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Fix partial unmap tracking in Unicorn binding

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Improve mapped-region bookkeeping so `UnmapMemory` correctly handles partial overlaps by splitting surviving segments and updating pointers. Track each region’s original buffer base to prevent invalid frees when regions are split, and only release buffers when no surviving alias remains. Disposal now also deduplicates buffer frees to avoid double-free risks.
This commit is contained in:
AdvDebug
2026-08-01 14:41:41 +03:00
parent 2105e750d6
commit cc7174690c
1 changed files with 92 additions and 17 deletions
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Brovan/Core/Emulation/UnicornBinding/Unicorn.cs
+92 -17
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@@ -41,6 +41,8 @@ namespace Brovan.Core.Emulation
private readonly List<int> _regionIndex = new List<int>();
private bool _regionIndexDirty = true;
private readonly List<IntPtr> _pendingFrees = new List<IntPtr>();
private readonly List<MappedRegion> _unmapSurvivors = new List<MappedRegion>();
private readonly List<IntPtr> _unmapReleasedBuffers = new List<IntPtr>();
private List<IntPtr> HooksList = new List<IntPtr>();
private sealed class MappedRegion
@@ -48,6 +50,7 @@ namespace Brovan.Core.Emulation
public ulong Address;
public ulong Size;
public IntPtr Ptr;
public IntPtr BufferBase;
}
private readonly struct RegionAddressComparer : IComparer<int>
@@ -177,7 +180,7 @@ namespace Brovan.Core.Emulation
_error = uc_mem_map_ptr(_uc, address, new UIntPtr(size), protection, (IntPtr)ptr);
if (_error == UCErrors.UC_ERR_OK)
{
_mappedRegions.Add(new MappedRegion { Address = address, Size = size, Ptr = (IntPtr)ptr });
_mappedRegions.Add(new MappedRegion { Address = address, Size = size, Ptr = (IntPtr)ptr, BufferBase = (IntPtr)ptr });
_regionIndexDirty = true;
return true;
}
@@ -187,7 +190,7 @@ namespace Brovan.Core.Emulation
_error = uc_mem_map(_uc, address, new UIntPtr(size), protection);
if (_error == UCErrors.UC_ERR_OK)
{
_mappedRegions.Add(new MappedRegion { Address = address, Size = size, Ptr = IntPtr.Zero });
_mappedRegions.Add(new MappedRegion { Address = address, Size = size, Ptr = IntPtr.Zero, BufferBase = IntPtr.Zero });
_regionIndexDirty = true;
return true;
}
@@ -212,24 +215,91 @@ namespace Brovan.Core.Emulation
if (_error == UCErrors.UC_ERR_OK)
{
FlushTlb();
for (int i = 0; i < _mappedRegions.Count; i++)
{
if (_mappedRegions[i].Address == address && _mappedRegions[i].Size == size)
{
if (_mappedRegions[i].Ptr != IntPtr.Zero)
_pendingFrees.Add(_mappedRegions[i].Ptr);
_mappedRegions.RemoveAt(i);
_regionIndexDirty = true;
break;
}
}
TrimMappedRegions(address, size);
return true;
}
}
return false;
}
private unsafe void TrimMappedRegions(ulong address, ulong size)
{
ulong end = address + size;
bool changed = false;
_unmapSurvivors.Clear();
_unmapReleasedBuffers.Clear();
for (int i = _mappedRegions.Count - 1; i >= 0; i--)
{
MappedRegion Region = _mappedRegions[i];
ulong RegionEnd = Region.Address + Region.Size;
if (RegionEnd <= address || end <= Region.Address)
continue;
ulong OverlapStart = Region.Address > address ? Region.Address : address;
ulong OverlapEnd = RegionEnd < end ? RegionEnd : end;
_mappedRegions.RemoveAt(i);
changed = true;
if (OverlapStart > Region.Address)
{
_unmapSurvivors.Add(new MappedRegion
{
Address = Region.Address,
Size = OverlapStart - Region.Address,
Ptr = Region.Ptr,
BufferBase = Region.BufferBase
});
}
if (RegionEnd > OverlapEnd)
{
IntPtr TailPtr = Region.Ptr == IntPtr.Zero
? IntPtr.Zero
: (IntPtr)((byte*)Region.Ptr + (OverlapEnd - Region.Address));
_unmapSurvivors.Add(new MappedRegion
{
Address = OverlapEnd,
Size = RegionEnd - OverlapEnd,
Ptr = TailPtr,
BufferBase = Region.BufferBase
});
}
if (Region.BufferBase != IntPtr.Zero && !_unmapReleasedBuffers.Contains(Region.BufferBase))
_unmapReleasedBuffers.Add(Region.BufferBase);
}
if (!changed)
return;
for (int i = 0; i < _unmapSurvivors.Count; i++)
_mappedRegions.Add(_unmapSurvivors[i]);
_regionIndexDirty = true;
for (int i = 0; i < _unmapReleasedBuffers.Count; i++)
{
IntPtr Buffer = _unmapReleasedBuffers[i];
bool StillAliased = false;
for (int j = 0; j < _mappedRegions.Count; j++)
{
if (_mappedRegions[j].BufferBase == Buffer)
{
StillAliased = true;
break;
}
}
if (!StillAliased)
_pendingFrees.Add(Buffer);
}
}
/// <summary>
/// Write to an emulated memory address.
/// </summary>
@@ -1523,11 +1593,16 @@ namespace Brovan.Core.Emulation
{
unsafe
{
_unmapReleasedBuffers.Clear();
foreach (var region in _mappedRegions)
{
if (region.Ptr != IntPtr.Zero)
NativeMemory.AlignedFree((void*)region.Ptr);
if (region.BufferBase != IntPtr.Zero && !_unmapReleasedBuffers.Contains(region.BufferBase))
_unmapReleasedBuffers.Add(region.BufferBase);
}
foreach (IntPtr buffer in _unmapReleasedBuffers)
NativeMemory.AlignedFree((void*)buffer);
_unmapReleasedBuffers.Clear();
_unmapSurvivors.Clear();
_mappedRegions.Clear();
_regionIndex.Clear();
_regionIndexDirty = true;
@@ -1552,4 +1627,4 @@ namespace Brovan.Core.Emulation
}
}
}
}
}