[BUG] Process crash when midhook calls back to C# layer

[ELDment]

SwiftlyS2 Version

latest

Game

Counter-Strike 2

Operating System

Windows

Bug Description

Process crash when midhook calls back to C# layer

Steps to Reproduce

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Expected Behavior

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Actual Behavior

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Logs/Console Output

Plugin Information

No response

Additional Context

No response

[ELDment]

idk why everything worked correctly in .NET 8, but the process crashes consistently after migrating to .NET 10

this is likely due to stricter GC transition and execution context validation in the .NET 10 CoreCLR (?)

regardless of the exact cause, we need a safer approach for invoking managed callbacks from unmanaged code, since Marshal.GetFunctionPointerForDelegate returns a managed thunk rather than a direct function pointer [1], which may not be compatible with the execution context of midhook callbacks

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[1] https://devblogs.microsoft.com/dotnet/improvements-in-native-code-interop-in-net-5-0/#unmanagedcallersonly

The above requires the allocation of a delegate and the marshalling of that delegate to a function pointer. If the native function being called could hold on to the callback, we also need to ensure the delegate is not garbage collected. This detail is often missed, leading to intermittent “Callback on collected delegate” crashes.

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Note: Confirmed that the crash was not caused by Marshal.GetFunctionPointerForDelegate returning thunk (stub) addresses, we just need to define TDelegate correctly

[ELDment]

#120