[PATCH AUTOSEL 4.9 14/64] i40e: use correct length for strncpy

[Sasha Levin]

From: Mitch Williams <mitch.a.williams@xxxxxxxxx>

[ 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@xxxxxxxxx>
Tested-by: Andrew Bowers <andrewx.bowers@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/intel/i40e/i40e_ptp.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_ptp.c b/drivers/net/ethernet/intel/i40e/i40e_ptp.c
index f1feceab758a5..41cbcb0ac2d94 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_ptp.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ptp.c
@@ -604,7 +604,8 @@ 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;
-- 
2.20.1