From b7a861a6c3fb8903d4806a12b9ec7806472faa9a Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Fri, 8 Apr 2022 01:56:53 -0700 Subject: xtensa: iss: clean up per-device locking in network driver Per-device locking in the ISS network driver is used to protect poll timer and stats updates. Stat collection is not protected. Remove per-device locking everywhere except the stats updates. Replace ndo_get_stats callback with ndo_get_stats64 and use proper locking there as well. As a side effect this fixes possible deadlock between iss_net_close and iss_net_timer. Reported by: Duoming Zhou Signed-off-by: Max Filippov --- arch/xtensa/platforms/iss/network.c | 39 +++++++++++++++++-------------------- 1 file changed, 18 insertions(+), 21 deletions(-) diff --git a/arch/xtensa/platforms/iss/network.c b/arch/xtensa/platforms/iss/network.c index e9454652551b..13802babba17 100644 --- a/arch/xtensa/platforms/iss/network.c +++ b/arch/xtensa/platforms/iss/network.c @@ -65,7 +65,7 @@ struct iss_net_private { struct net_device *dev; struct platform_device pdev; struct timer_list tl; - struct net_device_stats stats; + struct rtnl_link_stats64 stats; struct timer_list timer; unsigned int timer_val; @@ -281,7 +281,9 @@ static int iss_net_rx(struct net_device *dev) skb = dev_alloc_skb(dev->mtu + 2 + ETH_HEADER_OTHER); if (skb == NULL) { + spin_lock_bh(&lp->lock); lp->stats.rx_dropped++; + spin_unlock_bh(&lp->lock); return 0; } @@ -298,8 +300,10 @@ static int iss_net_rx(struct net_device *dev) skb_trim(skb, pkt_len); skb->protocol = lp->tp.protocol(skb); + spin_lock_bh(&lp->lock); lp->stats.rx_bytes += skb->len; lp->stats.rx_packets++; + spin_unlock_bh(&lp->lock); netif_rx(skb); return pkt_len; } @@ -314,13 +318,9 @@ static int iss_net_poll(struct iss_net_private *lp) if (!netif_running(lp->dev)) return 0; - spin_lock(&lp->lock); - while ((err = iss_net_rx(lp->dev)) > 0) ret++; - spin_unlock(&lp->lock); - if (err < 0) { pr_err("Device '%s' read returned %d, shutting it down\n", lp->dev->name, err); @@ -338,9 +338,7 @@ static void iss_net_timer(struct timer_list *t) struct iss_net_private *lp = from_timer(lp, t, timer); iss_net_poll(lp); - spin_lock(&lp->lock); mod_timer(&lp->timer, jiffies + lp->timer_val); - spin_unlock(&lp->lock); } @@ -349,11 +347,9 @@ static int iss_net_open(struct net_device *dev) struct iss_net_private *lp = netdev_priv(dev); int err; - spin_lock_bh(&lp->lock); - err = lp->tp.open(lp); if (err < 0) - goto out; + return err; netif_start_queue(dev); @@ -368,22 +364,17 @@ static int iss_net_open(struct net_device *dev) lp->timer_val = ISS_NET_TIMER_VALUE; mod_timer(&lp->timer, jiffies + lp->timer_val); -out: - spin_unlock_bh(&lp->lock); return err; } static int iss_net_close(struct net_device *dev) { struct iss_net_private *lp = netdev_priv(dev); - netif_stop_queue(dev); - spin_lock_bh(&lp->lock); + netif_stop_queue(dev); del_timer_sync(&lp->timer); - lp->tp.close(lp); - spin_unlock_bh(&lp->lock); return 0; } @@ -393,13 +384,14 @@ static int iss_net_start_xmit(struct sk_buff *skb, struct net_device *dev) int len; netif_stop_queue(dev); - spin_lock_bh(&lp->lock); len = lp->tp.write(lp, &skb); if (len == skb->len) { + spin_lock_bh(&lp->lock); lp->stats.tx_packets++; lp->stats.tx_bytes += skb->len; + spin_unlock_bh(&lp->lock); netif_trans_update(dev); netif_start_queue(dev); @@ -408,24 +400,29 @@ static int iss_net_start_xmit(struct sk_buff *skb, struct net_device *dev) } else if (len == 0) { netif_start_queue(dev); + spin_lock_bh(&lp->lock); lp->stats.tx_dropped++; + spin_unlock_bh(&lp->lock); } else { netif_start_queue(dev); pr_err("%s: %s failed(%d)\n", dev->name, __func__, len); } - spin_unlock_bh(&lp->lock); dev_kfree_skb(skb); return NETDEV_TX_OK; } -static struct net_device_stats *iss_net_get_stats(struct net_device *dev) +static void iss_net_get_stats64(struct net_device *dev, + struct rtnl_link_stats64 *stats) { struct iss_net_private *lp = netdev_priv(dev); - return &lp->stats; + + spin_lock_bh(&lp->lock); + *stats = lp->stats; + spin_unlock_bh(&lp->lock); } static void iss_net_set_multicast_list(struct net_device *dev) @@ -457,7 +454,7 @@ static int driver_registered; static const struct net_device_ops iss_netdev_ops = { .ndo_open = iss_net_open, .ndo_stop = iss_net_close, - .ndo_get_stats = iss_net_get_stats, + .ndo_get_stats64 = iss_net_get_stats64, .ndo_start_xmit = iss_net_start_xmit, .ndo_validate_addr = eth_validate_addr, .ndo_change_mtu = iss_net_change_mtu, -- cgit v1.2.3