protected override nint AllocateChunk(nint hint)
{
while (true)
{
var mbi = new WinApi.MEMORY_BASIC_INFORMATION();
if (WinApi.VirtualQuery(hint, ref mbi, Marshal.SizeOf <WinApi.MEMORY_BASIC_INFORMATION>()) == 0)
{
Logger.Log(LogLevel.Debug,
$"Skipping analysing 0x{(long) hint:X8} because VirtualQuery failed: {Win32Error()}");
goto next;
}
if (mbi.State == WinApi.PageState.MEM_FREE)
{
var nextAddress = RoundUp(mbi.BaseAddress, ALLOCATION_UNIT);
var d = nextAddress - mbi.BaseAddress;
if (d >= 0 && mbi.RegionSize - d >= ALLOCATION_UNIT)
{
hint = nextAddress;
break;
}
}
next:
hint = mbi.BaseAddress + mbi.RegionSize;
}
var chunk = WinApi.VirtualAlloc(hint, ALLOCATION_UNIT, WinApi.AllocationType.MEM_RESERVE,
WinApi.ProtectConstant.PAGE_NOACCESS);
if (chunk == 0)
{
throw Win32Error($"Failed to reserve address: 0x{(long) hint:X8}");
}
var addr = WinApi.VirtualAlloc(chunk, PAGE_SIZE, WinApi.AllocationType.MEM_COMMIT,
WinApi.ProtectConstant.PAGE_READWRITE);
if (addr == 0)
{
var error = Marshal.GetLastWin32Error();
WinApi.VirtualFree(chunk, 0, WinApi.FreeType.MEM_RELEASE);
throw
Win32Error($"Failed to commit memory 0x{(long) addr:X8} for read-write access for 0x{(long) chunk:X8}",
error);
}
return(chunk);
}
public static extern int VirtualQueryEx(IntPtr hProcess, IntPtr lpAddress, out MEMORY_BASIC_INFORMATION lpBuffer, uint dwLength);