;
                                //BasicConsole.WriteLine(result);

                                address = result;
                                size    = aSymbol.Size;
                                return(true);
                            }
                        }
                    }
                }
            }
            for (int k = 0; k < SharedObjectDependencies.Count; k++)
            {
                //BasicConsole.WriteLine("     Searching shared object's symbols...");

                ELFSharedObject SO = (ELFSharedObject)SharedObjectDependencies[k];
                for (int i = 0; i < SO.TheFile.Sections.Count; i++)
                {
                    ELFSection aSection = (ELFSection)SO.TheFile.Sections[i];
                    if (aSection is ELFSymbolTableSection)
                    {
                        ELFSymbolTableSection symTabSection = (ELFSymbolTableSection)aSection;
                        ELFStringTableSection strTabSection = (ELFStringTableSection)SO.TheFile.Sections[symTabSection.StringsSectionIndex];
                        for (int j = 0; j < symTabSection.Symbols.Count; j++)
                        {
                            ELFSymbolTableSection.Symbol aSymbol = (ELFSymbolTableSection.Symbol)symTabSection.Symbols[j];
                            if (aSymbol.Type == theSymbol.Type &&
                                aSymbol.Binding == ELFSymbolTableSection.SymbolBinding.Global &&
                                aSymbol.SectionIndex > 0)
                            {
                                if (strTabSection.IsMatch(aSymbol.NameIdx, theSymbolName))
                                {
                                    //BasicConsole.WriteLine("     Found symbol.");
                                    //BasicConsole.Write("     aSymbol Address : ");
                                    uint result = ((uint)aSymbol.Value - SO.TheFile.BaseAddress) + SO.BaseAddress;
                                    //BasicConsole.WriteLine(result);

                                    address = result;
                                    size    = aSymbol.Size;
                                    return(true);
                                }
                            }
                        }
                    }
                }
            }

            return(false);
        }