Re: [PATCH][next] wifi: ath12k: core.h: Avoid -Wflex-array-member-not-at-end warnings

From: Kees Cook
Date: Mon Apr 07 2025 - 15:10:13 EST


On Tue, Mar 11, 2025 at 12:02:15PM +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 ieee80211_chanctx_conf` is a flexible structure --a
> structure that contains a flexible-array member.
>
> Fix 30 of the following warnings:
>
> drivers/net/wireless/ath/ath12k/core.h:298:39: 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>

Hi, just checking in on this patch. Is some adjustment needed for this
to land?

Thanks!

-Kees

> ---
> drivers/net/wireless/ath/ath12k/core.h | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/ath/ath12k/core.h b/drivers/net/wireless/ath/ath12k/core.h
> index 3fac4f00d383..d6b4c4d2c400 100644
> --- a/drivers/net/wireless/ath/ath12k/core.h
> +++ b/drivers/net/wireless/ath/ath12k/core.h
> @@ -295,7 +295,6 @@ struct ath12k_link_vif {
> int txpower;
> bool rsnie_present;
> bool wpaie_present;
> - struct ieee80211_chanctx_conf chanctx;
> u8 vdev_stats_id;
> u32 punct_bitmap;
> u8 link_id;
> @@ -303,6 +302,13 @@ struct ath12k_link_vif {
> struct ath12k_rekey_data rekey_data;
>
> u8 current_cntdown_counter;
> +
> + /* Must be last - ends in a flexible-array member.
> + *
> + * FIXME: Driver should not copy struct ieee80211_chanctx_conf,
> + * especially because it has a flexible array. Find a better way.
> + */
> + struct ieee80211_chanctx_conf chanctx;
> };
>
> struct ath12k_vif {
> --
> 2.43.0
>

--
Kees Cook