Messages in this thread | | | Date | Wed, 14 Mar 2018 15:36:00 +0100 | From | Boris Brezillon <> | Subject | Re: [PATCH 1/2] mtd: use put_device() if device_register fail |
| |
On Fri, 9 Mar 2018 16:20:48 +0530 Arvind Yadav <arvind.yadav.cs@gmail.com> wrote:
> if device_register() returned an error! Always use put_device() > to give up the reference initialized. > > Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> > --- > drivers/mtd/mtdcore.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c > index 28553c8..4d77ca2 100644 > --- a/drivers/mtd/mtdcore.c > +++ b/drivers/mtd/mtdcore.c > @@ -586,6 +586,7 @@ int add_mtd_device(struct mtd_info *mtd) > return 0; > > fail_added: > + put_device(&mtd->dev);
Not sure this is a good idea: the put_device() call will trigger an mtd_devtype->release(), which will in turn call device_destroy() on something that does not exist yet. Not sure if this is a real problem, but it does not look like the right thing to do.
> of_node_put(mtd_get_of_node(mtd));
You're referencing an object that is supposed to have been freed/released by the put_device() call. Again, it's not really a problem because in our case ->release() does not free the mtd object (as is usually done in other parts of the kernel), but it still looks wrong. It's probably better to move the of_node_put() and the below idr_remove() call in the ->release() hook if you want to use put_device().
> idr_remove(&mtd_idr, i);
> fail_locked:
-- Boris Brezillon, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com
| |