internal static Pointer Allocate(int count, bool @protected = false)
{
if (!@protected)
{
return(new Pointer((byte *)Marshal.AllocHGlobal(count), count));
}
const ProtectedMemoryMode mode = ProtectedMemoryMode.Executable | ProtectedMemoryMode.Writable;
// VirtualAlloc rounds allocated size to a page size automatically.
var size = count.AlignTo(_pageSize);
// Windows XP SP2 / Vista allow Data Excution Prevention (DEP).
Win32.MemoryProtectionType protectFlags = 0;
if (mode.IsSet(ProtectedMemoryMode.Executable))
{
protectFlags |= mode.IsSet(ProtectedMemoryMode.Writable) ? Win32.MemoryProtectionType.ExecuteReadWrite : Win32.MemoryProtectionType.ExecuteRead;
}
else
{
protectFlags |= mode.IsSet(ProtectedMemoryMode.Writable) ? Win32.MemoryProtectionType.ReadWrite : Win32.MemoryProtectionType.ReadOnly;
}
var @base = Win32.NativeMethods.VirtualAlloc(IntPtr.Zero, (UIntPtr)size, Win32.VirtualAllocType.Commit | Win32.VirtualAllocType.Reserve, protectFlags);
if (@base.IsInvalid)
{
return(Pointer.Invalid);
}
var handle = @base.DangerousGetHandle();
return(new Pointer(handle, count, PointerFlags.Aligned | PointerFlags.Protected));
}
internal static Pointer Allocate(int count, bool @protected = false)
{
if (!@protected)
{
// Console.WriteLine("allocated unprotected");
return(new Pointer((byte *)Marshal.AllocHGlobal(count), null, count));
}
const ProtectedMemoryMode mode = ProtectedMemoryMode.Executable | ProtectedMemoryMode.Writable;
// VirtualAlloc rounds allocated size to a page size automatically.
var size = count.AlignTo(_pageSize);
// Windows XP SP2 / Vista allow Data Excution Prevention (DEP).
Win32.MemoryProtectionType protectFlags = 0;
if (mode.IsSet(ProtectedMemoryMode.Executable))
{
protectFlags |= mode.IsSet(ProtectedMemoryMode.Writable) ? Win32.MemoryProtectionType.ExecuteReadWrite : Win32.MemoryProtectionType.ExecuteRead;
}
else
{
protectFlags |= mode.IsSet(ProtectedMemoryMode.Writable) ? Win32.MemoryProtectionType.ReadWrite : Win32.MemoryProtectionType.ReadOnly;
}
var @base = Win32.NativeMethods.VirtualAlloc(IntPtr.Zero, (UIntPtr)size, Win32.VirtualAllocType.Commit | Win32.VirtualAllocType.Reserve, protectFlags);
if (@base.IsInvalid)
{
return(Pointer.Invalid);
}
var handle = @base.DangerousGetHandle();
/*
* Console.WriteLine($"Testing write to memory at 0x{(ulong) handle:X} up to {size}");
* Marshal.WriteInt32(handle + 0x26, 0);
* for (var i = 0; i < size; i++) {
* //Console.WriteLine($"Testing write to memory at 0x{(ulong)(handle + i):X}");
* Marshal.WriteByte(handle + i, 0);
* }
*/
Win32.MemoryProtectionType oldProtectFlags;
Action unprotectIt = () => Win32.NativeMethods.VirtualProtect(handle, (UIntPtr)size, protectFlags, out oldProtectFlags);
return(new Pointer(handle, unprotectIt, count, PointerFlags.Aligned | PointerFlags.Protected));
}
