Re: [PATCH] drivers/net: fixed drivers that support netpoll usendo_start_xmit()

[David Miller]

From: Matt Mackall <mpm@xxxxxxxxxxx>
Date: Fri, 14 Aug 2009 10:33:39 -0500

> On Fri, 2009-08-14 at 13:12 +0800, DDD wrote:
>> The NETPOLL API requires that interrupts remain disabled in
>> netpoll_send_skb(). The use of spin_lock_irq() and spin_unlock_irq()
>> in the NETPOLL API callbacks causes the interrupts to get enabled and
>> can lead to kernel instability.
>> 
>> The solution is to use spin_lock_irqsave() and spin_unlock_restore()
>> to prevent the irqs from getting enabled while in netpoll_send_skb().
 ...
>> Signed-off-by: Dongdong Deng <dongdong.deng@xxxxxxxxxxxxx>
>> Signed-off-by: Jason Wessel <jason.wessel@xxxxxxxxxxxxx>
>> Acked-by: Bruce Ashfield <bruce.ashfield@xxxxxxxxxxxxx>
> 
> Acked-by: Matt Mackall <mpm@xxxxxxxxxxx>

Applied, thanks everyone.

> Perhaps we should also have a WARN_ONCE if start_xmit returns with
> interrupts enabled?

Probably a good idea.
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