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authorYang Yingliang <yangyingliang@huawei.com>2022-12-12 16:41:37 +0800
committerJakub Kicinski <kuba@kernel.org>2022-12-13 19:24:52 -0800
commitddc9648db162eee556edd5222d2808fe33730203 (patch)
tree31f03c57ae1b9864d90bc64a452999625b8ce0eb /drivers/isdn
parentda2b5b43420456beef5d5e1b43582e579ed08ef1 (diff)
downloadlwn-ddc9648db162eee556edd5222d2808fe33730203.tar.gz
lwn-ddc9648db162eee556edd5222d2808fe33730203.zip
mISDN: hfcsusb: don't call dev_kfree_skb/kfree_skb() under spin_lock_irqsave()
It is not allowed to call kfree_skb() or consume_skb() from hardware interrupt context or with hardware interrupts being disabled. It should use dev_kfree_skb_irq() or dev_consume_skb_irq() instead. The difference between them is free reason, dev_kfree_skb_irq() means the SKB is dropped in error and dev_consume_skb_irq() means the SKB is consumed in normal. skb_queue_purge() is called under spin_lock_irqsave() in hfcusb_l2l1D(), kfree_skb() is called in it, to fix this, use skb_queue_splice_init() to move the dch->squeue to a free queue, also enqueue the tx_skb and rx_skb, at last calling __skb_queue_purge() to free the SKBs afer unlock. In tx_iso_complete(), dev_kfree_skb() is called to consume the transmitted SKB, so replace it with dev_consume_skb_irq(). Fixes: 69f52adb2d53 ("mISDN: Add HFC USB driver") Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/isdn')
-rw-r--r--drivers/isdn/hardware/mISDN/hfcsusb.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/isdn/hardware/mISDN/hfcsusb.c b/drivers/isdn/hardware/mISDN/hfcsusb.c
index 651f2f8f685b..1efd17979f24 100644
--- a/drivers/isdn/hardware/mISDN/hfcsusb.c
+++ b/drivers/isdn/hardware/mISDN/hfcsusb.c
@@ -326,20 +326,24 @@ hfcusb_l2l1D(struct mISDNchannel *ch, struct sk_buff *skb)
test_and_clear_bit(FLG_L2_ACTIVATED, &dch->Flags);
if (hw->protocol == ISDN_P_NT_S0) {
+ struct sk_buff_head free_queue;
+
+ __skb_queue_head_init(&free_queue);
hfcsusb_ph_command(hw, HFC_L1_DEACTIVATE_NT);
spin_lock_irqsave(&hw->lock, flags);
- skb_queue_purge(&dch->squeue);
+ skb_queue_splice_init(&dch->squeue, &free_queue);
if (dch->tx_skb) {
- dev_kfree_skb(dch->tx_skb);
+ __skb_queue_tail(&free_queue, dch->tx_skb);
dch->tx_skb = NULL;
}
dch->tx_idx = 0;
if (dch->rx_skb) {
- dev_kfree_skb(dch->rx_skb);
+ __skb_queue_tail(&free_queue, dch->rx_skb);
dch->rx_skb = NULL;
}
test_and_clear_bit(FLG_TX_BUSY, &dch->Flags);
spin_unlock_irqrestore(&hw->lock, flags);
+ __skb_queue_purge(&free_queue);
#ifdef FIXME
if (test_and_clear_bit(FLG_L1_BUSY, &dch->Flags))
dchannel_sched_event(&hc->dch, D_CLEARBUSY);
@@ -1330,7 +1334,7 @@ tx_iso_complete(struct urb *urb)
printk("\n");
}
- dev_kfree_skb(tx_skb);
+ dev_consume_skb_irq(tx_skb);
tx_skb = NULL;
if (fifo->dch && get_next_dframe(fifo->dch))
tx_skb = fifo->dch->tx_skb;