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 84bda12af3 ("libata:
align ap->sector_buf") and Commit 4ee34ea3a1 ("libata: Align
ata_device's id on a cacheline").
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Huacai Chen
35b4bfbda5