AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2024-12-16 19:06:45 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity

net: hns3: fix data race between ring->next_to_clean

Browse Source 
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: 76ad4f0ee7 ("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>
This commit is contained in:
Yunsheng Lin 2019-04-25 20:42:45 +08:00 committed by David S. Miller
parent 790d23e7c5
commit 26cda2f161
2 changed files with 16 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
View File

@ -2214,14 +2214,22 @@ static void hns3_reuse_buffer(struct hns3_enet_ring *ring, int i)
static void hns3_nic_reclaim_one_desc(struct hns3_enet_ring *ring, int *bytes,
int *pkts)
{
struct hns3_desc_cb *desc_cb = &ring->desc_cb[ring->next_to_clean];
int ntc = ring->next_to_clean;
struct hns3_desc_cb *desc_cb;
desc_cb = &ring->desc_cb[ntc];
(*pkts) += (desc_cb->type == DESC_TYPE_SKB);
(*bytes) += desc_cb->length;
/* desc_cb will be cleaned, after hnae3_free_buffer_detach*/
hns3_free_buffer_detach(ring, ring->next_to_clean);
hns3_free_buffer_detach(ring, ntc);
ring_ptr_move_fw(ring, next_to_clean);
if (++ntc == ring->desc_num)
ntc = 0;
/* This smp_store_release() pairs with smp_load_acquire() in
* ring_space called by hns3_nic_net_xmit.
*/
smp_store_release(&ring->next_to_clean, ntc);
}
static int is_valid_clean_head(struct hns3_enet_ring *ring, int h)

7
drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
View File

@ -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;