Merge branch 'misdn-don-t-call-dev_kfree_skb-kfree_skb-under-spin_lock_irqsave'

Yang Yingliang says:

====================
mISDN: 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. This
pachset try to avoid calling dev_kfree_skb/kfree_skb()() under
spin_lock_irqsave().
====================

Link: https://lore.kernel.org/r/20221212084139.3277913-1-yangyingliang@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/isdn/hardware/mISDN/hfcmulti.c

@@ -3217,6 +3217,7 @@ static int
 hfcm_l1callback(struct dchannel *dch, u_int cmd)
 {
 	struct hfc_multi	*hc = dch->hw;
+	struct sk_buff_head	free_queue;
 	u_long	flags;
 
 	switch (cmd) {
@@ -3245,6 +3246,7 @@ hfcm_l1callback(struct dchannel *dch, u_int cmd)
 		l1_event(dch->l1, HW_POWERUP_IND);
 		break;
 	case HW_DEACT_REQ:
+		__skb_queue_head_init(&free_queue);
 		/* start deactivation */
 		spin_lock_irqsave(&hc->lock, flags);
 		if (hc->ctype == HFC_TYPE_E1) {
@@ -3264,20 +3266,21 @@ hfcm_l1callback(struct dchannel *dch, u_int cmd)
 				plxsd_checksync(hc, 0);
 			}
 		}
-		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);
 		if (test_and_clear_bit(FLG_BUSY_TIMER, &dch->Flags))
 			del_timer(&dch->timer);
 		spin_unlock_irqrestore(&hc->lock, flags);
+		__skb_queue_purge(&free_queue);
 		break;
 	case HW_POWERUP_REQ:
 		spin_lock_irqsave(&hc->lock, flags);
@@ -3384,6 +3387,9 @@ handle_dmsg(struct mISDNchannel *ch, struct sk_buff *skb)
 	case PH_DEACTIVATE_REQ:
 		test_and_clear_bit(FLG_L2_ACTIVATED, &dch->Flags);
 		if (dch->dev.D.protocol != ISDN_P_TE_S0) {
+			struct sk_buff_head free_queue;
+
+			__skb_queue_head_init(&free_queue);
 			spin_lock_irqsave(&hc->lock, flags);
 			if (debug & DEBUG_HFCMULTI_MSG)
 				printk(KERN_DEBUG
@@ -3405,14 +3411,14 @@ handle_dmsg(struct mISDNchannel *ch, struct sk_buff *skb)
 				/* deactivate */
 				dch->state = 1;
 			}
-			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);
@@ -3424,6 +3430,7 @@ handle_dmsg(struct mISDNchannel *ch, struct sk_buff *skb)
 #endif
 			ret = 0;
 			spin_unlock_irqrestore(&hc->lock, flags);
+			__skb_queue_purge(&free_queue);
 		} else
 			ret = l1_event(dch->l1, hh->prim);
 		break;

drivers/isdn/hardware/mISDN/hfcpci.c

@@ -1617,16 +1617,19 @@ hfcpci_l2l1D(struct mISDNchannel *ch, struct sk_buff *skb)
 		test_and_clear_bit(FLG_L2_ACTIVATED, &dch->Flags);
 		spin_lock_irqsave(&hc->lock, flags);
 		if (hc->hw.protocol == ISDN_P_NT_S0) {
+			struct sk_buff_head free_queue;
+
+			__skb_queue_head_init(&free_queue);
 			/* prepare deactivation */
 			Write_hfc(hc, HFCPCI_STATES, 0x40);
-			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);
@@ -1639,10 +1642,12 @@ hfcpci_l2l1D(struct mISDNchannel *ch, struct sk_buff *skb)
 			hc->hw.mst_m &= ~HFCPCI_MASTER;
 			Write_hfc(hc, HFCPCI_MST_MODE, hc->hw.mst_m);
 			ret = 0;
+			spin_unlock_irqrestore(&hc->lock, flags);
+			__skb_queue_purge(&free_queue);
 		} else {
 			ret = l1_event(dch->l1, hh->prim);
+			spin_unlock_irqrestore(&hc->lock, flags);
 		}
-		spin_unlock_irqrestore(&hc->lock, flags);
 		break;
 	}
 	if (!ret)

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;