From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933207AbdKQEbC (ORCPT ); Thu, 16 Nov 2017 23:31:02 -0500 Received: from mail-pg0-f66.google.com ([74.125.83.66]:35634 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932720AbdKQEav (ORCPT ); Thu, 16 Nov 2017 23:30:51 -0500 X-Google-Smtp-Source: AGs4zMbyRIlQ8nitge4oIZ4LoHC1FYzZ/OnTiqT8Mdvqi7jWWz0Z6jLk3zvZDcs0aDlWywzTT1OGDg== From: Huacai Chen To: Christoph Hellwig Cc: Marek Szyprowski , Robin Murphy , Andrew Morton , Fuxin Zhang , linux-mips@linux-mips.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, Huacai Chen , stable@vger.kernel.org Subject: [PATCH V10 4/4] libsas: Align sata_device's rps_resp on a cacheline Date: Fri, 17 Nov 2017 12:30:51 +0800 Message-Id: <1510893051-376-1-git-send-email-chenhc@lemote.com> X-Mailer: git-send-email 2.7.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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 0f9cbf9..6df6fe0 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]; }; -- 2.7.0