Re: [PATCH] ibmphp: Fix module ref count underflow

From: Jesse Barnes
Date: Tue Dec 16 2008 - 13:42:23 EST


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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