Re: [PATCH] ptp: ocp: Fix the wrong format specifier

[Paolo Abeni]

On 11/20/24 07:26, zhangjiao2 wrote:
> From: zhang jiao <zhangjiao2@xxxxxxxxxxxxxxxxxxxx>
> 
> Use '%u' instead of '%d' for unsigned int.
> 
> Signed-off-by: zhang jiao <zhangjiao2@xxxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/ptp/ptp_ocp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
> index 5feecaadde8e..52e46fee8e5e 100644
> --- a/drivers/ptp/ptp_ocp.c
> +++ b/drivers/ptp/ptp_ocp.c
> @@ -1455,7 +1455,7 @@ ptp_ocp_verify(struct ptp_clock_info *ptp_info, unsigned pin,
>  		 * channels 1..4 are the frequency generators.
>  		 */
>  		if (chan)
> -			snprintf(buf, sizeof(buf), "OUT: GEN%d", chan);
> +			snprintf(buf, sizeof(buf), "OUT: GEN%u", chan);

Note that the above would still cause a warning, as the formatted string
could be theoretically truncated:

../drivers/ptp/ptp_ocp.c:1458:61: warning: ‘%u’ directive output may be
truncated writing between 1 and 10 bytes into a region of size 8
[-Wformat-truncation=]
                         snprintf(buf, sizeof(buf), "OUT: GEN%u", chan);

Since 'chan' range is [1,4] you can probably safely cast it an unsigned
byte, and update the format string accordingly.

/P