internal static VTableFixupEntry Load(IBinaryAccessor accessor, PEImage pe)
{
var fixup = new VTableFixupEntry();
// In this definition, RVA points to the location of the v-table slot containing the method token(s).
uint rva = accessor.ReadUInt32();
// Indicating the number of v-table slots grouped into one entry because their flags are identical.
// This grouping has no effect other than saving some space�you can emit a single slot per entry,
// but then you�ll have to emit as many v-table fixups as there are slots.
int count = accessor.ReadUInt16();
fixup._type = (VTableFixupType)accessor.ReadUInt16();
bool is32Bits = ((fixup.Type & VTableFixupType.SlotSize32Bit) == VTableFixupType.SlotSize32Bit);
// Save position
long position = accessor.Position;
accessor.Position = pe.ResolvePositionToSectionData(rva);
for (int i = 0; i < count; i++)
{
fixup._list.Add(accessor.ReadInt32());
if (!is32Bits)
{
accessor.ReadUInt32();
}
}
// Restore position
accessor.Position = position;
return(fixup);
}
private void BuildAMD64(BuildEntry entry)
{
int methodRID = _state.MethodDefHash.IndexOf(entry.MethodSignature) + 1;
// Add fixup entry
var fixup = new VTableFixupEntry();
fixup.Type = VTableFixupType.SlotSize64Bit | VTableFixupType.FromUnmanaged;
fixup.Add(MetadataToken.Get(MetadataTokenType.Method, methodRID));
_state.VTableFixupTable.Add(fixup);
int pos = _codeBlob.Length;
if (pos > 0)
{
pos = pos.Align(0x10);
}
PE.Fixups.Add(new AMD64Fixup(_codeBlob, pos, fixup));
// rex.w rex.b mov rax,[following address]
_state.ExportTable.AddRVAEntry(entry.MethodName, _codeBlob, pos);
_codeBlob.Write(ref pos, new byte[] { 0x48, 0xA1 });
// VA of method (through VTable)
_state.RelocTable.Add(_codeBlob, pos, BaseRelocationType.DIR64);
_codeBlob.Write(ref pos, (ulong)0);
// jmp [rax]
_codeBlob.Write(ref pos, new byte[] { 0xFF, 0xE0 });
}
private void BuildX86(BuildEntry entry)
{
int methodRID = _state.MethodDefHash.IndexOf(entry.MethodSignature) + 1;
// Add fixup entry
var fixup = new VTableFixupEntry();
fixup.Type = VTableFixupType.SlotSize32Bit | VTableFixupType.FromUnmanaged;
fixup.Add(MetadataToken.Get(MetadataTokenType.Method, methodRID));
_state.VTableFixupTable.Add(fixup);
int pos = _codeBlob.Length;
if (pos > 0)
{
pos = pos.Align(0x10);
}
PE.Fixups.Add(new X86Fixup(_codeBlob, pos, fixup));
// jmp
_state.ExportTable.AddRVAEntry(entry.MethodName, _codeBlob, pos);
_codeBlob.Write(ref pos, new byte[] { 0xFF, 0x25 });
// VA of method (through VTable)
_state.RelocTable.Add(_codeBlob, pos, BaseRelocationType.HIGHLOW);
_codeBlob.Write(ref pos, (uint)0);
}
public VTableFixupEntry Clone()
{
var copy = new VTableFixupEntry();
CopyTo(copy);
return(copy);
}
protected void CopyTo(VTableFixupEntry copy)
{
copy._type = _type;
foreach (var childNode in _list)
{
copy._list.Add(childNode);
}
}
public int GetFixupOffset(VTableFixupEntry searchFixup)
{
int offset = 0;
foreach (var fixup in _table)
{
if (object.ReferenceEquals(fixup, searchFixup))
{
return(offset);
}
int size = ((fixup.Type & VTableFixupType.SlotSize32Bit) == VTableFixupType.SlotSize32Bit) ? 4 : 8;
offset += (fixup.Count * size);
}
throw new InvalidOperationException();
}
private void BuildIA64(BuildEntry entry)
{
int methodRID = _state.MethodDefHash.IndexOf(entry.MethodSignature) + 1;
// Add fixup entry
var fixup = new VTableFixupEntry();
fixup.Type = VTableFixupType.SlotSize64Bit | VTableFixupType.FromUnmanaged;
fixup.Add(MetadataToken.Get(MetadataTokenType.Method, methodRID));
_state.VTableFixupTable.Add(fixup);
int pos = _codeBlob.Length;
if (pos > 0)
{
pos = pos.Align(0x10);
}
PE.Fixups.Add(new IA64Fixup(_codeBlob, pos, fixup));
// IA64 stub
// ld8 r9 = [gp] ;;
// ld8 r10 = [r9],8
// nop.i ;;
// ld8 gp = [r9]
// mov b6 = r10
// br.cond.sptk.few b6
_codeBlob.Write(ref pos,
new byte[]
{
0x0B, 0x48, 0x00, 0x02, 0x18, 0x10, 0xA0, 0x40,
0x24, 0x30, 0x28, 0x00, 0x00, 0x00, 0x04, 0x00,
0x10, 0x08, 0x00, 0x12, 0x18, 0x10, 0x60, 0x50,
0x04, 0x80, 0x03, 0x00, 0x60, 0x00, 0x80, 0x00,
});
// VA of IA64 stub
_state.ExportTable.AddRVAEntry(entry.MethodName, _codeBlob, pos);
_state.RelocTable.Add(_codeBlob, pos, BaseRelocationType.DIR64);
_codeBlob.Write(ref pos, (ulong)0);
// VA of method (through VTable)
_state.RelocTable.Add(_codeBlob, pos, BaseRelocationType.DIR64);
_codeBlob.Write(ref pos, (ulong)0);
}
public AMD64Fixup(BuildBlob codeBlob, int codeBlobPos, VTableFixupEntry fixup)
{
_codeBlob = codeBlob;
_codeBlobPos = codeBlobPos;
_fixup = fixup;
}
