From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fout-b3-smtp.messagingengine.com (fout-b3-smtp.messagingengine.com [202.12.124.146]) (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 CCAEB23AB88 for ; Sun, 11 Jan 2026 10:29:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.12.124.146 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768127395; cv=none; b=hn8AuPkCyzsnaP58LwemNAUwaVSYZzor3eL+eoY/Q+PPFiZz8g99gst3wCr/LpeutZt3hMIVu1neEaWuoE64pXpASmdiyvdOfNH59h1gjpqkjtBf8sRsEVopDEdaxdbB7U5uxRO0AbMz6g6U/WOXoZV+0o1h7YQwJsuM7sNunKA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768127395; c=relaxed/simple; bh=yheON5ZUbnn6ELwpk8zzv7Qh1BwJ8OdwbLEvQcYMY3w=; h=MIME-Version:Date:From:To:Cc:Message-Id:In-Reply-To:References: Subject:Content-Type; b=J853Zd1iRV8ICtgfbA0br2QKPlHC8F5cQvmQ+oS35fba7D91sul5oE47MUmaIERrPmJEOz9mubi4seoFmx9/AvXwDx1u7LzIA8ySAXCesXHsbsCQWNw0c4mEVOXSYFbDY9WqZTRNyUgWIHNgiBwQT4gpwYKOpZBtrwKCIAuAvGI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arndb.de; spf=pass smtp.mailfrom=arndb.de; dkim=pass (2048-bit key) header.d=arndb.de header.i=@arndb.de header.b=kkXfLBeF; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=VYN5UIgZ; arc=none smtp.client-ip=202.12.124.146 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arndb.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arndb.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=arndb.de header.i=@arndb.de header.b="kkXfLBeF"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="VYN5UIgZ" Received: from phl-compute-04.internal (phl-compute-04.internal [10.202.2.44]) by mailfout.stl.internal (Postfix) with ESMTP id C40801D00129; Sun, 11 Jan 2026 05:29:51 -0500 (EST) Received: from phl-imap-02 ([10.202.2.81]) by phl-compute-04.internal (MEProxy); Sun, 11 Jan 2026 05:29:52 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arndb.de; h=cc :cc:content-transfer-encoding:content-type:content-type:date :date:from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to; s=fm1; t=1768127391; x=1768213791; bh=6RMOPJc8MLLse1vRCBHrkSArguVZcEAgOQpWKXH1ESo=; b= kkXfLBeFbkVM+I3MkHzUbbdvNGJgv20iNAhceDK8f4zs35W4B/gedY/U5eKLR3tM rOWhaXDaMRyprCicbDlzTjlMgpqK+B3sNLgKnJGgRB7Uay2j39KvZZlMiL+M6xbM TVaArQiYNl9cZlfmyssXPJzDlk8KLYI0mdGmJOG/tTxIrjDqx6NUAqDCRIxNArC+ vP3hsdtynuSX42ySf0GuHVr+qpBppnRtxjXEGt9dY25ahYEmjPsxD7Wk09IRUIMt am7hvBroOb5NLrGQRyNSPoIPkavB9HEmuPtYLYGCGeUo2HchNPg4C2OfIcryzgs6 gGnvjVGlmg1UJMjf3F0dwQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:content-type:date:date:feedback-id:feedback-id :from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t=1768127391; x= 1768213791; bh=6RMOPJc8MLLse1vRCBHrkSArguVZcEAgOQpWKXH1ESo=; b=V YN5UIgZaHE6AJtSYxTU01H/IM4E5lFq4jHHhM+HWGLpR5IQ7mdt7MWfUzph04gTr vggEXRlhtK04iGSLvmsjMAoV9kgsoJklrgdx4ynmYlBVT1zxtJpL3ZUgz/8FmLHT QjFTOfjk+Ys2DcAkS6bwASfncg3jdsfHWu/xWkDR92MfsgF27KAe5FzdHkYdxVrb lEVmrhYMFmJJ/i1inNe3XwMrJXqXbhGPCvpMtmoUaMyuGYoVIdxa+kHmKstRmqug zSYMBl5QF/jWsGvICKsHQm3g8/PXpC79S6wyFG8/2sPly4DdkY4uWmBB/bXokptU yoTqQWBZn6t2P1AickaGQ== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefgedrtddtgdduudegfeegucetufdoteggodetrf dotffvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfurfetoffkrfgpnffqhgenuceu rghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujf gurhepofggfffhvfevkfgjfhfutgfgsehtjeertdertddtnecuhfhrohhmpedftehrnhgu uceuvghrghhmrghnnhdfuceorghrnhgusegrrhhnuggsrdguvgeqnecuggftrfgrthhtvg hrnhephfdthfdvtdefhedukeetgefggffhjeeggeetfefggfevudegudevledvkefhvdei necuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomheprghrnh