6.16-stable review patch. If anyone has any objections, please let me know.
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From: Jijie Shao shaojijie@huawei.com
[ Upstream commit 7004b26f0b64331143eb0b312e77a357a11427ce ]
When the network port is down, the queue is released, and ring->len is 0. In debugfs, hbg_get_queue_used_num() will be called, which may lead to a division by zero issue.
This patch adds a check, if ring->len is 0, hbg_get_queue_used_num() directly returns 0.
Fixes: 40735e7543f9 ("net: hibmcge: Implement .ndo_start_xmit function") Signed-off-by: Jijie Shao shaojijie@huawei.com Reviewed-by: Simon Horman horms@kernel.org Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.h b/drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.h index 2883a5899ae2..8b6110599e10 100644 --- a/drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.h +++ b/drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.h @@ -29,7 +29,12 @@ static inline bool hbg_fifo_is_full(struct hbg_priv *priv, enum hbg_dir dir)
static inline u32 hbg_get_queue_used_num(struct hbg_ring *ring) { - return (ring->ntu + ring->len - ring->ntc) % ring->len; + u32 len = READ_ONCE(ring->len); + + if (!len) + return 0; + + return (READ_ONCE(ring->ntu) + len - READ_ONCE(ring->ntc)) % len; }
netdev_tx_t hbg_net_start_xmit(struct sk_buff *skb, struct net_device *netdev);