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Subject: Re: e1000_netpoll() , BUG: sleeping function called from invalid
 context
To: Cong Wang <xiyou.wangcong@gmail.com>
References: <ce27a339-78ba-bb38-55ce-790c10f688af@gmail.com>
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Cc: lkml <linux-kernel@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        "David S. Miller" <davem@davemloft.net>,
        "Peter Zijlstra (Intel)" <peterz@infradead.org>
From: Gabriel C <nix.or.die@gmail.com>
Message-ID: <e7262413-f221-964b-8442-9f0d6fa3a4bf@gmail.com>
Date: Sat, 18 Feb 2017 00:53:12 +0100
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On 18.02.2017 00:44, Cong Wang wrote:
> On Fri, Feb 17, 2017 at 3:38 PM, Gabriel C <nix.or.die@gmail.com> wrote:
>>
>> My card seems to use the e1000e driver which is buit-in..
>>
>> Anyway here an objdump -x :
>>
>> http://ftp.frugalware.org/pub/other/people/crazy/kernel/t/objdump-x_e1000.ko.txt
>>
>
> Found disable_hardirq() but not disable_irq().
>
> Are you sure the kernel warning was emitted by this binary rather than
> some old one?
>

Yes , I use an clean build , remove any other files in /boot && /lib/modules before installing the new build kernel.

I've asked Thomas before I send this to lkml and to you and he said :

..


It's a real issue. netconsole calls disable_irq() which might sleep from an
interrupt and preemption disabled context.

 > [85362.132801]  __might_sleep+0x6b/0x80
 > [85362.132803]  synchronize_irq+0x33/0x90
 > [85362.132805]  ? __irq_put_desc_unlock+0x19/0x40
 > [85362.132807]  ? __disable_irq_nosync+0x4e/0x60
 > [85362.132808]  disable_irq+0x17/0x20
 > [85362.132810]  e1000_netpoll+0x3d/0x110

Though, what's weird is that the e1000_netpoll() does not longer call
disable_irq(). It calls disable_hardirq().

That got changed in commit 3111912971251 which got into Linus tree during
the 4.10 merge window. So it is in 4.10-rc8.

Confused.

...