waterbox: Add special handling for imports in XorStates. Fix a few other instances where managed pointers were leaking out into XorStates

BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.cs

@@ -123,6 +123,15 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx64
 					Region = VsyncNumerator / VsyncDenominator > 55 ? DisplayType.NTSC : DisplayType.PAL;
 				}
 
+				// when we call Seal, ANY pointer passed from managed code must be 0.
+				// this is so the initial state is clean
+				// the only two pointers set so far are LoadCallback, which the core zeroed itself,
+				// and CdCallback
+				Core.gpgx_set_cdd_callback(null);
+				_elf.Seal();
+				Core.gpgx_set_cdd_callback(cd_callback_handle);
+
+
 				// compute state size
 				InitStateBuffers();
 
@@ -150,8 +159,6 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx64
 
 				Tracer = new GPGXTraceBuffer(this, MemoryDomains, this);
 				(ServiceProvider as BasicServiceProvider).Register<ITraceable>(Tracer);
-
-				_elf.Seal();
 			}
 			catch
 			{

BizHawk.Emulation.Cores/Waterbox/PeRunner.cs

@@ -155,6 +155,11 @@ namespace BizHawk.Emulation.Cores.Waterbox
 				context.SyscallVtable = _syscallVtable = AllocVtable(340);
 				context.LdsoVtable = _ldsoVtable = AllocVtable(7);
 				context.PsxVtable = _psxVtable = AllocVtable(5);
+				// ctx comes from the native stack, where it could have any garbage in uninited fields
+				context.SysIdx = 0;
+				context.LibcIdx = 0;
+				context.DoGlobalCtors = IntPtr.Zero;
+				context.DoGlobalDtors = IntPtr.Zero;
 
 				ReloadVtables();
 
@@ -382,7 +387,7 @@ namespace BizHawk.Emulation.Cores.Waterbox
 			}
 
 			[BizExport(CallingConvention.Cdecl, EntryPoint = "n228")]
-			public int SysClockGetTime(int which, [In,Out] TimeSpec time)
+			public int SysClockGetTime(int which, [In, Out] TimeSpec time)
 			{
 				time.Seconds = 1495889068;
 				time.NanoSeconds = 0;
@@ -670,9 +675,14 @@ namespace BizHawk.Emulation.Cores.Waterbox
 			{
 				_sealedheap.Seal();
 				foreach (var h in _heaps)
-					h.Memory.SaveXorSnapshot();
+				{
+					if (h != _invisibleheap) // TODO: if we have more non-savestated heaps, refine this hack
+						h.Memory.SaveXorSnapshot();
+				}
 				foreach (var pe in _modules)
-					pe.Memory.SaveXorSnapshot();
+				{
+					pe.SealImportsAndTakeXorSnapshot();
+				}
 			}
 		}
 

BizHawk.Emulation.Cores/Waterbox/PeWrapper.cs

@@ -39,7 +39,7 @@ namespace BizHawk.Emulation.Cores.Waterbox
 
 		private readonly Dictionary<string, Section> _sectionsByName = new Dictionary<string, Section>();
 		private readonly List<Section> _sections = new List<Section>();
-
+		private Section _imports;
 
 		public string ModuleName { get; }
 
@@ -65,6 +65,9 @@ namespace BizHawk.Emulation.Cores.Waterbox
 		/// </summary>
 		public IntPtr DtorList { get; private set; }
 
+		// true if the imports have been set to readonly
+		private bool _importsSealed = false;
+
 		/*[UnmanagedFunctionPointer(CallingConvention.Winapi)]
 		private delegate bool DllEntry(IntPtr instance, int reason, IntPtr reserved);
 		[UnmanagedFunctionPointer(CallingConvention.Winapi)]
@@ -158,6 +161,7 @@ namespace BizHawk.Emulation.Cores.Waterbox
 				_sections.Add(section);
 				_sectionsByName.Add(section.Name, section);
 			}
+			_sectionsByName.TryGetValue(".idata", out _imports);
 
