Blog
Technical notes on what I'm breaking and fixing: reverse engineering, internals, weird bugs and vulnerabilities.
A years-old GTA V performance issue, FPS tanking at night when looking at the city, traced to six prefetchnta hints into write-combine vertex buffers, stalling the AMD Zen pipeline. The final fix is 25 NOPs in two places.
VR players' grabbed items appeared floating away from their hands on remote clients. The fix was a single mov instruction in the IL2CPP-compiled DLL.