[PATCH] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()

[PATCH] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()

[Yang Yingliang]

It is not allowed to call consume_skb() from hardware interrupt context
or with interrupts being disabled. So replace dev_kfree_skb() with
dev_consume_skb_irq() under spin_lock_irqsave(). Compile tested only.

Fixes: 26f1fad29ad9 ("New driver: rtl8xxxu (mac80211)")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index ac641a56efb0..d0600af5bef4 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -5274,7 +5274,7 @@ static void rtl8xxxu_queue_rx_urb(struct rtl8xxxu_priv *priv,
 		pending = priv->rx_urb_pending_count;
 	} else {
 		skb = (struct sk_buff *)rx_urb->urb.context;
-		dev_kfree_skb(skb);
+		dev_consume_skb_irq(skb);
 		usb_free_urb(&rx_urb->urb);
 	}
 
-- 
2.25.1

RE: [PATCH] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()

[Ping-Ke Shih]

> -----Original Message-----
> From: Yang Yingliang <yangyingliang@huawei.com>
> Sent: Wednesday, December 7, 2022 10:38 PM
> To: Jes.Sorensen@gmail.com; kvalo@kernel.org
> Cc: linux-wireless@vger.kernel.org
> Subject: [PATCH] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()
> 
> It is not allowed to call consume_skb() from hardware interrupt context
                            ^^^^^^^^^^^^^ kfree_skb()? 
because this patch is to replace dev_kfree_skb().

> or with interrupts being disabled. So replace dev_kfree_skb() with
> dev_consume_skb_irq() under spin_lock_irqsave(). Compile tested only.
> 
> Fixes: 26f1fad29ad9 ("New driver: rtl8xxxu (mac80211)")
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> ---
>  drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> index ac641a56efb0..d0600af5bef4 100644
> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> @@ -5274,7 +5274,7 @@ static void rtl8xxxu_queue_rx_urb(struct rtl8xxxu_priv *priv,
>  		pending = priv->rx_urb_pending_count;
>  	} else {
>  		skb = (struct sk_buff *)rx_urb->urb.context;
> -		dev_kfree_skb(skb);
> +		dev_consume_skb_irq(skb);

Why not dev_kfree_skb_irq() instead? any reason?

>  		usb_free_urb(&rx_urb->urb);
>  	}
> 
> --
> 2.25.1
> 
> 
> ------Please consider the environment before printing this e-mail.

Re: [PATCH] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()

[Yang Yingliang]

On 2022/12/8 8:38, Ping-Ke Shih wrote:
>> -----Original Message-----
>> From: Yang Yingliang <yangyingliang@huawei.com>
>> Sent: Wednesday, December 7, 2022 10:38 PM
>> To: Jes.Sorensen@gmail.com; kvalo@kernel.org
>> Cc: linux-wireless@vger.kernel.org
>> Subject: [PATCH] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()
>>
>> It is not allowed to call consume_skb() from hardware interrupt context
>                              ^^^^^^^^^^^^^ kfree_skb()?
> because this patch is to replace dev_kfree_skb().
>
>> or with interrupts being disabled. So replace dev_kfree_skb() with
>> dev_consume_skb_irq() under spin_lock_irqsave(). Compile tested only.
>>
>> Fixes: 26f1fad29ad9 ("New driver: rtl8xxxu (mac80211)")
>> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
>> ---
>>   drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> index ac641a56efb0..d0600af5bef4 100644
>> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> @@ -5274,7 +5274,7 @@ static void rtl8xxxu_queue_rx_urb(struct rtl8xxxu_priv *priv,
>>   		pending = priv->rx_urb_pending_count;
>>   	} else {
>>   		skb = (struct sk_buff *)rx_urb->urb.context;
>> -		dev_kfree_skb(skb);
>> +		dev_consume_skb_irq(skb);
> Why not dev_kfree_skb_irq() instead? any reason?
#define dev_kfree_skb(a)        consume_skb(a)
dev_kfree_skb() is consume_skb(), so use dev_consume_skb_irq() instead.

static inline void dev_kfree_skb_irq(struct sk_buff *skb)
{
         __dev_kfree_skb_irq(skb, SKB_REASON_DROPPED);
}

static inline void dev_consume_skb_irq(struct sk_buff *skb)
{
         __dev_kfree_skb_irq(skb, SKB_REASON_CONSUMED);
}
They have different free reasons.

Thanks,
Yang
>
>>   		usb_free_urb(&rx_urb->urb);
>>   	}
>>
>> --
>> 2.25.1
>>
>>
>> ------Please consider the environment before printing this e-mail.
> .

