From mboxrd@z Thu Jan 1 00:00:00 1970 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 A65E8305066; Mon, 10 Nov 2025 10:45:02 +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=1762771502; cv=none; b=m6AIOhh2xUOol0HkFLXVKJMJIoAK5ct6n48IZJ3VL+pgQH8GVSeKVbjGMbwLICqUESG9DVzUsCKHBMcAB0OywbgetNncfye9VdOCYmTP3X0hgwQDj6szJ6SZne7GIX9533/ATDXAeLI94INYUaMY6WtnVH82gIybcLxKu4DAKV8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762771502; c=relaxed/simple; bh=D4tyGM1CQgI1ziG0RQbhNZECmbMmY5A11qAo6a2a2e4=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=ItGQ5GHyjkGQt44pgPkFc3sp3qT82QGBfDVFM10Z9nOgXEO26o4c+MvONlyVO5FODim3/jQIznOFzSFQwFOd7FVhIHxJONtd23fu0b+FgPLYR/GuL5osnKSPJTv33cP4hwDXpNAehomzjGSmq/vczI7nc9fQ3O0cfIZitsGkXiw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tC88qsCi; 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="tC88qsCi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 291B8C4CEF5; Mon, 10 Nov 2025 10:44:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762771502; bh=D4tyGM1CQgI1ziG0RQbhNZECmbMmY5A11qAo6a2a2e4=; h=Date:From:To:Cc:Subject:From; b=tC88qsCi9k6L11GefVVW93h2kX10rCM4CGhI/FrZelUkSG+DGSi5jA07TGBQsILya E//UR9X52n4YzJrPtXggzh259gXb+zfHkquUgkQgwDmvdUem2AJFBhcnOujHTKdmQ1 KZScj0QcQ/Jh4Ru34+n4Amw/rDjWqSTi1XGoeXJMl4hulRv/i0GoJGjQOVA0cuo7D9 CiegkGp2nycTepeZww+v7I37a+UQgQhv2AeXjE6gsywxJSzLQLggjHmxj28JUAee++ RYP3OwlRmX/PROMxPhVIK6OKyFCTNukVRmpQCUUMYCt1eJ6nt+osHf7TaaCtK1EJBk grAKquaynQtNg== Date: Mon, 10 Nov 2025 19:44:56 +0900 From: "Gustavo A. R. Silva" To: Herbert Xu , "David S. Miller" Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH][next] crypto: drbg - Avoid -Wflex-array-member-not-at-end warning Message-ID: Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline -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: crypto/drbg.c:1445:27: warning: structure containing a flexible array 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 char ctx[]; onto the FAM struct shash_desc::__ctx,[] 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 --- crypto/drbg.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/crypto/drbg.c b/crypto/drbg.c index 511a27c91813..e9f9775c237f 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -1442,9 +1442,12 @@ static void drbg_kcapi_set_entropy(struct crypto_rng *tfm, #if defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_HMAC) struct sdesc { - struct shash_desc shash; - char ctx[]; + /* Must be last as it ends in a flexible-array member. */ + TRAILING_OVERLAP(struct shash_desc, shash, __ctx, + char ctx[]; + ); }; +static_assert(offsetof(struct sdesc, shash.__ctx) == offsetof(struct sdesc, ctx)); static int drbg_init_hash_kernel(struct drbg_state *drbg) { -- 2.43.0