From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17A21C433EF for ; Tue, 7 Jun 2022 22:19:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381695AbiFGWTs (ORCPT ); Tue, 7 Jun 2022 18:19:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50688 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379858AbiFGVN5 (ORCPT ); Tue, 7 Jun 2022 17:13:57 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5059821AC59; Tue, 7 Jun 2022 11:54:32 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 93BA2B8239E; Tue, 7 Jun 2022 18:54:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BC428C36B0F; Tue, 7 Jun 2022 18:54:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654628069; bh=8gQNAltN6BIULDhgTdmaQHw+k3XtzpJbkUP7TqeHUWw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YcIOiwzRj7woc6EZxFIe7MzNnsJCaKNkiz1qej11JpfPXbuFUJdDhFGRZVbSGcf1R xS8ufHYJoUbKjshu8nxuINkpHWVqdfQ/uYt44LFv+Gr4mYFpv15fVoiZ7dm1Uw4vob xGHth16cDxpuz3pn7RH98yD8MgYKdqQnGD2UwPTw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vincent Mailhol , kernel test robot , Marc Kleine-Budde , Sasha Levin , Nathan Chancellor Subject: [PATCH 5.18 193/879] can: mcp251xfd: silence clangs -Wunaligned-access warning Date: Tue, 7 Jun 2022 18:55:11 +0200 Message-Id: <20220607165008.444219311@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607165002.659942637@linuxfoundation.org> References: <20220607165002.659942637@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vincent Mailhol [ Upstream commit 1a6dd9996699889313327be03981716a8337656b ] clang emits a -Wunaligned-access warning on union mcp251xfd_tx_ojb_load_buf. The reason is that field hw_tx_obj (not declared as packed) is being packed right after a 16 bits field inside a packed struct: | union mcp251xfd_tx_obj_load_buf { | struct __packed { | struct mcp251xfd_buf_cmd cmd; | /* ^ 16 bits fields */ | struct mcp251xfd_hw_tx_obj_raw hw_tx_obj; | /* ^ not declared as packed */ | } nocrc; | struct __packed { | struct mcp251xfd_buf_cmd_crc cmd; | struct mcp251xfd_hw_tx_obj_raw hw_tx_obj; | __be16 crc; | } crc; | } ____cacheline_aligned; Starting from LLVM 14, having an unpacked struct nested in a packed struct triggers a warning. c.f. [1]. This is a false positive because the field is always being accessed with the relevant put_unaligned_*() function. Adding __packed to the structure declaration silences the warning. [1] https://github.com/llvm/llvm-project/issues/55520 Link: https://lore.kernel.org/all/20220518114357.55452-1-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol Reported-by: kernel test robot Tested-by: Nathan Chancellor # build Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin --- drivers/net/can/spi/mcp251xfd/mcp251xfd.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h index 9cb6b5ad8dda..60e56fa4601d 100644 --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h @@ -441,7 +441,7 @@ struct mcp251xfd_hw_tef_obj { /* The tx_obj_raw version is used in spi async, i.e. without * regmap. We have to take care of endianness ourselves. */ -struct mcp251xfd_hw_tx_obj_raw { +struct __packed mcp251xfd_hw_tx_obj_raw { __le32 id; __le32 flags; u8 data[sizeof_field(struct canfd_frame, data)]; -- 2.35.1