From mboxrd@z Thu Jan 1 00:00:00 1970 From: Huacai Chen Subject: [PATCH V9 4/4] libsas: Align sata_device's rps_resp on a cacheline Date: Mon, 23 Oct 2017 15:12:47 +0800 Message-ID: <1508742767-28366-4-git-send-email-chenhc@lemote.com> References: <1508742767-28366-1-git-send-email-chenhc@lemote.com> Return-path: Received: from smtpbgbr2.qq.com ([54.207.22.56]:34489 "EHLO smtpbgbr2.qq.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751291AbdJWHKk (ORCPT ); Mon, 23 Oct 2017 03:10:40 -0400 In-Reply-To: <1508742767-28366-1-git-send-email-chenhc@lemote.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Christoph Hellwig Cc: Marek Szyprowski , Robin Murphy , Andrew Morton , Fuxin Zhang , linux-kernel@vger.kernel.org, Ralf Baechle , James Hogan , linux-mips@linux-mips.org, "James E . J . Bottomley" , "Martin K . Petersen" , linux-scsi@vger.kernel.org, Huacai Chen , stable@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 6c0dc61..a966d28 100644 --- a/include/scsi/libsas.h +++ b/include/scsi/libsas.h @@ -165,11 +165,11 @@ 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