Re: [PATCH v6 2/4] virtio_rtc: Add PTP clocks

[kernel test robot]

Hi Peter,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 9d8960672d63db4b3b04542f5622748b345c637a]

url:    https://github.com/intel-lab-lkp/linux/commits/Peter-Hilber/virtio_rtc-Add-module-and-driver-core/20250314-014130
base:   9d8960672d63db4b3b04542f5622748b345c637a
patch link:    https://lore.kernel.org/r/20250313173707.1492-3-quic_philber%40quicinc.com
patch subject: [PATCH v6 2/4] virtio_rtc: Add PTP clocks
config: sparc-allyesconfig (https://download.01.org/0day-ci/archive/20250319/202503190602.IElWB74j-lkp@xxxxxxxxx/config)
compiler: sparc64-linux-gcc (GCC) 7.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250319/202503190602.IElWB74j-lkp@xxxxxxxxx/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503190602.IElWB74j-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

   drivers/virtio/virtio_rtc_driver.c: In function 'viortc_probe':
>> drivers/virtio/virtio_rtc_driver.c:665:23: warning: '/variant ' directive output may be truncated writing 9 bytes into a region of size between 6 and 15 [-Wformat-truncation=]
       "Virtio PTP type %d/variant %d", clock_type,
                          ^~~~~~~~~
   drivers/virtio/virtio_rtc_driver.c:665:4: note: directive argument in the range [0, 2147483647]
       "Virtio PTP type %d/variant %d", clock_type,
       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/virtio/virtio_rtc_driver.c:664:2: note: 'snprintf' output between 28 and 46 bytes into a destination of size 32
     snprintf(ptp_clock_name, PTP_CLOCK_NAME_LEN,
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       "Virtio PTP type %d/variant %d", clock_type,
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       leap_second_smearing);
       ~~~~~~~~~~~~~~~~~~~~~


vim +665 drivers/virtio/virtio_rtc_driver.c

   641	
   642	/*
   643	 * init, deinit
   644	 */
   645	
   646	/**
   647	 * viortc_init_ptp_clock() - init and register PTP clock
   648	 * @viortc: device data
   649	 * @vio_clk_id: virtio_rtc clock id
   650	 * @clock_type: virtio_rtc clock type
   651	 * @leap_second_smearing: virtio_rtc leap second smearing
   652	 *
   653	 * Context: Process context.
   654	 * Return: Positive if registered, zero if not supported by configuration,
   655	 *         negative error code otherwise.
   656	 */
   657	static int viortc_init_ptp_clock(struct viortc_dev *viortc, u16 vio_clk_id,
   658					 u8 clock_type, u8 leap_second_smearing)
   659	{
   660		struct device *dev = &viortc->vdev->dev;
   661		char ptp_clock_name[PTP_CLOCK_NAME_LEN];
   662		struct viortc_ptp_clock *vio_ptp;
   663	
   664		snprintf(ptp_clock_name, PTP_CLOCK_NAME_LEN,
 > 665			 "Virtio PTP type %d/variant %d", clock_type,
   666			 leap_second_smearing);
   667	
   668		vio_ptp = viortc_ptp_register(viortc, dev, vio_clk_id, ptp_clock_name);
   669		if (IS_ERR(vio_ptp)) {
   670			dev_err(dev, "failed to register PTP clock '%s'\n",
   671				ptp_clock_name);
   672			return PTR_ERR(vio_ptp);
   673		}
   674	
   675		viortc->clocks_to_unregister[vio_clk_id] = vio_ptp;
   676	
   677		return !!vio_ptp;
   678	}
   679	

-- 
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https://github.com/intel/lkp-tests/wiki