public ElfLoader(string moduleName, byte[] fileData, ulong assumedStart, bool skipCoreConsistencyCheck, bool skipMemoryConsistencyCheck)
{
ModuleName = moduleName;
_skipCoreConsistencyCheck = skipCoreConsistencyCheck;
_skipMemoryConsistencyCheck = skipMemoryConsistencyCheck;
_elfHash = WaterboxUtils.Hash(fileData);
_elf = ELFReader.Load <ulong>(new MemoryStream(fileData, false), true);
var loadsegs = _elf.Segments.Where(s => s.Type == SegmentType.Load);
var start = loadsegs.Min(s => s.Address);
start = WaterboxUtils.AlignDown(start);
var end = loadsegs.Max(s => s.Address + s.Size);
end = WaterboxUtils.AlignUp(end);
var size = end - start;
if (start != assumedStart)
{
throw new InvalidOperationException($"{nameof(assumedStart)} did not match actual origin in elf file");
}
if (_elf.Sections.Any(s => s.Name.StartsWith(".rel")))
{
throw new InvalidOperationException("Elf has relocations!");
}
_allSymbols = ((ISymbolTable)_elf.GetSection(".symtab"))
.Entries
.Cast <SymbolEntry <ulong> >()
.ToList();
_sectionsByName = _elf.Sections
.ToDictionary(s => s.Name);
_sectionsByName.TryGetValue(".wbxsyscall", out _imports);
if (_imports == null)
{
// Likely cause: This is a valid elf file, but it was not compiled by our toolchain at all
throw new InvalidOperationException("Missing .wbxsyscall section!");
}
_sectionsByName.TryGetValue(".sealed", out _sealed);
_sectionsByName.TryGetValue(".invis", out _invisible);
_visibleSymbols = _allSymbols
.Where(s => s.Binding == SymbolBinding.Global && s.Visibility == SymbolVisibility.Default)
.ToDictionary(s => s.Name);
_importSymbols = _allSymbols
// TODO: No matter what attributes I provide, I seem to end up with Local and/or Hidden symbols in
// .wbxsyscall a lot of the time on heavily optimized release builds.
// Fortunately, there's nothing else in .wbxsyscall so we can just not filter at all.
.Where(s => s.PointedSection == _imports)
.ToList();
Memory = MemoryBlock.Create(start, size);
Memory.Activate();
Memory.Protect(Memory.Start, Memory.Size, MemoryBlock.Protection.RW);
foreach (var seg in loadsegs)
{
var data = seg.GetFileContents();
Marshal.Copy(data, 0, Z.US(seg.Address), Math.Min((int)seg.Size, (int)seg.FileSize));
}
{
// Compute RW boundaries
var allocated = _elf.Sections
.Where(s => (s.Flags & SectionFlags.Allocatable) != 0);
var writable = allocated
.Where(s => (s.Flags & SectionFlags.Writable) != 0);
var postSealWritable = writable
.Where(s => !IsSpecialReadonlySection(s));
var saveable = postSealWritable
.Where(s => s != _invisible);
var executable = allocated
.Where(s => (s.Flags & SectionFlags.Executable) != 0);
_writeStart = WaterboxUtils.AlignDown(writable.Min(s => s.LoadAddress));
_postSealWriteStart = WaterboxUtils.AlignDown(postSealWritable.Min(s => s.LoadAddress));
_execEnd = WaterboxUtils.AlignUp(executable.Max(s => s.LoadAddress + s.Size));
// validate; this may require linkscript cooperation
// due to the segment limitations, the only thing we'd expect to catch is a custom eventually readonly section
// in the wrong place (because the linkscript doesn't know "eventually readonly")
if (_execEnd > _writeStart)
{
throw new InvalidOperationException($"ElfLoader: Executable data to {_execEnd:X16} overlaps writable data from {_writeStart}");
}
}
PrintSections();
PrintGdbData();
PrintTopSavableSymbols();
Protect();
}