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Message-ID: <d120d5000704161130j7ae89a1eyef89e015f0a3e97f@mail.gmail.com>
Date: Mon, 16 Apr 2007 14:30:17 -0400
From: "Dmitry Torokhov" <dmitry.torokhov@gmail.com>
To: "Cornelia Huck" <cornelia.huck@de.ibm.com>
Subject: Re: [Patch -mm 0/3] RFC: module unloading vs. release function
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
       "Alan Stern" <stern@rowland.harvard.edu>, "Greg K-H" <greg@kroah.com>,
       "Tejun Heo" <htejun@gmail.com>, "Rusty Russell" <rusty@rustcorp.com.au>
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On 4/16/07, Cornelia Huck <cornelia.huck@de.ibm.com> wrote:
> Hi,
>
> based on the discussion in "How should an exit routine wait for
> release() callbacks?", I've cooked up some patches that make module
> unload wait until the last reference for a kobject has been dropped.
> This should plug the "release function in already deleted module" race;
> however, if the last kobject_put() from the module containing the
> release function is not in the module's exit function, there's still a
> small window (not sure if and how to plug this).

Unfortunately all this "wait for refcount in module's exit" schemas
lead to the following deadlock:

        rmmod my_module < /path/to/some/file/incrementing/my/refcount

-- 
Dmitry