Major Description
Problem:
- Download msys 2022-10-28 from https://github.com/msys2/msys2-installer/releases/tag/2022-10-28 (needs NT6 enabled!)
- Run `flex --version`
See https://github.com/git-for-windows/msys2-runtime/commit/5fe6d81012e97a348608511450f6a63750c906b6
Needs a shim. Patch RtlGetCurrentDirectory_U export point to a decoy version written in asm:
#include <ksamd64.inc>
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EXTERN RtlGetCurrentDirectory_U:PROC
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EXTERN RtlAcquirePebLock:PROC
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EXTERN FastPebLock:QWORD
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EXTERN RtlEnterCriticalSection:PROC
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EXTERN RtlpCurDirRef:QWORD
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.code
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MsysDecoy_UseRtlpCurDirRef:
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// This path should never be executed!
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int HEX(2c)
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lea rcx, FastPebLock[rip]
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call RtlEnterCriticalSection
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mov rbx, qword ptr [RtlpCurDirRef]
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test rbx, rbx
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MsysDecoy_continue:
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jmp RtlGetCurrentDirectory_U
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PUBLIC RtlGetCurrentDirectory_U_RtlpMsysDecoy
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RtlGetCurrentDirectory_U_RtlpMsysDecoy:
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// Short jmp that hopefully does not contain a 0xe8
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jmp short MsysDecoy_continue
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// This emulates the call that msys/cygwin are looking for
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// and will never be executed
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call MsysDecoy_UseRtlpCurDirRefEND
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The shim should be registered to "msys-2.0.dll".