RE: [PATCH] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()

[Ping-Ke Shih]

> -----Original Message-----
> From: Yang Yingliang <yangyingliang@huawei.com>
> Sent: Thursday, December 8, 2022 9:26 AM
> To: Ping-Ke Shih <pkshih@realtek.com>; Jes.Sorensen@gmail.com; kvalo@kernel.org
> Cc: linux-wireless@vger.kernel.org; yangyingliang@huawei.com
> Subject: Re: [PATCH] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()
> 
> 
> On 2022/12/8 8:38, Ping-Ke Shih wrote:
> >> -----Original Message-----
> >> From: Yang Yingliang <yangyingliang@huawei.com>
> >> Sent: Wednesday, December 7, 2022 10:38 PM
> >> To: Jes.Sorensen@gmail.com; kvalo@kernel.org
> >> Cc: linux-wireless@vger.kernel.org
> >> Subject: [PATCH] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()
> >>
> >> It is not allowed to call consume_skb() from hardware interrupt context
> >                              ^^^^^^^^^^^^^ kfree_skb()?
> > because this patch is to replace dev_kfree_skb().
> >
> >> or with interrupts being disabled. So replace dev_kfree_skb() with
> >> dev_consume_skb_irq() under spin_lock_irqsave(). Compile tested only.
> >>
> >> Fixes: 26f1fad29ad9 ("New driver: rtl8xxxu (mac80211)")
> >> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> >> ---
> >>   drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 2 +-
> >>   1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> >> b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> >> index ac641a56efb0..d0600af5bef4 100644
> >> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> >> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> >> @@ -5274,7 +5274,7 @@ static void rtl8xxxu_queue_rx_urb(struct rtl8xxxu_priv *priv,
> >>   		pending = priv->rx_urb_pending_count;
> >>   	} else {
> >>   		skb = (struct sk_buff *)rx_urb->urb.context;
> >> -		dev_kfree_skb(skb);
> >> +		dev_consume_skb_irq(skb);
> > Why not dev_kfree_skb_irq() instead? any reason?
> #define dev_kfree_skb(a)        consume_skb(a)
> dev_kfree_skb() is consume_skb(), so use dev_consume_skb_irq() instead.
> 
> static inline void dev_kfree_skb_irq(struct sk_buff *skb)
> {
>          __dev_kfree_skb_irq(skb, SKB_REASON_DROPPED);
> }
> 
> static inline void dev_consume_skb_irq(struct sk_buff *skb)
> {
>          __dev_kfree_skb_irq(skb, SKB_REASON_CONSUMED);
> }
> They have different free reasons.
> 

It falls into this case because of 'priv->shutdown', so DROPPED reason makes
sense, no? Or I misunderstand the reason?

--
Ping-Ke

Re: [PATCH] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()

[Yang Yingliang]

On 2022/12/8 9:41, Ping-Ke Shih wrote:
>> -----Original Message-----
>> From: Yang Yingliang <yangyingliang@huawei.com>
>> Sent: Thursday, December 8, 2022 9:26 AM
>> To: Ping-Ke Shih <pkshih@realtek.com>; Jes.Sorensen@gmail.com; kvalo@kernel.org
>> Cc: linux-wireless@vger.kernel.org; yangyingliang@huawei.com
>> Subject: Re: [PATCH] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()
>>
>>
>> On 2022/12/8 8:38, Ping-Ke Shih wrote:
>>>> -----Original Message-----
>>>> From: Yang Yingliang <yangyingliang@huawei.com>
>>>> Sent: Wednesday, December 7, 2022 10:38 PM
>>>> To: Jes.Sorensen@gmail.com; kvalo@kernel.org
>>>> Cc: linux-wireless@vger.kernel.org
>>>> Subject: [PATCH] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()
>>>>
>>>> It is not allowed to call consume_skb() from hardware interrupt context
>>>                               ^^^^^^^^^^^^^ kfree_skb()?
>>> because this patch is to replace dev_kfree_skb().
>>>
>>>> or with interrupts being disabled. So replace dev_kfree_skb() with
>>>> dev_consume_skb_irq() under spin_lock_irqsave(). Compile tested only.
>>>>
>>>> Fixes: 26f1fad29ad9 ("New driver: rtl8xxxu (mac80211)")
>>>> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
>>>> ---
>>>>    drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 2 +-
>>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>>>> b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>>>> index ac641a56efb0..d0600af5bef4 100644
>>>> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>>>> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>>>> @@ -5274,7 +5274,7 @@ static void rtl8xxxu_queue_rx_urb(struct rtl8xxxu_priv *priv,
>>>>    		pending = priv->rx_urb_pending_count;
>>>>    	} else {
>>>>    		skb = (struct sk_buff *)rx_urb->urb.context;
>>>> -		dev_kfree_skb(skb);
>>>> +		dev_consume_skb_irq(skb);
>>> Why not dev_kfree_skb_irq() instead? any reason?
>> #define dev_kfree_skb(a)        consume_skb(a)
>> dev_kfree_skb() is consume_skb(), so use dev_consume_skb_irq() instead.
>>
>> static inline void dev_kfree_skb_irq(struct sk_buff *skb)
>> {
>>           __dev_kfree_skb_irq(skb, SKB_REASON_DROPPED);
>> }
>>
>> static inline void dev_consume_skb_irq(struct sk_buff *skb)
>> {
>>           __dev_kfree_skb_irq(skb, SKB_REASON_CONSUMED);
>> }
>> They have different free reasons.
>>
> It falls into this case because of 'priv->shutdown', so DROPPED reason makes
> sense, no? Or I misunderstand the reason?
Because the origin call is dev_kfree_skb() which is same as 
consume_skb(), I called
dev_consume_skb_irq() instead here.

