[CPU] Reject context transfers to unmapped guest addresses (#273)

2026-07-22 19:06:15 +08:00 · 2026-07-16 18:57:34 +02:00
parent f7981a7ed7
commit 33f96252da
3 changed files with 96 additions and 5 deletions
@@ -0,0 +1,61 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using SharpEmu.Core.Cpu.Native;
+using SharpEmu.HLE;
+using Xunit;
+
+namespace SharpEmu.Libs.Tests.Cpu;
+
+public sealed class GuestContextTransferValidationTests
+{
+    private const ulong MemoryBase = 0x1_0000_0000;
+
+    [Fact]
+    public void MappedGuestInstructionPointer_IsAccepted()
+    {
+        var memory = new FakeCpuMemory(MemoryBase, 0x1000);
+        var continuation = CreateContinuation(MemoryBase + 0x100, MemoryBase + 0x800);
+
+        Assert.True(DirectExecutionBackend.TryValidateGuestContextTransferTarget(
+            memory,
+            continuation,
+            out var error));
+        Assert.Null(error);
+    }
+
+    [Fact]
+    public void UnmappedGuestInstructionPointer_IsRejected()
+    {
+        var memory = new FakeCpuMemory(MemoryBase, 0x1000);
+        var continuation = CreateContinuation(MemoryBase + 0x2000, MemoryBase + 0x800);
+
+        Assert.False(DirectExecutionBackend.TryValidateGuestContextTransferTarget(
+            memory,
+            continuation,
+            out var error));
+        Assert.Contains("not mapped guest memory", error);
+    }
+
+    [Theory]
+    [InlineData(0UL, MemoryBase + 0x800)]
+    [InlineData(MemoryBase + 0x100, 0UL)]
+    public void InvalidInstructionOrStackPointer_IsRejected(ulong rip, ulong rsp)
+    {
+        var memory = new FakeCpuMemory(MemoryBase, 0x1000);
+        var continuation = CreateContinuation(rip, rsp);
+
+        Assert.False(DirectExecutionBackend.TryValidateGuestContextTransferTarget(
+            memory,
+            continuation,
+            out var error));
+        Assert.Contains("invalid guest context transfer target", error);
+    }
+
+    private static GuestCpuContinuation CreateContinuation(ulong rip, ulong rsp) =>
+        new()
+        {
+            Rip = rip,
+            Rsp = rsp,
+        };
+}