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 X-Spam-Level: X-Spam-Status: No, score=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_RED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE6D2C433E6 for ; Mon, 28 Dec 2020 12:58:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A0B922B40 for ; Mon, 28 Dec 2020 12:58:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729218AbgL1M6m (ORCPT ); Mon, 28 Dec 2020 07:58:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:54260 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728140AbgL1M6h (ORCPT ); Mon, 28 Dec 2020 07:58:37 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 377B2208BA; Mon, 28 Dec 2020 12:58:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609160301; bh=U/rmShT16J06mM0R42BKT9PDN+UC8RCxGEEbHBvPTYo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jWgeLIp9x61JO1Gou7m5vwwtt0qIps9fCCwHh4QkSNuOjtTptS6GgLHWtNUAEW3DL rVn6Kienlp3TCwNmEJ2GjQ+gJQXkSBibcTEa263jK0RvVLcaXYyGFxobTtAhs755SM hPVjGkalorv0nf1Il2hRqHtRfnO3RP7Zp3Gopk8A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars-Peter Clausen , Jonathan Cameron , Andy Shevchenko , Alexandru Ardelean , Peter Meerwald , Stable@vger.kernel.org Subject: [PATCH 4.4 126/132] iio:pressure:mpl3115: Force alignment of buffer Date: Mon, 28 Dec 2020 13:50:10 +0100 Message-Id: <20201228124852.501487166@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228124846.409999325@linuxfoundation.org> References: <20201228124846.409999325@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: Jonathan Cameron commit 198cf32f0503d2ad60d320b95ef6fb8243db857f upstream. Whilst this is another case of the issue Lars reported with an array of elements of smaller than 8 bytes being passed to iio_push_to_buffers_with_timestamp(), the solution here is a bit different from the other cases and relies on __aligned working on the stack (true since 4.6?) This one is unusual. We have to do an explicit memset() each time as we are reading 3 bytes into a potential 4 byte channel which may sometimes be a 2 byte channel depending on what is enabled. As such, moving the buffer to the heap in the iio_priv structure doesn't save us much. We can't use a nice explicit structure on the stack either as the data channels have different storage sizes and are all separately controlled. Fixes: cc26ad455f57 ("iio: Add Freescale MPL3115A2 pressure / temperature sensor driver") Reported-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Reviewed-by: Andy Shevchenko Reviewed-by: Alexandru Ardelean Cc: Peter Meerwald Cc: Link: https://lore.kernel.org/r/20200920112742.170751-7-jic23@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/iio/pressure/mpl3115.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/drivers/iio/pressure/mpl3115.c +++ b/drivers/iio/pressure/mpl3115.c @@ -139,7 +139,14 @@ static irqreturn_t mpl3115_trigger_handl struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct mpl3115_data *data = iio_priv(indio_dev); - u8 buffer[16]; /* 32-bit channel + 16-bit channel + padding + ts */ + /* + * 32-bit channel + 16-bit channel + padding + ts + * Note that it is possible for only one of the first 2 + * channels to be enabled. If that happens, the first element + * of the buffer may be either 16 or 32-bits. As such we cannot + * use a simple structure definition to express this data layout. + */ + u8 buffer[16] __aligned(8); int ret, pos = 0; mutex_lock(&data->lock);