2022-12-09 03:57:44

by Ping-Ke Shih

[permalink] [raw]
Subject: RE: [PATCH v2] wifi: rtl8xxxu: don't call dev_kfree_skb() under spin_lock_irqsave()



> -----Original Message-----
> From: Yang Yingliang <[email protected]>
> Sent: Thursday, December 8, 2022 10:35 PM
> To: [email protected]; [email protected]; Ping-Ke Shih <[email protected]>
> Cc: [email protected]; [email protected]
> Subject: [PATCH v2] wifi: rtl8xxxu: don't call dev_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.
>
> In this case, dev_kfree_skb() is called to free and drop the SKB when
> it's shutdown, so replace it with dev_kfree_skb_irq(). Compile tested
> only.
>
> Fixes: 26f1fad29ad9 ("New driver: rtl8xxxu (mac80211)")
> Signed-off-by: Yang Yingliang <[email protected]>

Reviewed-by: Ping-Ke Shih <[email protected]>

> ---
> v1 -> v2:
> Update commit message, and change to use dev_kfree_skb_irq().
> ---
> 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_kfree_skb_irq(skb);
> usb_free_urb(&rx_urb->urb);
> }
>
> --
> 2.25.1
>
>
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