Re: [PATCH v3 6/6] ata: libata-scsi: Check ATA_QCFLAG_RTF_FILLED before using result_tf

[Damien Le Moal <dlemoal@kernel.org>]

On 6/27/24 08:04, Igor Pylypiv wrote:
> qc->result_tf contents are only valid when the ATA_QCFLAG_RTF_FILLED flag
> is set. The ATA_QCFLAG_RTF_FILLED flag should be always set for commands
> that failed or for commands that have the ATA_QCFLAG_RESULT_TF flag set.
> 
> Signed-off-by: Igor Pylypiv <ipylypiv@google.com>

Please change "RTF" to "result TF" in the messages below, to be clear (RTF is
not). Feel free to split the ata_dev_dbg() lines after "dev," to avoid long lines.

With that:

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

> ---
>  drivers/ata/libata-scsi.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index 02af4d5d5799..d5874d4b9253 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -242,10 +242,16 @@ void ata_scsi_set_sense_information(struct ata_device *dev,
>   */
>  static void ata_scsi_set_passthru_sense_fields(struct ata_queued_cmd *qc)
>  {
> +	struct ata_device *dev = qc->dev;
>  	struct scsi_cmnd *cmd = qc->scsicmd;
>  	struct ata_taskfile *tf = &qc->result_tf;
>  	unsigned char *sb = cmd->sense_buffer;
>  
> +	if (!(qc->flags & ATA_QCFLAG_RTF_FILLED)) {
> +		ata_dev_dbg(dev, "Missing RTF: cannot set ATA PT sense fields.\n");
> +		return;
> +	}
> +
>  	if ((sb[0] & 0x7f) >= 0x72) {
>  		unsigned char *desc;
>  		u8 len;
> @@ -923,10 +929,16 @@ static void ata_to_sense_error(u8 drv_stat, u8 drv_err, u8 *sk, u8 *asc,
>   */
>  static void ata_gen_passthru_sense(struct ata_queued_cmd *qc)
>  {
> +	struct ata_device *dev = qc->dev;
>  	struct scsi_cmnd *cmd = qc->scsicmd;
>  	struct ata_taskfile *tf = &qc->result_tf;
>  	u8 sense_key, asc, ascq;
>  
> +	if (!(qc->flags & ATA_QCFLAG_RTF_FILLED)) {
> +		ata_dev_dbg(dev, "Missing RTF: cannot generate ATA PT sense data.\n");
> +		return;
> +	}
> +
>  	/*
>  	 * Use ata_to_sense_error() to map status register bits
>  	 * onto sense key, asc & ascq.
> @@ -970,6 +982,12 @@ static void ata_gen_ata_sense(struct ata_queued_cmd *qc)
>  		ata_scsi_set_sense(dev, cmd, NOT_READY, 0x04, 0x21);
>  		return;
>  	}
> +
> +	if (!(qc->flags & ATA_QCFLAG_RTF_FILLED)) {
> +		ata_dev_dbg(dev, "Missing RTF: cannot generate sense data.\n");
> +		return;
> +	}
> +
>  	/* Use ata_to_sense_error() to map status register bits
>  	 * onto sense key, asc & ascq.
>  	 */

-- 
Damien Le Moal
Western Digital Research