i40e: use correct length for strncpy

[ Upstream commit 7eb74ff891b4e94b8bac48f648a21e4b94ddee64 ]

Caught by GCC 8. When we provide a length for strncpy, we should not
include the terminating null. So we must tell it one less than the size
of the destination buffer.

Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_ptp.c b/drivers/net/ethernet/intel/i40e/i40e_ptp.c
index 565ca7c..e22ebe4 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_ptp.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ptp.c
@@ -605,7 +605,8 @@ static long i40e_ptp_create_clock(struct i40e_pf *pf)
        if (!IS_ERR_OR_NULL(pf->ptp_clock))
                return 0;
 
-       strncpy(pf->ptp_caps.name, i40e_driver_name, sizeof(pf->ptp_caps.name));
+       strncpy(pf->ptp_caps.name, i40e_driver_name,
+               sizeof(pf->ptp_caps.name) - 1);
        pf->ptp_caps.owner = THIS_MODULE;
        pf->ptp_caps.max_adj = 999999999;
        pf->ptp_caps.n_ext_ts = 0;