diff mbox series

[net,v2,3/3] mISDN: hfcmulti: don't call dev_kfree_skb/kfree_skb() under spin_lock_irqsave()

Message ID 20221212084139.3277913-4-yangyingliang@huawei.com (mailing list archive)
State Accepted
Commit 1232946cf522b8de9e398828bde325d7c41f29dd
Delegated to: Netdev Maintainers
Headers show
Series mISDN: don't call dev_kfree_skb/kfree_skb() under spin_lock_irqsave() | expand

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netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 9 this patch: 9
netdev/cc_maintainers success CCed 3 of 3 maintainers
netdev/build_clang success Errors and warnings before: 2 this patch: 2
netdev/module_param success Was 0 now: 0
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netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 9 this patch: 9
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 71 lines checked
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netdev/source_inline success Was 0 now: 0

Commit Message

Yang Yingliang Dec. 12, 2022, 8:41 a.m. UTC
It is not allowed to call kfree_skb() or consume_skb() from hardware
interrupt context or with hardware interrupts being disabled.

skb_queue_purge() is called under spin_lock_irqsave() in handle_dmsg()
and hfcm_l1callback(), kfree_skb() is called in them, 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.

Fixes: af69fb3a8ffa ("Add mISDN HFC multiport driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 drivers/isdn/hardware/mISDN/hfcmulti.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

Comments

Alexander Duyck Dec. 12, 2022, 9:48 p.m. UTC | #1
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.
> 
> skb_queue_purge() is called under spin_lock_irqsave() in handle_dmsg()
> and hfcm_l1callback(), kfree_skb() is called in them, 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.
> 
> Fixes: af69fb3a8ffa ("Add mISDN HFC multiport driver")
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> ---
>  drivers/isdn/hardware/mISDN/hfcmulti.c | 19 +++++++++++++------
>  1 file changed, 13 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/isdn/hardware/mISDN/hfcmulti.c b/drivers/isdn/hardware/mISDN/hfcmulti.c
> index 4f7eaa17fb27..e840609c50eb 100644
> --- a/drivers/isdn/hardware/mISDN/hfcmulti.c
> +++ b/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;

Looks good to me.

Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
diff mbox series

Patch

diff --git a/drivers/isdn/hardware/mISDN/hfcmulti.c b/drivers/isdn/hardware/mISDN/hfcmulti.c
index 4f7eaa17fb27..e840609c50eb 100644
--- a/drivers/isdn/hardware/mISDN/hfcmulti.c
+++ b/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;