On Tue, Nov 01, 2011 at 10:52:10AM -0700, Dmitry Torokhov wrote: > On Tue, Nov 01, 2011 at 10:01:56AM -0700, Greg KH wrote: > > On Tue, Nov 01, 2011 at 04:41:40PM +0100, David Herrmann wrote: > > > Hi Dmitry and Greg > > > > > > It doesn't make sense to take a reference to our own module. When we call > > > module_put(THIS_MODULE) we cannot make sure that our module is still alive when > > > this function returns. Therefore, module_put() will return to invalid memory and > > > our input_dev_release() function is no longer available. > > > > > > It would be interesting if Greg could elaborate what else we could do to replace > > > this module-refcount as it is definitely needed here. However, "struct device" > > > doesn't provide an owner field so there is no way for us to let the device core > > > keep a reference to our module. > > > > For a bus module, yes, this is needed, so don't remove these calls, it's > > wrong to do so. > > Strictly speaking, David is right, there is a race condition here. > However since we do module_put() as very last operation of > input_dev_release() it is extremely hard to trigger this race. > > Until we have a better way of pinning the bus (or class) implementation > in memory we should keep __module_get/module_put in input core. I agree, that's fine for a bus to do, as long as you are aware of how it is working. greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
