From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([65.50.211.133]:57795 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751115AbdKUNXx (ORCPT ); Tue, 21 Nov 2017 08:23:53 -0500 From: Christoph Hellwig To: "Martin K. Petersen" Cc: Huacai Chen , linux-scsi@vger.kernel.org, iommu@lists.linux-foundation.org, stable@vger.kernel.org Subject: [PATCH 3/3] libsas: align sata_device's rps_resp on a cacheline Date: Tue, 21 Nov 2017 14:23:39 +0100 Message-Id: <20171121132339.1702-4-hch@lst.de> In-Reply-To: <20171121132339.1702-1-hch@lst.de> References: <20171121132339.1702-1-hch@lst.de> Sender: stable-owner@vger.kernel.org List-ID: From: Huacai Chen The rps_resp 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 SATA device behind a SAS expander. Fix this by ensuring that the rps_resp buffer is cacheline aligned. This issue is similar to that fixed by Commit 84bda12af31f93 ("libata: align ap->sector_buf") and Commit 4ee34ea3a12396f35b26 ("libata: Align ata_device's id on a cacheline"). Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen Signed-off-by: Christoph Hellwig --- include/scsi/libsas.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h index 0f9cbf96c093..6df6fe0c2198 100644 --- a/include/scsi/libsas.h +++ b/include/scsi/libsas.h @@ -159,11 +159,11 @@ struct expander_device { struct sata_device { unsigned int class; - struct smp_resp rps_resp; /* report_phy_sata_resp */ u8 port_no; /* port number, if this is a PM (Port) */ struct ata_port *ap; struct ata_host ata_host; + struct smp_resp rps_resp ____cacheline_aligned; /* report_phy_sata_resp */ u8 fis[ATA_RESP_FIS_SIZE]; }; -- 2.14.2