Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759365AbcCVK7Z (ORCPT ); Tue, 22 Mar 2016 06:59:25 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:56794 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758829AbcCVKmo (ORCPT ); Tue, 22 Mar 2016 06:42:44 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Harvey Hunt , Tejun Heo , Luis Henriques Subject: [PATCH 3.16.y-ckt 084/142] libata: Align ata_device's id on a cacheline Date: Tue, 22 Mar 2016 10:40:13 +0000 Message-Id: <1458643271-4227-85-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1458643271-4227-1-git-send-email-luis.henriques@canonical.com> References: <1458643271-4227-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1421 Lines: 39 3.16.7-ckt26 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Harvey Hunt commit 4ee34ea3a12396f35b26d90a094c75db95080baa upstream. The id buffer in ata_device is a DMA target, but it isn't explicitly cacheline aligned. Due to this, adjacent fields can be overwritten with stale data from memory on non coherent architectures. As a result, the kernel is sometimes unable to communicate with an ATA device. Fix this by ensuring that the id buffer is cacheline aligned. This issue is similar to that fixed by Commit 84bda12af31f ("libata: align ap->sector_buf"). Signed-off-by: Harvey Hunt Cc: linux-kernel@vger.kernel.org Signed-off-by: Tejun Heo Signed-off-by: Luis Henriques --- include/linux/libata.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/libata.h b/include/linux/libata.h index 714274450c07..bd83b8e83cfe 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -714,7 +714,7 @@ struct ata_device { union { u16 id[ATA_ID_WORDS]; /* IDENTIFY xxx DEVICE data */ u32 gscr[SATA_PMP_GSCR_DWORDS]; /* PMP GSCR block */ - }; + } ____cacheline_aligned; /* DEVSLP Timing Variables from Identify Device Data Log */ u8 devslp_timing[ATA_LOG_DEVSLP_SIZE];