On Wed, Jan 08, 2014 at 06:12:27PM +0000, Opensource [Anthony Olech] wrote: > > -----Original Message----- > > From: Dmitry Torokhov [mailto:dmitry.torokhov@xxxxxxxxx] > > Sent: 08 January 2014 17:26 > > To: Opensource [Anthony Olech] > > Cc: linux-input@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Huqiu Liu; > > David Dajun Chen > > Subject: Re: [PATCH V1] input: fix memory leak in da9052 touchscreen driver > > Anthony Olech <anthony.olech.opensource@xxxxxxxxxxx> wrote: > > >The touchscreen component driver for the da9052/3 Dialog PMICs leaks > > >memory by not freeing the input device in the remove call. > > >This patch matches the existing call to input_alloc_device() in > > >da9052_ts_probe() to a new call to input_free_device() in > > >da9052_ts_remove() > > >Suggested-by: Huqiu Liu <liuhq11@xxxxxxxxxxxxxxxxxxxxx> > > >Signed-off-by: Anthony Olech <anthony.olech.opensource@xxxxxxxxxxx> > > >--- > > >This patch is relative to linux-next repository tag next-20140108 > > >Many thanks to Huqiu Liu who found the bug. > > No, this is not a bug. Please refer to input API spec in input.h > > Thanks. > > Hi Dmitry, > the spec *seems* to say that if the allocation is done via devm_input_allocate_device(dev) > then no explicit freeing must be done. > > However that is not the case here, so the bug exists. *sigh* /** * input_free_device - free memory occupied by input_dev structure * @dev: input device to free * * This function should only be used if input_register_device() * was not called yet or if it failed. Once device was registered * use input_unregister_device() and memory will be freed once last * reference to the device is dropped. THIS ^^^^^^^^^^^^^^^^^^^^ * * Device should be allocated by input_allocate_device(). * * NOTE: If there are references to the input device then memory * will not be freed until last reference is dropped. */ /** * input_allocate_device - allocate memory for new input device * * Returns prepared struct input_dev or %NULL. * * NOTE: Use input_free_device() to free devices that have not been * registered; input_unregister_device() should be used for already * registered devices. and this ^^^^^^^^^^^^^^^^^^^^^^^^ */ > > It does seem that there is an alternative way of resolving the issue, namely to: > 1) change from allocate_device() to devm_input_allocate_device(dev) and > 2) remove the exiosting input_free_device() from the error path in the probe() function There is no issue, but if you want to convert the driver to using managed resources that would be fine. Thanks. -- Dmitry -- 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
