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From: Ingo Molnar <mingo@kernel.org>
To: kernel-janitors@vger.kernel.org
Subject: Re: [tip:numa/core 10/10] mm/memory.c:3543 do_prot_none() error: double unlock 'spin_lock:ptl'
Date: Sun, 21 Oct 2012 13:45:17 +0000	[thread overview]
Message-ID: <20121021134517.GB23820@gmail.com> (raw)


* Fengguang Wu <fengguang.wu@intel.com> wrote:

> Hi Ingo,
> 
> FYI, there are new smatch warnings show up in
> 
> tree:   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git numa/core
> head:   eb4f84b1aaad78ca07e274b81410ec9d60abe434
> commit: eb4f84b1aaad78ca07e274b81410ec9d60abe434 [10/10] numa, mm: Fix 4K migration races
> 
>   mm/memory.c:805 vm_normal_page() info: ignoring unreachable code.
>   mm/memory.c:805 vm_normal_page() info: ignoring unreachable code.
>   mm/memory.c:984 copy_pte_range() warn: inconsistent returns spin_lock:dst_ptl: locked (940) unlocked (979,984)
>   mm/memory.c:984 copy_pte_range() warn: inconsistent returns spin_lock:__ptl: locked (979,984) unlocked (940)
>   mm/memory.c:1532 follow_page() info: ignoring unreachable code.
>   mm/memory.c:1651 follow_page() warn: inconsistent returns spin_lock:ptl: locked (1628,1650,1651) unlocked (1632,1637)
>   mm/memory.c:1651 follow_page() warn: inconsistent returns spin_lock:__ptl: locked (1632,1637) unlocked (1628,1650,1651)
>   mm/memory.c:2688 do_wp_page() error: double unlock 'spin_lock:ptl'
>   mm/memory.c:2733 do_wp_page() error: double unlock 'spin_lock:ptl'
>   mm/memory.c:2761 do_wp_page() error: double lock 'spin_lock:__ptl'
>   mm/memory.c:2823 do_wp_page() error: double unlock 'spin_lock:ptl'
>   mm/memory.c:2853 do_wp_page() warn: inconsistent returns spin_lock:__ptl: locked (2838) unlocked (2692,2725,2849,2853)
> + mm/memory.c:3543 do_prot_none() error: double unlock 'spin_lock:ptl'
> + mm/memory.c:3557 do_prot_none() error: double lock 'spin_lock:__ptl'
>   mm/memory.c:3632 handle_pte_fault() warn: inconsistent returns spin_lock:ptl: locked (3613) unlocked (3591,3594,3598,3600,3605,3632)

Hm, looks like smatch got confused by the 'locked' variable?

Or can you see real problems in the code?

Thanks,

	Ingo

             reply	other threads:[~2012-10-21 13:45 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-21 13:45 Ingo Molnar [this message]
2012-10-21 14:24 ` [tip:numa/core 10/10] mm/memory.c:3543 do_prot_none() error: double unlock 'spin_lock:ptl' Fengguang Wu

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