win32u: Set zero_bits correctly for large address aware applications on Wow64.

dlls/win32u/dc.c

@@ -112,7 +112,7 @@ static DC_ATTR *alloc_dc_attr(void)
     {
         SIZE_T size = system_info.AllocationGranularity;
         bucket->entries = NULL;
-        if (!NtAllocateVirtualMemory( GetCurrentProcess(), (void **)&bucket->entries, zero_bits(),
+        if (!NtAllocateVirtualMemory( GetCurrentProcess(), (void **)&bucket->entries, zero_bits,
                                       &size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE ))
         {
             bucket->next_free = NULL;

dlls/win32u/dib.c

@@ -1549,7 +1549,7 @@ HBITMAP WINAPI NtGdiCreateDIBSection( HDC hdc, HANDLE section, DWORD offset, con
     {
         SIZE_T size = bmp->dib.dsBmih.biSizeImage;
         offset = 0;
-        if (NtAllocateVirtualMemory( GetCurrentProcess(), &bmp->dib.dsBm.bmBits, zero_bits(),
+        if (NtAllocateVirtualMemory( GetCurrentProcess(), &bmp->dib.dsBm.bmBits, zero_bits,
                                      &size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE ))
             goto error;
     }

dlls/win32u/gdiobj.c

@@ -566,7 +566,7 @@ static void init_gdi_shared(void)
 {
     SIZE_T size = sizeof(*gdi_shared);
 
-    if (NtAllocateVirtualMemory( GetCurrentProcess(), (void **)&gdi_shared, zero_bits(),
+    if (NtAllocateVirtualMemory( GetCurrentProcess(), (void **)&gdi_shared, zero_bits,
                                  &size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE ))
         return;
     next_unused = gdi_shared->Handles + FIRST_GDI_HANDLE;

dlls/win32u/syscall.c

@@ -33,6 +33,7 @@
 #include "ntuser.h"
 #include "wine/unixlib.h"
 
+ULONG_PTR zero_bits = 0;
 
 static void * const syscalls[] =
 {
@@ -450,6 +451,16 @@ static SYSTEM_SERVICE_TABLE syscall_table =
 
 static NTSTATUS init( void *dispatcher )
 {
+#ifdef _WIN64
+    if (NtCurrentTeb()->WowTebOffset)
+    {
+        SYSTEM_BASIC_INFORMATION info;
+
+        NtQuerySystemInformation(SystemEmulationBasicInformation, &info, sizeof(info), NULL);
+        zero_bits = (ULONG_PTR)info.HighestUserAddress | 0x7fffffff;
+    }
+#endif
+
     return ntdll_init_syscalls( 1, &syscall_table, dispatcher );
 }
 

dlls/win32u/win32u_private.h

@@ -271,6 +271,8 @@ extern HKEY hkcu_key DECLSPEC_HIDDEN;
 
 extern const struct user_driver_funcs *user_driver DECLSPEC_HIDDEN;
 
+extern ULONG_PTR zero_bits DECLSPEC_HIDDEN;
+
 static inline BOOL set_ntstatus( NTSTATUS status )
 {
     if (status) RtlSetLastWin32Error( RtlNtStatusToDosError( status ));
@@ -330,15 +332,6 @@ static inline BOOL is_win9x(void)
     return NtCurrentTeb()->Peb->OSPlatformId == VER_PLATFORM_WIN32s;
 }
 
-static inline ULONG_PTR zero_bits(void)
-{
-#ifdef _WIN64
-    return !NtCurrentTeb()->WowTebOffset ? 0 : 0x7fffffff;
-#else
-    return 0;
-#endif
-}
-
 static inline const char *debugstr_us( const UNICODE_STRING *us )
 {
     if (!us) return "<null>";