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| author | Sergei Miroshnichenko <sergeimir@emcraft.com> | 2016-09-07 16:51:12 +0300 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2016-09-22 10:01:21 +0200 |
| commit | 9abefcb1aaa58b9d5aa40a8bb12c87d02415e4c8 (patch) | |
| tree | ff081f6644b855d62aae2a48a8f6f4a8c00d7a78 /drivers | |
| parent | 7e32b44361abc77fbc01f2b97b045c405b2583e5 (diff) | |
| download | linux-0-day-9abefcb1aaa58b9d5aa40a8bb12c87d02415e4c8.tar.gz linux-0-day-9abefcb1aaa58b9d5aa40a8bb12c87d02415e4c8.tar.xz | |
can: dev: fix deadlock reported after bus-off
A timer was used to restart after the bus-off state, leading to a
relatively large can_restart() executed in an interrupt context,
which in turn sets up pinctrl. When this happens during system boot,
there is a high probability of grabbing the pinctrl_list_mutex,
which is locked already by the probe() of other device, making the
kernel suspect a deadlock condition [1].
To resolve this issue, the restart_timer is replaced by a delayed
work.
[1] https://github.com/victronenergy/venus/issues/24
Signed-off-by: Sergei Miroshnichenko <sergeimir@emcraft.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/can/dev.c | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c index e21f7cc5ae4d3..8d6208c0b4003 100644 --- a/drivers/net/can/dev.c +++ b/drivers/net/can/dev.c @@ -21,6 +21,7 @@ #include <linux/slab.h> #include <linux/netdevice.h> #include <linux/if_arp.h> +#include <linux/workqueue.h> #include <linux/can.h> #include <linux/can/dev.h> #include <linux/can/skb.h> @@ -501,9 +502,8 @@ EXPORT_SYMBOL_GPL(can_free_echo_skb); /* * CAN device restart for bus-off recovery */ -static void can_restart(unsigned long data) +static void can_restart(struct net_device *dev) { - struct net_device *dev = (struct net_device *)data; struct can_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; struct sk_buff *skb; @@ -543,6 +543,14 @@ restart: netdev_err(dev, "Error %d during restart", err); } +static void can_restart_work(struct work_struct *work) +{ + struct delayed_work *dwork = to_delayed_work(work); + struct can_priv *priv = container_of(dwork, struct can_priv, restart_work); + + can_restart(priv->dev); +} + int can_restart_now(struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); @@ -556,8 +564,8 @@ int can_restart_now(struct net_device *dev) if (priv->state != CAN_STATE_BUS_OFF) return -EBUSY; - /* Runs as soon as possible in the timer context */ - mod_timer(&priv->restart_timer, jiffies); + cancel_delayed_work_sync(&priv->restart_work); + can_restart(dev); return 0; } @@ -578,8 +586,8 @@ void can_bus_off(struct net_device *dev) netif_carrier_off(dev); if (priv->restart_ms) - mod_timer(&priv->restart_timer, - jiffies + (priv->restart_ms * HZ) / 1000); + schedule_delayed_work(&priv->restart_work, + msecs_to_jiffies(priv->restart_ms)); } EXPORT_SYMBOL_GPL(can_bus_off); @@ -688,6 +696,7 @@ struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max) return NULL; priv = netdev_priv(dev); + priv->dev = dev; if (echo_skb_max) { priv->echo_skb_max = echo_skb_max; @@ -697,7 +706,7 @@ struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max) priv->state = CAN_STATE_STOPPED; - init_timer(&priv->restart_timer); + INIT_DELAYED_WORK(&priv->restart_work, can_restart_work); return dev; } @@ -778,8 +787,6 @@ int open_candev(struct net_device *dev) if (!netif_carrier_ok(dev)) netif_carrier_on(dev); - setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev); - return 0; } EXPORT_SYMBOL_GPL(open_candev); @@ -794,7 +801,7 @@ void close_candev(struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); - del_timer_sync(&priv->restart_timer); + cancel_delayed_work_sync(&priv->restart_work); can_flush_echo_skb(dev); } EXPORT_SYMBOL_GPL(close_candev); |