 			Mount();
 		}
@@ -263,7 +267,11 @@ namespace BizHawk.Emulation.Cores.Waterbox
 					module = new Dictionary<string, IntPtr>();
 					ImportsByModule.Add(import.DLL, module);
 				}
-				module.Add(import.Name, Z.US(Start + import.Thunk));
+				var dest = Start + import.Thunk;
+				if (_imports == null || dest >= _imports.Start + _imports.Size || dest < _imports.Start)
+					throw new InvalidOperationException("Import record outside of .idata!");
+
+				module.Add(import.Name, Z.US(dest));
 			}
 
 			Section midipix;
@@ -296,6 +304,12 @@ namespace BizHawk.Emulation.Cores.Waterbox
 
 		public void ConnectImports(string moduleName, IImportResolver module)
 		{
+			// this is called once internally when bootstrapping, and externally
+			// when we need to restore a savestate from another run.  so imports might or might not be sealed
+
+			if (_importsSealed && _imports != null)
+				Memory.Protect(_imports.Start, _imports.Size, MemoryBlock.Protection.RW);
+
 			Dictionary<string, IntPtr> imports;
 			if (ImportsByModule.TryGetValue(moduleName, out imports))
 			{
@@ -305,6 +319,34 @@ namespace BizHawk.Emulation.Cores.Waterbox
 					Marshal.Copy(valueArray, 0, kvp.Value, 1);
 				}
 			}
+
+			if (_importsSealed && _imports != null)
+				Memory.Protect(_imports.Start, _imports.Size, _imports.Prot);
+		}
+
+		public void SealImportsAndTakeXorSnapshot()
+		{
+			if (_importsSealed)
+				throw new InvalidOperationException("Imports already sealed!");
+
+			// save import values, then zero them all (for hash purposes), then take our snapshot, then load them again,
+			// then set the .idata area to read only
+			if (_imports != null)
+			{
+				var data = new byte[_imports.Size];
+				Marshal.Copy(Z.US(_imports.Start), data, 0, (int)_imports.Size);
+				WaterboxUtils.ZeroMemory(Z.US(_imports.Start), (long)_imports.Size);
+				Memory.SaveXorSnapshot();
+				Marshal.Copy(data, 0, Z.US(_imports.Start), (int)_imports.Size);
+				_imports.W = false;
+				Memory.Protect(_imports.Start, _imports.Size, _imports.Prot);
+			}
+			else
+			{
+				Memory.SaveXorSnapshot();
+			}
+
+			_importsSealed = true;
 		}
 
 		private bool _disposed = false;
@@ -323,6 +365,9 @@ namespace BizHawk.Emulation.Cores.Waterbox
 
 		public void SaveStateBinary(BinaryWriter bw)
 		{
+			if (!_importsSealed)
+				throw new InvalidOperationException(".idata sections must be closed before saving state");
+
 			bw.Write(MAGIC);
 			bw.Write(_fileHash);
 			bw.Write(Memory.XorHash);
@@ -341,6 +386,9 @@ namespace BizHawk.Emulation.Cores.Waterbox
 
 		public void LoadStateBinary(BinaryReader br)
 		{
+			if (!_importsSealed)
+				throw new InvalidOperationException(".idata sections must be closed before loading state");
+
 			if (br.ReadUInt64() != MAGIC)
 				throw new InvalidOperationException("Magic not magic enough!");
 			if (!br.ReadBytes(_fileHash.Length).SequenceEqual(_fileHash))

waterbox/gpgx/cinterface/cinterface.c

@@ -581,6 +581,8 @@ GPGX_EX int gpgx_init(const char *feromextension, ECL_ENTRY int (*feload_archive
 	update_viewport();
 	gpgx_clear_sram();
 
+	load_archive_cb = NULL; // don't hold onto load_archive_cb for longer than we need it for
+
 	return 1;
 }