Re: [PATCH 0/2] MR1949: Draft: win32u: Correct GetRawInputBuffer alignment under WoW64.

[Rémi Bernon (＠rbernon)]

On Fri Jan 13 07:11:10 2023 +0000, Rémi Bernon wrote:
> Are all these changes necessary? Why not simply fixup the existing fixup
> (which imho keeps this wow64 oddity localized and avoids having specific
> handling elsewhere where it's not needed) like this:
> diff --git a/dlls/win32u/rawinput.c b/dlls/win32u/rawinput.c
> index ab1252ccea6..f0be80924af 100644
> --- a/dlls/win32u/rawinput.c
> +++ b/dlls/win32u/rawinput.c
> @@ -48,7 +48,11 @@ typedef struct
>  {
>      DWORD dwType;
>      DWORD dwSize;
> -    ULONGLONG hDevice;
> +    union
> +    {
> +        HANDLE hDevice;
> +        ULONGLONG __align;
> +    };
>      ULONGLONG wParam;
>  } RAWINPUTHEADER64;
>
> @@ -671,10 +675,14 @@ UINT WINAPI NtUserGetRawInputBuffer( RAWINPUT
> *data, UINT *data_size, UINT heade
>          if (!rawinput_from_hardware_message( data, msg_data )) break;
>          if (overhead)
>          {
> +            /* Under WoW64, GetRawInputBuffer always gives 64-bit
> RAWINPUT structs. */
> +            RAWINPUT64 *ri64 = (RAWINPUT64 *)data;
>              memmove( (char *)&data->data + overhead, &data->data,
>                       data->header.dwSize - sizeof(RAWINPUTHEADER) );
> +            ri64->header.dwSize += overhead;
> +            ri64->header.hDevice = data->header.hDevice;
> +            ri64->header.wParam = data->header.wParam;
>          }
> -        data->header.dwSize += overhead;
>          remaining -= data->header.dwSize;
>          data = NEXTRAWINPUTBLOCK(data);
>          msg_data = (struct hardware_msg_data *)((char *)msg_data + msg_data->size);
>
> With a simple fix like that I think it'd even be acceptable to merge in 8.0.

(Well, I wanted to make it simpler, but I realize that __align high bits are left untouched here, probably better to keep the #ifdef and HandleToUlong)