[PATCH v4 1/8] ata: libata-scsi: Fix offsets for the fixed format sense data

Igor Pylypiv
2024-07-01T19:58:06Z

Correct the ATA PASS-THROUGH fixed format sense data offsets to conform
to SPC-6 and SAT-5 specifications. Additionally, set the VALID bit to
indicate that the INFORMATION field contains valid information.

INFORMATION
===========

SAT-5 Table 212 — "Fixed format sense data INFORMATION field for the ATA
PASS-THROUGH commands" defines the following format:

+------+------------+
| Byte | Field |
+------+------------+
| 0 | ERROR |
| 1 | STATUS |
| 2 | DEVICE |
| 3 | COUNT(7:0) |
+------+------------+

SPC-6 Table 48 - "Fixed format sense data" specifies that the INFORMATION
field starts at byte 3 in sense buffer resulting in the following offsets
for the ATA PASS-THROUGH commands:

+------------+-------------------------+
| Field | Offset in sense buffer |
+------------+-------------------------+
| ERROR | 3 |
| STATUS | 4 |
| DEVICE | 5 |
| COUNT(7:0) | 6 |
+------------+-------------------------+

COMMAND-SPECIFIC INFORMATION
============================

SAT-5 Table 213 - "Fixed format sense data COMMAND-SPECIFIC INFORMATION
field for ATA PASS-THROUGH" defines the following format:

+------+-------------------+
| Byte | Field |
+------+-------------------+
| 0 | FLAGS | LOG INDEX |
| 1 | LBA (7:0) |
| 2 | LBA (15:8) |
| 3 | LBA (23:16) |
+------+-------------------+

SPC-6 Table 48 - "Fixed format sense data" specifies that
the COMMAND-SPECIFIC-INFORMATION field starts at byte 8
in sense buffer resulting in the following offsets for
the ATA PASS-THROUGH commands:

Offsets of these fields in the fixed sense format are as follows:

+-------------------+-------------------------+
| Field | Offset in sense buffer |
+-------------------+-------------------------+
| FLAGS | LOG INDEX | 8 |
| LBA (7:0) | 9 |
| LBA (15:8) | 10 |
| LBA (23:16) | 11 |
+-------------------+-------------------------+

Reported-by: Akshat Jain <akshatzen@google.com>
Fixes: 11093cb1ef56 ("libata-scsi: generate correct ATA pass-through sense")
Cc: stable@vger.kernel.org
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
---
drivers/ata/libata-scsi.c | 26 +++++++++++++-------------
1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index bb4d30d377ae..a9e44ad4c2de 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -855,7 +855,6 @@ static void ata_gen_passthru_sense(struct ata_queued_cmd *qc)
struct scsi_cmnd *cmd = qc->scsicmd;
struct ata_taskfile *tf = &qc->result_tf;
unsigned char *sb = cmd->sense_buffer;
- unsigned char *desc = sb + 8;
u8 sense_key, asc, ascq;

memset(sb, 0, SCSI_SENSE_BUFFERSIZE);
@@ -877,7 +876,8 @@ static void ata_gen_passthru_sense(struct ata_queued_cmd *qc)
scsi_build_sense(cmd, 1, RECOVERED_ERROR, 0, 0x1D);
}

- if ((cmd->sense_buffer[0] & 0x7f) >= 0x72) {
+ if ((sb[0] & 0x7f) >= 0x72) {
+ unsigned char *desc;
u8 len;

/* descriptor format */
@@ -916,21 +916,21 @@ static void ata_gen_passthru_sense(struct ata_queued_cmd *qc)
}
} else {
/* Fixed sense format */
- desc[0] = tf->error;
- desc[1] = tf->status;
- desc[2] = tf->device;
- desc[3] = tf->nsect;
- desc[7] = 0;
+ sb[0] |= 0x80;
+ sb[3] = tf->error;
+ sb[4] = tf->status;
+ sb[5] = tf->device;
+ sb[6] = tf->nsect;
if (tf->flags & ATA_TFLAG_LBA48) {
- desc[8] |= 0x80;
+ sb[8] |= 0x80;
if (tf->hob_nsect)
- desc[8] |= 0x40;
+ sb[8] |= 0x40;
if (tf->hob_lbal || tf->hob_lbam || tf->hob_lbah)
- desc[8] |= 0x20;
+ sb[8] |= 0x20;
}
- desc[9] = tf->lbal;
- desc[10] = tf->lbam;
- desc[11] = tf->lbah;
+ sb[9] = tf->lbal;
+ sb[10] = tf->lbam;
+ sb[11] = tf->lbah;
}
}

--
2.45.2.803.g4e1b14247a-goog