private void memindex_emit(BinaryWriter writer, Byte r, X86Register32 basereg, Int32 disp, X86Register32 indexreg, Byte shift)
{
if (basereg == X86Register32.None)
{
address_byte(writer, 0, (byte)r, 4);
address_byte(writer, (byte)shift, (byte)indexreg, 5);
writer.Write((Int32)disp);
}
else if (disp == 0 && basereg == X86Register32.EBP)
{
address_byte(writer, 0, (byte)r, 4);
address_byte(writer, (byte)shift, (byte)indexreg, (byte)basereg);
}
else if (X86Writer.is_imm8(disp))
{
address_byte(writer, 1, (byte)r, 4);
address_byte(writer, (byte)shift, (byte)indexreg, (byte)basereg);
writer.Write((Byte)disp);
}
else
{
address_byte(writer, 2, (byte)r, 4);
address_byte(writer, (byte)shift, (byte)indexreg, 5);
writer.Write((Int32)disp);
}
}
private void membase_emit(BinaryWriter writer, Byte r, X86Register32 basereg, Int32 disp)
{
do
{
if ((basereg) == X86Register32.ESP)
{
if ((disp) == 0)
{
address_byte(writer, 0, (byte)r, (byte)X86Register32.ESP);
address_byte(writer, 0, (byte)X86Register32.ESP, (byte)X86Register32.ESP);
}
else if (X86Writer.is_imm8(disp))
{
address_byte(writer, 1, (byte)r, (byte)X86Register32.ESP);
address_byte(writer, 0, (byte)X86Register32.ESP, (byte)X86Register32.ESP);
writer.Write((byte)(disp));
}
else
{
address_byte(writer, 2, (byte)r, (byte)X86Register32.ESP);
address_byte(writer, 0, (byte)X86Register32.ESP, (byte)X86Register32.ESP);
writer.Write(disp);
}
break;
}
else if (disp == 0 && basereg != X86Register32.EBP)
{
address_byte(writer, 0, (byte)r, (byte)basereg);
}
else if (X86Writer.is_imm8(disp))
{
address_byte(writer, 1, (byte)r, (byte)basereg);
writer.Write((byte)(disp));
}
else
{
address_byte(writer, 2, (byte)r, (byte)basereg);
writer.Write(disp);
}
} while (false);
}
internal X86Label(X86Writer writer, IntPtr position)
: this(writer) {
mark = position;
}
internal X86Label(X86Writer writer) {
this.writer = writer;
}
internal X86Label(X86Writer writer, IntPtr position)
: this(writer) {
mark = position;
}
internal X86Label(X86Writer writer)
{
this.writer = writer;
}
unsafe static public MemoryPatch Patch(IntPtr target, Action action)
{
int size = 8;
var mr = GetPermissions(target);
if (mr != null) {
MemoryProtection(target, size, mprot.Read|mprot.Write);
var ums = new UnmanagedMemoryStream((byte *)target, 0, size, FileAccess.ReadWrite);
byte[] unpatched = new byte[size];
ums.Read(unpatched, 0, size);
ums.Seek(0, SeekOrigin.Begin);
var writer = new X86Writer(ums, (IntPtr)size);
writer.Mov32(X86Register32.EAX, Marshal.GetFunctionPointerForDelegate(action).ToInt32());
writer.Jmp(X86Register32.EAX);
ums.Seek(0, SeekOrigin.Begin);
byte[] patched = new byte[size];
ums.Read(patched, 0, size);
return new MemoryPatch(target, action, patched, unpatched);
} else {
throw new Exception();
}
}