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Message-ID: <a6093892d7201fb940e14a571bc853829e704d0f.camel@linux.ibm.com>
Subject: Re: [PATCH] scsi: isci: convert sysfs sprintf/snprintf family to
 sysfs_emit
From:   James Bottomley <jejb@linux.ibm.com>
Reply-To: jejb@linux.ibm.com
To:     Jiapeng Chong <jiapeng.chong@linux.alibaba.com>,
        intel-linux-scu@intel.com
Cc:     artur.paszkiewicz@intel.com, martin.petersen@oracle.com,
        linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
Date:   Wed, 03 Feb 2021 08:15:22 -0800
In-Reply-To: <1612341806-30230-1-git-send-email-jiapeng.chong@linux.alibaba.com>
References: <1612341806-30230-1-git-send-email-jiapeng.chong@linux.alibaba.com>
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On Wed, 2021-02-03 at 16:43 +0800, Jiapeng Chong wrote:
> Fix the following coccicheck warning:
> 
>  ./drivers/scsi/isci/init.c:140:8-16: WARNING: use scnprintf or
> sprintf.
> 
> Reported-by: Abaci Robot<abaci@linux.alibaba.com>
> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
> ---
>  drivers/scsi/isci/init.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/isci/init.c b/drivers/scsi/isci/init.c
> index c452849..741a98e 100644
> --- a/drivers/scsi/isci/init.c
> +++ b/drivers/scsi/isci/init.c
> @@ -137,7 +137,7 @@ static ssize_t isci_show_id(struct device *dev,
> struct device_attribute *attr, c
>  	struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
>  	struct isci_host *ihost = container_of(sas_ha, typeof(*ihost),
> sas_ha);
>  
> -	return snprintf(buf, PAGE_SIZE, "%d\n", ihost->id);
> +	return sysfs_emit(buf, "%d\n", ihost->id);

What's the point of doing this change?  We'd have to have 13,600 bit
integer types before this could ever possibly overflow and the
difference between snprintf and scnprintf actually matter from a
practical point of view.  Perhaps the coccinelle check should be
updated to account for these common impossible to overflow situations.

James