Re: [PATCH 02/11] scsi: devinfo: rework scsi_strcpy_devinfo()

From: Bart Van Assche <bvanassche@acm.org>
To: Arnd Bergmann <arnd@kernel.org>,
	linux-kernel@vger.kernel.org,
	"James E.J. Bottomley" <jejb@linux.ibm.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Arnd Bergmann <arnd@arndb.de>, Chris Down <chris@chrisdown.name>,
	Petr Mladek <pmladek@suse.com>,
	linux-scsi@vger.kernel.org
Subject: Re: [PATCH 02/11] scsi: devinfo: rework scsi_strcpy_devinfo()
Date: Thu, 28 Mar 2024 09:46:58 -0700	[thread overview]
Message-ID: <73de2cd5-9770-453c-b002-7cd561bdbc7b@acm.org> (raw)
In-Reply-To: <20240328140512.4148825-3-arnd@kernel.org>

On 3/28/24 07:04, Arnd Bergmann wrote:
> diff --git a/drivers/scsi/scsi_devinfo.c b/drivers/scsi/scsi_devinfo.c
> index ba7237e83863..58726c15ebac 100644
> --- a/drivers/scsi/scsi_devinfo.c
> +++ b/drivers/scsi/scsi_devinfo.c
> @@ -290,18 +290,28 @@ static struct scsi_dev_info_list_table *scsi_devinfo_lookup_by_key(int key)
>   static void scsi_strcpy_devinfo(char *name, char *to, size_t to_length,
>   				char *from, int compatible)
>   {
> -	size_t from_length;
> +	int ret;
>   
> -	from_length = strlen(from);
> -	/* This zero-pads the destination */
> -	strncpy(to, from, to_length);
> -	if (from_length < to_length && !compatible) {
> -		/*
> -		 * space pad the string if it is short.
> -		 */
> -		memset(&to[from_length], ' ', to_length - from_length);
> +	if (compatible) {
> +		/* This zero-pads and nul-terminates the destination */
> +		ret = strscpy_pad(to, from, to_length);
> +	} else {
> +		/* no nul-termination but space-padding for short strings */
> +		size_t from_length = strlen(from);
> +		ret = from_length;
> +
> +		if (from_length > to_length) {
> +			from_length = to_length;
> +			ret = -E2BIG;
> +		}
> +
> +		memcpy(to, from, from_length);
> +
> +		if (from_length < to_length)
> +			memset(&to[from_length], ' ', to_length - from_length);
>   	}
> -	if (from_length > to_length)
> +
> +	if (ret < 0)
>   		 printk(KERN_WARNING "%s: %s string '%s' is too long\n",
>   			__func__, name, from);
>   }

Please eliminate the variable 'ret'. I think that will improve
readability of the new code.

Thanks,

Bart.