Messages in this thread | | | Date | Tue, 26 Feb 2013 14:28:42 -0800 | From | Dmitry Torokhov <> | Subject | Re: [PATCH] ipack: add missing put_device() after device_register() failed |
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On Tue, Feb 26, 2013 at 10:03:15AM +0100, Samuel Iglesias Gonsalvez wrote: > put_device() must be called after device_register() fails, > since device_register() always initializes the refcount > on the device structure to one. > > dev->id is free'd inside of ipack_device_release function. > So, it's not needed to do it here. > > Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com> > --- > drivers/ipack/ipack.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/ipack/ipack.c b/drivers/ipack/ipack.c > index 7ec6b20..3588ccf 100644 > --- a/drivers/ipack/ipack.c > +++ b/drivers/ipack/ipack.c > @@ -449,7 +449,7 @@ int ipack_device_register(struct ipack_device *dev) > > ret = device_register(&dev->dev); > if (ret < 0) > - kfree(dev->id); > + put_device(&dev->dev);
Now callers have no idea if they have to free (put_device) it in case of failure or it is already done for them, because a few lines earlier, if pack_device_read_id() fails, it simply returns error code.
IMO if a function did not allocate object it should not try to free it, callers should dispose of the device as they see fit.
What is missing, however, is dev->id = NULL assignment so that if caller does put_device() kit won't double-free the memory. Also it would make sense to split device_register into device_init() and device_add() so that device_init() is very first thing you do and in case of all failures callers should use put_device().
Also tpci200.c need to learn to clean up after itself and I also not sure why it tries to provide its own release function.
Thanks.
-- Dmitry
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