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authorYunsheng Lin <linyunsheng@huawei.com>2019-04-25 20:42:45 +0800
committerDavid S. Miller <davem@davemloft.net>2019-04-26 12:13:28 -0400
commit26cda2f1613878d9bde11325559f4fca92fff395 (patch)
tree96d9e8b0e49c895a426e2725d195ed2e4580629f /drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
parent790d23e7c577ed2ef7c49f246ad8d53691fb1b20 (diff)
net: hns3: fix data race between ring->next_to_clean
hns3_clean_tx_ring calls hns3_nic_reclaim_one_desc to clean buffers and set ring->next_to_clean, then hns3_nic_net_xmit reuses the cleaned buffers. But there are no memory barriers when buffers gets recycled, so the recycled buffers can be corrupted. This patch uses smp_store_release to update ring->next_to_clean and smp_load_acquire to read ring->next_to_clean to properly hand off buffers from hns3_clean_tx_ring to hns3_nic_net_xmit. Fixes: 76ad4f0ee747 ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC") Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> Signed-off-by: Peng Li <lipeng321@huawei.com> Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/hisilicon/hns3/hns3_enet.h')
-rw-r--r--drivers/net/ethernet/hisilicon/hns3/hns3_enet.h7
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
index cec56a505e85..2b4f5ea3fddf 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
@@ -581,8 +581,11 @@ union l4_hdr_info {
static inline int ring_space(struct hns3_enet_ring *ring)
{
- int begin = ring->next_to_clean;
- int end = ring->next_to_use;
+ /* This smp_load_acquire() pairs with smp_store_release() in
+ * hns3_nic_reclaim_one_desc called by hns3_clean_tx_ring.
+ */
+ int begin = smp_load_acquire(&ring->next_to_clean);
+ int end = READ_ONCE(ring->next_to_use);
return ((end >= begin) ? (ring->desc_num - end + begin) :
(begin - end)) - 1;