On Mon, Mar 17, 2025 at 11:22:51AM +1030, Gustavo A. R. Silva wrote:
> -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
> getting ready to enable it, globally.
>
> Move the conflicting declaration to the end of the structure. Notice
> that `struct uvc_input_header_descriptor` is a flexible structure --a
> structure that contains a flexible-array member.
>
> With this, fix three of the following warnings:
>
> drivers/usb/gadget/function/uvc_configfs.h:77:57: 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 <[email protected]>
> ---
> drivers/usb/gadget/function/uvc_configfs.h | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/gadget/function/uvc_configfs.h
> b/drivers/usb/gadget/function/uvc_configfs.h
> index 2f78cd4f396f..9391614135e9 100644
> --- a/drivers/usb/gadget/function/uvc_configfs.h
> +++ b/drivers/usb/gadget/function/uvc_configfs.h
> @@ -74,10 +74,12 @@ static inline struct uvcg_format *to_uvcg_format(struct
> config_item *item)
>
> struct uvcg_streaming_header {
> struct config_item item;
> - struct uvc_input_header_descriptor desc;
> unsigned linked;
> struct list_head formats;
> unsigned num_fmt;
> +
> + /* Must be last --ends in a flexible-array member. */
> + struct uvc_input_header_descriptor desc;
> };
>
> static inline struct uvcg_streaming_header *to_uvcg_streaming_header(struct
> config_item *item)
This looks correct to me, and may be fixing some bugs -- I can see the
allocation routine for this is already expecting the bmaControls (in
desc) to be trailing:
/* bmaControls */
*size += h->num_fmt * UVCG_STREAMING_CONTROL_SIZE;
Reviewed-by: Kees Cook <[email protected]>
--
Kees Cook