Thanks,
Yang
>
> --
> Ping-Ke
>

Re: [PATCH] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()

[Yang Yingliang]

On 2022/12/8 9:41, Ping-Ke Shih wrote:
>> -----Original Message-----
>> From: Yang Yingliang <yangyingliang@huawei.com>
>> Sent: Thursday, December 8, 2022 9:26 AM
>> To: Ping-Ke Shih <pkshih@realtek.com>; Jes.Sorensen@gmail.com; kvalo@kernel.org
>> Cc: linux-wireless@vger.kernel.org; yangyingliang@huawei.com
>> Subject: Re: [PATCH] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()
>>
>>
>> On 2022/12/8 8:38, Ping-Ke Shih wrote:
>>>> -----Original Message-----
>>>> From: Yang Yingliang <yangyingliang@huawei.com>
>>>> Sent: Wednesday, December 7, 2022 10:38 PM
>>>> To: Jes.Sorensen@gmail.com; kvalo@kernel.org
>>>> Cc: linux-wireless@vger.kernel.org
>>>> Subject: [PATCH] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()
>>>>
>>>> It is not allowed to call consume_skb() from hardware interrupt context
>>>                               ^^^^^^^^^^^^^ kfree_skb()?
>>> because this patch is to replace dev_kfree_skb().
>>>
>>>> or with interrupts being disabled. So replace dev_kfree_skb() with
>>>> dev_consume_skb_irq() under spin_lock_irqsave(). Compile tested only.
>>>>
>>>> Fixes: 26f1fad29ad9 ("New driver: rtl8xxxu (mac80211)")
>>>> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
>>>> ---
>>>>    drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 2 +-
>>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>>>> b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>>>> index ac641a56efb0..d0600af5bef4 100644
>>>> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>>>> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>>>> @@ -5274,7 +5274,7 @@ static void rtl8xxxu_queue_rx_urb(struct rtl8xxxu_priv *priv,
>>>>    		pending = priv->rx_urb_pending_count;
>>>>    	} else {
>>>>    		skb = (struct sk_buff *)rx_urb->urb.context;
>>>> -		dev_kfree_skb(skb);
>>>> +		dev_consume_skb_irq(skb);
>>> Why not dev_kfree_skb_irq() instead? any reason?
>> #define dev_kfree_skb(a)        consume_skb(a)
>> dev_kfree_skb() is consume_skb(), so use dev_consume_skb_irq() instead.
>>
>> static inline void dev_kfree_skb_irq(struct sk_buff *skb)
>> {
>>           __dev_kfree_skb_irq(skb, SKB_REASON_DROPPED);
>> }
>>
>> static inline void dev_consume_skb_irq(struct sk_buff *skb)
>> {
>>           __dev_kfree_skb_irq(skb, SKB_REASON_CONSUMED);
>> }
>> They have different free reasons.
>>
> It falls into this case because of 'priv->shutdown', so DROPPED reason makes
> sense, no? Or I misunderstand the reason?
You are right, it's better to use dev_kfree_skb_irq(), because this is 
called when it's
stopped and need to drop the SKB, I will send a v2 to change it.

Thanks,
Yang
>
> --
> Ping-Ke
>