Re: [PATCH 2/2] scsi: core: Convert inquiry information

[Hannes Reinecke <hare@suse.de>]

On 5/12/26 21:46, Bart Van Assche wrote:
> Currently the vendor, model, and revision members of struct scsi_device
> are pointers to fixed-length strings that are not NUL-terminated.
> Fixed-precision format specifiers (e.g., "%.8s") are required whenever
> they are printed and strncmp() must be used to compare these fields.
> This is error-prone.
> 
> Convert these fields to fixed-size character arrays within struct
> scsi_device. Remove an !sdev->model check because sdev->model is now
> guaranteed not to be NULL.
> 
> This patch fixes a bug in the qla2xxx driver. It makes the following
> code safe:
> 
> 		if (state_flags & BIT_4)
> 			scmd_printk(KERN_WARNING, cp,
> 			    "Unsupported device '%s' found.\n",
> 			    cp->device->vendor);
> 
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
>   drivers/hwmon/drivetemp.c  |  5 +----
>   drivers/scsi/scsi_scan.c   | 12 ++++++------
>   include/scsi/scsi_device.h |  7 ++++---
>   3 files changed, 11 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/hwmon/drivetemp.c b/drivers/hwmon/drivetemp.c
> index 002e0660a0b8..efe8b229bdbe 100644
> --- a/drivers/hwmon/drivetemp.c
> +++ b/drivers/hwmon/drivetemp.c
> @@ -306,13 +306,10 @@ static bool drivetemp_sct_avoid(struct drivetemp_data *st)
>   	struct scsi_device *sdev = st->sdev;
>   	unsigned int ctr;
>   
> -	if (!sdev->model)
> -		return false;
> -
>   	/*
>   	 * The "model" field contains just the raw SCSI INQUIRY response
>   	 * "product identification" field, which has a width of 16 bytes.
> -	 * This field is space-filled, but is NOT NULL-terminated.
> +	 * This field is space-filled and NUL-terminated.
>   	 */
>   	for (ctr = 0; ctr < ARRAY_SIZE(sct_avoid_models); ctr++)
>   		if (!strncmp(sdev->model, sct_avoid_models[ctr],
> diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
> index ef22a4228b85..6c3a5d451c1d 100644
> --- a/drivers/scsi/scsi_scan.c
> +++ b/drivers/scsi/scsi_scan.c
> @@ -292,9 +292,9 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
>   	if (!sdev)
>   		goto out;
>   
> -	sdev->vendor = scsi_null_device_strs;
> -	sdev->model = scsi_null_device_strs;
> -	sdev->rev = scsi_null_device_strs;
> +	strscpy(sdev->vendor, scsi_null_device_strs);
> +	strscpy(sdev->model, scsi_null_device_strs);
> +	strscpy(sdev->rev, scsi_null_device_strs);
>   	sdev->host = shost;
>   	sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD;
>   	sdev->id = starget->id;
> @@ -905,9 +905,9 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
>   	if (sdev->inquiry == NULL)
>   		return SCSI_SCAN_NO_RESPONSE;
>   
> -	sdev->vendor = (char *) (sdev->inquiry + 8);
> -	sdev->model = (char *) (sdev->inquiry + 16);
> -	sdev->rev = (char *) (sdev->inquiry + 32);
> +	strscpy(sdev->vendor, sdev->inquiry + 8);
> +	strscpy(sdev->model, sdev->inquiry + 16);
> +	strscpy(sdev->rev, sdev->inquiry + 32);
>   
>   	sdev->is_ata = strncmp(sdev->vendor, "ATA     ", 8) == 0;
>   	if (sdev->is_ata) {


Question is whether we shouldn't make this generic, ie treat 'inquiry'
as a temporary blob, copy things over to fields in 'sdev', and then
free the 'inquiry' blob again.
There are soo many things tacked onto the standard inquiry data 
(especially for storage array trying to mimic SCSI-2 inquiry data),
that we're better of copying over only fields which we _know_.
_And_ it'll save us a permanent data allocation for the scsi device...

Hmm?

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
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