[PATCH 4.18 009/228] net: hns3: Fix warning bug when doing lp selftest

From: Greg Kroah-Hartman
Date: Tue Oct 02 2018 - 09:27:13 EST


4.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Yunsheng Lin <linyunsheng@xxxxxxxxxx>

[ Upstream commit d7099d15478e89edb9bc6c6e3ab4cd341884a367 ]

The napi_alloc_skb is excepted to be called under the
non-preemptible code path when it is called by hns3_clean_rx_ring
during loopback selftest, otherwise the below warning will be
logged:

[ 92.420780] BUG: using smp_processor_id() in preemptible
[00000000] code: ethtool/1873
<SNIP>
[ 92.463202] check_preemption_disabled+0xf8/0x100
[ 92.467893] debug_smp_processor_id+0x1c/0x28
[ 92.472239] __napi_alloc_skb+0x30/0x130
[ 92.476158] hns3_clean_rx_ring+0x118/0x5f0 [hns3]
[ 92.480941] hns3_self_test+0x32c/0x4d0 [hns3]
[ 92.485375] ethtool_self_test+0xdc/0x1e8
[ 92.489372] dev_ethtool+0x1020/0x1da8
[ 92.493109] dev_ioctl+0x188/0x3a0
[ 92.496499] sock_do_ioctl+0xf4/0x208
[ 92.500148] sock_ioctl+0x228/0x3e8
[ 92.503626] do_vfs_ioctl+0xc4/0x880
[ 92.507189] SyS_ioctl+0x94/0xa8
[ 92.510404] el0_svc_naked+0x30/0x34

This patch fix it by disabling preemption when calling
hns3_clean_rx_ring during loopback selftest.

Fixes: c39c4d98dc65 ("net: hns3: Add mac loopback selftest support in hns3 driver")
Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
Signed-off-by: Peng Li <lipeng321@xxxxxxxxxx>
Signed-off-by: Salil Mehta <salil.mehta@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c
@@ -201,7 +201,9 @@ static u32 hns3_lb_check_rx_ring(struct
rx_group = &ring->tqp_vector->rx_group;
pre_rx_pkt = rx_group->total_packets;

+ preempt_disable();
hns3_clean_rx_ring(ring, budget, hns3_lb_check_skb_data);
+ preempt_enable();

rcv_good_pkt_total += (rx_group->total_packets - pre_rx_pkt);
rx_group->total_packets = pre_rx_pkt;