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authorHuacai Chen <chenhc@lemote.com>2017-11-21 14:23:39 +0100
committerMartin K. Petersen <martin.petersen@oracle.com>2017-11-21 23:06:32 -0500
commitc2e8fbf908afd81ad502b567a6639598f92c9b9d (patch)
treeda52dc8f0f0298711ddb13259e95e88668bf8a1d
parent90addc6b3c9cda0146fbd62a08e234c2b224a80c (diff)
scsi: libsas: align sata_device's rps_resp on a cacheline
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 <chenhc@lemote.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
-rw-r--r--include/scsi/libsas.h2
1 files changed, 1 insertions, 1 deletions
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];
};