Replace `dev_kfree_skb()` with `dev_kfree_skb_any()` in `start_xmit()`
which can be called from netpoll (hard IRQ) and from other contexts.
Also, `np->link_status` can be changed at any time by interrupt handler.
<idle>-0 [011] dNh4. 4541.754603: start_xmit <-netpoll_start_xmit
<idle>-0 [011] dNh4. 4541.754622: <stack trace>
=> [FTRACE TRAMPOLINE]
=> start_xmit
=> netpoll_start_xmit
=> netpoll_send_skb
=> write_msg
=> console_flush_all
=> console_unlock
=> vprintk_emit
=> _printk
=> rio_interrupt
=> __handle_irq_event_percpu
=> handle_irq_event
=> handle_fasteoi_irq
=> __common_interrupt
=> common_interrupt
=> asm_common_interrupt
=> mwait_idle
=> default_idle_call
=> do_idle
=> cpu_startup_entry
=> start_secondary
=> common_startup_64
This issue can occur when the link state changes from off to on
(e.g., plugging or unplugging the LAN cable) while transmitting a
packet. If the skb has a destructor, a warning message may be
printed in this situation.
-> consume_skb (dev_kfree_skb())
-> __kfree_skb()
-> skb_release_all()
-> skb_release_head_state(skb)
if (skb->destructor) {
DEBUG_NET_WARN_ON_ONCE(in_hardirq());
skb->destructor(skb);
}
Found by inspection.
Signed-off-by: Yeounsu Moon <yyyynoom@gmail.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Tested-on: D-Link DGE-550T Rev-A3
Reviewed-by: Simon Horman <horms@kernel.org>
---
drivers/net/ethernet/dlink/dl2k.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/dlink/dl2k.c b/drivers/net/ethernet/dlink/dl2k.c
index 7077d705e471..6e4f17142519 100644
--- a/drivers/net/ethernet/dlink/dl2k.c
+++ b/drivers/net/ethernet/dlink/dl2k.c
@@ -733,7 +733,7 @@ start_xmit (struct sk_buff *skb, struct net_device *dev)
u64 tfc_vlan_tag = 0;
if (np->link_status == 0) { /* Link Down */
- dev_kfree_skb(skb);
+ dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
entry = np->cur_tx % TX_RING_SIZE;
--
2.51.0