[PATCH AUTOSEL 4.19 099/177] ixgbe: protect TX timestamping from API misuse

[Sasha Levin]

From: Manjunath Patil <manjunath.b.patil@xxxxxxxxxx>

[ Upstream commit 07066d9dc3d2326fbad8f7b0cb0120cff7b7dedb ]

HW timestamping can only be requested for a packet if the NIC is first
setup via ioctl(SIOCSHWTSTAMP). If this step was skipped, then the ixgbe
driver still allowed TX packets to request HW timestamping. In this
situation, we see 'clearing Tx Timestamp hang' noise in the log.

Fix this by checking that the NIC is configured for HW TX timestamping
before accepting a HW TX timestamping request.

Similar-to:
   commit 26bd4e2db06b ("igb: protect TX timestamping from API misuse")
   commit 0a6f2f05a2f5 ("igb: Fix a test with HWTSTAMP_TX_ON")

Signed-off-by: Manjunath Patil <manjunath.b.patil@xxxxxxxxxx>
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/ixgbe/ixgbe_main.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index b45a6e2ed8d15..de65ca1e65580 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -8551,7 +8551,8 @@ netdev_tx_t ixgbe_xmit_frame_ring(struct sk_buff *skb,
 
 	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) &&
 	    adapter->ptp_clock) {
-		if (!test_and_set_bit_lock(__IXGBE_PTP_TX_IN_PROGRESS,
+		if (adapter->tstamp_config.tx_type == HWTSTAMP_TX_ON &&
+		    !test_and_set_bit_lock(__IXGBE_PTP_TX_IN_PROGRESS,
 					   &adapter->state)) {
 			skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
 			tx_flags |= IXGBE_TX_FLAGS_TSTAMP;
-- 
2.20.1