net: hns3: fix kernel crash when 1588 is sent on HIP08 devices

Currently, HIP08 devices does not register the ptp devices, so the
hdev->ptp is NULL. But the tx process would still try to set hardware time
stamp info with SKBTX_HW_TSTAMP flag and cause a kernel crash.

[  128.087798] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000018
...
[  128.280251] pc : hclge_ptp_set_tx_info+0x2c/0x140 [hclge]
[  128.286600] lr : hclge_ptp_set_tx_info+0x20/0x140 [hclge]
[  128.292938] sp : ffff800059b93140
[  128.297200] x29: ffff800059b93140 x28: 0000000000003280
[  128.303455] x27: ffff800020d48280 x26: ffff0cb9dc814080
[  128.309715] x25: ffff0cb9cde93fa0 x24: 0000000000000001
[  128.315969] x23: 0000000000000000 x22: 0000000000000194
[  128.322219] x21: ffff0cd94f986000 x20: 0000000000000000
[  128.328462] x19: ffff0cb9d2a166c0 x18: 0000000000000000
[  128.334698] x17: 0000000000000000 x16: ffffcf1fc523ed24
[  128.340934] x15: 0000ffffd530a518 x14: 0000000000000000
[  128.347162] x13: ffff0cd6bdb31310 x12: 0000000000000368
[  128.353388] x11: ffff0cb9cfbc7070 x10: ffff2cf55dd11e02
[  128.359606] x9 : ffffcf1f85a212b4 x8 : ffff0cd7cf27dab0
[  128.365831] x7 : 0000000000000a20 x6 : ffff0cd7cf27d000
[  128.372040] x5 : 0000000000000000 x4 : 000000000000ffff
[  128.378243] x3 : 0000000000000400 x2 : ffffcf1f85a21294
[  128.384437] x1 : ffff0cb9db520080 x0 : ffff0cb9db500080
[  128.390626] Call trace:
[  128.393964]  hclge_ptp_set_tx_info+0x2c/0x140 [hclge]
[  128.399893]  hns3_nic_net_xmit+0x39c/0x4c4 [hns3]
[  128.405468]  xmit_one.constprop.0+0xc4/0x200
[  128.410600]  dev_hard_start_xmit+0x54/0xf0
[  128.415556]  sch_direct_xmit+0xe8/0x634
[  128.420246]  __dev_queue_xmit+0x224/0xc70
[  128.425101]  dev_queue_xmit+0x1c/0x40
[  128.429608]  ovs_vport_send+0xac/0x1a0 [openvswitch]
[  128.435409]  do_output+0x60/0x17c [openvswitch]
[  128.440770]  do_execute_actions+0x898/0x8c4 [openvswitch]
[  128.446993]  ovs_execute_actions+0x64/0xf0 [openvswitch]
[  128.453129]  ovs_dp_process_packet+0xa0/0x224 [openvswitch]
[  128.459530]  ovs_vport_receive+0x7c/0xfc [openvswitch]
[  128.465497]  internal_dev_xmit+0x34/0xb0 [openvswitch]
[  128.471460]  xmit_one.constprop.0+0xc4/0x200
[  128.476561]  dev_hard_start_xmit+0x54/0xf0
[  128.481489]  __dev_queue_xmit+0x968/0xc70
[  128.486330]  dev_queue_xmit+0x1c/0x40
[  128.490856]  ip_finish_output2+0x250/0x570
[  128.495810]  __ip_finish_output+0x170/0x1e0
[  128.500832]  ip_finish_output+0x3c/0xf0
[  128.505504]  ip_output+0xbc/0x160
[  128.509654]  ip_send_skb+0x58/0xd4
[  128.513892]  udp_send_skb+0x12c/0x354
[  128.518387]  udp_sendmsg+0x7a8/0x9c0
[  128.522793]  inet_sendmsg+0x4c/0x8c
[  128.527116]  __sock_sendmsg+0x48/0x80
[  128.531609]  __sys_sendto+0x124/0x164
[  128.536099]  __arm64_sys_sendto+0x30/0x5c
[  128.540935]  invoke_syscall+0x50/0x130
[  128.545508]  el0_svc_common.constprop.0+0x10c/0x124
[  128.551205]  do_el0_svc+0x34/0xdc
[  128.555347]  el0_svc+0x20/0x30
[  128.559227]  el0_sync_handler+0xb8/0xc0
[  128.563883]  el0_sync+0x160/0x180

Fixes: 0bf5eb7 ("net: hns3: add support for PTP")
Signed-off-by: Jie Wang <wangjie125@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: NipaLocal <nipa@local>

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_ptp.c

@@ -58,6 +58,9 @@ bool hclge_ptp_set_tx_info(struct hnae3_handle *handle, struct sk_buff *skb)
 	struct hclge_dev *hdev = vport->back;
 	struct hclge_ptp *ptp = hdev->ptp;
 
+	if (!ptp)
+		return false;
+
 	if (!test_bit(HCLGE_PTP_FLAG_TX_EN, &ptp->flags) ||
 	    test_and_set_bit(HCLGE_STATE_PTP_TX_HANDLING, &hdev->state)) {
 		ptp->tx_skipped++;