Date: Tue, 12 Dec 2017 10:22:40 -0800
From: Stephen Hemminger <stephen@networkplumber.org>
To: David Miller <davem@davemloft.net>
Cc: baijiaju1990@gmail.com, mlindner@marvell.com, shemminger@osdl.org,
        shemminger@linux-foundation.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [BUG] skge: a possible sleep-in-atomic bug in skge_remove
Message-ID: <20171212102240.4a09cf9a@xeon-e3>
In-Reply-To: <20171212.083445.2256119006373036925.davem@davemloft.net>
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        <20171212.083445.2256119006373036925.davem@davemloft.net>
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On Tue, 12 Dec 2017 08:34:45 -0500 (EST)
David Miller <davem@davemloft.net> wrote:

> From: Jia-Ju Bai <baijiaju1990@gmail.com>
> Date: Tue, 12 Dec 2017 16:38:12 +0800
> 
> > According to drivers/net/ethernet/marvell/skge.c, the driver may sleep
> > under a spinlock.
> > The function call path is:
> > skge_remove (acquire the spinlock)
> >   free_irq --> may sleep
> > 
> > I do not find a good way to fix it, so I only report.
> > This possible bug is found by my static analysis tool (DSAC) and
> > checked by my code review.  
> 
> This was added by:
> 
> commit a9e9fd7182332d0cf5f3e601df3e71dd431b70d7
> Author: Stephen Hemminger <shemminger@vyatta.com>
> Date:   Tue Sep 27 13:41:37 2011 -0400
> 
>     skge: handle irq better on single port card
> 
> I think the free_irq() can be moved below the unlock.
> 
> Stephen, please take a look.

The IRQ was being free twice.
How did you see it, I really doubt any multi-port SKGE cards
still exist.