[SCSI] libsas: fix taskfile corruption in sas_ata_qc_fill_rtf

fill_result_tf() grabs the taskfile flags from the originating qc which
sas_ata_qc_fill_rtf() promptly overwrites.  The presence of an
ata_taskfile in the sata_device makes it tempting to just copy the full
contents in sas_ata_qc_fill_rtf().  However, libata really only wants
the fis contents and expects the other portions of the taskfile to not
be touched by ->qc_fill_rtf.  To that end store a fis buffer in the
sata_device and use ata_tf_from_fis() like every other ->qc_fill_rtf()
implementation.

Cc: <stable@vger.kernel.org>
Reported-by: Praveen Murali <pmurali@logicube.com>
Tested-by: Praveen Murali <pmurali@logicube.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

3 files changed, 11 insertions, 9 deletions

diff --git a/drivers/scsi/aic94xx/aic94xx_task.c b/drivers/scsi/aic94xx/aic94xx_task.c
index 532d212b6b2c..393e7ce8e95a 100644
--- a/drivers/scsi/aic94xx/aic94xx_task.c
+++ b/drivers/scsi/aic94xx/aic94xx_task.c
@@ -201,7 +201,7 @@ static void asd_get_response_tasklet(struct asd_ascb *ascb,
 
                 if (SAS_STATUS_BUF_SIZE >= sizeof(*resp)) {
                         resp->frame_len = le16_to_cpu(*(__le16 *)(r+6));
-                        memcpy(&resp->ending_fis[0], r+16, 24);
+                        memcpy(&resp->ending_fis[0], r+16, ATA_RESP_FIS_SIZE);
                         ts->buf_valid_size = sizeof(*resp);
                 }
         }
diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index 441d88ad99a7..d109cc3a17b6 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -139,12 +139,12 @@ static void sas_ata_task_done(struct sas_task *task)
         if (stat->stat == SAS_PROTO_RESPONSE || stat->stat == SAM_STAT_GOOD ||
             ((stat->stat == SAM_STAT_CHECK_CONDITION &&
               dev->sata_dev.command_set == ATAPI_COMMAND_SET))) {
-                ata_tf_from_fis(resp->ending_fis, &dev->sata_dev.tf);
+                memcpy(dev->sata_dev.fis, resp->ending_fis, ATA_RESP_FIS_SIZE);
 
                 if (!link->sactive) {
-                        qc->err_mask |= ac_err_mask(dev->sata_dev.tf.command);
+                        qc->err_mask |= ac_err_mask(dev->sata_dev.fis[2]);
                 } else {
-                        link->eh_info.err_mask |= ac_err_mask(dev->sata_dev.tf.command);
+                        link->eh_info.err_mask |= ac_err_mask(dev->sata_dev.fis[2]);
                         if (unlikely(link->eh_info.err_mask))
                                 qc->flags |= ATA_QCFLAG_FAILED;
                 }
@@ -161,8 +161,8 @@ static void sas_ata_task_done(struct sas_task *task)
                                 qc->flags |= ATA_QCFLAG_FAILED;
                         }
 
-                        dev->sata_dev.tf.feature = 0x04; /* status err */
-                        dev->sata_dev.tf.command = ATA_ERR;
+                        dev->sata_dev.fis[3] = 0x04; /* status err */
+                        dev->sata_dev.fis[2] = ATA_ERR;
                 }
         }
 
@@ -269,7 +269,7 @@ static bool sas_ata_qc_fill_rtf(struct ata_queued_cmd *qc)
 {
         struct domain_device *dev = qc->ap->private_data;
 
-        memcpy(&qc->result_tf, &dev->sata_dev.tf, sizeof(qc->result_tf));
+        ata_tf_from_fis(dev->sata_dev.fis, &qc->result_tf);
         return true;
 }
 
diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index f4f1c96dca72..10ce74f589c5 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -163,6 +163,8 @@ enum ata_command_set {
         ATAPI_COMMAND_SET = 1,
 };
 
+#define ATA_RESP_FIS_SIZE 24
+
 struct sata_device {
         enum   ata_command_set command_set;
         struct smp_resp        rps_resp; /* report_phy_sata_resp */
@@ -171,7 +173,7 @@ struct sata_device {
 
         struct ata_port *ap;
         struct ata_host ata_host;
-        struct ata_taskfile tf;
+        u8     fis[ATA_RESP_FIS_SIZE];
 };
 
 enum {
@@ -537,7 +539,7 @@ enum exec_status {
  */
 struct ata_task_resp {
         u16  frame_len;
-        u8   ending_fis[24];      /* dev to host or data-in */
+        u8   ending_fis[ATA_RESP_FIS_SIZE];       /* dev to host or data-in */
 };
 
 #define SAS_STATUS_BUF_SIZE 96