From nobody Sun Feb 8 11:26:27 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 230181DF72C; Mon, 10 Nov 2025 10:59:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762772350; cv=none; b=I1Y2wsmOefVb41HSwEGVHENqBvp0pO+M5yImMfGpYdLAk2iVLr5ltdnglQh1H/uLIId6eRZAxvPldzJ6TZBCfaQvC6YWV7IZ1i5Ek5zqdQjVxkCuS6QY0xUQZFeQEt0TQkMMnxtnltjo2NuJTwhbMcZW4utfGDrHMAjIy2rVfWY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762772350; c=relaxed/simple; bh=H1KCquvsgrEEnjmZA9EO1r7LzKOIv3jfOjS0aZILJ2k=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=iKrIep12pos1OlLmWspLFRjCR8+cY72QFgGJH0QaCXOR+lAQJjM6MJ0LkHaZ7QXk19Myo0Clds+ZQAFX9eq0GVTYBfv9N7r26ZgtDVy3uQGTKM6jbPeymypOp2qstydrlE1mTMqIlEj/fox2p1UZmxgCfWIXCS7Y8uFiLKxMsdM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ULyG0SvA; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ULyG0SvA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CCCE8C116D0; Mon, 10 Nov 2025 10:59:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762772344; bh=H1KCquvsgrEEnjmZA9EO1r7LzKOIv3jfOjS0aZILJ2k=; h=Date:From:To:Cc:Subject:From; b=ULyG0SvAVnId7zgahBYhEKxlY5GLjXTO3HXMynN1QZK1UYmxo8bs1yYpgTWAFNsgP wEaWGCkXbgHszISgWAazEQJdjzCLijfRPQsRwbRlkaFAuL/G0CvfJc0Xu7kHoRl/EP STQ45AXBjweppvYfrkq6T/VmnzqXZ5huw9uSV/kFF1gLEZctclzaxQ3GBdOhKF4Thj MI2T5Zqd41uLQ0L55PpuOINrNH+/4XE6Otf4kgn4uevJsiJuQDzaVwetP67qyxPaqu nb3WZa4raCiDaEPJTC4E3ACr0+pQzAaBY9lYUuNXIBlPN1UjimXyHvIedvbP2j9Xl0 fCf3/3UT6LVRA== Date: Mon, 10 Nov 2025 19:58:58 +0900 From: "Gustavo A. R. Silva" To: Coly Li , Andrew Morton Cc: linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH][next] bcache: Avoid -Wflex-array-member-not-at-end warning Message-ID: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" -Wflex-array-member-not-at-end was introduced in GCC-14, and we are getting ready to enable it, globally. Use the new TRAILING_OVERLAP() helper to fix the following warning: drivers/md/bcache/bset.h:330:27: warning: structure containing a flexible a= rray member is not at the end of another structure [-Wflex-array-member-not= -at-end] This helper creates a union between a flexible-array member (FAM) and a set of MEMBERS that would otherwise follow it. This overlays the trailing MEMBER struct btree_iter_set stack_data[MAX_BSET= S]; onto the FAM struct btree_iter::data[], while keeping the FAM and the start of MEMBER aligned. The static_assert() ensures this alignment remains, and it's intentionally placed inmediately after the corresponding structures --no blank line in between. Signed-off-by: Gustavo A. R. Silva --- drivers/md/bcache/bset.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/md/bcache/bset.h b/drivers/md/bcache/bset.h index 011f6062c4c0..6ee2c6a506a2 100644 --- a/drivers/md/bcache/bset.h +++ b/drivers/md/bcache/bset.h @@ -327,9 +327,13 @@ struct btree_iter { /* Fixed-size btree_iter that can be allocated on the stack */ =20 struct btree_iter_stack { - struct btree_iter iter; - struct btree_iter_set stack_data[MAX_BSETS]; + /* Must be last as it ends in a flexible-array member. */ + TRAILING_OVERLAP(struct btree_iter, iter, data, + struct btree_iter_set stack_data[MAX_BSETS]; + ); }; +static_assert(offsetof(struct btree_iter_stack, iter.data) =3D=3D + offsetof(struct btree_iter_stack, stack_data)); =20 typedef bool (*ptr_filter_fn)(struct btree_keys *b, const struct bkey *k); =20 --=20 2.43.0