[Spice-devel] [PATCH spice-protocol 2/3] qxl_dev: Fix alignment for QXLReleaseInfo

[Frediano Ziglio]

ping

> 
> Do not declare the structure as aligned.
> The start/end-packed.h headers affects only MingW or Microsoft
> compilers. To have unaligned structure with GCC compiler you have
> to use SPICE_ATTR_PACKED. This way the definition are the same for
> all compiler.
> This structure is used in a lot of QXL structures which are not
> aligned causing to have an aligned structure to be potentially
> unaligned.
> As this structure has no holes this change does not make any size
> change using any compiler.
> The change will only change the alignment from 4/8 to 1.
> This could affect structures containing this union however beside
> packed structure in qxl_dev.h (which are not affected) there are no
> other usages as such by spice-gtk, Qemu or spice-server.
> 
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> ---
>  spice/qxl_dev.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/spice/qxl_dev.h b/spice/qxl_dev.h
> index a9cc4f4..659f930 100644
> --- a/spice/qxl_dev.h
> +++ b/spice/qxl_dev.h
> @@ -275,7 +275,7 @@ typedef struct SPICE_ATTR_ALIGNED(4) SPICE_ATTR_PACKED
> QXLRam {
>  
>  } QXLRam;
>  
> -typedef union QXLReleaseInfo {
> +typedef union SPICE_ATTR_PACKED QXLReleaseInfo {
>      uint64_t id;      // in
>      uint64_t next;    // out
>  } QXLReleaseInfo;