Alexandre Julliard : ntdll: Mark the Wow64 TLS slots as reserved.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: aa3e772abf636663313ff0dfe299c6c383ed1b0a
URL:    https://gitlab.winehq.org/wine/wine/-/commit/aa3e772abf636663313ff0dfe299c6c...

Author: Alexandre Julliard 
Date:   Fri Feb 24 11:51:35 2023 +0100

ntdll: Mark the Wow64 TLS slots as reserved.

---

dlls/ntdll/loader.c | 3 ++-
 include/winternl.h  | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/dlls/ntdll/loader.c b/dlls/ntdll/loader.c
index f533db060d0..d0d9bae7f0b 100644
--- a/dlls/ntdll/loader.c
+++ b/dlls/ntdll/loader.c
@@ -4176,7 +4176,8 @@ void WINAPI LdrInitializeThunk( CONTEXT *context, ULONG_PTR unknown2, ULONG_PTR
         RtlInitializeBitMap( &tls_bitmap, peb->TlsBitmapBits, sizeof(peb->TlsBitmapBits) * 8 );
         RtlInitializeBitMap( &tls_expansion_bitmap, peb->TlsExpansionBitmapBits,
                              sizeof(peb->TlsExpansionBitmapBits) * 8 );
-        RtlSetBits( peb->TlsBitmap, 0, 1 ); /* TLS index 0 is reserved and should be initialized to NULL. */
+        /* TLS index 0 is always reserved, and wow64 reserves extra TLS entries */
+        RtlSetBits( peb->TlsBitmap, 0, NtCurrentTeb()->WowTebOffset ? WOW64_TLS_MAX_NUMBER : 1 );

init_user_process_params();
         load_global_options();
diff --git a/include/winternl.h b/include/winternl.h
index 3a6c89a5f7a..93bd32e3786 100644
--- a/include/winternl.h
+++ b/include/winternl.h
@@ -1084,6 +1084,7 @@ typedef struct _TEB64
 #define WOW64_TLS_TEMPLIST         3
 #define WOW64_TLS_USERCALLBACKDATA 5
 #define WOW64_TLS_FILESYSREDIR     8
+#define WOW64_TLS_MAX_NUMBER       19

/***********************************************************************