From: Jiajin Cui cuijiajin@uniontech.com
Changed wparam and lparam parameter types from LONG to ULONG in wow64_NtUserMessageCall function to match the expected data types from the get_ulong function. The get_ulong function returns unsigned 32- bit values, so using ULONG type ensures proper type compatibility and prevents potential sign extension issues when handling message parameters in 64-bit Windows emulation.
When a 32-bit program sets the IMAGE_FILE_LARGE_ADDRESS_AWARE flag, lparam may be an address exceeding 2GB, such as 0x8defddef. If using ULONG to receive it, due to sign extension, the address becomes 0xffffffff8defddef, causing exceptions during subsequent address access.
Signed-off-by: Jiajin Cui cuijiajin@uniontech.com --- dlls/wow64win/user.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/dlls/wow64win/user.c b/dlls/wow64win/user.c index d4f47773abe..398f0fa2f6f 100644 --- a/dlls/wow64win/user.c +++ b/dlls/wow64win/user.c @@ -3624,8 +3624,8 @@ NTSTATUS WINAPI wow64_NtUserMessageCall( UINT *args ) { HWND hwnd = get_handle( &args ); UINT msg = get_ulong( &args ); - LONG wparam = get_ulong( &args ); - LONG lparam = get_ulong( &args ); + ULONG wparam = get_ulong( &args ); + ULONG lparam = get_ulong( &args ); void *result_info = get_ptr( &args ); UINT type = get_ulong ( &args ); BOOL ansi = get_ulong( &args );