From: Huacai Chen Date: Tue, 21 Nov 2017 13:23:39 +0000 (+0100) Subject: scsi: libsas: align sata_device's rps_resp on a cacheline X-Git-Tag: v4.4.106~94 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7e0091c2951fa831992d2f00e4453951d84a58b6;p=thirdparty%2Fkernel%2Fstable.git scsi: libsas: align sata_device's rps_resp on a cacheline commit c2e8fbf908afd81ad502b567a6639598f92c9b9d upstream. 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"). Signed-off-by: Huacai Chen Signed-off-by: Christoph Hellwig Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman --- diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h index dae99d7d2bc05..706a7017885c2 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]; };