gusegrrhhnuggsrdguvgdpnhgspghrtghpthhtohepledpmhhouggvpehsmhhtphhouhht pdhrtghpthhtohepnhhitghkrdguvghsrghulhhnihgvrhhsodhlkhhmlhesghhmrghilh drtghomhdprhgtphhtthhopehjuhhsthhinhhsthhithhtsehgohhoghhlvgdrtghomhdp rhgtphhtthhopehmohhrsghosehgohhoghhlvgdrtghomhdprhgtphhtthhopehnrghthh grnheskhgvrhhnvghlrdhorhhgpdhrtghpthhtohepnhhstgeskhgvrhhnvghlrdhorhhg pdhrtghpthhtohepthhhohhmrghsrdifvghishhsshgthhhuhheslhhinhhuthhrohhnih igrdguvgdprhgtphhtthhopehllhhvmheslhhishhtshdrlhhinhhugidruggvvhdprhgt phhtthhopehprghttghhvghssehlihhsthhsrdhlihhnuhigrdguvghvpdhrtghpthhtoh eplhhinhhugidqkhgsuhhilhgusehvghgvrhdrkhgvrhhnvghlrdhorhhg X-ME-Proxy: Feedback-ID: i56a14606:Fastmail Received: by mailuser.phl.internal (Postfix, from userid 501) id 59B19700065; Sun, 11 Jan 2026 05:29:51 -0500 (EST) X-Mailer: MessagingEngine.com Webmail Interface Precedence: bulk X-Mailing-List: linux-kbuild@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ThreadId: Al1egLVrYt0c Date: Sun, 11 Jan 2026 11:29:31 +0100 From: "Arnd Bergmann" To: "Nathan Chancellor" , "Nicolas Schier" , =?UTF-8?Q?Thomas_Wei=C3=9Fschuh?= Cc: "Nick Desaulniers" , "Bill Wendling" , "Justin Stitt" , linux-kbuild@vger.kernel.org, llvm@lists.linux.dev, patches@lists.linux.dev Message-Id: <29b2e736-d462-45b7-a0a9-85f8d8a3de56@app.fastmail.com> In-Reply-To: <20260110-uapi-test-disable-headers-arm-clang-unaligned-access-v1-1-b7b0fa541daa@kernel.org> References: <20260110-uapi-test-disable-headers-arm-clang-unaligned-access-v1-1-b7b0fa541daa@kernel.org> Subject: Re: [PATCH] kbuild: uapi: Avoid testing certain headers on ARCH=arm with CC=clang Content-Type: text/plain Content-Transfer-Encoding: 7bit On Sun, Jan 11, 2026, at 01:52, Nathan Chancellor wrote: > > To keep the build working while the root cause of the warnings is > investigated and resolved, disable testing these header files for > ARCH=arm when building with clang. I think we can just safely mark the internal unions as __packed as well. The (untested) change below would annotate all of them as being potentially misaligned so they can be stored at an odd start offset, and correctly produce warnings when someone takes the address of a member. Arnd diff --git a/include/uapi/linux/hyperv.h b/include/uapi/linux/hyperv.h index aaa502a7bff4..02ea5f2e43d4 100644 --- a/include/uapi/linux/hyperv.h +++ b/include/uapi/linux/hyperv.h @@ -362,7 +362,7 @@ struct hv_kvp_exchg_msg_value { __u8 value[HV_KVP_EXCHANGE_MAX_VALUE_SIZE]; __u32 value_u32; __u64 value_u64; - }; + } __packed; } __attribute__((packed)); struct hv_kvp_msg_enumerate { diff --git a/include/uapi/linux/vbox_vmmdev_types.h b/include/uapi/linux/vbox_vmmdev_types.h index 6073858d52a2..15ccfb5d624c 100644 --- a/include/uapi/linux/vbox_vmmdev_types.h +++ b/include/uapi/linux/vbox_vmmdev_types.h @@ -229,14 +229,14 @@ struct vmmdev_hgcm_function_parameter32 { __u32 phys_addr; __u32 linear_addr; } u; - } pointer; + } __packed pointer; struct { /** Size of the buffer described by the page list. */ __u32 size; /** Relative to the request header. */ __u32 offset; - } page_list; - } u; + } __packed page_list; + } __packed u; } __packed; VMMDEV_ASSERT_SIZE(vmmdev_hgcm_function_parameter32, 4 + 8); @@ -251,14 +251,14 @@ struct vmmdev_hgcm_function_parameter64 { union { __u64 phys_addr; __u64 linear_addr; - } u; + } __packed u; } __packed pointer; struct { /** Size of the buffer described by the page list. */ __u32 size; /** Relative to the request header. */ __u32 offset; - } page_list; + } __packed page_list; } __packed u; } __packed; VMMDEV_ASSERT_SIZE(vmmdev_hgcm_function_parameter64, 4 + 12);