Messages in this thread | | | Subject | Re: [PATCH] drivers/net: fixed drivers that support netpoll use ndo_start_xmit() | From | Matt Mackall <> | Date | Fri, 14 Aug 2009 10:33:39 -0500 |
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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(). > > Call trace: > netpoll_send_skb() > { > -> local_irq_save(flags) > ---> dev->ndo_start_xmit(skb, dev) > ---> spin_lock_irq() > ---> spin_unlock_irq() *******here would enable the interrupt. > ... > -> local_irq_restore(flags) > } > > Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com> > Signed-off-by: Jason Wessel <jason.wessel@windriver.com> > Acked-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Perhaps we should also have a WARN_ONCE if start_xmit returns with interrupts enabled?
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