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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
Date: Tue, 12 Dec 2017 21:18:49 -0800	[thread overview]
Message-ID: <20171212211849.3e8b43b9@xeon-e3> (raw)
In-Reply-To: <20171212.205701.569779668163323943.davem@davemloft.net>

On Tue, 12 Dec 2017 20:57:01 -0500 (EST)
David Miller <davem@davemloft.net> wrote:

> From: Stephen Hemminger <stephen@networkplumber.org>
> Date: Tue, 12 Dec 2017 10:22:40 -0800
> 
> > 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.  
> 
> He sees it by reading the code, please take a look at this
> and move the free_irq() out of the spin locked section since
> it can sleep.

Thanks, I was hoping for some automated static analysis tool.

  reply	other threads:[~2017-12-13  5:18 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-12  8:38 [BUG] skge: a possible sleep-in-atomic bug in skge_remove Jia-Ju Bai
2017-12-12 13:34 ` David Miller
2017-12-12 18:22   ` Stephen Hemminger
2017-12-13  1:57     ` David Miller
2017-12-13  5:18       ` Stephen Hemminger [this message]
2017-12-13  7:42         ` Jia-Ju Bai
2017-12-13 16:50           ` Stephen Hemminger
2017-12-14  3:06             ` Jia-Ju Bai

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