linux-kernel - Re: [PATCH] ibmphp: Fix module ref count underflow

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Message-Id: <200812161042.09345.jbarnes@virtuousgeek.org>
Date:	Tue, 16 Dec 2008 10:42:08 -0800
From:	Jesse Barnes <jbarnes@...tuousgeek.org>
To:	Neil Horman <nhorman@...driver.com>
Cc:	greg@...ah.com, linux-pci@...r.kernel.org,
	linux-kernel@...r.kernel.org, akpm@...ux-foundation.org
Subject: Re: [PATCH] ibmphp: Fix module ref count underflow

On Wednesday, December 10, 2008 11:43 am Neil Horman wrote:
> Hey-
> 	I happened to notice that the ibmphp hotplug driver does something
> rather silly in its init routine.  It purposely calls module_put so as to
> underflow its module ref count to avoid being removed from the kernel. 
> This is bad practice, and wrong, since it provides a window for subsequent
> module_gets to reset the refcount to zero, allowing an unload to race in
> and cause all sorts of mysterious panics.  If the module is unsafe to load,
> it should inform the kernel as such with a call to __unsafe.  The patch
> below does that.

Thanks Neil, applied this to my for-linus branch since it sounds potentially 
serious (but also low risk since who uses ibmphp anymore? :)

Jesse
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