Re: [patch 4/6] drivers/scsi/sg.c: convert to kstrtoul_from_user()

[Douglas Gilbert <dgilbert@interlog.com>]

On 12-01-11 10:42 AM, akpm@linux-foundation.org wrote:
> From: Stephen Boyd<sboyd@codeaurora.org>
> Subject: drivers/scsi/sg.c: convert to kstrtoul_from_user()
>
> Instead of open coding this function use kstrtoul_from_user() directly.
>
> Signed-off-by: Stephen Boyd<sboyd@codeaurora.org>
> Cc: Doug Gilbert<dgilbert@interlog.com>
> Cc: Douglas Gilbert<dougg@torque.net>
> Cc: James Bottomley<James.Bottomley@HansenPartnership.com>
> Signed-off-by: Andrew Morton<akpm@linux-foundation.org>

Acked-by: Douglas Gilbert<dgilbert@interlog.com>

> ---
>
>   drivers/scsi/sg.c |   25 +++++++++++--------------
>   1 file changed, 11 insertions(+), 14 deletions(-)
>
> diff -puN drivers/scsi/sg.c~drivers-scsi-sgc-convert-to-kstrtoul_from_user drivers/scsi/sg.c
> --- a/drivers/scsi/sg.c~drivers-scsi-sgc-convert-to-kstrtoul_from_user
> +++ a/drivers/scsi/sg.c
> @@ -2368,16 +2368,15 @@ static ssize_t
>   sg_proc_write_adio(struct file *filp, const char __user *buffer,
>   		   size_t count, loff_t *off)
>   {
> -	int num;
> -	char buff[11];
> +	int err;
> +	unsigned long num;
>
>   	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
>   		return -EACCES;
> -	num = (count<  10) ? count : 10;
> -	if (copy_from_user(buff, buffer, num))
> -		return -EFAULT;
> -	buff[num] = '\0';
> -	sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
> +	err = kstrtoul_from_user(buffer, count, 0,&num);
> +	if (err)
> +		return err;
> +	sg_allow_dio = num ? 1 : 0;
>   	return count;
>   }
>
> @@ -2390,17 +2389,15 @@ static ssize_t
>   sg_proc_write_dressz(struct file *filp, const char __user *buffer,
>   		     size_t count, loff_t *off)
>   {
> -	int num;
> +	int err;
>   	unsigned long k = ULONG_MAX;
> -	char buff[11];
>
>   	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
>   		return -EACCES;
> -	num = (count<  10) ? count : 10;
> -	if (copy_from_user(buff, buffer, num))
> -		return -EFAULT;
> -	buff[num] = '\0';
> -	k = simple_strtoul(buff, NULL, 10);
> +
> +	err = kstrtoul_from_user(buffer, count, 0,&k);
> +	if (err)
> +		return err;
>   	if (k<= 1048576) {	/* limit "big buff" to 1 MB */
>   		sg_big_buff = k;
>   		return count;
> _
>