| Message ID | 20221212084139.3277913-2-yangyingliang@huawei.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | ddc9648db162eee556edd5222d2808fe33730203 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | mISDN: don't call dev_kfree_skb/kfree_skb() under spin_lock_irqsave() | expand |
On Mon, 2022-12-12 at 16:41 +0800, Yang Yingliang wrote: > 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> > --- > drivers/isdn/hardware/mISDN/hfcsusb.c | 12 ++++++++---- > 1 file 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; Looks good to me. Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
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;
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> --- drivers/isdn/hardware/mISDN/hfcsusb.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)