[openeuler:OLK-5.10 3011/3011] drivers/net/ethernet/mucse/rnpm/rnpm_sysfs.c:1524:2: warning: 'strncpy' specified bound 100 equals destination size

[kernel test robot <lkp@intel.com>]

tree:   https://gitee.com/openeuler/kernel.git OLK-5.10
head:   41b7827f33a9fc1fe425b85029312de34b0f0abe
commit: a0c5bfdbc099daf30cbadb9657803f0cb3f89d0b [3011/3011] drivers: support for rnpm drivers from Mucse Technology N10/N400
config: arm64-randconfig-004-20250704 (https://download.01.org/0day-ci/archive/20250704/202507041638.fqBxner2-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 10.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250704/202507041638.fqBxner2-lkp@intel.com/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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202507041638.fqBxner2-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/net/ethernet/mucse/rnpm/rnpm_sysfs.c:263:5: warning: no previous prototype for 'rnpm_mbx_get_pn_sn' [-Wmissing-prototypes]
     263 | int rnpm_mbx_get_pn_sn(struct rnpm_hw *hw, char pn[33], char sn[33])
         |     ^~~~~~~~~~~~~~~~~~
   drivers/net/ethernet/mucse/rnpm/rnpm_sysfs.c: In function '_switch_loopback':
>> drivers/net/ethernet/mucse/rnpm/rnpm_sysfs.c:1524:2: warning: 'strncpy' specified bound 100 equals destination size [-Wstringop-truncation]
    1524 |  strncpy(name, peer_eth, sizeof(name));
         |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/strncpy +1524 drivers/net/ethernet/mucse/rnpm/rnpm_sysfs.c

  1515	
  1516	static ssize_t _switch_loopback(struct rnpm_adapter *adapter,
  1517					const char *peer_eth, int en)
  1518	{
  1519		struct net_device *peer_netdev = NULL;
  1520		struct rnpm_adapter *peer_adapter = NULL;
  1521		int i;
  1522		char name[100];
  1523	
> 1524		strncpy(name, peer_eth, sizeof(name));
  1525		strim(name);
  1526	
  1527		peer_netdev = dev_get_by_name(&init_net, name);
  1528		if (!peer_netdev) {
  1529			e_dev_info("canot' find [%s]\n", name);
  1530			return -EINVAL;
  1531		}
  1532		peer_adapter = netdev_priv(peer_netdev);
  1533	
  1534		// check if in same slot
  1535		if (PCI_SLOT(peer_adapter->pdev->devfn) !=
  1536		    PCI_SLOT(adapter->pdev->devfn)) {
  1537			e_dev_info("%s %s not in same slot\n",
  1538				   netdev_name(adapter->netdev),
  1539				   netdev_name(peer_adapter->netdev));
  1540			dev_put(peer_netdev);
  1541			return -EINVAL;
  1542		}
  1543	
  1544		e_dev_info("%s: %s(%d,%d) <-> %s(%d,%d) en:%d\n", __func__,
  1545			   netdev_name(adapter->netdev), adapter->lane, adapter->port,
  1546			   netdev_name(peer_adapter->netdev), peer_adapter->lane,
  1547			   peer_adapter->port, en);
  1548	
  1549		/* clear pf0/pf1 input port policy eth reg */
  1550		for (i = 0; i < MAX_PORT_NUM; i++) {
  1551			wr32(&adapter->hw, RNPM_ETH_INPORT_POLICY_REG(i), 0);
  1552			wr32(&peer_adapter->hw, RNPM_ETH_INPORT_POLICY_REG(i), 0);
  1553		}
  1554	
  1555		wr32(&adapter->hw, RNPM_ETH_INPORT_POLICY_VAL, 0);
  1556		wr32(&peer_adapter->hw, RNPM_ETH_INPORT_POLICY_VAL, 0);
  1557	
  1558		do_switch_loopback_set(adapter, en, adapter->lane,
  1559				       to_switch_port(peer_adapter));
  1560	
  1561		do_switch_loopback_set(peer_adapter, en, peer_adapter->lane,
  1562				       to_switch_port(adapter));
  1563	
  1564		if (peer_netdev)
  1565			dev_put(peer_netdev);
  1566	
  1567		return 0;
  1568	}
  1569	static ssize_t switch_loopback_on_store(struct device *dev,
  1570						struct device_attribute *attr,
  1571						const char *buf, size_t count)
  1572	{
  1573		struct rnpm_adapter *adapter = netdev_priv(to_net_device(dev));
  1574	
  1575		return _switch_loopback(adapter, buf, 1) == 0 ? count : -EINVAL;
  1576	}
  1577	static DEVICE_ATTR_WO(switch_loopback_on);
  1578	

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