Re: [PATCH][next] xen/pci: Avoid -Wflex-array-member-not-at-end warning

[Kees Cook <kees@xxxxxxxxxx>]

On Tue, Aug 20, 2024 at 06:50:56PM -0600, Gustavo A. R. Silva wrote:
> Use the `DEFINE_RAW_FLEX()` helper for an on-stack definition of
> a flexible structure where the size of the flexible-array member
> is known at compile-time, and refactor the rest of the code,
> accordingly.
> 
> So, with this, fix the following warning:
> 
> drivers/xen/pci.c:48:55: warning: structure containing a flexible array 
> member is not at the end of another structure [-Wflex-array-member-not-at-end]
> 
> Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
> ---
>  drivers/xen/pci.c | 14 +++++---------
>  1 file changed, 5 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/xen/pci.c b/drivers/xen/pci.c
> index 72d4e3f193af..a2facd8f7e51 100644
> --- a/drivers/xen/pci.c
> +++ b/drivers/xen/pci.c
> @@ -44,15 +44,11 @@ static int xen_add_device(struct device *dev)
>       }
>  #endif
>       if (pci_seg_supported) {
> -             struct {
> -                     struct physdev_pci_device_add add;
> -                     uint32_t pxm;
> -             } add_ext = {
> -                     .add.seg = pci_domain_nr(pci_dev->bus),
> -                     .add.bus = pci_dev->bus->number,
> -                     .add.devfn = pci_dev->devfn
> -             };
> -             struct physdev_pci_device_add *add = &add_ext.add;
> +             DEFINE_RAW_FLEX(struct physdev_pci_device_add, add, optarr, 1);
> +
> +             add->seg = pci_domain_nr(pci_dev->bus);
> +             add->bus = pci_dev->bus->number;
> +             add->devfn = pci_dev->devfn;
>  
>  #ifdef CONFIG_ACPI
>               acpi_handle handle;

Looks correct to me!

Reviewed-by: Kees Cook <kees@xxxxxxxxxx>

-- 
Kees Cook