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| author |   Huacai Chen <chenhc@lemote.com> | 2017-11-21 14:23:39 +0100 |
|---|---|---|
| committer |   Martin K. Petersen <martin.petersen@oracle.com> | 2017-11-21 23:06:32 -0500 |
| commit | c2e8fbf908afd81ad502b567a6639598f92c9b9d (patch) | |
| tree | da52dc8f0f0298711ddb13259e95e88668bf8a1d /include/scsi | |
| parent | scsi: use dma_get_cache_alignment() as minimum DMA alignment (diff) | |
| download | linux-dev-c2e8fbf908afd81ad502b567a6639598f92c9b9d.tar.xz linux-dev-c2e8fbf908afd81ad502b567a6639598f92c9b9d.zip | |
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>
Diffstat (limited to 'include/scsi')
| -rw-r--r-- | include/scsi/libsas.h | 2 |
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]; }; |